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Sample records for color tuber starch

  1. Amylose Content in Tuber Starch of Potato Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tuber is mostly water and starch. Approximately 20% of fresh tuber weight is the starch and the remainder is water. Most of the starch in the tuber, approximately 75%, is amylopectin and 25% amylose, but can vary depending on the cultivar. A total of 162 American (85) and foreign (77) potato ...

  2. Regulation of starch synthesis in potato tubers

    SciTech Connect

    Davies, H.; Oparka, K.; Viola, R.; Wright, K.; Ross, H. )

    1990-05-01

    Following tuber excision from the mother plant sucrose synthase activity fell from 3,120 to 960 nmol/g.f. wt./h within 7 days and starch synthesis ({sup 14}C sucrose incorporated into isolated discs) from 23 to 7 nmol/g.f. wt./h. While the maximum catalytic activity of sucrose synthase was more than sufficient to account for the observed rate of starch synthesis a maximum of 27% of sucrose incorporated by discs was converted into starch within 3 h. This compared with 80% conversion of {sup 14}C glucose incorporated. Tuber excision also reduced the rate of starch biosynthesis with glucose as a substrate (from 206 to 64 nmol/g.f. wt./h). The activities of UDPG-pyrophosphorylase, PPi-PFK, ATP-PFK, starch synthase and hexokinase (glucose or fructose substrates) were unaffected by tuber removal. ADPG pyrophosphorylase activity was reduced from 8,000 to 4,500 nmol/g.f. wt./h. Preliminary experiments indicate that the decline in sucrose synthease activity is prevented by maintaining sucrose flux into tubers through the cut stolon.

  3. Amylose Content in Tuber Starch of Wild Potato Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 20% of potato tuber fresh weight is starch, which is composed of amylose (straight chains of glucose) and amylopectin (branched chains). Potato starch is low in amylose (~25%), but high amylose starch has superior nutritional qualities. Amylose content has been determined in tuber samp...

  4. Characterization and development mechanism of Apios americana tuber starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apios americana is a wild legume-bearing plant with edible tubers. Domestication of Apios is in progress because of the superior nutritional value and health benefits of the tuber. Objectives of this study were to: 1) characterize physicochemical properties of Apios-tuber starch; and 2) understand d...

  5. Experiment 9: ASTROCULTURE: Growth and Starch Accumulation of Potato Tuber

    NASA Technical Reports Server (NTRS)

    Tibbitts, Theodore W.; Brown, Christopher S.; Croxdale, Judith G.; Wheeler, Raymond M.

    1998-01-01

    Potato explants (leaf, small stem section, and axillary bud) flown on STS-73 developed tubers of 1.5 cm diameter and 1.7 g mass during the 16-day period of space flight. The experiment was undertaken in the ASTROCULTURE(TM) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers that formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was similar in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in space flight and ground controls, but activity of ADP-glucose pyrophosphorylase was reduced in the space flight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in space flight as on the ground. Thus, this data provides the potential for effective utilization of potatoes in life support systems of space bases.

  6. Space Experiment on Tuber Development and Starch Accumulation for CELSS

    NASA Technical Reports Server (NTRS)

    Tibbitts,Theodore W.; Croxdale, Judith C.; Brown, Christopher S.

    1997-01-01

    Potato explants (leaf, small stem section, and axillary bud), flown on STS-73, developed tubers of 1.5 cm diameter and 1.7 g mass during the 16 day period of spaceflight. The experiment was undertaken in the ASTROCULTURE(Trademark) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was singular in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in spaceflight and ground controls but activity of ADP-glucose pyrophosphorylase was reduced in the spaceflight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in spaceflight as on the ground and thus this data provides the potential for effective utilization of potatoes in life support systems of space bases.

  7. Characterization of starch from tubers of yam bean (Pachyrhizus ahipa).

    PubMed

    Forsyth, Jane L; Ring, Steve G; Noel, Timothy R; Parker, Roger; Cairns, Paul; Findlay, Kim; Shewry, Peter R

    2002-01-16

    Detailed studies of the starch present in tubers of six accessions of Pachyrhizus ahipa (ahipa) have been carried out using starches from tubers of P. erosus (Mexican yam bean) and seeds of ahipa and wheat for comparison. Starch accounted for 56-58% of the tuber dry weight with granules occurring in a range of geometric forms and in sizes from below 5 microm to about 35 microm (mean about 10 microm in all accessions except two). The amylose content ranged from 11.6 to 16.8% compared with 16.9% in P. erosus tubers and over 23% in the seed starches. X- ray diffraction analysis showed A-type or C(A)-type diffraction patterns. The chain-length distribution of the amylopectin after enzyme debranching showed a peak at DP11 similar to that of wheat starch, but had a less marked shoulder at DP 21-22 and contained a higher proportion of longer chains. Differential scanning calorimitry showed an endothermic peak corresponding to gelatinization with T(max) ranging from 59 to 63 degrees C, which was similar to the T(max) of wheat (about 64 degrees C). The composition of the ahipa starch may mean that it is suitable for food applications that require low amylose content and low retrogradation after processing.

  8. Physicochemical Properties of Starch from Dioscorea pyrifolia tubers.

    PubMed

    Elmi Sharlina, M S; Yaacob, W A; Lazim, Azwan Mat; Fazry, Shazrul; Lim, Seng Joe; Abdullah, Sapina; Noordin, Akram; Kumaran, Malina

    2017-04-01

    Starch from Dioscorea pyrifolia tubers was characterized for its proximate composition, physicochemical properties and toxicity. This starch contains 44.47±1.86% amylose, 4.84±0.29% moisture, 0.88±0.21% ash, 1.34±0.11% proteins and 92.73±0.48% carbohydrates. X-ray diffraction (XRD) analysis showed a type-C starch with a relative crystallinity of 23.31±2.41%. The starch granules are polyhedral, with a diameter of 2.8 to 5.6μm and average size of 3.93±1.47μm. Initial, peak and finishing gelatinization temperatures for the starch were 71.51±0.07, 75.05±0.15, and 78.25±0.18°C, respectively; the gelatinization enthalpy was 3.86±0.02J/g, and the peak height index was 1.09±0.05. Thermogravimetric analysis showed a weight loss of 85.81±0.52% and a decomposition temperature of 320.16±0.35°C, which indicated that there was good thermal stability of the starch. Fish embryo toxicity (FET) showed that the starch was not toxic and that it was suitable for food and non-food industries.

  9. Starch granule initiation is controlled by a heteromultimeric isoamylase in potato tubers

    PubMed Central

    Bustos, Regla; Fahy, Brendan; Hylton, Christopher M.; Seale, Robert; Nebane, N. Miranda; Edwards, Anne; Martin, Cathie; Smith, Alison M.

    2004-01-01

    Starch granule initiation is not understood, but recent evidence implicates a starch debranching enzyme, isoamylase, in the control of this process. Potato tubers contain isoamylase activity attributable to a heteromultimeric protein containing Stisa1 and Stisa2, the products of two of the three isoamylase genes of potato. To discover whether this enzyme is involved in starch granule initiation, activity was reduced by expression of antisense RNA for Stisa1 or Stisa2. Transgenic tubers accumulated a small amount of a soluble glucan, similar in structure to the phytoglycogen of cereal, Arabidopsis, and Chlamydomonas mutants lacking isoamylase. The major effect, however, was on the number of starch granules. Transgenic tubers accumulated large numbers of tiny granules not seen in normal tubers. These data indicate that the heteromultimeric isoamylase functions during starch synthesis to suppress the initiation of glucan molecules in the plastid stroma that would otherwise crystallize to nucleate new starch granules. PMID:14766984

  10. Decreased sucrose content triggers starch breakdown and respiration in stored potato tubers (Solanum tuberosum).

    PubMed

    Hajirezaei, Mohammad-Reza; Börnke, Frederik; Peisker, Martin; Takahata, Yasuhiro; Lerchl, Jens; Kirakosyan, Ara; Sonnewald, Uwe

    2003-01-01

    To change the hexose-to-sucrose ratio within phloem cells, yeast-derived cytosolic invertase was expressed in transgenic potato (Solanum tuberosum cv. Desirée) plants under control of the rolC promoter. Vascular tissue specific expression of the transgene was verified by histochemical detection of invertase activity in tuber cross-sections. Vegetative growth and tuber yield of transgenic plants was unaltered as compared to wild-type plants. However, the sprout growth of stored tubers was much delayed, indicating impaired phloem-transport of sucrose towards the developing bud. Biochemical analysis of growing tubers revealed that, in contrast to sucrose levels, which rapidly declined in growing invertase-expressing tubers, hexose and starch levels remained unchanged as compared to wild-type controls. During storage, sucrose and starch content declined in wild-type tubers, whereas glucose and fructose levels remained unchanged. A similar response was found in transgenic tubers with the exception that starch degradation was accelerated and fructose levels increased slightly. Furthermore, changes in carbohydrate metabolism were accompanied by an elevated level of phosphorylated intermediates, and a stimulated rate of respiration. Considering that sucrose breakdown was restricted to phloem cells it is concluded that, in response to phloem-associated sucrose depletion or hexose elevation, starch degradation and respiration is triggered in parenchyma cells. To study further whether elevated hexose and/or hexose-phosphates or decreased sucrose levels are responsible for the metabolic changes observed, sucrose content was decreased by tuber-specific expression of a bacterial sucrose isomerase. Sucrose isomerase catalyses the reversible conversion of sucrose into palatinose, which is not further metabolizable by plant cells. Tubers harvested from these plants were found to accumulate high levels of palatinose at the expense of sucrose. In addition, starch content decreased

  11. Ultrastructure of underutilized tuber starches and its relation to physicochemical properties.

    PubMed

    Lan, Xiaohong; Li, Yongfu; Xie, Shichao; Wang, Zhengwu

    2015-12-01

    Starches from five underutilized tubers (canna, potato, Chinese yam, water chestnut, and taro) were extracted to investigate quantitative structure-property relationships (QSPR) in each starch using a combination of X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS). Structural parameters of the tuber starches were determined using the paracrystalline model. Swelling power (SP), water solubility index (WSI), amylose leaching (AML), and thermal properties were also measured. The XRD results indicated that starches from Chinese yam, water chestnut, and taro are C-type starches with relatively high crystallinity (29.23-35.02%). In contrast, canna and potato starches are B-type starches exhibiting lower crystallinity and higher amylose content. The paracrystalline model provided a better fit for the C-type starches than for the B-type starches because the former was highly compressible (indicated by a higher "β" value). B-type starches, on the other hand, tend to be more rigid along the lamellar repeat direction, requiring the layers to bend to accommodate internal stress. The QSPR analysis showed that three structural parameters, "Ø", "β", and "Δρu", correlate well with the SP and WSI, and thus can be used to predict certain physicochemical properties.

  12. Effect of nanocellulose as a filler on biodegradable thermoplastic starch films from tuber, cereal and legume.

    PubMed

    Montero, Belén; Rico, Maite; Rodríguez-Llamazares, Saddys; Barral, Luis; Bouza, Rebeca

    2017-02-10

    Starches from different vegetal sources (tuber, cereal and legume) were plasticized with an invariant glycerol content and reinforced with cellulose nanocrystals by solution casting method. The influence of both, starch nature and filler amount, in the crystallinity and the extension of plasticization have been analyzed by X-ray diffraction. Thermoplastic starches (TPS) morphologies were obtained by scanning electron microscopy. Mechanical properties and thermal stability were analyzed by dynamomechanical and thermogravimetric analysis. Water absorption evolution was studied as well. A major extension in plasticization (high amylopectin starches) led to matrices with large starch-rich domains, a good thermal stability and resistance to water absorption but low stiffness. The incorporation of cellulose nanoparticles favoured plasticization and increased the rigidity in TPS films, as well as the thermal stability and moisture resistance. The aim of this work was to obtain bio-based thermoplastic starch films for replacing petroleum-derived ones in packaging industry, especially for short-life applications.

  13. Properties of cast films made of chayote (Sechium edule Sw.) tuber starch reinforced with cellulose nanocrystals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, cellulose (C) and cellulose nanocrystals (CN) were blended with chayote tuber (Sechium edule Sw.) starch (CS) in formulations cast into films. The films were conditioned at different storage temperatures and relative humidity (RH), and analyzed by mechanical tests, X-ray diffraction, ...

  14. Electrical and absorption properties of fresh cassava tubers and cassava starch

    NASA Astrophysics Data System (ADS)

    Harnsoongnoen, S.; Siritaratiwat, A.

    2015-09-01

    The objective of this study was to analyze the electrical and absorption properties of fresh cassava tubers and cassava starch at various frequencies using electric impedance spectroscopy and near-infrared spectroscopy, as well as determine the classification of the electrical parameters of both materials using the principle component analysis (PCA) method. All samples were measured at room temperature. The electrical and absorption parameters consisted of dielectric constant, dissipation factor, parallel capacitance, resistance, reactance, impedance and absorbance. It was found that the electrical and absorption properties of fresh cassava tubers and cassava starch were a function of frequency, and there were significant differences between the materials. The dielectric constant, parallel capacitance, resistance and impedance of fresh cassava tubers and cassava starch had similar dramatic decreases with increasing frequency. However, the reactance of both materials increased with an increasing frequency. The electrical parameters of both materials could be classified into two groups. Moreover, the dissipation factor and phase of impedance were the parameters that could be used in the separation of both materials. According to the absorbance patterns of the fresh cassava tubers and cassava starch, there were significant differences.

  15. Physicochemical properties of flours and starches derived from traditional Indonesian tubers and roots.

    PubMed

    Aprianita, Aprianita; Vasiljevic, Todor; Bannikova, Anna; Kasapis, Stefan

    2014-12-01

    Flours and starches isolated from traditional tubers and roots grown in Indonesia have physical and chemical properties suitable for certain food applications. Compared to other flour samples, cassava and canna flours contained the highest amount of total starch (TS) (77.4 and 77.1 %, respectively). Taro starch had the lowest amount of TS among other starch samples with 75.4 %. The highest amount of amylose was observed from yam and canna flours (25.2 and 23.2 %, respectively). Among starch samples, canna starch contained the highest amylose content (30.4 %), while taro had the lowest (7.6 %). In terms of protein content, arrowroot flour had the highest amount (7.7 %), in contrast to cassava flour which had the lowest (1.5 %). Compared to other flours, canna and konjac flour were the most slowly digested which indicated by their high amount of resistant starch (RS). Canna starch had the highest swelling power and viscosity than other starches and flours. The clearest paste was observed from cassava flour and starch as opposed to konjac starch which was the most opaque paste.

  16. Manipulation of starch granule size distribution in potato tubers by modulation of plastid division.

    PubMed

    de Pater, Sylvia; Caspers, Martien; Kottenhagen, Marijke; Meima, Henk; ter Stege, Renaldo; de Vetten, Nick

    2006-01-01

    Starch granule size is an important parameter for starch applications in industry. Starch granules are formed in amyloplasts, which are, like chloroplasts, derived from proplastids. Division processes and associated machinery are likely to be similar for all plastids. Essential roles for FtsZ proteins in plastid division in land plants have been revealed. FtsZ forms the so-called Z ring which, together with inner and outer plastid division rings, brings about constriction of the plastid. It has been shown that modulation of the expression level of FtsZ may result in altered chloroplast size and number. To test whether FtsZ is also involved in amyloplast division and whether this, in turn, may affect the starch granule size in crop plants, FtsZ protein levels were either reduced or increased in potato. As shown previously in other plant species, decreased StFtsZ1 protein levels in leaves resulted in a decrease in the number of chloroplasts in guard cells. More interestingly, plants with increased StFtsZ1 protein levels in tubers resulted in less, but larger, starch granules. This suggests that the stoichiometry between StFtsZ1 and other components of the plastid division machinery is important for its function. Starch from these tubers also had altered pasting properties and phosphate content. The importance of our results for the starch industry is discussed.

  17. Starch phosphorylation in potato tubers is influenced by allelic variation in the genes encoding glucan water dikinase, starch branching enzymes I and II, and starch synthase III.

    PubMed

    Carpenter, Margaret A; Joyce, Nigel I; Genet, Russell A; Cooper, Rebecca D; Murray, Sarah R; Noble, Alasdair D; Butler, Ruth C; Timmerman-Vaughan, Gail M

    2015-01-01

    Starch phosphorylation is an important aspect of plant metabolism due to its role in starch degradation. Moreover, the degree of phosphorylation of starch determines its physicochemical properties and is therefore relevant for industrial uses of starch. Currently, starch is chemically phosphorylated to increase viscosity and paste stability. Potato cultivars with elevated starch phosphorylation would make this process unnecessary, thereby bestowing economic and environmental benefits. Starch phosphorylation is a complex trait which has been previously shown by antisense gene repression to be influenced by a number of genes including those involved in starch synthesis and degradation. We have used an association mapping approach to discover genetic markers associated with the degree of starch phosphorylation. A diverse collection of 193 potato lines was grown in replicated field trials, and the levels of starch phosphorylation at the C6 and C3 positions of the glucosyl residues were determined by mass spectrometry of hydrolyzed starch from tubers. In addition, the potato lines were genotyped by amplicon sequencing and microsatellite analysis, focusing on candidate genes known to be involved in starch synthesis. As potato is an autotetraploid, genotyping included determination of allele dosage. Significant associations (p < 0.001) were found with SNPs in the glucan water dikinase (GWD), starch branching enzyme I (SBEI) and the starch synthase III (SSIII) genes, and with a SSR allele in the SBEII gene. SNPs in the GWD gene were associated with C6 phosphorylation, whereas polymorphisms in the SBEI and SBEII genes were associated with both C6 and C3 phosphorylation and the SNP in the SSIII gene was associated with C3 phosphorylation. These allelic variants have potential as genetic markers for starch phosphorylation in potato.

  18. SNPs in genes functional in starch-sugar interconversion associate with natural variation of tuber starch and sugar content of potato (Solanum tuberosum L.).

    PubMed

    Schreiber, Lena; Nader-Nieto, Anna Camila; Schönhals, Elske Maria; Walkemeier, Birgit; Gebhardt, Christiane

    2014-07-31

    Starch accumulation and breakdown are vital processes in plant storage organs such as seeds, roots, and tubers. In tubers of potato (Solanum tuberosum L.) a small fraction of starch is converted into the reducing sugars glucose and fructose. Reducing sugars accumulate in response to cold temperatures. Even small quantities of reducing sugars affect negatively the quality of processed products such as chips and French fries. Tuber starch and sugar content are inversely correlated complex traits that are controlled by multiple genetic and environmental factors. Based on in silico annotation of the potato genome sequence, 123 loci are involved in starch-sugar interconversion, approximately half of which have been previously cloned and characterized. By means of candidate gene association mapping, we identified single-nucleotide polymorphisms (SNPs) in eight genes known to have key functions in starch-sugar interconversion, which were diagnostic for increased tuber starch and/or decreased sugar content and vice versa. Most positive or negative effects of SNPs on tuber-reducing sugar content were reproducible in two different collections of potato cultivars. The diagnostic SNP markers are useful for breeding applications. An allele of the plastidic starch phosphorylase PHO1a associated with increased tuber starch content was cloned as full-length cDNA and characterized. The PHO1a-HA allele has several amino acid changes, one of which is unique among all known starch/glycogen phosphorylases. This mutation might cause reduced enzyme activity due to impaired formation of the active dimers, thereby limiting starch breakdown.

  19. Formation and Deposition of Amylose in the Potato Tuber Starch Granule Are Affected by the Reduction of Granule-Bound Starch Synthase Gene Expression.

    PubMed Central

    Kuipers, AGJ.; Jacobsen, E.; Visser, RGF.

    1994-01-01

    The synthesis of amylose in amyloplasts is catalyzed by granule-bound starch synthase (GBSS). GBSS gene expression was inhibited via antisense RNA in Agrobacterium rhizogenes-transformed potato plants. Analysis of starch production and starch granule composition in transgenic tubers revealed that reduction of GBSS activity always resulted in a reduction of the production of amylose. Field experiments, performed over a 2-year period, showed that stable inhibition of GBSS gene expression can be obtained. Microscopic evaluation of iodine-stained starch granules was shown to be a sensitive system for qualitative and quantitative examination of amylose formation in starch granules of transgenic potato tubers. In plants showing inhibition of GBSS gene expression, the reduced amylose content in tuber starch was not a consequence of a lower amylose content throughout the entire starch granule. Starch granules of transgenic tubers were found to contain amylose at a percentage similar to wild-type starch in a core of varying size at the hilum of each granule. This indicated that reduced GBSS gene expression results in amylose formation in a restricted zone of the granules. The size of this zone is suggested to be dependent on the GBSS protein level. During development of the granules, the available GBSS protein is thought to become limiting, resulting in the formation of starch that lacks amylose. RNA gel blot analysis of tuber tissue showed that inhibition of GBSS gene expression resulted in a reduced GBSS mRNA level but did not affect the expression level of other starch synthesizing enzymes. Antisense RNA could only be detected in leaf tissue of the transgenic plants. PMID:12244219

  20. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water

    NASA Astrophysics Data System (ADS)

    Safarik, Ivo; Horska, Katerina; Martinez, Lluis M.; Safarikova, Mirka

    2010-12-01

    A simple procedure for large scale isolation of Solanum tuberosum tuber lectin from potato starch industry waste water has been developed. The procedure employed magnetic chitosan microparticles as an affinity adsorbent. Magnetic separation was performed in a flow-through magnetic separation system. The adsorbed lectin was eluted with glycine/HCl buffer, pH 2.2. The specific activity of separated lectin increased approximately 27 times during the isolation process.

  1. Thermodynamic and structural properties of tuber starches from transgenic potato plants grown in vitro and in vivo.

    PubMed

    Wasserman, Luybov A; Sergeev, Andrey I; Vasil'ev, Viktor G; Plashchina, Irina G; Aksenova, Nina P; Konstantinova, Tatyana N; Golyanovskaya, Svetlana A; Sergeeva, Lidiya I; Romanov, Georgy A

    2015-07-10

    Potato plants harboring Phytochrome B (PHYB) gene from Arabidopsis thaliana or rol genes from Agrobacterium rhizogenes were used to study the effect of transgene expression on structure and properties of starch in tubers. Thermodynamic characteristics of starch (melting temperature, enthalpy of melting, thickness of crystalline lamellae) were shown to be variable depending on the transgene expression and plant culturing mode: in vitro or in soil. The expression of rolB or rolC genes in in vitro cultured plants evoked opposite effects on starch melting temperature and crystalline lamellae thickness. AtPHYB or rolB expression in the soil-grown potato led to the formation of more defective or more ordered starch structures, respectively, in comparison with starches of the same lines grown in vitro. On the whole, our study revealed genotype-dependent differences between starches extracted from tubers of in vitro or in vivo grown plants.

  2. Simultaneous boosting of source and sink capacities doubles tuber starch yield of potato plants.

    PubMed

    Jonik, Claudia; Sonnewald, Uwe; Hajirezaei, Mohammad-Reza; Flügge, Ulf-Ingo; Ludewig, Frank

    2012-12-01

    An important goal in biotechnological research is to improve the yield of crop plants. Here, we genetically modified simultaneously source and sink capacities in potato (Solanum tuberosum cv. Desirée) plants to improve starch yield. Source capacity was increased by mesophyll-specific overexpression of a pyrophosphatase or, alternatively, by antisense expression of the ADP-glucose pyrophosphorylase in leaves. Both approaches make use of re-routing photoassimilates to sink organs at the expense of leaf starch accumulation. Simultaneous increase in sink capacity was accomplished by overexpression of two plastidic metabolite translocators, that is, a glucose 6-phosphate/phosphate translocator and an adenylate translocator in tubers. Employing such a 'pull' approach, we have previously shown that potato starch content and yield can be increased when sink strength is elevated. In the current biotechnological approach, we successfully enhanced source and sink capacities by a combination of 'pull' and 'push' approaches using two different attempts. A doubling in tuber starch yield was achieved. This successful approach might be transferable to other crop plants in the future.

  3. Molecular properties and activities of tuber proteins from starch potato cv. Kuras.

    PubMed

    Jørgensen, Malene; Bauw, Guy; Welinder, Karen G

    2006-12-13

    Potato starch production leaves behind a huge amount of juice. This juice is rich in protein, which might be exploited for food, biotechnological, and pharmaceutical applications. In northern Europe cv. Kuras is dominant for industrial starch production, and juice protein of freshly harvested mature tubers was fractionated by Superdex 200 gel filtration. The fractions were subjected to selected activity assays (patatin, peroxidase, glyoxalases I and II, alpha-mannosidase, inhibition of trypsin, Fusarium protease, and alcalase) and protein subunit size determination by SDS-PAGE and mass spectrometry. Proteins present in SDS-PAGE bands were identified by tryptic peptide mass fingerprinting. Protein complexes such as ribosomes and proteasomes eluted with the void volume of the gel filtration. Large proteins were enzymes of starch synthesis dominated by starch phosphorylase L-1 (ca. 4% of total protein). Five identified dimeric patatin variants (25%) coeluted with four monomeric lipoxygenase variants (10%) at 97 kDa. Protease inhibitor I variants (4%) at 46 kDa (hexamer) inhibited alcalase. Fourteen Kunitz protease inhibitor variants (30%) at 19 kDa inhibited trypsin and Fusarium protease. Carboxypeptidase inhibitor variants (5%) and defensins (5%) coeluted with phenolics. The native sizes and molecular properties were determined for 43 different potato tuber proteins, several for the first time.

  4. Physical modification and characterization of starch using pregelatinization and co-process of various tubers from Yogyakarta as an excipient

    NASA Astrophysics Data System (ADS)

    Awaluddin, Rizki; Prasetya, Arif Widya; Nugraha, Yayan; Suweleh, Mohammad Fahmi; Kusuma, Aris Perdana; Indrati, Oktavia

    2017-03-01

    Starch is an economical excipient that is used in oral dosage form. It has poor compressibility and flowability. Pregelatinization and co-process as a physical modification technique have been conducted widely; nevertheless, the single modification shows a limitation. This study aims to assess and characterize the starch result of the modification of various tubers by a combination of modification methods. The starches from various tubers were extracted by sedimentation. Starch pregelatinization was conducted by manufacturing a starch suspension and was heated at 55°C for 70 minutes, and then it was mixed using concentrations HPMC k15 of 2, 3, and 4% (w/w) of the starch weight. The evaluations that were conducted are general identification, amylose concentration, physical properties, and physicochemical identification. The obtained starch of the extraction was 10-18% of the fresh tubers, with the concentration of amylose around 21-37%. The shape and particle size of the starch affected the amylose concentration. The starch modification showed an improvement of the granules physical properties by addition of HPMC. The amylose concentration of yam starch was 37.60% and showed the optimum modification result in the addition of HPMC 4%. There were no changes in the physicochemical properties of the result of IR and X-ray diffraction analysis. The melting point of yam starch-HPMC 4% was 151.24°C with reduction of the maximum weight at 328.52°C. This study indicated that the yam starch has the highest amylose concentration with optimum granules result of the modification in addition of HPMC 4% that could be used as an alternative excipient.

  5. Glucose 1-phosphate is efficiently taken up by potato (Solanum tuberosum) tuber parenchyma cells and converted to reserve starch granules.

    PubMed

    Fettke, Joerg; Albrecht, Tanja; Hejazi, Mahdi; Mahlow, Sebastian; Nakamura, Yasunori; Steup, Martin

    2010-02-01

    Reserve starch is an important plant product but the actual biosynthetic process is not yet fully understood. Potato (Solanum tuberosum) tuber discs from various transgenic plants were used to analyse the conversion of external sugars or sugar derivatives to starch. By using in vitro assays, a direct glucosyl transfer from glucose 1-phosphate to native starch granules as mediated by recombinant plastidial phosphorylase was analysed. Compared with labelled glucose, glucose 6-phosphate or sucrose, tuber discs converted externally supplied [(14)C]glucose 1-phosphate into starch at a much higher rate. Likewise, tuber discs from transgenic lines with a strongly reduced expression of cytosolic phosphoglucomutase, phosphorylase or transglucosidase converted glucose 1-phosphate to starch with the same or even an increased rate compared with the wild-type. Similar results were obtained with transgenic potato lines possessing a strongly reduced activity of both the cytosolic and the plastidial phosphoglucomutase. Starch labelling was, however, significantly diminished in transgenic lines, with a reduced concentration of the plastidial phosphorylase isozymes. Two distinct paths of reserve starch biosynthesis are proposed that explain, at a biochemical level, the phenotype of several transgenic plant lines.

  6. Structural and physicochemical characterization of Sphenostylis stenocarpa (Hochst. ex A. Rich.) Harms tuber starch.

    PubMed

    Malumba, Paul; Bungu, Mulombo Denis; Katanga, Kabalevi Joseph; Doran, Lynn; Danthine, Sabine; Béra, François

    2016-12-01

    Several characteristics of African Yam Bean tuber starch (AYB) were studied and compared with that of a well-known native potato starch (P). The diameter of AYB granules ranged from 5.7μ to 49μ with a median at 19.5μ. During its pasting, AYB exhibited a low peak of viscosity in accordance with its low granules swelling and disintegration capacity. The gelatinization temperature of AYB was 75.2°C while that of P was 60.4°C. AYB was observed to be more stable during thermo-gravimetrical Analysis. Its degradation peak was observed at 308°C while that of P was 303°C. The X-ray diffraction analysis revealed that AYB belongs to the A-type crystalline group instead of C-type as claimed for several legumes starches. The stability of AYB and its capacity to structure starch-water systems make this resource an interesting ingredient for new food and non-food products.

  7. Enhancing sucrose synthase activity in transgenic potato (Solanum tuberosum L.) tubers results in increased levels of starch, ADPglucose and UDPglucose and total yield.

    PubMed

    Baroja-Fernández, Edurne; Muñoz, Francisco José; Montero, Manuel; Etxeberria, Ed; Sesma, María Teresa; Ovecka, Miroslav; Bahaji, Abdellatif; Ezquer, Ignacio; Li, Jun; Prat, Salomé; Pozueta-Romero, Javier

    2009-09-01

    Sucrose synthase (SuSy) is a highly regulated cytosolic enzyme that catalyzes the conversion of sucrose and a nucleoside diphosphate into the corresponding nucleoside diphosphate glucose and fructose. To determine the impact of SuSy activity in starch metabolism and yield in potato (Solanum tuberosum L.) tubers we measured sugar levels and enzyme activities in tubers of SuSy-overexpressing potato plants grown in greenhouse and open field conditions. We also transcriptionally characterized tubers of SuSy-overexpressing and -antisensed potato plants. SuSy-overexpressing tubers exhibited a substantial increase in starch, UDPglucose and ADPglucose content when compared with controls. Tuber dry weight, starch content per plant and total yield of SuSy-overexpressing tubers increased significantly over those of control plants. In contrast, activities of enzymes directly involved in starch metabolism in SuSy-overexpressing tubers were normal when compared with controls. Transcriptomic analyses using POCI arrays and the MapMan software revealed that changes in SuSy activity affect the expression of genes involved in multiple biological processes, but not that of genes directly involved in starch metabolism. These analyses also revealed a reverse correlation between the expressions of acid invertase and SuSy-encoding genes, indicating that the balance between SuSy- and acid invertase-mediated sucrolytic pathways is a major determinant of starch accumulation in potato tubers. Results presented in this work show that SuSy strongly determines the intracellular levels of UDPglucose, ADPglucose and starch, and total yield in potato tubers. We also show that enhancement of SuSy activity represents a useful strategy for increasing starch accumulation and yield in potato tubers.

  8. Simultaneous utilization of non-starch polysaccharides and starch and viscosity reduction for bioethanol fermentation from fresh Canna edulis Ker. tubers.

    PubMed

    Huang, Yuhong; Jin, Yanling; Fang, Yang; Li, Yuhao; Zhao, Hai

    2013-01-01

    Viscosity reduction and the effect of cell-wall degrading enzymes (CWDEs) were investigated using Canna edulis Ker. for bioethanol fermentation. The fermentation mash treated with CWDEs was much thinner (2.12 Pas) than the control mash (8.42 Pas), the fermentation efficiency was increased from 90.46% to 96.11%. HPLC analysis revealed that after treated with CWDEs, glucose and total sugar were increased by 28.07% and 7.60%, respectively. Changes in the starch granules were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM). The results suggested that the reduction in viscosity was caused by changes in saccharide composition and physical changes of the starch granules. This present study is of significance that non-starch polysaccharides and starch can be simultaneously utilized for bioethanol production using roots and tubers as feedstock.

  9. Large-scale isolation, fractionation, and purification of soluble starch-synthesizing enzymes: starch synthase and branching enzyme from potato tubers.

    PubMed

    Mukerjea, Rupendra; Falconer, Daniel J; Yoon, Seung-Heon; Robyt, John F

    2010-07-19

    Soluble starch-synthesizing enzymes, starch synthase (SSS) and starch-branching enzyme (SBE), were isolated, fractionated, and purified from white potato tubers (Solanum tuberosum) on a large scale. Five steps were used: potato tuber extract from 2 kg of peeled potatoes, two acetone precipitations, and two fractionations on a large ultrafiltration polysulfone hollow fiber 100 kDa cartridge. Three kinds of fractions were obtained: (1) mixtures of SSS and SBE; (2) SSS, free of SBE; and (3) SBE, free of SSS. Contaminating enzymes (amylase, phosphorylase, and disproportionating enzyme) and carbohydrates were absent from the 2nd acetone precipitate and from the column fractions, as judged by the Molisch test and starch triiodide test. Activity yields of 122% (300,000-400,000 units) of SSS fractions and 187% (40,000-50,000 units) of SBE fractions were routinely obtained from the cartridge. Addition of 0.04% (w/v) polyvinyl alcohol 50K and 1 mM dithiothreitol to the glycine buffer (pH 8.4) gave long-term stability and higher yields of SSS and SBE, due to activation of inactive enzymes. Several SSS and SBE fractions from the two fractionations had very high specific activities, indicating high degrees of purification. Polyacrylamide gel electrophoresis of selected SSS and SBE fractions gave two to five SSS and/or SBE activity bands, corresponding to the one to five protein bands present in the 2nd acetone precipitate.

  10. Two carbon fluxes to reserve starch in potato (Solanum tuberosum L.) tuber cells are closely interconnected but differently modulated by temperature.

    PubMed

    Fettke, Joerg; Leifels, Lydia; Brust, Henrike; Herbst, Karoline; Steup, Martin

    2012-05-01

    Parenchyma cells from tubers of Solanum tuberosum L. convert several externally supplied sugars to starch but the rates vary largely. Conversion of glucose 1-phosphate to starch is exceptionally efficient. In this communication, tuber slices were incubated with either of four solutions containing equimolar [U-¹⁴C]glucose 1-phosphate, [U-¹⁴C]sucrose, [U-¹⁴C]glucose 1-phosphate plus unlabelled equimolar sucrose or [U-¹⁴C]sucrose plus unlabelled equimolar glucose 1-phosphate. C¹⁴-incorporation into starch was monitored. In slices from freshly harvested tubers each unlabelled compound strongly enhanced ¹⁴C incorporation into starch indicating closely interacting paths of starch biosynthesis. However, enhancement disappeared when the tubers were stored. The two paths (and, consequently, the mutual enhancement effect) differ in temperature dependence. At lower temperatures, the glucose 1-phosphate-dependent path is functional, reaching maximal activity at approximately 20 °C but the flux of the sucrose-dependent route strongly increases above 20 °C. Results are confirmed by in vitro experiments using [U-¹⁴C]glucose 1-phosphate or adenosine-[U-¹⁴C]glucose and by quantitative zymograms of starch synthase or phosphorylase activity. In mutants almost completely lacking the plastidial phosphorylase isozyme(s), the glucose 1-phosphate-dependent path is largely impeded. Irrespective of the size of the granules, glucose 1-phosphate-dependent incorporation per granule surface area is essentially equal. Furthermore, within the granules no preference of distinct glucosyl acceptor sites was detectable. Thus, the path is integrated into the entire granule biosynthesis. In vitro C¹⁴C-incorporation into starch granules mediated by the recombinant plastidial phosphorylase isozyme clearly differed from the in situ results. Taken together, the data clearly demonstrate that two closely but flexibly interacting general paths of starch biosynthesis are functional

  11. Bioactive Compounds in Potato Tubers: Effects of Farming System, Cooking Method, and Flesh Color

    PubMed Central

    Czerko, Zbigniew; Zarzyńska, Krystyna; Borowska-Komenda, Monika

    2016-01-01

    We investigated the effect of cultivation system (conventional or organic), cooking method, and flesh color on the contents of ascorbic acid (AA) and total phenolics (TPs), and on total antioxidant activity (Trolox equivalents, TE) in Solanum tuberosum (potato) tubers. The research material, consisting of 4 potato cultivars, was grown in experimental fields, using organic and conventional systems, at the experimental station in 2012 and 2013. The analysis showed that organically grown potatoes with creamy, light yellow, and yellow flesh had significantly higher TPs than did potatoes grown conventionally. Flesh color and cooking method also affected AA. The greatest losses of AA occurred in yellow-fleshed potatoes grown conventionally and cooked in the microwave; such losses were not observed in potatoes grown organically. A dry cooking method (baking in a microwave) increased the TP contents in potatoes by about 30%, regardless of the flesh color and the production system. TE was significantly higher in organically grown potatoes (raw and cooked in a steamer) than in conventionally grown potatoes. TE and AA contents showed a significant positive correlation, but only in potatoes from the organic system [R2 = 0.686]. By contrast, the positive correlation between TE and TPs was observed regardless of the production system. Therefore, we have identified the effects of farming system, cooking method, and flesh color on the contents of bioactive compounds in potato tubers. PMID:27139188

  12. [Effects of antisense acid invertase gene on reducing sugar and starch contents of potato (Solanum tuberosum L.) tuber stored at low temperature].

    PubMed

    Wang, Qing; Huang, Hui-Ying; Zhang, Jin-Wen; Li, Xue-Cai

    2005-10-01

    Two transgenic potato lines with antisense AcInv gene and the non-transgenic varieties were used to test the reducing sugar and starch contents. The results indicated that the reducing sugar content increased and total starch content decreased in all samples after tubers were stored at 4 degrees C for 40 d. The reducing sugar content in tubers of transgenic line "Anti-AcInv Atlantic" and "Anti-AcInv Gannongshu No.2" were lower about 23% and 18% than those of Atlantic and Gannongshu No.2 (Table 1). The total starch and the amylopectin were also decreased by 1% and 1.3% in "Anti-AcInv Atlantic" and 1.4% and 1.7% in "Anti-AcInv Gannongshu No.2" respectively (Table 2). The proportions of amylose and amylopectin were lower in the transgenic lines than the non-transgenic varieties (Figs. 1 and 2). It was only 0.29 for "Anti-AcInv Atlantic" and 0.38 for "Anti-AcInv Gannongshu No.2". Meanwhile, there are fewer dark blue starch particles in transgenic tuber, which is less than in tuber of the non-transgenic varieties by paraffin-cut section method (Fig. 3). After the tubers were transferred to the storage temperature 15-17 degrees C for 20 d, the reducing sugar contents in tubers of the two transgenic lines were significantly lower than that of non-transgenic varieties. It was 0.23% for "Anti-AcInv Atlantic" and 0.24% for "Anti-AcInv Gannongshu No.2" (Table 1). It is suggested that the trans-antisense AcInv gene in the transgenic potato down-regulates the AcInv gene expression after the tubers were stored under low temperature.

  13. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    PubMed

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-21

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement.

  14. [Role of the digestive microflora and of the crystalline structure of starch in digestion and dietary efficiency in the chicken. Study of tropical tubers].

    PubMed

    Bewa, H; Charlet-Lery, G; Szylit, O

    1979-01-01

    The influence of microflora in the utilization of starches, the X ray pattern which was of A or B type, was studied by balances and carcasses analysis with growing axenic or holoxenic chickens, put in isolators. Five tropical tubers were used : Manihot utilissima and Dioscorea dumetorum of A-type, Dioscorea cayenensis and alata and Canna edulis of B-type. They were introduced in isoenergetic (4,460 Kcal/g D.M.) and isoproteic (18 p. 100) diets. The A-type starches are entirely digested (95 p. 100) and the B-type are poorly digested (40-60 p. 100). The first ones induced a better growth than the second. The influence of digestive microflora changes with the two types of tubers used. With A-type starches the microflora lowered the feed intake, the growth and the energy and protein efficiency respectively--25 and--10 p. 100. When the diet included tubers with B-type starches, the low digestibility of starch and the low metabolisable energy in the diets induced poor growth and retentions. The results are discussed in relation with the starch breakdown into glucose, lactic acid and volatile fatty acids.

  15. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization

    PubMed Central

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  16. Starch extraction process coupled to protein recovery from leguminous tuberous roots (Pachyrhizus ahipa).

    PubMed

    Díaz, Andrea; Dini, Cecilia; Viña, Sonia Z; García, María A

    2016-11-05

    The objective of this work was to fit together the starch extraction from Pachyrhizus ahipa roots and the recovery of the proteins present in these storage organs, making an improved use of this novel raw material. The replacement of water by buffer PO4(-3)/NaCl as solvent in the first extraction steps improved protein extraction without lowering the starch yield. The starches obtained from the traditional and the proposed methods exhibited some differences in appearance and technological and thermal properties, which were endorsed to the adjustment in the methodology of extraction rather than to the use of buffer as solvent. Thus, P. ahipa starch obtaining procedure could be coupled to protein extraction with a minimum change in the methodology. This innovation did not significantly shift the characteristics of the starch obtained and allowed to obtain a protein yield of 135.7mg BSA equivalent protein/100g of fresh roots.

  17. Extensive Variation in Fried Chip Color and Tuber Composition in Cold-Stored Tubers of Wild Potato (Solanum) Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold-induced sweetening and browning in the Maillard reaction have driven extensive research in the areas of plant physiology, biochemistry, and food science in Solanum tuberosum. To date, research in these areas excluded wild relatives of potato. This is the first assessment of cold-stored tuber c...

  18. Ethylene in the atmosphere of commercial potato (Solanum tuberosum) storage bins and potential effects on tuber respiration rate and fried chip color

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Careful storage management is required to maintain post-harvest potato tuber quality. The plant growth regulator ethylene has well documented effects on potato tuber respiration rate, fried product color, and sprouting, but data on the amount of ethylene present in ventilated potato storages and how...

  19. Characterization of films made with chayote tuber and potato starches blending with cellulose nanoparticles.

    PubMed

    Aila-Suárez, Selene; Palma-Rodríguez, Heidi M; Rodríguez-Hernández, Adriana I; Hernández-Uribe, Juan P; Bello-Pérez, Luis A; Vargas-Torres, Apolonio

    2013-10-15

    The aim of this study was to characterize chayotextle starch films reinforced with cellulose (C) and cellulose nanoparticle (CN) (at concentrations of 0.3%, 0.5%, 0.8% and 1.2%), using thermal, mechanical, physicochemical, permeability, and water solubility tests. C was acid-treated to obtain CN. The films were prepared by casting; potato starch and C were used as the control. The solubility of the starch films decreased with the addition of C and CN compared with its respective film without C and CN. No statistical difference (α=0.05) was found in the films added with different concentrations of C and CN. In general, the mechanical properties were improved with the addition of C and CN, and higher values of tensile strength and elastic modulus were determined in the films reinforced with CN. The melting temperature and enthalpy increased with the addition of C and CN, and the values of both thermal parameters were higher in the films with CN than with C; the enthalpy value of the film decreased when the concentration of C or CN increased in the composite. Low concentration of C and CN is better distributed in the matrix film. The addition of C and CN in the starch films improved some mechanical, barrier, and functional properties.

  20. Antisense Repression of Hexokinase 1 Leads to an Overaccumulation of Starch in Leaves of Transgenic Potato Plants But Not to Significant Changes in Tuber Carbohydrate Metabolism1

    PubMed Central

    Veramendi, Jon; Roessner, Ute; Renz, Andreas; Willmitzer, Lothar; Trethewey, Richard N.

    1999-01-01

    Potato (Solanum tuberosum L.) plants transformed with sense and antisense constructs of a cDNA encoding the potato hexokinase 1 (StHK1) exhibited altered enzyme activities and expression of StHK1 mRNA. Measurements of the maximum catalytic activity of hexokinase revealed a 22-fold variation in leaves (from 22% of the wild-type activity in antisense transformants to 485% activity in sense transformants) and a 7-fold variation in developing tubers (from 32% of the wild-type activity in antisense transformants to 222% activity in sense transformants). Despite the wide range of hexokinase activities, no change was found in the fresh weight yield, starch, sugar, or metabolite levels of transgenic tubers. However, there was a 3-fold increase in the starch content of leaves from the antisense transformants after the dark period. Starch accumulation at the end of the night period was correlated with a 2-fold increase of glucose and a decrease of sucrose content. These results provide strong support for the hypothesis that glucose is a primary product of transitory starch degradation and is the sugar that is exported to the cytosol at night to support sucrose biosynthesis. PMID:10482667

  1. Decreasing the mitochondrial synthesis of malate in potato tubers does not affect plastidial starch synthesis, suggesting that the physiological regulation of ADPglucose pyrophosphorylase is context dependent.

    PubMed

    Szecowka, Marek; Osorio, Sonia; Obata, Toshihiro; Araújo, Wagner L; Rohrmann, Johannes; Nunes-Nesi, Adriano; Fernie, Alisdair R

    2012-12-01

    Modulation of the malate content of tomato (Solanum lycopersicum) fruit by altering the expression of mitochondrially localized enzymes of the tricarboxylic acid cycle resulted in enhanced transitory starch accumulation and subsequent effects on postharvest fruit physiology. In this study, we assessed whether such a manipulation would similarly affect starch biosynthesis in an organ that displays a linear, as opposed to a transient, kinetic of starch accumulation. For this purpose, we used RNA interference to down-regulate the expression of fumarase in potato (Solanum tuberosum) under the control of the tuber-specific B33 promoter. Despite displaying similar reductions in both fumarase activity and malate content as observed in tomato fruit expressing the same construct, the resultant transformants were neither characterized by an increased flux to, or accumulation of, starch, nor by alteration in yield parameters. Since the effect in tomato was mechanistically linked to derepression of the reaction catalyzed by ADP-glucose pyrophosphorylase, we evaluated whether the lack of effect on starch biosynthesis was due to differences in enzymatic properties of the enzyme from potato and tomato or rather due to differential subcellular compartmentation of reductant in the different organs. The results are discussed in the context both of current models of metabolic compartmentation and engineering.

  2. Potato Tuber Callus

    PubMed Central

    Shaw, Roy; Varns, Jerry L.; Miller, Karon A.; Talley, Eugene A.

    1976-01-01

    Callus was initiated from explants of tubers of the Norchip cultivar of Solanum tuberosum L. and grown on medium with a single carbon source and without addition of coconut milk, protein hydrolysate, or amino acid. Callus samples were harvested at intervals and compared to mature tubers for which there was good biochemical knowledge. The amino acid spectrum, the glycoalkaloid content, and the properties of the isolated invertase and sucrose synthetase were similar in callus and in tuber. Significantly the level of sucrose synthetase varied with the age of the developing callus just as it did with the age of the developing tuber. Of greater significance, levels of reducing sugars and invertase varied with the age of developing callus and also with time and temperature of storage after the callus has ceased growth. Similar changes occur in intact tubers. Callus and tuber biochemistry differed in the amount of deposited starch and in the absence of potato invertase inhibitor. PMID:16659698

  3. Structure of potato tubers formed during spaceflight

    NASA Technical Reports Server (NTRS)

    Croxdale, J.; Cook, M.; Tibbitts, T. W.; Brown, C. S.; Wheeler, R. M.

    1997-01-01

    Potato (Solanum tuberosum L. cv. Norland) explants, consisting of a leaf, axillary bud, and small stem segment, were used as a model system to study the influence of spaceflight on the formation of sessile tubers from axillary buds. The explants were flown on the space shuttle Columbia (STS-73, 20 October to 5 November 1995) in the ASTROCULTURE (TM) flight package, which provided a controlled environment for plant growth. Light and scanning electron microscopy were used to compare the precisely ordered tissues of tubers formed on Earth with those formed during spaceflight. The structure of tubers produced during spaceflight was similar to that of tubers produced in a control experiment. The size and shape of tubers, the geometry of tuber tissues, and the distribution of starch grains and proteinaceous crystals were comparable in tubers formed in both environments. The shape, surface texture, and size range of starch grains from both environments were similar, but a greater percentage of smaller starch grains formed in spaceflight than on Earth. Since explant leaves must be of given developmental age before tubers form, instructions regarding the regular shape and ordered tissue geometry of tubers may have been provided in the presence of gravity. Regardless of when the signalling occurred, gravity was not required to produce a tuber of typical structure.

  4. Starch Granule Variability in Wild Solanum Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because most of the dry matter of potato tubers is starch, an understanding of starch properties is important in potato improvement programs. Starch granule size is considered to influence tuber processing quality parameters such as gelatinization temperature, viscosity, and water holding capacity. ...

  5. Comparison of Color Fundus Photography, Infrared Fundus Photography, and Optical Coherence Tomography in Detecting Retinal Hamartoma in Patients with Tuberous Sclerosis Complex

    PubMed Central

    Bai, Da-Yong; Wang, Xu; Zhao, Jun-Yang; Li, Li; Gao, Jun; Wang, Ning-Li

    2016-01-01

    Background: A sensitive method is required to detect retinal hamartomas in patients with tuberous sclerosis complex (TSC). The aim of the present study was to compare the color fundus photography, infrared imaging (IFG), and optical coherence tomography (OCT) in the detection rate of retinal hamartoma in patients with TSC. Methods: This study included 11 patients (22 eyes) with TSC, who underwent color fundus photography, IFG, and spectral-domain OCT to detect retinal hamartomas. TSC1 and TSC2 mutations were tested in eight patients. Results: The mean age of the 11 patients was 8.0 ± 2.1 years. The mean spherical equivalent was −0.55 ± 1.42 D by autorefraction with cycloplegia. In 11 patients (22 eyes), OCT, infrared fundus photography, and color fundus photography revealed 26, 18, and 9 hamartomas, respectively. The predominant hamartoma was type I (55.6%). All the hamartomas that detected by color fundus photography or IFG can be detected by OCT. Conclusion: Among the methods of color fundus photography, IFG, and OCT, the OCT has higher detection rate for retinal hamartoma in TSC patients; therefore, OCT might be promising for the clinical diagnosis of TSC. PMID:27174333

  6. Differences between the Bud End and Stem End of Potatoes in Dry Matter Content, Starch Granule Size, and Carbohydrate Metabolic Gene Expression at the Growing and Sprouting Stages.

    PubMed

    Liu, Bailin; Zhang, Guodong; Murphy, Agnes; De Koeyer, David; Tai, Helen; Bizimungu, Benoit; Si, Huaijun; Li, Xiu-Qing

    2016-02-10

    Potatoes usually have the tuber bud end dominance in growth during tuber bulking and in tuber sprouting, likely using carbohydrates from the tuber stem end. We hypothesized that the tuber bud end and tuber stem end coordination in carbohydrate metabolism gene expression is different between the bulking dominance and sprouting dominance of the tuber bud end. After comparing the growing tubers at harvest from a green vine and the stage that sprouts just started to emerge after storage of tubers at room temperature, we found the following: (1) Dry matter content was higher in the tuber stem end than the tuber bud end at both stages. (2) The starch granule size was larger in the tuber bud end than in the tuber stem end. (3) The tuber bud end had higher gene expression for starch synthesis but a lower gene expression of sucrose transporters than the tuber stem end during tuber growing. (4) The tuber stem end at the sprouting stage showed more active gene expression in both starch degradation and resynthesis, suggesting more active export of carbohydrates, than the tuber bud end. The results indicate that the starch accumulation mechanism in the tuber bud end was different between field growing and post-harvest sprouting tubers and that tubers already increased dry matter and average starch granule sizes in the tuber bud end prior to the rapid growth of sprouts.

  7. Tuberous Sclerosis

    MedlinePlus

    ... or other symptoms can be life-threatening. Tuberous sclerosis has no cure, but treatments can help symptoms. Options include medicines, educational and occupational therapy, surgery, or surgery to ...

  8. Production of ethyl alcohol from tubers

    SciTech Connect

    Sreekantiah, K.R.; Rao, B.A.S.

    1980-01-01

    Ethanol was produced from starchy tubers by gelatinization in a boiling acidic solution, saccharification with Rhizopus niveus, and fermentation with Saccharomyces ellipsoideus in the presence of the saccharifying fungus. The efficiency of ethanol production from potato, tapioca, and sweet potato starch was 68, 81, and 75% respectively.

  9. Immunocytochemical localization of ADPglucose pyrophosphorylase in developing potato tuber cells

    SciTech Connect

    Kim, Woo Taek; Franceschi, V.R.; Okita, T.W. ); Robinson, N.L.; Morell, M.; Preiss, J. )

    1989-09-01

    The subcellular localization of ADPglucose pyrophosphorylase, a key regulatory enzyme in starch biosynthesis, was determined in developing potato tuber cells by immunocytochemical localization techniques at the light microscopy level. Specific labeling of ADPglucose pyrophosphorylase by either immunofluorescence or immunogold followed by silver enhancement was detected only in the amyloplasts and indicates that this enzyme is located exclusively in the amyloplasts in developing potato tuber cells. Labeling occurred on the starch grains and, in some instances, specific labeling patterns were evident which may be related to sites active in starch deposition.

  10. Development and growth of potato tubers in microgravity

    NASA Astrophysics Data System (ADS)

    Cook, M. E.; Croxdale, J. L.; Tibbitts, T. W.; Goins, G.; Brown, C. S.; Wheeler, R. M.

    A potato explant consisting of a leaf, its axillary bud, and a small segment of stem will develop a tuber in 10-14 days when grown on earth. The tubers develop from the axillary buds and accumulate starch derived from sugars produced through photosynthesis and/or mobilized from leaf tissue. Potato explants were harvested and maintained in the Astroculture^TM unit, a plant growth chamber designed for spaceflight. The unit provides an environment with controlled temperature, humidity, CO_2 level, light intensity, and a nutrient delivery system. The hardware was loaded onto the space shuttle Columbia 24 hours prior to the launch of the STS-73 mission. Explant leaf tissue appeared turgid and green for the first 11 days of flight, but then became chlorotic and eventually necrotic by the end of the mission. The same events occurred to ground control explants with approximately the same timing. At the end of the 16-day mission, tubers were present on each explant. The size and shape of the space-grown tubers were similar to the ground-control tubers. The arrangement of cells in the tuber interior and at the exterior in the periderm was similar in both environments. Starch and protein were present in the tubers grown in space and on the ground. The range in starch grain size was similar in tubers from both environments, but the distribution of grains into size classes differed somewhat, with the space-grown tubers having more small grains than the ground control tubers. Proteinaceous crystals were found in tubers formed in each condition.

  11. Sources and intake of resistant starch in the Chinese diet.

    PubMed

    Chen, Liyong; Liu, Ruiping; Qin, Chengyong; Meng, Yan; Zhang, Jie; Wang, Yun; Xu, Guifa

    2010-01-01

    Resistant starch (RS) escapes digestion in the small intestine and may ferment in the large intestine. The purpose of this study was to determine the resistant starch content in typical starchy foods and to estimate the daily resistant starch intake and identify key sources of dietary resistant starch in the Chinese diets. The resistant starch contents of 121 foods were determined using a method that mimicked gastrointestinal conditions. Tubers and legumes had high resistant starch contents. Rough food processing retained large amounts of resistant starch. In general, the content of RS decreased when foods were cooked. Deep fried and roasted foods had higher levels of resistant starch than braised foods. The average resistant starch intake in the Chinese population was estimated to be 14.9 g per day based on a dietary survey. The main resistant starch sources in the Chinese diet were cereal and tuber products. Based on dietary habits, however, the resistant starch intake varies considerably among individuals.

  12. Physicochemical Characteristics and Composition of Three Morphotypes of Cyperus esculentus Tubers and Tuber Oils

    PubMed Central

    Bado, Souleymane; Bazongo, Patrice; Son, Gouyahali; Kyaw, Moe Thida; Forster, Brian Peter; Nielen, Stephan; Lykke, Anne Mette; Ouédraogo, Amadé; Bassolé, Imaël Henri Nestor

    2015-01-01

    Tuber characteristics and nutrient composition of three morphotypes of Cyperus esculentus tubers and tuber oils were determined. The mean value for length and width of the tuber and one thousand dried tuber weights ranged from 0.98 to 1.31 cm, 0.90 to 1.19 cm, and 598 to 1044 g, respectively. Tubers displayed high level of starch (30.54–33.21 g 100 g−1), lipid (24.91–28.94 g 100 g−1), and sucrose (17.98–20.39 g 100 g−1). The yellow tubers had significantly higher content in lipid compared to black ones. Levels of ascorbic acid, tocopherol, and β-carotene of the three morphotypes differed significantly. Yellow ones (morphotypes 1 and 2) were the richest in tocopherol and the poorest in β-carotene. Saturated fatty acid content of morphotype 2 was significantly lower than that of morphotypes 1 and 3. Morphotype 3 had the significantly lowest PUFA content compared to morphotypes 1 and 2. Morphotype 1 was found to be richer in Ca, Cu, and Mn contents. Al, Mg, P, S, and Si were most abundant in morphotype 2. Morphotype 3 had the highest content of Cl, K, and Zn. PMID:26539305

  13. Sweet potato [Ipomoea batatas (L.) Lam.] cultivated as tuber or leafy vegetable supplier as affected by elevated tropospheric ozone.

    PubMed

    Keutgen, Norbert; Keutgen, Anna J; Janssens, Marc J J

    2008-08-13

    Sweet potato cultivars respond differently to elevated tropospheric ozone concentrations of ca. 130 mug m (-3), 8 h a day for 4 weeks, which affects their selection for cultivation. In the first cultivar presented here, an adequate leafy vegetable supplier, the ozone load resulted in a shift of biomass to maintain the canopy at the expense of tuber development. Starch content of leaves was reduced, indicating an impairment of quality, but carotenoid content remained stable. The second cultivar may be grown for tuber production. Although the ratio tuber/plant remained stable under ozone, tuber yield and its starch content were significantly reduced. The lower starch content indicated a worse quality for certain industrial processing, but it is desirable for chip production. Elevated tropospheric ozone concentrations also influenced free amino acids and macronutrient contents of tubers, but these modifications were of minor significance for tuber quality in the second cultivar.

  14. Morphological and molecular characterization of a spontaneously tuberizing potato mutant: an insight into the regulatory mechanisms of tuber induction

    PubMed Central

    Fischer, Lukas; Lipavska, Helena; Hausman, Jean-Francois; Opatrny, Zdenek

    2008-01-01

    Background Tuberization in potato (Solanum tuberosum L.) represents a morphogenetic transition of stolon growth to tuber formation, which is under complex environmental and endogenous regulation. In the present work, we studied the regulatory mechanisms and the role of different morphogenetic factors in a newly isolated potato mutant, which exhibited spontaneous tuberization (ST). The ST mutant was characterized in detail at morphological, physiological and biochemical levels. Results Tuberization of the ST mutant grown in the soil was photoperiod-insensitive; predominantly sessile tubers formed directly from axillary buds even under continuous light. Single-node cuttings of the ST mutant cultured in vitro frequently formed tubers or basal tuber-like swellings instead of normal shoots under conditions routinely used for shoot propagation. The tuberization response of ST cuttings under light was dependent on sucrose, the concentration of which had to exceed certain threshold that inversely correlated with irradiance. Gibberellic acid prevented tuberization of ST cuttings, but failed to restore normal shoot phenotype and caused severe malformations. Carbohydrate analysis showed increased levels of both soluble sugars and starch in ST plants, with altered carbohydrate partitioning and metabolism. Comparative proteomic analysis revealed only a few differences between ST- and wild-type plants, primary amongst which seemed to be the absence of an isoform of manganese-stabilizing protein, a key subunit of photosystem II. Conclusion ST mutant exhibits complex developmental and phenotypic modifications, with features that are typical for plants strongly induced to tuberize. These changes are likely to be related to altered regulation of photosynthesis and carbohydrate metabolism rather than impaired transduction of inhibitory gibberellin or photoperiod-based signals. The effect of gibberellins on tuberization of ST mutant suggests that gibberellins inhibit tuberization

  15. Encapsulation altered starch digestion: toward developing starch-based delivery systems.

    PubMed

    Janaswamy, Srinivas

    2014-01-30

    Starch is an abundant biomaterial that forms a vital energy source for humans. Altering its digestion, e.g. increasing the proportions of slowly digestible starch (SDS) and resistant starch (RS), would revolutionize starch utility in addressing a number of health issues related to glucose absorption, glycemic index and colon health. The research reported in this article is based on my hypothesis that water channels present in the B-type starch crystalline matrix, particularly in tuber starches, can embed guest molecules such as nutraceuticals, drugs, flavor compounds and vitamins leading to altered starch digestion. Toward this goal, potato starch has been chosen as the model tuber starch, and ibuprofen, benzocaine, sulfapyridine, curcumin, thymol and ascorbic acid as model guest molecules. X-ray powder diffraction and FT-IR analyses clearly suggest the incorporation of guest molecules in the water channels of potato starch. Furthermore, the in vitro digestion profiles of complexes are intriguing with major variations occurring after 60 min of starch digestion and finally at 120 min. These changes are concomitantly reflected in the SDS and RS amounts, with about 24% decrease in SDS for benzocaine complex and 6% increase in RS for ibuprofen complex, attesting the ability of guest molecule encapsulation in modulating the digestion properties of potato starch. Overall, this research provides an elegant opportunity for the design and development of novel starch-based stable carriers that not only bestow tailored glucose release rates but could also transport health promoting and disease preventing compounds.

  16. Starch Metabolism in Arabidopsis

    PubMed Central

    Streb, Sebastian; Zeeman, Samuel C.

    2012-01-01

    Starch is the major non-structural carbohydrate in plants. It serves as an important store of carbon that fuels plant metabolism and growth when they are unable to photosynthesise. This storage can be in leaves and other green tissues, where it is degraded during the night, or in heterotrophic tissues such as roots, seeds and tubers, where it is stored over longer time periods. Arabidopsis accumulates starch in many of its tissues, but mostly in its leaves during the day. It has proven to be a powerful genetic system for discovering how starch is synthesised and degraded, and new proteins and processes have been discovered. Such work has major significance for our starch crops, whose yield and quality could be improved by the application of this knowledge. Research into Arabidopsis starch metabolism has begun to reveal how its daily turnover is integrated into the rest of metabolism and adapted to the environmental conditions. Furthermore, Arabidopsis mutant lines deficient in starch metabolism have been employed as tools to study other biological processes ranging from sugar sensing to gravitropism and flowering time control. This review gives a detailed account of the use of Arabidopsis to study starch metabolism. It describes the major discoveries made and presents an overview of our understanding today, together with some as-yet unresolved questions. PMID:23393426

  17. A transgenic study on affecting potato tuber yield by expressing the rice sucrose transporter genes OsSUT5Z and OsSUT2M.

    PubMed

    Sun, Aijun; Dai, Yan; Zhang, Xinsheng; Li, Chunmin; Meng, Kun; Xu, Honglin; Wei, Xiaoli; Xiao, Guifang; Ouwerkerk, Pieter B F; Wang, Mei; Zhu, Zhen

    2011-07-01

    In many plants, sucrose transporters are essential for both sucrose exports from sources and imports into sinks, indicating a function in assimilate partitioning. To investigate whether sucrose transporters can improve the yield of starch plant, potato plants (Solanum tuberosum L. cv. Désirée) were transformed with cDNAs of the rice sucrose transporter genes OsSUT5Z and OsSUT2M under the control of a tuber-specific, class-I patatin promoter. Compared to the controls, the average fructose content of OsSUT5Z transgenic tubers significantly increased. However, the content of the sugars and starch in the OsSUT2M transgenic potato tubers showed no obvious difference. Correspondingly, the average tuber yield, average number of tubers per plant and average weight of single tuber showed no significant difference in OsSUT2M transgenic tubers with controls. In the OsSUT5Z transgenic lines, the average tuber yield per plant was 1.9-fold higher than the controls, and the average number of tubers per plant increased by more than 10 tubers on average, whereas the average weight of a single tuber did not increase significantly. These results suggested that the average number of tubers per plant showed more contribution than the average weight of a single tuber to the tuber yield per plant.

  18. Genetic enhancement of oil content in potato tuber (Solanum tuberosum L.) through an integrated metabolic engineering strategy.

    PubMed

    Liu, Qing; Guo, Qigao; Akbar, Sehrish; Zhi, Yao; El Tahchy, Anna; Mitchell, Madeline; Li, Zhongyi; Shrestha, Pushkar; Vanhercke, Thomas; Ral, Jean-Philippe; Liang, Guolu; Wang, Ming-Bo; White, Rosemary; Larkin, Philip; Singh, Surinder; Petrie, James

    2017-01-01

    Potato tuber is a high yielding food crop known for its high levels of starch accumulation but only negligible levels of triacylglycerol (TAG). In this study, we evaluated the potential for lipid production in potato tubers by simultaneously introducing three transgenes, including WRINKLED 1 (WRI1), DIACYLGLYCEROL ACYLTRANSFERASE 1 (DGAT1) and OLEOSIN under the transcriptional control of tuber-specific (patatin) and constitutive (CaMV-35S) promoters. This coordinated metabolic engineering approach resulted in over a 100-fold increase in TAG accumulation to levels up to 3.3% of tuber dry weight (DW). Phospholipids and galactolipids were also found to be significantly increased in the potato tuber. The increase of lipids in these transgenic tubers was accompanied by a significant reduction in starch content and an increase in soluble sugars. Microscopic examination revealed that starch granules in the transgenic tubers had more irregular shapes and surface indentations when compared with the relatively smooth surfaces of wild-type starch granules. Ultrastructural examination of lipid droplets showed their close proximity to endoplasmic reticulum and mitochondria, which may indicate a dynamic interaction with these organelles during the processes of lipid biosynthesis and turnover. Increases in lipid levels were also observed in the transgenic potato leaves, likely due to the constitutive expression of DGAT1 and incomplete tuber specificity of the patatin promoter. This study represents an important proof-of-concept demonstration of oil increase in tubers and provides a model system to further study carbon reallocation during development of nonphotosynthetic underground storage organs.

  19. Cytological examination of pink eye afflicted tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pink eye is a tuber disorder of undetermined cause that can result in serious processing complications and storage losses throughout North America. Pink eye symptoms progress from ephemeral light pink colorations around bud-end eyes to water-soaked or dried and cracked “corky-patch” periderm. Late s...

  20. Functional properties of yam bean (Pachyrhizus erosus) starch.

    PubMed

    Mélo, E A; Stamford, T L M; Silva, M P C; Krieger, N; Stamford, N P

    2003-08-01

    The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53-63 degrees C) and the pasting temperature (64.5 degrees C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.

  1. Understanding and influencing starch biochemistry.

    PubMed

    Kossmann, J; Lloyd, J

    2000-01-01

    Starch is one of the most important products synthesized by plants that is used in industrial processes. If it were possible to increase production or modify starches in vivo, using combinations or either genetically altered or mutant plants, it may make them cheaper for use by industry, or open up new markets for the modified starches. The conversion of sucrose to starch in storage organs is, therefore, discussed. In particular the roles of the different enzymes directly involved in synthesizing the starch molecules on altering starch structure are reviewed, as well as the different models for the production of the fine structure of amylopectin. In addition, the process of starch phosphorylation, which is also important in determining the physical properties of starches, is reviewed. It is hoped that detailed knowledge of these processes will lead to the rational design of tailored starches. Starch degradation is also an important process, for example, in the cold-sweetening of potato tubers, but outside of cereal endosperm little is known about the processes involved. The enzymes thought to be involved and the evidence for this are discussed.

  2. Rapid high throughput amylose determination in freeze dried potato tuber samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 80% of the fresh weight of a potato tuber is water; nearly all of the remaining dry matter is starch. Most of the starch (70%) is composed of amylopectin, while the remainder is amylose. The ratio between amylose and amylopectin is the most important property influencing the physical p...

  3. Starch digestibility of foods: a nutritional perspective.

    PubMed

    Dreher, M L; Dreher, C J; Berry, J W

    1984-01-01

    Dietary starch varies greatly in digestibility and its effects on the utilization of other nutrients. The variation appears to be due to differences in starch components and their crystallinity. Processing treatments, storage conditions, chemical modification, and genetic breeding influence the digestibility of starch. Cereal starches are generally more digestible than root/tuber and legume starches. Although cooking often significantly improves the digestibility of poor and intermediately digestible starches, some foods such as bananas with starches of these types are consumed uncooked. The efficient digestion of starch is especially important to specific groups of people such as infants under 6 months of age. Ruminants must also be provided with highly digestible starch to assure maximum production efficiency. Poor digestibility of starch may have negative effects on the utilization of protein and minerals but is likely to have positive effects on the availability of certain vitamins. Decreases in the rate of starch digestion may have therapeutic application. Most clinical studies have reported that starch blockers do not elicit a significant decrease in the digestion of starch in humans. Much remains to be learned, clarified, and understood about starch digestion and its effects on diabetes and weight control.

  4. Structural and molecular basis of starch viscosity in hexaploid wheat.

    PubMed

    Ral, J-P; Cavanagh, C R; Larroque, O; Regina, A; Morell, M K

    2008-06-11

    Wheat starch is considered to have a low paste viscosity relative to other starches. Consequently, wheat starch is not preferred for many applications as compared to other high paste viscosity starches. Increasing the viscosity of wheat starch is expected to increase the functionality of a range of wheat flour-based products in which the texture is an important aspect of consumer acceptance (e.g., pasta, and instant and yellow alkaline noodles). To understand the molecular basis of starch viscosity, we have undertaken a comprehensive structural and rheological analysis of starches from a genetically diverse set of wheat genotypes, which revealed significant variation in starch traits including starch granule protein content, starch-associated lipid content and composition, phosphate content, and the structures of the amylose and amylopectin fractions. Statistical analysis highlighted the association between amylopectin chains of 18-25 glucose residues and starch pasting properties. Principal component analysis also identified an association between monoesterified phosphate and starch pasting properties in wheat despite the low starch-phosphate level in wheat as compared to tuber starches. We also found a strong negative correlation between the phosphate ester content and the starch content in flour. Previously observed associations between internal starch granule fatty acids and the swelling peak time and pasting temperature have been confirmed. This study has highlighted a range of parameters associated with increased starch viscosity that could be used in prebreeding/breeding programs to modify wheat starch pasting properties.

  5. Optimization of starch isolation from taro using combination of enzymes and comparison of properties of starches isolated by enzymatic and conventional methods.

    PubMed

    Sit, Nandan; Deka, Sankar Chandra; Misra, Sudip

    2015-07-01

    The optimization of enzymatic starch isolation process from taro tubers using cellulase and xylanase was carried out. The functional properties of starch isolated by optimized enzymatic process were compared with starch isolated by conventional method without the use of enzymes. A central composite rotatable design (CCRD) with four numerical factors was employed to design the experiments. The numerical factors were cellulase concentration (0-100 U/100 g tuber), xylanase concentration (0-100 U/100 g tuber), temperature of incubation (30-50 °C) and incubation time (1-5 h). Statistical analysis showed that the main effects of all the factors were significant on starch yield and effect of cellulase was more significant compared to xylanase. The effectiveness of xylanase in increasing the yield of starch from taro tubers confirmed that xylan is an important component of the cell walls of taro tubers. The optimized condition with maximum starch yield (17.22 %) was obtained when cellulase and xylanase concentration were 299.86 and 300 U/100 g tuber, temperature was 35 °C and incubation time was 2 h. The swelling of the starch granules increased whereas solubility decreased for enzymatic method. The clarity of the starch paste isolated by enzymatic method was found to be better compared to the clarity of starch paste isolated by conventional method. The pasting temperature of the starch paste was slightly higher and viscosity was lower for the starch isolated by enzymatic method. Freeze-thaw stability of the starch paste was also found to be better for the enzymatically isolated starch.

  6. Physical and functional properties of arrowroot starch extrudates.

    PubMed

    Jyothi, A N; Sheriff, J T; Sajeev, M S

    2009-03-01

    Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food.

  7. Symplastic connection is required for bud outgrowth following dormancy in potato (Solanum tuberosum L.) tubers.

    PubMed

    Viola, Roberto; Pelloux, Jérôme; van der Ploeg, Anke; Gillespie, Trudi; Marquis, Nicola; Roberts, Alison G; Hancock, Robert D

    2007-08-01

    To gain greater insight into the mechanism of dormancy release in the potato tuber, an investigation into physiological and biochemical changes in tuber and bud tissues during the transition from bud dormancy (immediately after harvest) to active bud growth was undertaken. Within the tuber, a rapid shift from storage metabolism (starch synthesis) to reserve mobilization within days of detachment from the mother plant suggested transition from sink to source. Over the same period, a shift in the pattern of [U-(14)C]sucrose uptake by tuber discs from diffuse to punctate accumulation was consistent with a transition from phloem unloading to phloem loading within the tuber parenchyma. There were no gross differences in metabolic capacity between resting and actively growing tuber buds as determined by [U-(14)C]glucose labelling. However, marked differences in metabolite pools were observed with large increases in starch and sucrose, and the accumulation of several organic acids in growing buds. Carboxyfluorescein labelling of tubers clearly demonstrated strong symplastic connection in actively growing buds and symplastic isolation in resting buds. It is proposed that potato tubers rapidly undergo metabolic transitions consistent with bud outgrowth; however, growth is initially prevented by substrate limitation mediated via symplastic isolation.

  8. Sugar metabolism, chip color, invertase activity, and gene expression during long-term cold storage of potato (Solanum tuberosum) tubers from wild-type and vacuolar invertase silencing lines of Katahdin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Storing potato tubers at low temperatures helps to minimize losses from sprouting and disease but often leads to an accumulation of reducing sugars in a process called cold-induced sweetening. When tubers with increased amounts of reducing sugars are processed at high temperatures, as by frying, the...

  9. Preparation and characterization of polymeric nanoparticles from Gadong starch

    NASA Astrophysics Data System (ADS)

    Sisika, Regina; Ahmad, Wan Yaacob Wan; Fazry, Shazrul; Lazim, Azwan Mat

    2015-09-01

    Dioscorea hispida (Gadong tuber) was seldom used and forgotten as a food source due to their toxicity. In contrast to that, the Gadong tuber can be a source of polysaccharides which can be manipulated as an alternative source for industrial applications. This research reported on how to synthesize starch nanoparticles from Gadong tuber by using a simple acid hydrolysis process. The yield of starch nanoparticles obtained from seven days of acid hydrolysis was reduced to 13%. The X-ray diffraction measurements showed that the native Gadong starch particle is of the C-crystalline type, and that the synthesized nanoparticles showed an increase in crystallinity compared to the native particles. Transmission electron microscopy results demonstrated that the starch particle morphologies were either round or irregular shape, with diameters ranging from 96-110 nm.

  10. Preparation and characterization of polymeric nanoparticles from Gadong starch

    SciTech Connect

    Sisika, Regina; Ahmad, Wan Yaacob Wan; Lazim, Azwan Mat; Fazry, Shazrul

    2015-09-25

    Dioscorea hispida (Gadong tuber) was seldom used and forgotten as a food source due to their toxicity. In contrast to that, the Gadong tuber can be a source of polysaccharides which can be manipulated as an alternative source for industrial applications. This research reported on how to synthesize starch nanoparticles from Gadong tuber by using a simple acid hydrolysis process. The yield of starch nanoparticles obtained from seven days of acid hydrolysis was reduced to 13%. The X-ray diffraction measurements showed that the native Gadong starch particle is of the C-crystalline type, and that the synthesized nanoparticles showed an increase in crystallinity compared to the native particles. Transmission electron microscopy results demonstrated that the starch particle morphologies were either round or irregular shape, with diameters ranging from 96-110 nm.

  11. Subcellular pyrophosphate metabolism in developing tubers of potato (Solanum tuberosum).

    PubMed

    Farré, Eva M; Tech, Susanne; Trethewey, Richard N; Fernie, Alisdair R; Willmitzer, Lothar

    2006-09-01

    PPi has previously been implicated specifically in the co-ordination of the sucrose-starch transition and in the broader context of its role as co-factor in heterotrophic plant metabolism. In order to assess the compartmentation of pyrophosphate (PPi) metabolism in the potato tuber we analysed the effect of expressing a bacterial pyrophosphatase in the amyloplast of wild type tubers or in the cytosol or amyloplast of invertase-expressing tubers. The second and third approaches were adopted since we have previously characterized the invertase expressing lines to both exhibit highly altered sucrose metabolism and to contain elevated levels of PPi (Farré et al. (2000a) Plant Physiol 123:681) and therefore this background rendered questions concerning the level of communication between the plastidic and cytosolic pyrophosphate pools relatively facile. In this study we observed that the increase in PPi in the invertase expressing lines was mainly confined to the cytosol. Accordingly, the expression of a bacterial pyrophosphatase in the plastid of either wild type or invertase-expressing tubers did not lead to a decrease in total PPi content. However, the expression of the heterologous pyrophosphatase in the cytosol of cytosolic invertase-expressing tubers led to strong metabolic changes. These results are discussed both with respect to our previous hypotheses and to current models of the compartmentation of potato tuber metabolism.

  12. Starch poisoning

    MedlinePlus

    Cooking starch poisoning; Laundry starch poisoning ... Cooking and laundry starch are both made from vegetable products, most commonly: Corn Potatoes Rice Wheat Both are usually considered nonpoisonous (nontoxic), but ...

  13. Plant age and genotype affect the bacterial community composition in the tuber rhizosphere of field-grown sweet potato plants.

    PubMed

    Marques, Joana M; da Silva, Thais F; Vollu, Renata E; Blank, Arie F; Ding, Guo-Chun; Seldin, Lucy; Smalla, Kornelia

    2014-05-01

    The hypothesis that sweet potato genotypes containing different starch yields in their tuberous roots can affect the bacterial communities present in the rhizosphere (soil adhering to tubers) was tested in this study. Tuberous roots of field-grown sweet potato of genotypes IPB-149 (commercial genotype), IPB-052, and IPB-137 were sampled three and six months after planting and analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analysis of 16S rRNA genes PCR-amplified from total community DNA. The statistical analysis of the DGGE fingerprints showed that both plant age and genotypes influenced the bacterial community structure in the tuber rhizosphere. Pyrosequencing analysis showed that the IPB-149 and IPB-052 (both with high starch content) displayed similar bacterial composition in the tuber rhizosphere, while IPB-137 with the lowest starch content was distinct. In comparison with bulk soil, higher 16S rRNA gene copy numbers (qPCR) and numerous genera with significantly increased abundance in the tuber rhizosphere of IPB-137 (Sphingobium, Pseudomonas, Acinetobacter, Stenotrophomonas, Chryseobacterium) indicated a stronger rhizosphere effect. The genus Bacillus was strongly enriched in the tuber rhizosphere samples of all sweet potato genotypes studied, while other genera showed a plant genotype-dependent abundance. This is the first report on the molecular identification of bacteria being associated with the tuber rhizosphere of different sweet potato genotypes.

  14. Heat stress during development alters post-harvest sugar contents and chip processing quality of potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental stresses that increase tuber contents of the reducing sugars glucose and fructose decrease the value of chipping potatoes because such tubers produce dark-colored chips that are unacceptable to processors and consumers. Stem-end chip defect (SECD), which causes regions of dark color al...

  15. Polysaccharide composition of raw and cooked chayote (Sechium edule Sw.) fruits and tuberous roots.

    PubMed

    Shiga, Tânia M; Peroni-Okita, Fernanda Helena Gonçalves; Carpita, Nicholas C; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

    2015-10-05

    Chayote is a multipurpose table vegetable widely consumed in Latin America countries. Chayote fruits, leaves and tuberous roots contain complex carbohydrates as dietary fiber and starch, vitamins and minerals. The complex polysaccharides (cell walls and starch) were analyzed in the black and green varieties of chayote fruits as well as in green chayote tuberous root before and after a controlled cooking process to assess changes in their composition and structure. The monosaccharide composition and linkage analysis indicated pectins homogalacturonans and rhamnogalacturonan I backbones constitute about 15-20% of the wall mass, but are heavily substituted with, up to 60% neutral arabinans, galactans, arabinogalactans. The remainder is composed of xyloglucan, glucomannans and galactoglucomannans. Chayote cell-wall polysaccharides are highly stable under normal cooking conditions, as confirmed by the optical microscopy of wall structure. We found also that tuberous roots constitute a valuable additional source of quality starch and fiber.

  16. Tuber-specific cytosolic expression of a bacterial phosphoglucomutase in potato (Solanum tuberosum L.) dramatically alters carbon partitioning.

    PubMed

    Lytovchenko, Anna; Schauer, Nicolas; Willmitzer, Lothar; Fernie, Alisdair R

    2005-04-01

    Constitutive antisense inhibition of the cytosolic isoform of phosphoglucomutase in the potato (Solanum tuberosum L.) results in restriction of photosynthesis, growth inhibition and modified tuber morphology, and a severe restriction of tuber starch synthesis. Here we describe the consequences of the tuber-specific expression of an Escherichia coli phosphoglucomutase in the cytosol. Analysis of [14C]glucose metabolism by tuber discs isolated from wild type and transformants revealed that the rates of sucrose and starch synthesis were unaltered but that the rate of glycolysis was depressed in the transgenics. The transformant tubers also contained dramatically reduced amino acid content and significantly higher levels of ADP, but were characterized by elevated levels of Krebs cycle intermediates and an unaltered rate of respiration. In addition to these metabolic consequences of the overexpression of the E. coli enzyme, we observed morphological changes in tubers, with the transformants having a smaller number of larger tubers which exhibited delayed rates of sprouting with respect to the wild type. These results are discussed with respect to current models of the regulation of central plant metabolism and tuber dormancy.

  17. Starch gelatinization.

    PubMed

    Ratnayake, Wajira S; Jackson, David S

    2009-01-01

    Starch occurs as highly organized structures, known as starch granules. Starch has unique thermal properties and functionality that have permitted its wide use in food products and industrial applications. When heated in water, starch undergoes a transition process, during which the granules break down into a mixture of polymers-in-solution, known as gelatinization. The sequence of structural transformations that the starch granule undergoes during this order-to-disorder transition has been extensively researched. None of the published starch gelatinization theories can fully and adequately explain the exact mechanism of sequential structural changes that starch granules undergo during gelatinization. This chapter analyzes several published theories and summarizes our current understanding of the starch gelatinization process.

  18. A GC-MS-based metabolomics study on the tubers of commercial potato cultivars upon storage.

    PubMed

    Uri, Csilla; Juhász, Zsófia; Polgár, Zsolt; Bánfalvi, Zsófia

    2014-09-15

    Using gas chromatography-mass spectrometry (GC-MS) as a system for the detection of amino acids, organic acids, sugars, sugar alcohols, and fatty acids, we characterised six commercial potato cultivars (Hópehely, Katica, Lorett, Somogyi kifli, Vénusz Gold, and White Lady) with different pedigrees, starch contents, cooking types, and dormancy periods, in five developmental stages from harvest to sprouting. The tubers were stored at 20-22°C in the dark. The metabolite data were subjected to principal component analysis. No correlation between metabolite contents of freshly harvested tubers and starch content or cooking type of the cultivars was detected. The storage decreased the fructose and sucrose and increased the proline concentrations of tubers. Irrespective of the length of dormancy a substantial difference in metabolite composition at each time point upon storage was detected in each cultivar except Somogyi kifli, the only cultivar amongst those tested with a pure Solanum tuberosum origin and A cooking type.

  19. In situ observation of crystallinity disruption patterns during starch gelatinization.

    PubMed

    Cai, Canhui; Wei, Cunxu

    2013-01-30

    Twelve starches were isolated from the tuberous root of sweet potato, the rhizomes of lotus and yam, the tuber of potato, the corm of water chestnut, and the seeds of pea, bean, barley, wheat, lotus, water caltrop, and ginkgo. Their gelatinization processes were in situ viewed using a polarizing microscope in combination with a hot stage. Four patterns of crystallinity disruption during heating were proposed. The crystallinity disruption initially occurred on the proximal surface of the eccentric hilum, on the distal surface of the eccentric hilum, from the central hilum, or on the surface of the central hilum starch granule. The patterns of initial disruption on the distal surface of the eccentric hilum and on the surface of the central hilum starch were reported for the first time. The heterogeneous distribution of amylose in starch granule might partly explain the different patterns of crystallinity disruption and swelling during gelatinization.

  20. Characteristics of taro (Colocasia esculenta) starches planted in different seasons and their relations to the molecular structure of starch.

    PubMed

    Lu, Ting-Jang; Lin, Jheng-Hua; Chen, Jia-Ci; Chang, Yung-Ho

    2008-03-26

    Physico-chemical properties and molecular structure of starches from three cultivars (Dog hoof, Mein, and KS01) of taro tubers planted in summer, winter, and spring were investigated. The effects of the planting season on the physico-chemical properties and the molecular structure of starch were determined, and the relations between the physico-chemical properties and the molecular structure of starch are discussed. Results indicate that taro starches from tubers planted in summer had the largest granule size, a low uniformity of gelatinization, and a high tendency to swell and collapse when heated in water. Taro starch planted in summer also showed an elasticity during gelatinization that was higher than that of starches planted in the other seasons. In addition to the planting season and the variety, rheological and pasting properties of taro starches studied are influenced not only by the amylose content but also by the chain-length distribution of amylopectin, whereas swelling power and solubility only depend on the amylose content of starch. Taro starch with relatively high amylose content, high short-to-long-chain ratio, and long average chain length of long-chain fraction of amylopectin displayed high elasticity and strong gel during heating.

  1. Truffle diversity (Tuber, Tuberaceae) in British Columbia.

    PubMed

    Berch, Shannon M; Bonito, Gregory

    2016-08-01

    To improve baseline data for the developing truffle industry in British Columbia, we compiled existing Tuber species sequences from published and unpublished studies and generated new ITS sequences for truffles belonging to Tuber collected in the province. In doing so, we obtained evidence that 13 species of Tuber occur in the province, including six introduced and seven native species, two of which are putative undescribed species. Of the native species, the Tuber anniae species complex is widely distributed in the province while Tuber beyerlei appears to be much more restricted in distribution. Four of the introduced species have commercial value (Tuber melanosporum, Tuber aestivum, Tuber brumale, and Tuber borchii) as do two of the native species (Tuber gibbosum and Tuber oregonense). Focused sampling on likely tree hosts, both hardwood and Pinaceae species, as well as in currently unexplored parts of the province seems likely to expand our knowledge of the diversity and distribution of Tuber species in British Columbia.

  2. The diurnal metabolism of leaf starch.

    PubMed

    Zeeman, Samuel C; Smith, Steven M; Smith, Alison M

    2007-01-01

    Starch is a primary product of photosynthesis in leaves. In most plants, a large fraction of the carbon assimilated during the day is stored transiently in the chloroplast as starch for use during the subsequent night. Photosynthetic partitioning into starch is finely regulated, and the amount of carbohydrate stored is dependent on the environmental conditions, particularly day length. This regulation is applied at several levels to control the flux of carbon from the Calvin cycle into starch biosynthesis. Starch is composed primarily of branched glucans with an architecture that allows the formation of a semi-crystalline insoluble granule. Biosynthesis has been most intensively studied in non-photosynthetic starch-storing organs, such as developing seeds and tubers. Biosynthesis in leaves has received less attention, but recent reverse-genetic studies of Arabidopsis (thale cress) have produced data generally consistent with what is known for storage tissues. The pathway involves starch synthases, which elongate the glucan chains, and branching enzymes. Remarkably, enzymes that partially debranch glucans are also required for normal amylopectin synthesis. In the last decade, our understanding of starch breakdown in leaves has advanced considerably. Starch is hydrolysed to maltose and glucose at night via a pathway that requires recently discovered proteins in addition to well-known enzymes. These sugars are exported from the plastid to support sucrose synthesis, respiration and growth. In the present review we provide an overview of starch biosynthesis, starch structure and starch degradation in the leaves of plants. We focus on recent advances in each area and highlight outstanding questions.

  3. Tuberous sclerosis and parathyroid adenoma.

    PubMed Central

    Mortensen, L S; Rungby, J

    1991-01-01

    Very little is known about the pathogenesis of tuberous sclerosis. Over the past 10 years, however, increasing numbers of reports on adenomatous diseases in association with tuberous sclerosis have been published. A case of hypercalcaemia and parathyroid adenoma in association with tuberous sclerosis is presented, of which there has been one such report published previously. This association might be another manifestation of this complex disease: it is therefore recommended that plasma calcium concentrations should be measured in such patients. PMID:1752991

  4. Tuber Storage Proteins

    PubMed Central

    SHEWRY, PETER R.

    2003-01-01

    A wide range of plants are grown for their edible tubers, but five species together account for almost 90 % of the total world production. These are potato (Solanum tuberosum), cassava (Manihot esculenta), sweet potato (Ipomoea batatus), yams (Dioscorea spp.) and taro (Colocasia, Cyrtosperma and Xanthosoma spp.). All of these, except cassava, contain groups of storage proteins, but these differ in the biological properties and evolutionary relationships. Thus, patatin from potato exhibits activity as an acylhydrolase and esterase, sporamin from sweet potato is an inhibitor of trypsin, and dioscorin from yam is a carbonic anhydrase. Both sporamin and dioscorin also exhibit antioxidant and radical scavenging activity. Taro differs from the other three crops in that it contains two major types of storage protein: a trypsin inhibitor related to sporamin and a mannose‐binding lectin. These characteristics indicate that tuber storage proteins have evolved independently in different species, which contrasts with the highly conserved families of storage proteins present in seeds. Furthermore, all exhibit biological activities which could contribute to resistance to pests, pathogens or abiotic stresses, indicating that they may have dual roles in the tubers. PMID:12730067

  5. Tuber storage proteins.

    PubMed

    Shewry, Peter R

    2003-06-01

    A wide range of plants are grown for their edible tubers, but five species together account for almost 90 % of the total world production. These are potato (Solanum tuberosum), cassava (Manihot esculenta), sweet potato (Ipomoea batatus), yams (Dioscorea spp.) and taro (Colocasia, Cyrtosperma and Xanthosoma spp.). All of these, except cassava, contain groups of storage proteins, but these differ in the biological properties and evolutionary relationships. Thus, patatin from potato exhibits activity as an acylhydrolase and esterase, sporamin from sweet potato is an inhibitor of trypsin, and dioscorin from yam is a carbonic anhydrase. Both sporamin and dioscorin also exhibit antioxidant and radical scavenging activity. Taro differs from the other three crops in that it contains two major types of storage protein: a trypsin inhibitor related to sporamin and a mannose-binding lectin. These characteristics indicate that tuber storage proteins have evolved independently in different species, which contrasts with the highly conserved families of storage proteins present in seeds. Furthermore, all exhibit biological activities which could contribute to resistance to pests, pathogens or abiotic stresses, indicating that they may have dual roles in the tubers.

  6. Potato tuber expression of Arabidopsis WRINKLED1 increase triacylglycerol and membrane lipids while affecting central carbohydrate metabolism.

    PubMed

    Hofvander, Per; Ischebeck, Till; Turesson, Helle; Kushwaha, Sandeep K; Feussner, Ivo; Carlsson, Anders S; Andersson, Mariette

    2016-09-01

    Tuber and root crops virtually exclusively accumulate storage products in the form of carbohydrates. An exception is yellow nutsedge (Cyperus esculentus) in which tubers have the capacity to store starch and triacylglycerols (TAG) in roughly equal amounts. This suggests that a tuber crop can efficiently handle accumulation of energy dense oil. From a nutritional as well as economic aspect, it would be of interest to utilize the high yield capacity of tuber or root crops for oil accumulation similar to yellow nutsedge. The transcription factor WRINKLED1 from Arabidopsis thaliana, which in seed embryos induce fatty acid synthesis, has been shown to be a major factor for oil accumulation. WRINKLED1 was expressed in potato (Solanum tuberosum) tubers to explore whether this factor could impact tuber metabolism. This study shows that a WRINKLED1 transcription factor could induce triacylglycerol accumulation in tubers of transformed potato plants grown in field (up to 12 nmol TAG/mg dry weight, 1% of dry weight) together with a large increase in polar membrane lipids. The changes in metabolism further affected starch accumulation and composition concomitant with massive increases in sugar content.

  7. Studies on the Carbon Dioxide Promotion and Ethylene Inhibition of Tuberization in Potato Explants Cultured in Vitro1

    PubMed Central

    Mingo-Castel, Angel M.; Smith, Orrin E.; Kumamoto, Junji

    1976-01-01

    Ethylene inhibited the tuberization of etiolated potato (Solanum tuberosum L. var. Red La Soda) sprout sections cultured in vitro. Carbon dioxide did not overcome the C2H4 inhibition but it was required for normal tuberization. Ethylene totally prevented root formation and development. It inhibited stolon elongation, and caused thickening and diageotropical growth of the stolon. In addition, C2H4 prevented the accumulation of both starch and red anthocyanin which are always present in a tuber. Ethylene also inhibited the kinetin-increased tuberization of sprout sections. Three to five days of exposure to CO2 were required to obtain promotion of tuberization of stolons cultured in vitro. Bicarbonate ion did not affect starch synthetase activity isolated from potato tubers in vitro. The evidence presented suggests that CO2 gas rather than HCO−3 or CO2−3 ions in equilibrium with dissolved CO2 was probably responsible for the stimulation. Morphological changes elicited by CO2 and C2H4 are described and the mechanism of action of both on tuberization is discussed. Images PMID:16659510

  8. Isolation and partial characterization of delayed releasing starches of Colocasia species from Jharkhand, India.

    PubMed

    Deepika, V; Jayaram Kumar, K; Anima, P

    2013-07-01

    There is an increasing interest in starch manufactured from edible tubers for controlled delivery of drug. Starches of different cultivars of Colocasia from Jharkhand, North Eastern State of India, were isolated and their morphological, physicochemical, structural properties were studied. The yield of starches was estimated in the range of 6.46-13.75%. All the isolated starches revealed their irregular shape with a diameter of 5-10 μm. There was considerable variation in amylose content, swelling and solubility power, water hydration capacity. FTIR spectra confirmed their carbohydrate nature. Powder studies revealed that these starches possess potential for pharmaceutical industries. In vitro release data revealed the delayed release of all tablets made by using Colocasia starches at pH 6.8 and 7.4 when compared with maize starch. Delayed release of all starches showed there is a great potential to be used these starches as pharmaceutical excipient in sustained release dosage form with minimum modification.

  9. Amylopectin small chain glucans form structure fingerprint that determines botanical origin of starch.

    PubMed

    Jaiswal, Sarita; Chibbar, Ravindra N

    2017-02-20

    Starch granule size, shape and structure of amylopectin are species specific and influence starch properties and end-use of starch. Amylopectin glucan chain structure was used to predict the starch botanical sources. Mathematical probability for accumulation of small glucan chains DP 6-10 reveal exponential fit curve with maximum R(2) in smallest granule size starches (Chlamydomonas, quinoa, buckwheat). Cereal and cassava showed R(2) of 0.81-0.96 while in pulses and tubers it was less than 0.7. The amylopectin small glucan chains form a unique 'finger print region' that identified starch botanical source. Differential amylopectin chain length distribution (APCLD) graphs between DP 6-80 of all species from Chlamydomonas starch distinguished five structural groups that clustered the 31 analyzed starches into four major patterns. APCLD analyses of amylopectin combined with characteristic pattern of small linear DP (6-9) glucan chains predicted the starch botanical source.

  10. Effects of selenium treatments on potato (Solanum tuberosum L.) growth and concentrations of soluble sugars and starch.

    PubMed

    Turakainen, Marja; Hartikainen, Helinä; Seppänen, Mervi M

    2004-08-25

    The effect of selenium (Se) treatments on potato growth and Se, soluble sugar, and starch accumulation was investigated. Potato plants were cultivated in quartz sand without or with sodium selenate (0, 0.075, 0.3 mg Se kg(-1) sand). In young potato plants, Se treatment resulted in higher starch concentrations in upper leaves. The tuber yield of Se-treated potato plants was higher and composed of relatively few but large tubers. At harvest, the starch concentration in tubers did not differ significantly between treatments. The higher Se addition (0.3 mg Se kg(-1)) may have delayed the aging of stolons and roots, which was observed as high concentrations of soluble sugar and starch. Together with the earlier results showing elevated starch concentration in Se-treated lettuce, the findings of this research justify the conclusion that Se has positive effects also on potato carbohydrate accumulation and possibly on yield formation.

  11. Nematicides induced changes in the chemical constituents of potato tubers.

    PubMed

    Marwaha, R S

    1988-01-01

    Changes in the chemical constitutents of potato tubers grown under different concentrations of 3 synthetic organic nematicides (carbofuran, aldicarb and phorate) and a natural plant product (sawdust) were investigated. There were no significant differences in the specific gravity, dry matter and starch content of tubers from different treatments. A significant increase in the content of non-reducing and total sugars was observed in all the treatments. Nematicidal treatments had significant effects on reducing sugars, true protein, free amino acids, orthodihydroxy phenols, beta-carotene and ascorbic acid. Application of nematicides reduced the content of total phenolic compounds which is a desirable change from a processing viewpoint. Potatoes grown under different nematicidal treatments can be processed into chips and French fries as they contain permissible levels of reducing sugars required for these forms of processing.

  12. Two alternative methods to predict amylose content in rice grain by using tristimulus CIELAB values and developing a specific color board of starch-iodine complex solution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amylose content was predicted by measuring tridimensional L*a*b* values in starch-iodine solutions and building a regression model. The developed regression model showed a highly significant relationship (R2= 0.99) between the L*a*b values and the amylose content. Apparent amylose content was strong...

  13. Dynamic transcriptional profiling provides insights into tuberous root development in Rehmannia glutinosa

    PubMed Central

    Sun, Peng; Xiao, Xingguo; Duan, Liusheng; Guo, Yuhai; Qi, Jianjun; Liao, Dengqun; Zhao, Chunli; Liu, Yan; Zhou, Lili; Li, Xianen

    2015-01-01

    Rehmannia glutinosa, an herb of the Scrophulariaceae family, is widely cultivated in the Northern part of China. The tuberous root has well-known medicinal properties; however, yield and quality are threatened by abiotic and biotic stresses. Understanding the molecular process of tuberous root development may help identify novel targets for its control. In the present study, we used Illumina sequencing and de novo assembly strategies to obtain a reference transcriptome that is relevant to tuberous root development. We then conducted RNA-seq quantification analysis to determine gene expression profiles of the adventitious root (AR), thickening adventitious root (TAR), and the developing tuberous root (DTR). Expression profiling identified a total of 6794 differentially expressed unigenes during root development. Bioinformatics analysis and gene expression profiling revealed changes in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone biosynthesis during root development. Moreover, we identified and allocated putative functions to the genes involved in tuberous root development, including genes related to major carbohydrate metabolism, hormone metabolism, and transcription regulation. The present study provides the initial description of gene expression profiles of AR, TAR, and DTR, which facilitates identification of genes of interest. Moreover, our work provides insights into the molecular mechanisms underlying tuberous root development and may assist in the design and development of improved breeding schemes for different R. glutinosa varieties through genetic manipulation. PMID:26113849

  14. Improved method for detection of starch hydrolysis

    SciTech Connect

    Ohawale, M.R.; Wilson, J.J.; Khachatourians, G.G.; Ingledew, W.M.

    1982-09-01

    A new starch hydrolysis detection method which does not rely on iodine staining or the use of color-complexed starch is described. A linear relationship was obtained with agar-starch plates when net clearing zones around colonies of yeasts were plotted against enzyme levels (semilogarithm scale) produced by the same yeast strains in liquid medium. A similar relationship between starch clearing zones and alpha-amylase levels from three different sources was observed. These observations suggest that the method is useful in mutant isolations, strain improvement programs, and the prediction of alpha-amylase activities in culture filtrates or column effluents. (Refs. 18).

  15. The future of starch bioengineering: GM microorganisms or GM plants?

    PubMed

    Hebelstrup, Kim H; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However, in some situations, GM crops for starch bioengineering without deleterious effects have been achieved.

  16. Starch: Structure, Properties, Chemistry, and Enzymology

    NASA Astrophysics Data System (ADS)

    Robyt, John F.

    Starch is a very important and widely distributed natural product, occurring in the leaves of green plants, seeds, fruits, stems, roots, and tubers. It serves as the chemical storage form of the energy of the sun and is the primary source of energy for the organisms on the Earth. Starch is composed of two kinds of polysaccharides, amylose and amylopectin, exclusively composed of D-glucose residues with α-(1→4) linkages in a linear amylose and α-(1→4) linkages and ˜5% α-(1→6) branch linkages in amylopectin, both combined in a water-insoluble granule that is partially crystalline and whose size, shape, and morphology are dependent on its biological source. The properties, isolation, fractionation, enzymatic degradation, biosynthesis, chemical modification, and specific methods of analysis of starch are presented.

  17. The potato amylase inhibitor gene SbAI regulates cold-induced sweetening in potato tubers by modulating amylase activity.

    PubMed

    Zhang, Huiling; Liu, Jun; Hou, Juan; Yao, Ying; Lin, Yuan; Ou, Yongbin; Song, Botao; Xie, Conghua

    2014-09-01

    Potato cold-induced sweetening (CIS) is critical for the postharvest quality of potato tubers. Starch degradation is considered to be one of the key pathways in the CIS process. However, the functions of the genes that encode enzymes related to starch degradation in CIS and the activity regulation of these enzymes have received less attention. A potato amylase inhibitor gene known as SbAI was cloned from the wild potato species Solanum berthaultii. This genetic transformation confirmed that in contrast to the SbAI suppression in CIS-resistant potatoes, overexpressing SbAI in CIS-sensitive potatoes resulted in less amylase activity and a lower rate of starch degradation accompanied by a lower reducing sugar (RS) content in cold-stored tubers. This finding suggested that the SbAI gene may play crucial roles in potato CIS by modulating the amylase activity. Further investigations indicated that pairwise protein-protein interactions occurred between SbAI and α-amylase StAmy23, β-amylases StBAM1 and StBAM9. SbAI could inhibit the activities of both α-amylase and β-amylase in potato tubers primarily by repressing StAmy23 and StBAM1, respectively. These findings provide the first evidence that SbAI is a key regulator of the amylases that confer starch degradation and RS accumulation in cold-stored potato tubers.

  18. The tuberous sclerosis complex

    PubMed Central

    Orlova, Ksenia A.; Crino, Peter B.

    2010-01-01

    Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that results from mutations in the TSC1 or TSC2 genes and is associated with hamartoma formation in multiple organ systems. The neurological manifestations of TSC are particularly challenging and include infantile spasms, intractable epilepsy, cognitive disabilities, and autism. Progress over the past 15 years has demonstrated that the TSC1 or TSC2 encoded proteins modulate cell function via the mTOR signaling cascade and serve as keystones in regulating cell growth and proliferation. The mTOR pathway provides an intersection for an intricate network of protein cascades that respond to cellular nutrition, energy levels, and growth-factor stimulation. In the brain, TSC1 and TSC2 have been implicated in cell body size, dendritic arborization, axonal outgrowth and targeting, neuronal migration, cortical lamination, and spine formation. Antagonism of the mTOR pathway with rapamycin and related compounds may provide new therapeutic options for TSC patients. PMID:20146692

  19. Orofacial manifestations in tuberous sclerosis.

    PubMed

    Scully, C

    1977-11-01

    Tuberous sclerosis is a rare congenital disorder with characteristic neurologic, dermatologic, and orofacial lesions. There have been very few case reports in the dental literature. Four cases demonstrating the range of orofacial anomalies and problems in management are presented.

  20. Tuberous sclerosis: a case report.

    PubMed

    Cross, Nicola Jayne; Fung, Diane E

    2010-01-01

    Tuberous sclerosis is an inherited neurocutaneous disorder that occurs in approximately 1 in 7,500 live births. It is characterized by benign neoplasms of the skin, heart, kidneys, lungs, central nervous system, and mucosa. Oral lesions are usually fibrous in nature and most commonly occur on the anterior gingivae. Patients may suffer with epilepsy and learning difficulties, which may complicate dental management. When a 10-year-old girl with a history of tuberous sclerosis was brought in for a routine dental check-up, a leafy growth on the anterior gingiva was detected. An excisional biopsy was carried out. Histologically, the appearance was described as nonspecific, but was consistent with a diagnosis of tuberous sclerosis. Tuberous sclerosis is a rare condition that may exhibit oral manifestations. The patients may also exhibit epilepsy and learning difficulties. Dental management of affected patients may therefore be more complicated and complex.

  1. Application of calcium alginate-starch entrapped bitter gourd (Momordica charantia) peroxidase for the removal of colored compounds from a textile effluent in batch as well as in continuous reactor.

    PubMed

    Matto, Mahreen; Satar, Rukhsana; Husain, Qayyum

    2009-09-01

    Calcium alginate-starch entrapped bitter gourd peroxidase has been employed for the treatment of a textile industrial effluent in batch as well as in continuous reactor. The textile effluent was recalcitrant to decolorization by bitter gourd peroxidase; thus, its decolorization was examined in the presence of a redox mediator, 1.0 mM 1-hydroxybenzotriazole. Immobilized enzyme exhibited same pH and temperature optima for effluent decolorization as attained by soluble enzyme. Immobilized enzyme could effectively remove more than 70% of effluent color in a stirred batch process after 3 h of incubation. Entrapped bitter gourd peroxidase retained 59% effluent decolorization reusability even after its tenth repeated use. The two-reactor system containing calcium alginate-starch entrapped enzyme retained more than 50% textile effluent decolorization efficiency even after 2 months of its operation. The absorption spectra of the treated effluent exhibited a marked difference in the absorption at various wavelengths as compared to untreated effluent. The use of a two-reactor system containing immobilized enzyme and an adsorbent will be significantly successful for treating industrial effluents at large scale, and it will help in getting water free from aromatic pollutants.

  2. Inhibitory effect of chlorogenic acid on digestion of potato starch.

    PubMed

    Karim, Zida; Holmes, Melvin; Orfila, Caroline

    2017-02-15

    The effect of the chlorogenic acid isomer 5-O-caffeoylquinic acid (5-CQA) on digestion of potato starch by porcine pancreatic alpha amylase (PPAA) was investigated using isolated starch and cooked potato tuber as substrates. In vitro digestion was performed on five varieties of potato with varying phenolic content. Co- and pre-incubation of PPAA with 5-CQA significantly reduced PPAA activity in a dose dependent manner with an IC50 value of about 2mgmL(-1). Lineweaver-Burk plots indicated that 5-CQA exerts a mixed type inhibition as km increased and Vmax decreased. The total polyphenol content (TPC) of peeled tuber tissue ranged from 320.59 to 528.94mg 100g(-1)dry weight (DW) in raw tubers and 282.03-543.96mg 100g(-1)DW in cooked tubers. With the exception of Désirée, TPC and 5-CQA levels decreased after cooking. Principle component analysis indicated that digestibility is affected by multiple factors including phenolic, dry matter and starch content.

  3. Making starch.

    PubMed

    Smith, A M

    1999-06-01

    Improvements in understanding the structure of the starch granule and the nature and roles of starch-synthesising enzymes have allowed detailed mechanisms of the synthesis of the amylopectin and amylose components of the granule to be suggested. However, none of these proposed mechanisms has yet been shown to operate in vivo. Several critical aspects of granule synthesis, including granule initiation and the formation of the growth rings, remain a mystery.

  4. Heterologous expression of AtPAP2 in transgenic potato influences carbon metabolism and tuber development.

    PubMed

    Zhang, Youjun; Sun, Feng; Fettke, Joerg; Schöttler, Mark Aurel; Ramsden, Lawrence; Fernie, Alisdair R; Lim, Boon Leong

    2014-10-16

    Changes in carbon flow and sink/source activities can affect floral, architectural, and reproductive traits of plants. In potato, overexpression (OE) of the purple acid phosphatase 2 of Arabidopsis (AtPAP2) resulted in earlier flowering, faster growth rate, increased tubers and tuber starch content, and higher photosynthesis rate. There was a significant change in sucrose, glucose and fructose levels in leaves, phloem and sink biomass of the OE lines, consistent with an increased expression of sucrose transporter 1 (StSUT1). Furthermore, the expression levels and enzyme activity of sucrose-phosphate synthase (SPS) were also significantly increased in the OE lines. These findings strongly suggest that higher carbon supply from the source and improved sink strength can improve potato tuber yield.

  5. Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner

    ERIC Educational Resources Information Center

    Matthews, Kurt R.; Landmark, James D.; Stickle, Douglas F.

    2004-01-01

    The procedure to produce standard curve for starch concentration measurement by image analysis using a color scanner and computer for data acquisition and color analysis is described. Color analysis is performed by a Visual Basic program that measures red, green, and blue (RGB) color intensities for pixels within the scanner image.

  6. Enzymatic production of DFA III from fresh dahlia tubers as raw material

    NASA Astrophysics Data System (ADS)

    Budiwati, Thelma A.; Ratnaningrum, D.; Pudjiraharti, S.

    2017-01-01

    Dahlia is an annual ornamental plants and tubers that have not been widely used in Indonesia. Dahlia tubers contain nearly 70 per cent of the starch in the form of inulin. Inulin addition can be used as a food ingredient can also be used as a raw material for making DFA III (ie functional oligosaccharides), using inulin fructotransferase (IFTase) Nonomuraea sp. In this study conducted production of DFA III through enzymatic reactions and yeast fermentation, using inulin from fresh dahlia tubers and fresh dahlia tuber extract. Dahlia tubers which is one source of inulin, do blanching before extracted. Most dahlia tuber extract used directly for enzymatic reactions in the production of DFA III and some extracts are processed to produce inulin by precipitation using ethanol and then inulin is used for the enzymatic reaction. Syrup DFA III was measured volume and viscosity, and then do decolorization and then crystallization. The analysis was done of Thin Layer Chromatography (to see DFA III formed) and HPLC to see the purity of the product. The results showed that the average of inulin from precipitation with ethanol in the two batch of 113,5 g with an average water content of 7.41%, average whiteness degree 62.29% and an average yield 7.345% (w/w, wb dahlia tuber). From the average of DFA III liquid of 480 mL with density of 14.15%, the result of the average of DFA III crystal from enzyme reaction in the two reactor using inulin dahlia tubers as a substrate, was obtained of 55.4 g with an average whiteness degree of 93.8%, and the average of yield 3.56% w/w (wb dahlia tuber) or 48.89% w/w (db inulin). And then from the average of 475 mL with density of 16.85% was obtained an average DFA III crystals of 29 g from the enzyme reaction in the two reactor using fresh dahlia tuber extract as a substrate, with an average whiteness degree o 80.75% and the average of the yield of 1.86% w/w (wb dahlia tuber).

  7. 'Green' crosslinking of native starches with malonic acid and their properties.

    PubMed

    Ghosh Dastidar, Trina; Netravali, Anil N

    2012-11-06

    Starch is a highly hydrophilic biomaterial with weak mechanical properties rendering it useless for commercial applications. A fully 'green' water based process is presented to crosslink corn (cereal) and potato (tuber) starch to enhance mechanical properties as well as lower hydrophilicity. In addition, malonic acid, a green, plant based water soluble and relatively inexpensive polycarboxylic acid, was used as the crosslinker. The reactivity of potato starch toward esterification and crosslinking was found to be higher than that of corn starch owing to the inherent differences in the granule morphology and internal structure of the two starches. It was observed that potato starch granules had a higher degree of substitution (DS) of 0.19 than corn starch granules (DS=0.1) under similar reaction conditions. Chemical, thermal and mechanical test results confirmed the crosslinking as well as reduced moisture sensitivity.

  8. Potato poisoning - green tubers and sprouts

    MedlinePlus

    ... gov/ency/article/002875.htm Potato plant poisoning - green tubers and sprouts To use the sharing features ... Potato plant poisoning occurs when someone eats the green tubers or new sprouts of the potato plant. ...

  9. Tuberous sclerosis complex.

    PubMed

    Islam, Monica P; Roach, E Steve

    2015-01-01

    Tuberous sclerosis complex (TSC) is a neurocutaneous syndrome that can affect the brain, skin, eyes, kidneys, heart, and lungs. TSC alters cellular proliferation and differentiation, resulting in hamartomas of various organs, tumor formation, and altered neuronal migration. The phenotype is highly variable. Most individuals have seizures, commonly including infantile spasms, and there is variable intellectual disability and autism. Neonates can present with cardiac failure due to intracardiac rhabdomyomas. The likelihood of renal angiomyolipomas increases with age, and renal disease is the most common cause of death in adults with TSC. Pulmonary involvement occurs predominantly in women and carries a high morbidity and mortality. TSC is inherited as an autosomal dominant trait, but spontaneous mutations are common. A mutation of either TSC1 on chromosome 9 or TSC2 on chromosome 16 leads to dysfunction of hamartin or tuberin, respectively. These two proteins form a functional complex that modulates the mammalian target of rapamycin (mTOR) pathway. Medications that inhibit mTOR are being used to treat TSC-related tumors, and current studies are investigating whether these agents could alleviate other TSC complications. Consensus statements guide identification and optimal management of many of the TSC-related complications at diagnosis and throughout the lifespan. A multidisciplinary approach is necessary for optimal management of individuals with TSC.

  10. Tuberous sclerosis complex.

    PubMed

    Henske, Elizabeth P; Jóźwiak, Sergiusz; Kingswood, J Christopher; Sampson, Julian R; Thiele, Elizabeth A

    2016-05-26

    Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects multiple organ systems and is caused by loss-of-function mutations in one of two genes: TSC1 or TSC2. The disorder can affect both adults and children. First described in depth by Bourneville in 1880, it is now estimated that nearly 2 million people are affected by the disease worldwide. The clinical features of TSC are distinctive and can vary widely between individuals, even within one family. Major features of the disease include tumours of the brain, skin, heart, lungs and kidneys, seizures and TSC-associated neuropsychiatric disorders, which can include autism spectrum disorder and cognitive disability. TSC1 (also known as hamartin) and TSC2 (also known as tuberin) form the TSC protein complex that acts as an inhibitor of the mechanistic target of rapamycin (mTOR) signalling pathway, which in turn plays a pivotal part in regulating cell growth, proliferation, autophagy and protein and lipid synthesis. Remarkable progress in basic and translational research, in addition to several randomized controlled trials worldwide, has led to regulatory approval of the use of mTOR inhibitors for the treatment of renal angiomyolipomas, brain subependymal giant cell astrocytomas and pulmonary lymphangioleiomyomatosis, but further research is needed to establish full indications of therapeutic treatment. In this Primer, we review the state-of-the-art knowledge in the TSC field, including the molecular and cellular basis of the disease, medical management, major knowledge gaps and ongoing research towards a cure.

  11. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions.

    PubMed

    Cook, Martha E; Croxdale, Judith G

    2003-09-01

    Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

  12. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

    NASA Technical Reports Server (NTRS)

    Cook, Martha E.; Croxdale, Judith G.; Tibbitts, T. W. (Principal Investigator)

    2003-01-01

    Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

  13. Translucent tissue defect in potato (Solanum tuberosum L.) tubers is associated with oxidative stress accompanying an accelerated aging phenotype.

    PubMed

    Zommick, Daniel H; Kumar, G N Mohan; Knowles, Lisa O; Knowles, N Richard

    2013-12-01

    Translucent tissue defect (TTD) is an undesirable postharvest disorder of potato tubers characterized by the development of random pockets of semi-transparent tissue containing high concentrations of reducing sugars. Translucent areas turn dark during frying due to the Maillard reaction. The newly released cultivar, Premier Russet, is highly resistant to low temperature sweetening, but susceptible to TTD. Symptoms appeared as early as 170 days after harvest and worsened with time in storage (4-9 °C, 95 % RH). In addition to higher concentrations of glucose, fructose and sucrose, TTD resulted in lower dry matter, higher specific activities of starch phosphorylase and glc-6-phosphate dehydrogenase, higher protease activity, loss of protein, and increased concentrations of free amino acids (esp. asparagine and glutamine). The mechanism of TTD is unknown; however, the disorder has similarities with the irreversible senescent sweetening that occurs in tubers during long-term storage, where much of the decline in quality is a consequence of progressive increases in oxidative stress with advancing age. The respiration rate of non-TTD 'Premier Russet' tubers was inherently higher (ca. 40 %) than that of 'Russet Burbank' tubers (a non-TTD cultivar). Moreover, translucent tissue from 'Premier Russet' tubers had a 1.9-fold higher respiration rate than the average of non-translucent tissue and tissue from non-TTD tubers. Peroxidation of membrane lipids during TTD development resulted in increased levels of malondialdehyde and likely contributed to a measurable increase in membrane permeability. Superoxide dismutase and catalase activities and the ratio of oxidized to total glutathione were substantially higher in translucent tissue. TTD tubers also contained twofold less ascorbate than non-TTD tubers. TTD appears to be a consequence of oxidative stress associated with accelerated aging of 'Premier Russet' tubers.

  14. Tuberous sclerosis with pulmonary involvement.

    PubMed Central

    Liberman, B. A.; Chamberlain, D. W.; Goldstein, R. S.

    1984-01-01

    Pulmonary tuberous sclerosis produced interstitial disease in a woman with normal-sized lungs; numerous hemosiderin-laden macrophages were found in the fluid obtained through bronchoalveolar lavage. The pathological changes seen in the lungs were identical to those of pulmonary lymphangiomyomatosis, in which the constellation of clinical signs usually found in tuberous sclerosis is absent. The two conditions are sufficiently similar in clinical presentation, pathological changes and prognosis to be considered variants of the same disease. The recent findings of progestin receptors in lung tissue from patients with pulmonary lymphangiomyomatosis will likely direct future management towards hormonal manipulation. Images FIG. 1 FIG. 2 FIG. 3 PMID:6692213

  15. Transcriptome Analysis Suggests That Starch Synthesis May Proceed via Multiple Metabolic Routes in High Yielding Potato Cultivars

    PubMed Central

    Kaminski, Kacper Piotr; Petersen, Annabeth Høgh; Sønderkær, Mads; Pedersen, Lars Haastrup; Pedersen, Henrik; Feder, Christian; Nielsen, Kåre L.

    2012-01-01

    Background Glucose-6-phosphate is imported into the amyloplast of potato tubers and thought to constitute the precursor for starch synthesis in potato tubers. However, recently it was shown that glucose-1-phosphate can also be imported into the amyloplast and incorporated into starch via an ATP independent mechanism under special conditions. Nonetheless, glucose-6-phosphate is believed to be the quantitatively important precursor for starch synthesis in potato. Principal Finding Potato tubers of the high yielding cv Kuras had low gene expression of plastidial phophoglucomutase (PGM) and normal levels of transcripts for other enzymes involved in starch metabolism in comparison with medium and low yielding cultivars as determined by DeepSAGE transcriptome profiling. The decrease in PGM activity in Kuras was confirmed by measuring the enzyme activity from potato tuber extracts. Contrary to expectations, this combination lead to a higher level of intracellular glucose-1-phosphate (G1P) in Kuras suggesting that G1P is directly imported into plastids and can be quantitatively important for starch synthesis under normal conditions in high yielding cultivars. Significance This could open entirely new possibilities for metabolic engineering of the starch metabolism in potato via the so far uncharacterized G1P transporter. The perspectives are to increase yield and space efficiency of this important crop. In the light of the increasing demands imposed on agriculture to support a growing global population this presents an exciting new possibility. PMID:23284672

  16. Autism in Tuberous Sclerosis Complex.

    ERIC Educational Resources Information Center

    Gutierrez, Griselda C.; Smalley, Susan L.; Tanguay, Peter E.

    1998-01-01

    The frequency and clinical presentation of autism in 28 probands with tuberous sclerosis complex (TSC), an autosomal dominant disorder characterized by benign tissue growths and a high frequency of seizure disorders and mental retardation, was examined. Eight probands met criteria for autism. Implications for understanding the association of…

  17. Fate of starch in food processing: from raw materials to final food products.

    PubMed

    Delcour, Jan A; Bruneel, Charlotte; Derde, Liesbeth J; Gomand, Sara V; Pareyt, Bram; Putseys, Joke A; Wilderjans, Edith; Lamberts, Lieve

    2010-01-01

    Starch, an essential component of an equilibrated diet, is present in cereals such as common and durum wheat, maize, rice, and rye, in roots and tubers such as potato and cassava, and in legumes such as peas. During food processing, starch mainly undergoes nonchemical transformations. Here, we focus on the occurrence of starch in food raw materials, its composition and properties, and its transformations from raw material to final products. We therefore describe a number of predominant food processes and identify research needs. Nonchemical transformations that are dealt with include physical damage to starch, gelatinization, amylose-lipid complex formation, amylose crystallization, and amylopectin retrogradation. A main focus is on wheat-based processes. (Bio)chemical modifications of starch by amylolytic enzymes are dealt with only in the context of understanding the starch component in bread making.

  18. The starch and total sugar content of Mexican fruit and vegetables.

    PubMed

    Sánchez Castillo, C P; Dewey, P J; Finnie, S; Solano, M L; James, W P

    1997-06-01

    The starch and total sugar contents of 20 types of fruit, 28 types of vegetables and six different herbs, grown in Mexico, were analysed. The selection was based on dietary surveys to identify those foods most widely consumed. Starch was determined by an enzymatic method whilst total sugar was determined gravimetrically. The foods were grouped according to the Southgate classification. Fruits contained little starch (range 0-4 g/100 g fresh weight (FW) except in the case of the plantain (31 g/100 g FW starch), whereas vegetables showed a higher concentration with tubers in the range 10-20 g/100 g FW starch. Legumes contained 0-5 g/100 g FW; amongst the capsicum group the chilli poblano had the highest concentration at 1.3 g/100 g FW starch. The concentration of sugars in fruits ranged from 0.6 g/100 g FW to 21.1 g/100 g FW.

  19. Influence of incorporated wild Solanum genomes on potato properties in terms of starch nanostructure and glycoalkaloid content.

    PubMed

    Väänänen, Tiina; Ikonen, Teemu; Rokka, Veli-Matti; Kuronen, Pirjo; Serimaa, Ritva; Ollilainen, Velimatti

    2005-06-29

    Interspecific somatic hybrids produced by protoplast fusion between two wild Solanum species (S. acaule, acl; S. brevidens, brd) and cultivated potato Solanum tuberosum (tbr) were analyzed in terms of the starch nanometer-range structure and glycoalkaloid (GA) contents. The crystallinity of starch granules, the average size of starch crystallites, and the lamellar distances were obtained from tuber samples using wide-angle and small-angle X-ray scattering methods. These measurements showed that incorporation of wild genomes from either nontuberous (brd) or tuberous (acl) Solanum species caused no significant modifications of the nanostructure of potato starch. In contrast, the GA profiles of the hybrids, which were analyzed by LC-ESI-MS in both tuber and foliage samples, differed considerably from those of cultivated potato. Regardless of the low total tuber GA concentrations (approximately 9 mg/100 g of fresh weight), the somatic hybrids contained GAs not detected in the parental species. A high proportion of spirotype GAs consisting of 5,6-dihydrogenated aglycons, for example, alpha-tomatine and tomatidine bound with solatriose, and chacotriose were found in the hybrids. In conclusion, the foliage of interspecific hybrids contained a higher variation in the structures of GAs than did the tubers.

  20. Reduction of the plastidial phosphorylase in potato (Solanum tuberosum L.) reveals impact on storage starch structure during growth at low temperature.

    PubMed

    Orawetz, Tom; Malinova, Irina; Orzechowski, Slawomir; Fettke, Joerg

    2016-03-01

    Tubers of potato (Solanum tuberosum L.), one of the most important crops, are a prominent example for an efficient production of storage starch. Nevertheless, the synthesis of this storage starch is not completely understood. The plastidial phosphorylase (Pho1; EC 2.4.1.1) catalyzes the reversible transfer of glucosyl residues from glucose-1-phosphate to the non-reducing end of α-glucans with the release of orthophosphate. Thus, the enzyme is in principle able to act during starch synthesis. However, so far under normal growth conditions no alterations in tuber starch metabolism were observed. Based on analyses of other species and also from in vitro experiments with potato tuber slices it was supposed, that Pho1 has a stronger impact on starch metabolism, when plants grow under low temperature conditions. Therefore, we analyzed the starch content, granule size, as well as the internal structure of starch granules isolated from potato plants grown under low temperatures. Besides wild type, transgenic potato plants with a strong reduction in the Pho1 activity were analyzed. No significant alterations in starch content and granule size were detected. In contrast, when plants were cultivated at low temperatures the chain length distributions of the starch granules were altered. Thus, the granules contained more short glucan chains. That was not observed in the transgenic plants, revealing that Pho1 in wild type is involved in the formation of the short glucan chains, at least at low temperatures.

  1. Antimicrobial nanostructured starch based films for packaging.

    PubMed

    Abreu, Ana S; Oliveira, M; de Sá, Arsénio; Rodrigues, Rui M; Cerqueira, Miguel A; Vicente, António A; Machado, A V

    2015-09-20

    Montmorillonite modified with a quaternary ammonium salt C30B/starch nanocomposite (C30B/ST-NC), silver nanoparticles/starch nanocomposite (Ag-NPs/ST-NC) and both silver nanoparticles/C30B/starch nanocomposites (Ag-NPs/C30B/ST-NC) films were produced. The nanoclay (C30B) was dispersed in a starch solution using an ultrasonic probe. Different concentrations of Ag-NPs (0.3, 0.5, 0.8 and 1.0mM) were synthesized directly in starch and in clay/starch solutions via chemical reduction method. Dispersion of C30B silicate layers and Ag-NPs in ST films characterized by X-ray and scanning electron microscopy showed that the presence of Ag-NPs enhanced clay dispersion. Color and opacity measurements, barrier properties (water vapor and oxygen permeabilities), dynamic mechanical analysis and contact angle were evaluated and related with the incorporation of C30B and Ag-NPs. Films presented antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans without significant differences between Ag-NPs concentrations. The migration of components from the nanostructured starch films, assessed by food contact tests, was minor and under the legal limits. These results indicated that the starch films incorporated with C30B and Ag-NPs have potential to be used as packaging nanostructured material.

  2. Relationship between the physicochemical properties of starches and the glycemic indices of some Jamaican yams (Dioscorea spp.).

    PubMed

    Riley, Cliff K; Bahado-Singh, Perceval S; Wheatley, Andrew O; Ahmad, Mohammed H; Asemota, Helen N

    2008-11-01

    Starch granules from round leaf yellow yam (RY), Lucea yam (LY), white yam (WY), and Chinese yam (CY) grown in Jamaica were isolated and the relationship between starch amylose content, crystallinity, microscopic properties, in vitro digestibility, and the glycemic index (GI) of the tubers was investigated. The results indicate that RY had the highest amylose content (265.30 +/- 0.09 g/kg starch) while CY the lowest (111.44 +/- 0.03 g/kg starch). A corresponding variation in starch digestibility and GI was also observed, as CY which had the highest in vitro digestibility had the highest GI (21.27 +/- 0.01 and 97.42 +/- 0.62%, respectively), while RY, LY, and WY starches with low digestibility had lowest GI. Differences in the crystalline pattern of the different starches were observed, where RY, LY, and WY displayed the type B crystalline pattern while CY had the intermediate crystallite (type C).

  3. Physicochemical, morphological, and rheological characterization of Xanthosoma robustum Lego-like starch.

    PubMed

    Londoño-Restrepo, Sandra M; Rincón-Londoño, Natalia; Contreras-Padilla, Margarita; Acosta-Osorio, Andrés A; Bello-Pérez, Luis A; Lucas-Aguirre, Juan C; Quintero, Víctor D; Pineda-Gómez, Posidia; del Real-López, Alicia; Rodríguez-García, Mario E

    2014-04-01

    This work presents the physicochemical and pasting characterization of isolated mafafa starch and mafafa flour (Xanthosoma robustum). According to SEM images of mafafa starches in the tuber, these starches form Lego-like shaped structures with diameters between 8 and 35 μm conformed by several starch granules of wedge shape that range from 2 to 7 μm. The isolated mafafa starch is characterized by its low contents of protein, fat, and ash. The starch content in isolated starch was found to be 88.58% while the amylose content obtained was 35.43%. X-ray diffraction studies confirm that isolated starch is composed mainly by amylopectin. These results were confirmed by differential scanning calorimetry and thermo gravimetric analysis. This is the first report of the molecular parameters for mafafa starch: molar mass that ranged between 2×10(8) and 4×10(8) g/mol, size (Rg) value between 279 and 295 nm, and molecular density value between 9.2 and 9.7 g/(mol nm(3)). This study indicates that mafafa starch shows long chains of amylopectin this fact contributes to higher viscosity development and higher gel stability. The obtained gel phase is transparent in the UV-vis region. The viscosity, gel stability and optical properties suggest that there is potential for mafafa starch applications in the food industry.

  4. Chemical, morphological and functional properties of Brazilian jackfruit (Artocarpus heterophyllus L.) seeds starch.

    PubMed

    Madruga, Marta Suely; de Albuquerque, Fabíola Samara Medeiros; Silva, Izis Rafaela Alves; do Amaral, Deborah Silva; Magnani, Marciane; Queiroga Neto, Vicente

    2014-01-15

    Starches used in food industry are extracted from roots, tubers and cereals. Seeds of jackfruit are abundant and contain high amounts of starch. They are discarded during the fruit processing or consumption and can be an alternative source of starch. The starch was extract from the jackfruit seeds and characterised to chemical, morphological and functional properties. Soft and hard jackfruit seeds showed starch content of 92.8% and 94.5%, respectively. Starch granules showed round and bell shape and some irregular cuts on their surface with type-A crystallinity pattern, similar to cereals starches. The swelling power and solubility of jackfruit starch increased with increasing temperature, showing opaque pastes. The soft seeds starch showed initial and final gelatinisation temperature of 36°C and 56°C, respectively; while hard seeds starch presented initial gelatinisation at 40°C and final at 61°C. These results suggest that the Brazilian jackfruit seeds starches could be used in food products.

  5. Battle of the starches: Insoluble versus soluble at the refinery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study using the USDA starch research method has been conducted to evaluate the effects of total, insoluble, and soluble starch on raw sugar filterability and viscosity in international carbonatation refineries. Raw sugar qualities, i.e., pol, color, % invert, ash, and dextran, were also studied in...

  6. cDNA cloning, expression, and characterization of Taro SSII: a novel member of starch synthase II family.

    PubMed

    Lin, Da-Gin; Jeang, Chii-Ling

    2005-10-05

    A novel soluble starch synthase II (SSII) gene was isolated from taro (Colocasia esculenta var. esculenta) tubers. This 2939 bp SSII transcript encodes 804 amino acids with a putative transit peptide of 52 residues. It displays 58-63% identity and 63-69% similarity with SSIIs from other sources. Alignment and phylogenetic analyses showed that taro SSII is more closely related with dicot SSIIs than with the monocot ones, though taro is a monocot. The identification of taro SSII clone as starch synthase was confirmed by the expression of its enzymatic activity in Escherichia coli. Genomic DNA blot analysis revealed a single copy or low number copies of SSII in taro. Expression profile showed that more transcript and protein were accumulated in tubers of 597 +/- 37 g fresh weight, that is, a stage of rapid starch synthesis, than tubers of other stages. By Western blot analysis, SSII was found in both soluble and granule bound portions of tuber extracts, and more SSII protein was found in aged leaves than in leaves of other stages. These results suggest that taro SSII is a novel starch synthase for the synthesis of both transit and storage starch.

  7. Extraction of glucomannan of porang tuber (Amorphophallus onchophillus) by using IPA

    NASA Astrophysics Data System (ADS)

    Wardhani, Dyah Hesti; Nugroho, Fatoni; Muslihuddin, Mohammad

    2015-12-01

    Amorphophallus oncophyllus also known as porang tuber is a local tuber rich of glucomannan. Due to the unique rheological and the gelling properties, glucomannan is widely employed as emulsifier and stabilizer and has been approved as a food additive by the U.S. Food and Drug Administration (FDA). Isolation method of glucomannan from the tuber affects the mannan properties which in turn influence the scope of the applications. Ethanol solution combined with thermal treatment is commonly applied to purify glucomannan. However, the Amorphophallus sp also contains ˜0.2 mg b-carotenes/100 g dry weight, an impurities which difficult to be removed by ethanol-2 propyl alcohol (IPA) is more effective to remove undesirable components of glucomannan including carotenes compared to ethanol. This research objective was to study the effect of extraction time, temperature, IPA concentration, and ratio of solvent and flour on purification of glucomannan of A. onchophillus. Glucomannan content, starch content and viscosity were determined after the extraction. The highest glucomannan concentration was obtained at extraction by using 80% IPA and ratio of solvent/sample 8:1 (ml/g) for 4 h at 75°C. This condition gave 72.8% glucomannan and 2.69% starch with 4,300 cPs viscosity.

  8. Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz).

    PubMed

    Koehorst-van Putten, Herma J J; Wolters, Anne-Marie A; Pereira-Bertram, Isolde M; van den Berg, Hans H J; van der Krol, Alexander R; Visser, Richard G F

    2012-12-01

    In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,167 bp) was cloned into binary vectors to drive expression of the firefly luciferase gene. Cassava cultivar Adira 4 was transformed with this construct or a control construct in which the luciferase gene was cloned behind the 35S promoter. Luciferase activity was measured in leaves, stems, roots and tuberous roots. As expected, the 35S promoter induced luciferase activity in all organs at similar levels, whereas the GBSSI promoter showed very low expression in leaves, stems and roots, but very high expression in tuberous roots. These results show that the cassava GBSSI promoter is an excellent candidate to achieve tuberous root-specific expression in cassava.

  9. Effect of cooking on the anthocyanins, phenolic acids, glycoalkaloids, and resistant starch content in two pigmented cultivars of Solanum tuberosum L.

    PubMed

    Mulinacci, Nadia; Ieri, Francesca; Giaccherini, Catia; Innocenti, Marzia; Andrenelli, Luisa; Canova, Giulia; Saracchi, Marco; Casiraghi, Maria Cristina

    2008-12-24

    HPLC/DAD/MS analysis of the phenolic acids and anthocyanin content of three cultivars of Solanum tuberosum L. (Vitelotte Noire, Highland Burgundy Red, with pigmented flesh, and Kennebec with white pulp) was performed. The analyses were carried out both on fresh tubers and after cooking treatments (boiling and microwaves). Starch digestibility and the % of resistant starch were also determined on cooked tubers by in vitro methods. For the pigmented potatoes, the heating treatment did not cause any changes in the phenolic acids content, while anthocyanins showed only a small decrement (16-29%). The cv. Highland Burgundy Red showed anthocyanins and phenolic acid concentrations close to 1 g/kg and more than 1.1 g/kg, respectively. Vitellotte Noire showed the highest amounts of resistant starch. Potato starch digestibility and % of resistant starch, considered as a component of dietary fiber, were affected both by cultivar and by heating/cooling treatments.

  10. Tuberous legumes: preliminary evaluation of tropical Australian and introduced species as fuel crops

    SciTech Connect

    Saxon, E.C.

    1981-04-01

    The evaluation of native and introduced legumes with starch-storing roots or tubers was undertaken to test whether plants traditionally collected as food by Australian aborigines might have a role in the development of crops for liquid fuel production (by fermentation of carbohydrates to ethanol). Tuberous-rooted legumes from overseas were planted at the Commonwealth Scientific and Industrial Research Organization, division of Tropical Crops and Pastures, Kimberley Research Station, Western Australia (15/sup 0/39'S, 128/sup 0/42'E) in December 1974, March 1978 and February 1979. Roots from the latter plantings were harvested in June 1979. Native plant material was collected during visits to aboriginal communities in the Kimberleys between April and June 1979. The native and introduced specimens were analyzed for fermentable carbohydrate and protein content. Several native plants appear more promising than introduced species as liquid fuel crops.

  11. Hormone Metabolism During Potato Tuber Dormancy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At harvest and for an indeterminate period thereafter potato tubers will not sprout and are physiologically dormant. The length of tuber dormancy is dependent on cultivar and pre- and postharvest environmental conditions. Plant hormones have been shown to be involved in all phases of dormancy prog...

  12. [The inhibition of potato tubers wound reparation].

    PubMed

    Chalenko, G I; Vasiukova, N I; Gerasimova, N G; Ozeretskovskaia, O l

    2009-01-01

    The multiple washing of the wound surface of potato tubers by water adversely affected the protective properties of wound periderm. Immune inhibitor beta-1,3-beta-1,6 glucan had a property of local effect and inhibited the process of wound healing. The pentasaccharide of xyloglucan caused necrosis of potato tuber tissue and prevented the wound reparation process.

  13. Gene expression associated with tuber periderm maturation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato periderm maturation and associated resistance to tuber excoriation, i.e. skinning injury, is of scientific and agricultural importance because of the losses created by shrinkage, tuber market quality defects and infections. The cells and cellular changes responsible for the development of re...

  14. Expression of an Escherichia coli phosphoglucomutase in potato (Solanum tuberosum L.) results in minor changes in tuber metabolism and a considerable delay in tuber sprouting.

    PubMed

    Lytovchenko, Anna; Hajirezaei, Mohammad; Eickmeier, Ira; Mittendorf, Volker; Sonnewald, Uwe; Willmitzer, Lothar; Fernie, Alisdair R

    2005-08-01

    The aim of this work was to evaluate the influence of elevating the cytosolic activity of phosphoglucomutase (PGM; EC 5.4.2.2) on photosynthesis, growth and heterotrophic metabolism. Here we describe the generation of novel transgenic plants expressing an Escherichia coli phosphoglucomutase (EcPGM) under the control of the 35S promoter. These lines were characterised by an accumulation of leaf sucrose, despite displaying no alterations in photosynthetic carbon partitioning, and a reduced tuber starch content. Determinations of the levels of a wide range of other metabolites revealed dramatic reductions in maltose and other sugars in leaves of the transformants, as well as a modification of the pattern of organic and amino acid content in tubers of these lines. Intriguingly, the transgenics also displayed a dramatically delayed rate of sprouting and significantly enhanced rate of respiration, however, it is important to note that the severity of these traits did not always correlate with the level of transgene expression. These results are discussed in the context of current understanding of the control of respiration and the breaking of tuber dormancy.

  15. Enhanced resistance to Phytophthora infestans and Alternaria solani in leaves and tubers, respectively, of potato plants with decreased activity of the plastidic ATP/ADP transporter.

    PubMed

    Conrath, Uwe; Linke, Christoph; Jeblick, Wolfgang; Geigenberger, Peter; Quick, W Paul; Neuhaus, H Ekkehard

    2003-05-01

    Recently, it has been reported that tubers of transgenic potato ( Solanum tuberosum L.) plants with decreased activity of the plastidic ATP/ADP transporter (AATP1) contain less starch, despite having an increased glucose level [P. Geigenberger et al. (2001) Plant Physiol 125:1667-1678]. The metabolic alterations correlated with enhanced resistance to the bacterium Erwinia carotovora. Here it is shown that transgenic potato tubers, possessing less starch yet increased glucose levels due to the expression of a cytoplasm-localized yeast invertase, exhibit drastic susceptibility to E. carotovora. In addition, it is demonstrated that AATP1 anti-sense tubers show an increased capacity to ward off the pathogenic fungus Alternaria solani. In contrast to AATP1 anti-sense tubers, the corresponding leaf tissue does not show changes in carbohydrate accumulation. However, upon elicitor treatment, AATP1 anti-sense leaves possess an increased capacity to release H(2)O(2) and activate various defence-related genes, reactions that are associated with substantially delayed appearance of disease symptoms caused by Phytophthora infestans. Grafting experiments between AATP1 anti-sense plants and wild-type plants indicate the presence of a signal that is generated in AATP1 rootstocks and primes wild-type scions for potentiated activation of cellular defence responses in leaves. Together, the results suggest that (i) the enhanced pathogen tolerance of AATP1 anti-sense tubers is not due to "high sugar resistance", (ii) the increased disease resistance of AATP1 anti-sense tubers is effective against different types of pathogen and (iii) a systemic signal induced by antisensing the plastidic ATP/ADP transporter in potato tubers confers increased resistance to pathogens.

  16. Comparison of pasting and gel stabilities of waxy and normal starches from potato, maize, and rice with those of a novel waxy cassava starch under thermal, chemical, and mechanical stress.

    PubMed

    Sánchez, Teresa; Dufour, Dominique; Moreno, Isabel Ximena; Ceballos, Hernán

    2010-04-28

    Functional properties of normal and waxy starches from maize, rice, potato, and cassava as well as the modified waxy maize starch COLFLO 67 were compared. The main objective of this study is to position the recently discovered spontaneous mutation for amylose-free cassava starch in relation to the other starches with well-known characteristics. Paste clarity, wavelength of maximum absorption (lambda(max)), pasting properties, swelling power, solubility, and dispersed volume fraction measurements and gel stability (acid and alkaline resistance, shear, refrigeration, and freeze/thaw stability) were evaluated in the different types and sources of starch included in this study. lambda(max) in the waxy cassava starch was reduced considerably in comparison with that of normal cassava starch (535 vs 592 nm). RVA peak viscosity of waxy cassava starch was larger than in normal cassava starch (1119 vs 937 cP) and assumed a position intermediate between the waxy potato and maize starches. Acid, alkaline, and shear stability of waxy cassava starch were similar to normal cassava except for alkaline pH, at which it showed a low effect. Gels from normal root and tuber starches after refrigeration and freeze/thaw had lower syneresis than cereal starches. Gels from waxy starches (except for potato) did not present any syneresis after 5 weeks of storage at 4 degrees C. Waxy cassava starch was the only one not showing any syneresis after 5 weeks of storage at -20 degrees C. Natural waxy cassava starch is, therefore, a promising ingredient to formulate refrigerated or frozen food.

  17. Red Dyeing Silk in Room Temperature Using Fermented Rice (Oryza Sativa) and Yam Tuber (Pachyrhizus erosus) by Monascus purpureus as an Alternatives of an Eco-friendly Textile Dyes

    NASA Astrophysics Data System (ADS)

    Mauliza, I. N.; Mardiyati; Sunendar, B.

    2016-01-01

    Potential dyes to be developed derived from fermentation by Monascus purpureus. As a staple food, rice can be replace to the yam tuber lees as a substrates. The purpose of this study was to compare the dyeability between fermented rice and yam tuber by Monascus purpureus on silk fabrics at the room temperature in any different pH of dyebath. Monascus purpureus first cultured on Potato Dextrose Agar for 7 days. Yam tuber peeled, grated and squeezed. The material is taken from yam tuber lees, then inoculated with Monascus purpureus for 14 days until an uniform red color obtained. The substrate is dried and then characterized by UV-Vis spectrophotometry and Fourier Transform Infrared Spectroscopy (FTIR). Dyes obtained from fermented rice and yam tuber then extracted and used for dyeing silk at room temperature with various pH of the dyebath. Results showed that dyeing silk with fermented yam tuber having the same color characteristics as fermented rice. The optimum color absorption at a wavelength of 520 nm for both, except on the results of dyeing using fermented yam tuber extract with pH 6 and pH 7. The maximum absorption is achieved at pH 3 with values dyeing K/S 5.840. Color fastness to rubbing are excellent (5 point) in dry rub, while the wet rub still good at the range of 4 to 4/5.

  18. Expression of Escherichia coli branching enzyme in tubers of amylose-free transgenic potato leads to an increased branching degree of the amylopectin.

    PubMed

    Kortstee, A J; Vermeesch, A M; de Vries, B J; Jacobsen, E; Visser, R G

    1996-07-01

    In order to increase the branching degree of potato tuber starch, the gene encoding branching enzyme (glgB) of Escherichia coli was expressed in the amylose-free potato mutant. The E. coli glgB was cloned in the binary vector pBIN19 under the transcriptional control of the potato Granule Bound Starch Synthase (GBSS) promoter and transitpeptide sequence. The E. coli glgB was cloned behind the two N-terminal amino acids of the GBSS mature protein, creating a chimeric protein. Transgenic plants were obtained which expressed the E. coli branching enzyme as was shown by the presence of mRNA and protein in the tubers. Correctly processed protein was found both in the soluble and starch granule bound protein fraction. Analysis of the starch showed an increase in the branching degree (DE) of up to 25% more branchpoints. The increase in the number of branchpoints was due to the presence of more short chains, with a degree of polymerization (DP) of 16 glucose-residues or less in the amylopectin. Changes in other characteristics of the starch, such as average chain length (CL) and lambda max, indicated a more branched structure for starch of transformed plants as well.

  19. Tubers are neither static nor discrete

    PubMed Central

    Peters, Jurriaan M.; Prohl, Anna K.; Tomas-Fernandez, Xavier K.; Taquet, Maxime; Scherrer, Benoit; Prabhu, Sanjay P.; Lidov, Hart G.; Singh, Jolene M.; Jansen, Floor E.; Braun, Kees P.J.; Sahin, Mustafa; Stamm, Aymeric

    2015-01-01

    Objective: To assess the extent and evolution of tissue abnormality of tubers, perituber tissue, and normal-appearing white matter (NAWM) in patients with tuberous sclerosis complex using serial diffusion tensor imaging. Methods: We applied automatic segmentation based on a combined global-local intensity mixture model of 3T structural and 35 direction diffusion tensor MRIs (diffusion tensor imaging) to define 3 regions: tuber tissue, an equal volume perituber rim, and the remaining NAWM. For each patient, scan, lobe, and tissue type, we analyzed the averages of mean diffusivity (MD) and fractional anisotropy (FA) in a generalized additive mixed model. Results: Twenty-five patients (mean age 5.9 years; range 0.5–24.5 years) underwent 2 to 6 scans each, totaling 70 scans. Average time between scans was 1.2 years (range 0.4–2.9). Patient scans were compared with those of 73 healthy controls. FA values were lowest, and MD values were highest in tubers, next in perituber tissue, then in NAWM. Longitudinal analysis showed a positive (FA) and negative (MD) correlation with age in tubers, perituber tissue, and NAWM. All 3 tissue types followed a biexponential developmental trajectory, similar to the white matter of controls. An additional qualitative analysis showed a gradual transition of diffusion values across the tissue type boundaries. Conclusions: Similar to NAWM, tuber and perituber tissues in tuberous sclerosis complex undergo microstructural evolution with age. The extent of diffusion abnormality decreases with distance to the tuber, in line with known extension of histologic, immunohistochemical, and molecular abnormalities beyond tuber pathology. PMID:26432846

  20. Effects of storage temperatures and annealing conditions on the structure and properties of potato (Solanum tuberosum) starch.

    PubMed

    Tester, R F; Ansell, R; Snape, C E; Yusuph, M

    2005-07-01

    Starches were extracted from freshly harvested potatoes (12 cultivars, grown in Perthshire) and the properties of the starches of six cultivars were compared with starches extracted from the same samples but stored at 5, 25 or 55 degrees C for 7 days before extraction. The amylose (total) content of the freshly extracted starches from tubers stored at 5, 25 or 55 degrees C was on average 27.9+/-2.3, 28.3+/-1.7, 29.2+/-2.2 and 28.8+/-1.5%, respectively, with corresponding phosphorus representing 60+/-16, 64+/-9, 61+/-5 and 63+/-9 mg 100 g(-1). The unit chain distribution by chromatography of the amylopectin molecules from the starches extracted from the different conditions was very similar with an average degree of polymerisation (DP) of 26+/-2 where the two major fractions (F1 and F2) represented 54+/-2 and 19+/-1, respectively. Peak gelatinisation temperatures (Tp) and enthalpies (DeltaH) for the freshly extracted starches and from tubers stored at 5 or 25 degrees C were very similar (63.3+/-1.5 degrees C and 18.6+/-0.8 J g(-1); 63.1+/-1.0 degrees C and 17.7+/-1.5 J g(-1) and; 62.9+/-0.7 degrees C and 18.7+/-1.1 J g(-1), respectively) although starches stored at 55 degrees C were annealed, where Tp represented 71.1+/-1.1 degrees C and DeltaH 18.1+/-1.4 J g(-1). These in situ-annealed starches were comparable in terms of gelatinisation characteristics to annealed freshly extracted starches where on average, T(p) represented 72.7+/-1.0 degrees C and DeltaH 20.8+/-1.0 J g(-1). Annealing of tubers in situ prior to processing might be beneficial with respect to developing new potato-based products.

  1. [Chemical characterization and quantification of fructooligosaccharides, phenolic compounds and antiradical activity of Andean roots and tubers grown in Northwest of Argentina].

    PubMed

    Jiménez, María Eugenia; Sammán, Norma

    2014-06-01

    There is great interest in consuming foods that can provide the nutrients for a good nutrition and other health beneficial compounds. The aim of this work was to determine the chemical composition of native foods of the Andean region and to quantify some functional com-ponents. Proximal composition, vitamin C, total phenolic compounds, antiradical activity (DPPH) in peel and pulp, dietary fiber soluble and insoluble, fructooligosaccharides (FOS), total and resistant starch (in tubers and raw roots, boiled and boiled and stored) of 6 varieties of Oca (Oxalis tuberosa), 4 clones of manioc (Manihot esculenta Crantz) and yacon (Smallanthus sonchifolius were determined. The results showed greater amount of bioactive compounds and antiradical activity in the skin of these products. The highest content was found in the oca peel. In all cases, the content of insoluble fiber was greater than the soluble. The manioc had higher total starch than Andean roots and tubers. The boiling process decreased the resistant starch content of ocas and maniocs, but when these are stored for 48 h at 5 ° C, the resistant starch content increased. The FOS content of the ocas was similar for all varieties (7%). The main component of yacon carbohydrates were FOS (8.89%). The maniocs did not contain FOS. It can be concluded that the roots and tubers studied, in addition to provide nutrients, contain functional compounds that confer additional helpful value for preventing no communicable diseases.

  2. Alpine Russet: A potato cultivar having long tuber dormancy making it suitable for processing from long-term storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alpine Russet is a later maturing, oblong-long, lightly russeted potato cultivar, notable for having tuber dormancy comparable to Russet Burbank. Processing quality of Alpine Russet from long-term storage is superior to Russet Burbank, with low percent reducing sugars and uniform fry color due to a...

  3. Echocardiography and genetic counselling in tuberous sclerosis.

    PubMed Central

    Webb, D W; Thomas, R D; Osborne, J P

    1992-01-01

    OBJECTIVE--To assess echocardiography as an investigation for the detection of occult gene carriers in tuberous sclerosis. PATIENTS--Sixty parents of children with tuberous sclerosis who had been extensively investigated for signs of the disease and 60 age and sex matched controls. PROCEDURE--Blind study by two experienced echocardiographers and blind interpretation of video recordings by an adult cardiologist. SETTING--Cardiology department of a district general hospital. RESULTS--Two parents and three controls had bright echodense areas interpreted as possible rhabdomyomas. CONCLUSIONS--In our hands echocardiography of adults is not an investigation with a high specificity for gene detection in tuberous sclerosis. Images PMID:1640428

  4. Fundamental Study on the Impact of Gluten-Free Starches on the Quality of Gluten-Free Model Breads

    PubMed Central

    Horstmann, Stefan W.; Belz, Markus C. E.; Heitmann, Mareile; Zannini, Emanuele; Arendt, Elke K.

    2016-01-01

    Starch is widely used as an ingredient and significantly contributes to texture, appearance, and overall acceptability of cereal based foods, playing an important role due to its ability to form a matrix, entrapping air bubbles. A detailed characterisation of five gluten-free starches (corn, wheat, rice, tapioca, potato) was performed in this study. In addition, the influence of these starches, with different compositional and morphological properties, was evaluated on a simple gluten-free model bread system. The morphological characterisation, evaluated using scanning electron microscopy, revealed some similarities among the starches, which could be linked to the baking performance of the breads. Moreover, the lipid content, though representing one of the minor components in starch, was found to have an influence on pasting, bread making, and staling. Quality differences in cereal root and tuber starch based breads were observed. However, under the baking conditions used, gluten-free rendered wheat starch performed best, followed by potato starch, in terms of loaf volume and cell structure. Tapioca starch and rice starch based breads were not further analysed, due to an inferior baking performance. This is the first study to evaluate gluten-free starch on a simple model bread system. PMID:28231125

  5. HRE-type genes are regulated by growth-related changes in internal oxygen concentrations during the normal development of potato (Solanum tuberosum) tubers.

    PubMed

    Licausi, Francesco; Giorgi, Federico Manuel; Schmälzlin, Elmar; Usadel, Björn; Perata, Pierdomenico; van Dongen, Joost Thomas; Geigenberger, Peter

    2011-11-01

    The occurrence of hypoxic conditions in plants not only represents a stress condition but is also associated with the normal development and growth of many organs, leading to adaptive changes in metabolism and growth to prevent internal anoxia. Internal oxygen concentrations decrease inside growing potato tubers, due to their active metabolism and increased resistance to gas diffusion as tubers grow. In the present work, we identified three hypoxia-responsive ERF (StHRE) genes whose expression is regulated by the gradual decrease in oxygen tensions that occur when potato tubers grow larger. Increasing the external oxygen concentration counteracted the modification of StHRE expression during tuber growth, supporting the idea that the actual oxygen levels inside the organs, rather than development itself, are responsible for the regulation of StHRE genes. We identified several sugar metabolism-related genes co-regulated with StHRE genes during tuber development and possibly involved in starch accumulation. All together, our data suggest a possible role for low oxygen in the regulation of sugar metabolism in the potato tuber, similar to what happens in storage tissues during seed development.

  6. The Role of 5-Hydroxymethylcytosine in Gene Dysregulation of Epileptogenic Tubers in Tuberous Sclerosis Complex Patients

    DTIC Science & Technology

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0345 TITLE: The Role of 5-Hydroxymethylcytosine in Gene Dysregulation of Epileptogenic Tubers in Tuberous Sclerosis...30 Sep 2014 - 29 Sep 2015 4. TITLE AND SUBTITLE The Role of 5-Hydroxymethylcytosine in Gene Dysregulation of Epileptogenic Tubers in Tuberous... Changes /Problems...….……………………………………………… 10 6. Products…………………………………….……….….……………. 11 7. Participants & Other Collaborating Organizations………………. 11 8

  7. Light-colored, Low Acrylamide Potato Chips

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tubers are stored at cold temperatures to prevent sprouting, minimize disease losses and increase the marketing window. Cold storage also causes an accumulation of reducing sugars, a phenomenon referred to as cold-induced sweetening. Unacceptable, dark colored chips and fries are formed durin...

  8. Starch metabolism in leaves.

    PubMed

    Orzechowski, Sławomir

    2008-01-01

    Starch is the most abundant storage carbohydrate produced in plants. The initiation of transitory starch synthesis and degradation in plastids depends mainly on diurnal cycle, post-translational regulation of enzyme activity and starch phosphorylation. For the proper structure of starch granule the activities of all starch synthase isoenzymes, branching enzymes and debranching enzymes are needed. The intensity of starch biosynthesis depends mainly on the activity of AGPase (adenosine 5'-diphosphate glucose pyrophosphorylase). The key enzymes in starch degradation are beta-amylase, isoamylase 3 and disproportionating enzyme. However, it should be underlined that there are some crucial differences in starch metabolism between heterotrophic and autotrophic tissues, e.g. is the ability to build multiprotein complexes responsible for biosynthesis and degradation of starch granules in chloroplasts. The observed huge progress in understanding of starch metabolism was possible mainly due to analyses of the complete Arabidopsis and rice genomes and of numerous mutants with altered starch metabolism in leaves. The aim of this paper is to review current knowledge on transient starch metabolism in higher plants.

  9. The potato developer (D) locus encodes an R2R3 MYB transcription factor that regulates expression of multiple anthocyanin structural genes in tuber skin.

    PubMed

    Jung, Chun Suk; Griffiths, Helen M; De Jong, Darlene M; Cheng, Shuping; Bodis, Mary; Kim, Tae Sung; De Jong, Walter S

    2009-12-01

    A dominant allele at the D locus (also known as I in diploid potato) is required for the synthesis of red and purple anthocyanin pigments in tuber skin. It has previously been reported that D maps to a region of chromosome 10 that harbors one or more homologs of Petunia an2, an R2R3 MYB transcription factor that coordinately regulates the expression of multiple anthocyanin biosynthetic genes in the floral limb. To test whether D acts similarly in tuber skin, RT-PCR was used to evaluate the expression of flavanone 3-hydroxylase (f3h), dihydroflavonol 4-reductase (dfr) and flavonoid 3',5'-hydroxylase (f3'5'h). All three genes were expressed in the periderm of red- and purple-skinned clones, while dfr and f3'5'h were not expressed, and f3h was only weakly expressed, in white-skinned clones. A potato cDNA clone with similarity to an2 was isolated from an expression library prepared from red tuber skin, and an assay developed to distinguish the two alleles of this gene in a diploid potato clone known to be heterozygous Dd. One allele was observed to cosegregate with pigmented skin in an F(1) population of 136 individuals. This allele was expressed in tuber skin of red- and purple-colored progeny, but not in white tubers, while other parental alleles were not expressed in white or colored tubers. The allele was placed under the control of a doubled 35S promoter and transformed into the light red-colored cultivar Désirée, the white-skinned cultivar Bintje, and two white diploid clones known to lack the functional allele of D. Transformants accumulated pigment in tuber skin, as well as in other tissues, including young foliage, flower petals, and tuber flesh.

  10. Genetics Home Reference: tuberous sclerosis complex

    MedlinePlus

    ... phenotype in tuberous sclerosis. J Med Genet. 2004 Mar;41(3):203-7. Citation on PubMed or ... sclerosis complex: a review. Semin Pediatr Neurol. 2006 Mar;13(1):27-36. Review. Citation on PubMed ...

  11. Physiology of Tuberization in Solanum tuberosum L

    PubMed Central

    Mauk, Craighton S.; Langille, Alan R.

    1978-01-01

    Using high pressure liquid chromatography, the cucumber cotyledon bioassay, and mass spectrometry a cytokinin isolated from Solanum tuberosum L. cv. Katahdin plant tissues has been identified as cis-zeatin riboside. Zeatin riboside (ZR) levels in plants grown under inducing conditions (28 C day and 13 C night with a 10-hour photoperiod) were significantly higher than those in plants grown under noninducing conditions (30 C day and 28 C night with an 18-hour photoperiod). The highest level of ZR was noted in below-ground tissue after 4 days exposure to inducing conditions, with tuber initiation observed after 8 days. A companion study conducted to determine the effect of ZR on in vitro tuberization of noninduced rhizomes revealed that after 1 month in culture, controls exhibited 0% tuberization, while ZR treatments of 0.3 and 3.0 milligrams per liter showed 39 and 75% tuberization, respectively. PMID:16660533

  12. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits

    PubMed Central

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  13. Potato Tuber UDP-Glucose:Protein Transglucosylase Catalyzes Its Own Glucosylation 1

    PubMed Central

    Ardila, Fernando J.; Tandecarz, Juana S.

    1992-01-01

    Potato (Solanum tuberosum L.) tuber UDP-glucose:protein transglucosylase (UPTG) (EC 2.4.1.112) is involved in the first of a two-step mechanism proposed for protein-bound α-glucan synthesis by catalyzing the covalent attachment of a single glucose residue to an acceptor protein. The resulting glucosylated 38-kilodalton polypeptide would then serve as a primer for enzymic glucan chain elongation during the second step. In the present report, we describe the fast protein liquid chromatography purification of UPTG from a membrane pellet of potato tuber. An apparently close association of UPTG, phosphorylase, and starch synthase was observed under native conditions during different purification steps. Enrichment of a 38-kilodalton polypeptide was found throughout enzyme purification. It is now shown that the purified UPTG, with an apparent molecular mass of 38 kilodaltons, undergoes self-glucosylation in a UDP-glucose- and Mn2+-dependent reaction. Therefore, it is concluded that UPTG is the enzyme and at the same time the priming protein required for the biogenesis of protein-bound α-glucan in potato tuber. ImagesFigure 1Figure 2Figure 5Figure 6 PMID:16669042

  14. Effect of the mode of incorporation on the disintegrant properties of acid modified water and white yam starches.

    PubMed

    Odeku, Oluwatoyin A; Akinwande, Babatunde L

    2012-04-01

    Acid modified starches obtained from two species of yam tubers namely white yam - Dioscorea rotundata L. and water yam - D. alata L. DIAL2 have been investigated as intra- and extra-granular disintegrants in paracetamol tablet formulations. The native starches were modified by acid hydrolysis and employed as disintegrant at concentrations of 5 and 10% w/w and their disintegrant properties compared with those of corn starch BP. The tensile strength and drug release properties of the tablets, assessed using the disintegration and dissolution (t 50 and t 80 - time required for 50% and 80% of paracetamol to be released) times, were evaluated. The results showed that the tensile strength and the disintegration and dissolution times of the tablets decreased with increase in the concentration of the starch disintegrants. The acid modified yam starches showed better disintegrant efficiency than corn starch in the tablet formulations. Acid modification appeared to improve the disintegrant efficiency of the yam starches. Furthermore, tablets containing starches incorporated extragranularly showed faster disintegration but lower tensile strength than those containing starches incorporated intragranularly. This emphasizes the importance of the mode of incorporation of starch disintegrant.

  15. Effect of the mode of incorporation on the disintegrant properties of acid modified water and white yam starches

    PubMed Central

    Odeku, Oluwatoyin A.; Akinwande, Babatunde L.

    2011-01-01

    Acid modified starches obtained from two species of yam tubers namely white yam – Dioscorearotundata L. and water yam – D. alata L. DIAL2 have been investigated as intra- and extra-granular disintegrants in paracetamol tablet formulations. The native starches were modified by acid hydrolysis and employed as disintegrant at concentrations of 5 and 10% w/w and their disintegrant properties compared with those of corn starch BP. The tensile strength and drug release properties of the tablets, assessed using the disintegration and dissolution (t50 and t80 – time required for 50% and 80% of paracetamol to be released) times, were evaluated. The results showed that the tensile strength and the disintegration and dissolution times of the tablets decreased with increase in the concentration of the starch disintegrants. The acid modified yam starches showed better disintegrant efficiency than corn starch in the tablet formulations. Acid modification appeared to improve the disintegrant efficiency of the yam starches. Furthermore, tablets containing starches incorporated extragranularly showed faster disintegration but lower tensile strength than those containing starches incorporated intragranularly. This emphasizes the importance of the mode of incorporation of starch disintegrant. PMID:23960789

  16. Preparation and characterization of new and improved soluble-starches, -amylose, and -amylopectin by reaction with benzaldehyde/zinc chloride.

    PubMed

    Johnston, David A; Mukerjea, Rupendra; Robyt, John F

    2011-12-13

    Seven different starches from potato, rice, maize, waxymaize, amylomaize-VII, shoti, and tapioca, and potato amylose and potato amylopectin have been reacted with benzaldehyde, catalyzed by ZnCl(2), to give new water-soluble starches and water soluble-amylose and soluble-amylopectin. In contrast to the native starches, aqueous solutions of the modified starches could not be precipitated with 2-, 3-, or 4-volumes of ethanol. β-Amylase gave no reaction with the modified starches, in contrast to the native starches, indicating that the modification occurred exclusively at the nonreducing-ends, giving 4,6-benzylidene-D-glucopyranose at the nonreducing-ends. Reactions of α-amylase with native and modified potato and rice starches gave a decrease in the triiodide blue color and an increase in the reducing-value that were similar for the native- and modified-starches, indicating the modified starches had not been significantly altered by the modification. The benzaldehyde-modified starches and benzaldehyde-modified potato amylose and potato amylopectin components, therefore, have a starch structure very much like their native counterparts, in contrast to the Lintner, Small, and the alcohol/acid-hydrolyzed soluble-starches that have undergone acid hydrolysis. The benzaldehyde-modified starches and starch components have significantly higher water solubility than their native counterparts even though the structures of the modified starches had only been slightly altered from the structures of their native counterparts. They all gave crystal-clear solutions that did not retrograde.

  17. Direct fermentation of raw starch using a Kluyveromyces marxianus strain that expresses glucoamylase and alpha-amylase to produce ethanol.

    PubMed

    Wang, Rongliang; Wang, Dongmei; Gao, Xiaolian; Hong, Jiong

    2014-01-01

    Raw starch and raw cassava tuber powder were directly and efficiently fermented at elevated temperatures to produce ethanol using the thermotolerant yeast Kluyveromyces marxianus that expresses α-amylase from Aspergillus oryzae as well as α-amylase and glucoamylase from Debaryomyces occidentalis. Among the constructed K. marxianus strains, YRL 009 had the highest efficiency in direct starch fermentation. Raw starch from corn, potato, cassava, or wheat can be fermented at temperatures higher than 40°C. At the optimal fermentation temperature 42°C, YRL 009 produced 66.52 g/L ethanol from 200 g/L cassava starch, which was the highest production among the selected raw starches. This production increased to 79.75 g/L ethanol with a 78.3% theoretical yield (with all cassava starch were consumed) from raw cassava starch at higher initial cell densities. Fermentation was also carried out at 45 and 48°C. By using 200 g/L raw cassava starch, 137.11 and 87.71 g/L sugar were consumed with 55.36 and 32.16 g/L ethanol produced, respectively. Furthermore, this strain could directly ferment 200 g/L nonsterile raw cassava tuber powder (containing 178.52 g/L cassava starch) without additional nutritional supplements to produce 69.73 g/L ethanol by consuming 166.07 g/L sugar at 42°C. YRL 009, which has consolidated bioprocessing ability, is the best strain for fermenting starches at elevated temperatures that has been reported to date.

  18. Modification of Cilembu sweet potato starch with ethanoic acid

    NASA Astrophysics Data System (ADS)

    Mahmudatussa'adah, A.; Rahmawati, Y.; Sudewi

    2016-04-01

    Cilembu sweet potato harvest was abundant, its use was still limited. Starch was required by various industries. Starch is generally beige, and requires a long time for the drying process. The purpose of this research was to produce a modified starch with ethanoic acid. The method used in this study was the experimental method. The results showed acid modified starch yield was 18%, with the color characteristics of L*: 96.38 ± 0.82; a*: -0.70±0.02 b*: 2.70±0.03 C: 2.79±0.02. Native starch yield was 16%, with the color characteristics of L*: 93.55 ± 0.91; a*: -0.86±0.06 b*: 2.93±0.04 C: 3.05±0.03. The conclusion of this study was modified starch of Cilembu sweet potato using ethanoic acid have higher yield and more white bright than native starch.

  19. Modulation of fructokinase activity of potato (Solanum tuberosum) results in substantial shifts in tuber metabolism.

    PubMed

    Davies, Howard V; Shepherd, Louise V T; Burrell, Michael M; Carrari, Fernando; Urbanczyk-Wochniak, Ewa; Leisse, Andrea; Hancock, Robert D; Taylor, Mark; Viola, Roberto; Ross, Heather; McRae, Diane; Willmitzer, Lothar; Fernie, Alisdair R

    2005-07-01

    Potato plants (Solanum tuberosum L. cvs Desiree and Record) transformed with sense and antisense constructs of a cDNA encoding the potato fructokinase StFK1 exhibited altered transcription of this gene, altered amount of protein and altered enzyme activities. Measurement of the maximal catalytic activity of fructokinase revealed a 2-fold variation in leaf (from 90 to 180% of wild type activity) and either a 10- or 30-fold variation in tuber (from 10 or 30% to 300% in Record and Desiree, respectively) activity. The comparative effect of the antisense construct in leaf and tuber tissue suggests that this isoform is only a minor contributor to the total fructokinase activity in the leaf but the predominant isoform in the tuber. Antisense inhibition of the fructokinase resulted in a reduced tuber yield; however, its overexpression had no impact on this parameter. The modulation of fructokinase activity had few, consistent effects on carbohydrate levels, with the exception of a general increase in glucose content in the antisense lines, suggesting that this enzyme is not important for the control of starch synthesis. However, when metabolic fluxes were estimated, it became apparent that the transgenic lines display a marked shift in metabolism, with the rate of redistribution of radiolabel to sucrose markedly affected by the activity of fructokinase. These data suggest an important role for fructokinase, acting in concert with sucrose synthase, in maintaining a balance between sucrose synthesis and degradation by a mechanism independent of that controlled by the hexose phosphate-mediated activation of sucrose phosphate synthase.

  20. Tuberous Sclerosis Complex: Perioperative Considerations

    PubMed Central

    Rabito, Matthew J.; Kaye, Alan David

    2014-01-01

    Background Tuberous sclerosis complex (TSC), also known as Bourneville disease, is an inherited, progressive neurocutaneous disorder characterized by the potential for hamartoma formation throughout the body. TSC is an autosomal dominant genetic disorder, but more than two-thirds of cases are sporadic. Methods Clinical manifestations and treatment options are discussed. Both surgical and anesthetic perioperative considerations are described in this review. Results Routine monitoring is appropriate for minor surgical procedures for patients with TSC who have mild disease manifestations. More extensive monitoring is indicated for major procedures that have the potential for significant blood loss and for patients with more severe pathology. Postoperatively, TSC patients should be admitted for monitoring and treatment after more extensive procedures or if significant organ dysfunction occurs. Postoperative complications, which may be related to either the surgery or the TSC pathology itself, may have origins in many different organs and may include seizures, severe hypertension, and bradyarrhythmias. Conclusion TSC is a rare disease with a highly variable clinical presentation and provides a multitude of challenges for the patient, the family, and the healthcare team. PMID:24940133

  1. Expression of an engineered granule-bound Escherichia coli glycogen branching enzyme in potato results in severe morphological changes in starch granules.

    PubMed

    Huang, Xing-Feng; Nazarian-Firouzabadi, Farhad; Vincken, Jean-Paul; Ji, Qin; Suurs, Luc C J M; Visser, Richard G F; Trindade, Luisa M

    2013-05-01

    The Escherichia coli glycogen branching enzyme (GLGB) was fused to either the C- or N-terminus of a starch-binding domain (SBD) and expressed in two potato genetic backgrounds: the amylose-free mutant (amf) and an amylose-containing line (Kardal). Regardless of background or construct used, a large amount of GLGB/SBD fusion protein was accumulated inside the starch granules, however, without an increase in branching. The presence of GLGB/SBD fusion proteins resulted in altered morphology of the starch granules in both genetic backgrounds. In the amf genetic background, the starch granules showed both amalgamated granules and porous starch granules, whereas in Kardal background, the starch granules showed an irregular rough surface. The altered starch granules in both amf and Kardal backgrounds were visible from the initial stage of potato tuber development. High-throughput transcriptomic analysis showed that expression of GLGB/SBD fusion protein in potato tubers did not affect the expression level of most genes directly involved in the starch biosynthesis except for the up-regulation of a beta-amylase gene in Kardal background. The beta-amylase protein could be responsible for the degradation of the extra branches potentially introduced by GLGB.

  2. Memristors: Memory elements in potato tubers.

    PubMed

    Volkov, Alexander G; Nyasani, Eunice K; Blockmon, Avery L; Volkova, Maya I

    2015-01-01

    A memristor is a nonlinear element because its current-voltage characteristic is similar to that of a Lissajous pattern for nonlinear systems. This element was postulated recently and researchers are looking for it in different biosystems. We investigated electrical circuitry of red Irish potato tubers (Solanum tuberosum L.). The goal was to discover if potato tubers might have a new electrical component - a resistor with memory. The analysis was based on a cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation by bipolar sinusoidal or triangle periodic waves induces electrical responses in the potato tubers with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in potato tubers. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of potato tubers has properties of a memristor. Uncoupler carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decreases the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. The discovery of memristors in plants creates a new direction in the understanding of electrical phenomena in plants.

  3. Memristors: Memory elements in potato tubers

    PubMed Central

    Volkov, Alexander G; Nyasani, Eunice K; Blockmon, Avery L; Volkova, Maya I

    2015-01-01

    A memristor is a nonlinear element because its current-voltage characteristic is similar to that of a Lissajous pattern for nonlinear systems. This element was postulated recently and researchers are looking for it in different biosystems. We investigated electrical circuitry of red Irish potato tubers (Solanum tuberosum L.). The goal was to discover if potato tubers might have a new electrical component - a resistor with memory. The analysis was based on a cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation by bipolar sinusoidal or triangle periodic waves induces electrical responses in the potato tubers with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K+ channels, transforms a memristor to a resistor in potato tubers. Our results demonstrate that a voltage gated K+ channel in the excitable tissue of potato tubers has properties of a memristor. Uncoupler carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decreases the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. The discovery of memristors in plants creates a new direction in the understanding of electrical phenomena in plants. PMID:26237427

  4. Signals involved in tuber wound-healing

    PubMed Central

    Suttle, Jeffrey C

    2009-01-01

    The induction and regulation of wound-healing (WH) processes in potato tubers and other vegetables are of great nutritional and economic importance. The rapid accumulation of waxes to restrict water vapor loss and formation of suberin barriers to block infection are crucial components of WH. Recently we determined the regulatory involvement of abscisic acid (ABA) and ethylene in WH. In this addendum we integrate and interpret features from this recent research with additional information on ABA and data on the association of jasmonic acid (JA) in tuber WH. Results show that wounding dramatically increased tuber ethylene production and ABA and JA content. Blockage of wound-induced ABA biosynthesis and ethylene action/biosynthesis showed that ABA is a potent regulator in reduction of water vapor loss and hastening of suberization while ethylene had no discernable effect. The collective results also imply that ethylene has no effect on ABA regulation of WH. JA content in dormant and non-dormant minitubers is very low (≤l ng gFW−1) but rapidly increases upon wounding then decreases, all before wound-induced ABA or ethylene accumulation reach their maxima. Results gathered to date do not support a role for ethylene in potato tuber WH but do implicate ABA in this process. Although JA content increases rapidly after wounding, its role in tuber WH remains speculative. PMID:19820323

  5. Comparative Proteome Analysis of the Tuberous Roots of Six Cassava (Manihot esculenta) Varieties Reveals Proteins Related to Phenotypic Traits.

    PubMed

    Schmitz, Gabriela Justamante Händel; de Magalhães Andrade, Jonathan; Valle, Teresa Losada; Labate, Carlos Alberto; do Nascimento, João Roberto Oliveira

    2016-04-27

    Cassava (Manihot esculenta Crantz) is a staple food and an important source of starch, and the attributes of its tuberous root largely depend on the variety. The proteome of cassava has been investigated; however, to date, no study has focused on varieties that reveal the molecular basis of phenotypical characteristics. Therefore, we aimed to compare the proteome of the tuberous roots of six cassava varieties that differed in carbohydrates, carotenoids, and resistance to diseases, among other attributes. Two-dimensional gels showed 146 differential spots between the varieties, and the functional roles of some differential proteins were correlated to phenotypic characteristics of the varieties, such as the amount of carbohydrates or carotenoids and the resistance to biotic or abiotic stresses. The results obtained here highlight elements that might help to direct the improvement of new cultivars of cassava, which is an economically and socially relevant crop worldwide.

  6. Novel Histopathological Patterns in Cortical Tubers of Epilepsy Surgery Patients with Tuberous Sclerosis Complex

    PubMed Central

    Hulshof, Hanna M.; Scholl, Theresa; Iyer, Anand M.; Anink, Jasper J.; van den Ouweland, Ans M. W.; Nellist, Mark D.; Jansen, Floor E.; Spliet, Wim G. M.; Krsek, Pavel; Benova, Barbora; Zamecnik, Josef; Crino, Peter B.; Prayer, Daniela; Czech, Thomas; Wöhrer, Adelheid; Rahimi, Jasmin; Höftberger, Romana; Hainfellner, Johannes A.; Feucht, Martha; Aronica, Eleonora

    2016-01-01

    Tuberous Sclerosis Complex (TSC) is a genetic hamartoma syndrome frequently associated with severe intractable epilepsy. In some TSC patients epilepsy surgery is a promising treatment option provided that the epileptogenic zone can be precisely delineated. TSC brain lesions (cortical tubers) contain dysmorphic neurons, brightly eosinophilic giant cells and white matter alterations in various proportions. However, a histological classification system has not been established for tubers. Therefore, the aim of this study was to define distinct histological patterns within tubers based on semi-automated histological quantification and to find clinically significant correlations. In total, we studied 28 cortical tubers and seven samples of perituberal cortex from 28 TSC patients who had undergone epilepsy surgery. We assessed mammalian target of rapamycin complex 1 (mTORC1) activation, the numbers of giant cells, dysmorphic neurons, neurons, and oligodendrocytes, and calcification, gliosis, angiogenesis, inflammation, and myelin content. Three distinct histological profiles emerged based on the proportion of calcifications, dysmorphic neurons and giant cells designated types A, B, and C. In the latter two types we were able to subsequently associate them with specific features on presurgical MRI. Therefore, these histopathological patterns provide consistent criteria for improved definition of the clinico-pathological features of cortical tubers identified by MRI and provide a basis for further exploration of the functional and molecular features of cortical tubers in TSC. PMID:27295297

  7. Potato tuber cytokinin oxidase/dehydrogenase genes: biochemical properties, activity, and expression during tuber dormancy progression.

    PubMed

    Suttle, Jeffrey C; Huckle, Linda L; Lu, Shunwen; Knauber, Donna C

    2014-03-15

    The enzymatic and biochemical properties of the proteins encoded by five potato cytokinin oxidase/dehydrogenase (CKX)-like genes functionally expressed in yeast and the effects of tuber dormancy progression on StCKX expression and cytokinin metabolism were examined in lateral buds isolated from field-grown tubers. All five putative StCKX genes encoded proteins with in vitro CKX activity. All five enzymes were maximally active at neutral to slightly alkaline pH with 2,6-dichloro-indophenol as the electron acceptor. In silico analyses indicated that four proteins were likely secreted. Substrate dependence of two of the most active enzymes varied; one exhibiting greater activity with isopentenyl-type cytokinins while the other was maximally active with cis-zeatin as a substrate. [(3)H]-isopentenyl-adenosine was readily metabolized by excised tuber buds to adenine/adenosine demonstrating that CKX was active in planta. There was no change in apparent in planta CKX activity during either natural or chemically forced dormancy progression. Similarly although expression of individual StCKX genes varied modestly during tuber dormancy, there was no clear correlation between StCKX gene expression and tuber dormancy status. Thus although CKX gene expression and enzyme activity are present in potato tuber buds throughout dormancy, they do not appear to play a significant role in the regulation of cytokinin content during tuber dormancy progression.

  8. Genetic Improvement of Potato for Tuber Calcium Uptake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tuber internal quality is a major limiting factor for the U.S. potato industry. Breeders invest time and money in producing advanced selections which, in the end, often fail because of tuber internal defects, tuber bruising, or storage quality issues. In-season fertilization with calcium is known to...

  9. Validation of a tuber blight (Phytophthora infestans) prediction model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tuber blight caused by Phytophthora infestans accounts for significant losses in storage. There is limited published quantitative data on predicting tuber blight. We validated a tuber blight prediction model developed in New York with cultivars Allegany, NY 101, and Katahdin using independent...

  10. Starch nanoparticles: a review.

    PubMed

    Le Corre, Déborah; Bras, Julien; Dufresne, Alain

    2010-05-10

    Starch is a natural, renewable, and biodegradable polymer produced by many plants as a source of stored energy. It is the second most abundant biomass material in nature. The starch structure has been under research for years, and because of its complexity, an universally accepted model is still lacking (Buleon, A.; et al. Int. J. Biol. Macromol. 1998, 23, 85-112). However, the predominant model for starch is a concentric semicrystalline multiscale structure that allows the production of new nanoelements: (i) starch nanocrystals resulting from the disruption of amorphous domains from semicrystalline granules by acid hydrolysis and (ii) starch nanoparticles produced from gelatinized starch. This paper intends to give a clear overview of starch nanoparticle preparation, characterization, properties, and applications. Recent studies have shown that they could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging, continuously looking for innovative solutions for efficient and sustainable systems, is being investigated. Therefore, recently, starch nanoparticles have been the focus of an exponentially increasing number of works devoted to develop biocomposites by blending starch nanoparticles with different biopolymeric matrices. To our knowledge, this topic has never been reviewed, despite several published strategies and conclusions.

  11. Protein synthesis inhibitor from potato tuber

    SciTech Connect

    Romaen, R. )

    1989-04-01

    A protein fraction capable of inhibit in vitro protein synthesis was found in potato tubers in fresh and wounded tissue. Inhibitor activity from fresh tissue decays with wounding. Inhibition activity was detected absorbed to ribsomal fraction and cytosol of potato tuber tissue by a partially reconstituted in vitro system from potato tuber and wheat germ. Adsorbed ribosomal fraction was more suitable of purification. This fraction was washed from ribosomes with 0.3M KCl, concentrated with ammonium sulfate precipitation and purified through sephadex G100 and sephadex G-75 columns chromatography. After 61 fold purification adsorbed protein fraction can inhibit germination of maize, wheat and sesame seeds, as well as {sup 3}H-leucine incorporation into protein by imbibed maize embryos. Inhibition activity was lost by temperature, alkali and protease-K hydrolysis. Preliminar analysis could not show presence of reductor sugars. Physiological role of this inhibitor in relation to rest and active tissue remains to be studied.

  12. Blue maize: morphology and starch synthase characterization of starch granule.

    PubMed

    Utrilla-Coello, Rubi G; Agama-Acevedo, Edith; de la Rosa, Ana Paulina Barba; Martinez-Salgado, Jose L; Rodriguez-Ambriz, Sandra L; Bello-Perez, Luis A

    2009-03-01

    The use of pigmented maize varieties has increased due to their high anthocyanins content, but very few studies are reported about the starch properties of these grains. The aim of this work was to isolate the starch granules from pigmented blue maize and carry out the morphological, physicochemical, and biochemical characterization studies. The proximate composition of starch granules showed high protein contents, after purification, the blue maize starch presented lower protein amount than starch from white maize (control). Although the purity of starch granules was increased, the damaged starch (determined for the Maltase cross absence) was also increased. Scanning electron microscopy showed the presence of some pores and channels in the blue maize starch. The electrophoretic protein profiles showed differences in the bands that correspond to the enzymes involved in the starch biosynthesis; these differences could explain the variation in morphological characteristics of blue maize starches against starch from white maize.

  13. Expression of auxin synthesis gene tms1 under control of tuber-specific promoter enhances potato tuberization in vitro.

    PubMed

    Kolachevskaya, Oksana O; Alekseeva, Valeriya V; Sergeeva, Lidiya I; Rukavtsova, Elena B; Getman, Irina A; Vreugdenhil, Dick; Buryanov, Yaroslav I; Romanov, Georgy A

    2015-09-01

    Phytohormones, auxins in particular, play an important role in plant development and productivity. Earlier data showed positive impact of exogenous auxin on potato (Solanum tuberosum L.) tuberization. The aim of this study was to generate potato plants with increased auxin level predominantly in tubers. To this end, a pBinB33-tms1 vector was constructed harboring the Agrobacterium auxin biosynthesis gene tms1 fused to tuber-specific promoter of the class I patatin gene (B33-promoter) of potato. Among numerous independently generated B33:tms1 lines, those without visible differences from control were selected for detailed studies. In the majority of transgenic lines, tms1 gene transcription was detected, mostly in tubers rather than in shoots. Indoleacetic acid (IAA) content in tubers and the auxin tuber-to-shoot ratio were increased in tms1-expressing transformants. The organ-specific increase in auxin synthesis in B33:tms1-transformants accelerated and intensified the process of tuber formation, reduced the dose of carbohydrate supply required for in vitro tuberization, and decreased the photoperiodic dependence of tuber initiation. Overall, a positive correlation was observed between tms1 expression, IAA content in tubers, and stimulation of tuber formation. The revealed properties of B33:tms1 transformants imply an important role for auxin in potato tuberization and offer prospects to magnify potato productivity by a moderate organ-specific enhancement of auxin content.

  14. Production of cyclodextrins by CGTase from Bacillus clausii using different starches as substrates.

    PubMed

    Alves-Prado, H F; Carneiro, A A J; Pavezzi, F C; Gomes, E; Boscolo, M; Franco, C M L; da Silva, R

    2008-03-01

    Cyclodextrins (CDs) are cyclic oligasaccharides composed by D-glucose monomers joined by alpha-1,4-D glicosidic linkages. The main types of CDs are alpha-, beta- and gamma-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a beta-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for alpha/beta/gamma. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

  15. Production of Cyclodextrins by CGTase from Bacillus clausii Using Different Starches as Substrates

    NASA Astrophysics Data System (ADS)

    Alves-Prado, H. F.; Carneiro, A. A. J.; Pavezzi, F. C.; Gomes, E.; Boscolo, M.; Franco, C. M. L.; da Silva, R.

    Cyclodextrins (CDs) are cyclic oligasaccharides composed by d-glucose monomers joined by α-1,4-d glicosidic linkages. The main types of CDs are α-, β- and γ-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a β-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for α/β/γ. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

  16. Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways.

    PubMed

    Hou, Juan; Zhang, Huiling; Liu, Jun; Reid, Stephen; Liu, Tengfei; Xu, Shijing; Tian, Zhendong; Sonnewald, Uwe; Song, Botao; Xie, Conghua

    2017-03-28

    Cold-induced sweetening (CIS) in potato is detrimental to the quality of processed products. Conversion of starch to reducing sugars (RS) by amylases is considered one of the main pathways in CIS but is not well studied. The amylase genes StAmy23, StBAM1, and StBAM9 were studied for their functions in potato CIS. StAmy23 is localized in the cytoplasm, whereas StBAM1 and StBAM9 are targeted to the plastid stroma and starch granules, respectively. Genetic transformation of these amylases in potatoes by RNA interference showed that β-amylase activity could be decreased in cold-stored tubers by silencing of StBAM1 and collective silencing of StBAM1 and StBAM9. However, StBAM9 silencing did not decrease β-amylase activity. Silencing StBAM1 and StBAM9 caused starch accumulation and lower RS, which was more evident in simultaneously silenced lines, suggesting functional redundancy. Soluble starch content increased in RNAi-StBAM1 lines but decreased in RNAi-StBAM9 lines, suggesting that StBAM1 may regulate CIS by hydrolysing soluble starch and StBAM9 by directly acting on starch granules. Moreover, StBAM9 interacted with StBAM1 on the starch granules. StAmy23 silencing resulted in higher phytoglycogen and lower RS accumulation in cold-stored tubers, implying that StAmy23 regulates CIS by degrading cytosolic phytoglycogen. Our findings suggest that StAmy23, StBAM1, and StBAM9 function in potato CIS with varying levels of impact.

  17. Preparation of potato starch microfibers obtained by electro wet spinning

    NASA Astrophysics Data System (ADS)

    Cárdenas, W.; Gómez-Pachon, E. Y.; Muñoz, E.; Vera-Graziano, R.

    2016-07-01

    Starch is one of the most abundant biopolymer in nature. It has been primarily used as a thickener in the food industry. Starch is found in greater amounts in the potato tubers, which is one of the largest food productions in the region of Boyacá-Colombia. Thus, potatoes are a viable source of starch. The main objective of this study is the preparation and characterization of native starch's microfiber by electro wet-spinning technique. The parameters that were changed for each treatment were as follows: the amount of potential applied to the solution, the distance between the needle and the collector and the rate of injection of the solution in order to determine the physical and chemical properties of the membranes, conformed by potatoes starch microfiber. Diverse instrumental analysis techniques were applied. They were: Scanning Electron Microscopy (SEM) to determine the morphologies and diameters of microfibers, Fourier Transform Infrared Spectroscopy (FTIR) to determine the chemical changes, Thermogravimetric Analysis (TGA) and Differential Calorimetry Scanning (DSC) to obtain the thermal transitions and the temperatures of useful. The microfibers were analysed in order to determine their structural properties and thus define the range of application. In conclusion, potatoes starch microfibers were obtained with average diameters of 15, 17, 23 and 25 micrometres, besides the fibers presented a degradation temperature of 304 °C, indicating that fibers are available with diameters of small scale, with good thermal properties. This study will enable the implementation of the microfibers to obtain bio packaging for food products and other applications.

  18. Insight on Genes Affecting Tuber Development in Potato upon Potato spindle tuber viroid (PSTVd) Infection.

    PubMed

    Katsarou, Konstantina; Wu, Yun; Zhang, Runxuan; Bonar, Nicola; Morris, Jenny; Hedley, Pete E; Bryan, Glenn J; Kalantidis, Kriton; Hornyik, Csaba

    2016-01-01

    Potato (Solanum tuberosum L) is a natural host of Potato spindle tuber viroid (PSTVd) which can cause characteristic symptoms on developing plants including stunting phenotype and distortion of leaves and tubers. PSTVd is the type species of the family Pospiviroidae, and can replicate in the nucleus and move systemically throughout the plant. It is not well understood how the viroid can affect host genes for successful invasion and which genes show altered expression levels upon infection. Our primary focus in this study is the identification of genes which can affect tuber formation since viroid infection can strongly influence tuber development and especially tuber shape. In this study, we used a large-scale method to identify differentially expressed genes in potato. We have identified defence, stress and sugar metabolism related genes having altered expression levels upon infection. Additionally, hormone pathway related genes showed significant up- or down-regulation. DWARF1/DIMINUTO, Gibberellin 7-oxidase and BEL5 transcripts were identified and validated showing differential expression in viroid infected tissues. Our study suggests that gibberellin and brassinosteroid pathways have a possible role in tuber development upon PSTVd infection.

  19. Insight on Genes Affecting Tuber Development in Potato upon Potato spindle tuber viroid (PSTVd) Infection

    PubMed Central

    Zhang, Runxuan; Bonar, Nicola; Morris, Jenny; Hedley, Pete E.; Bryan, Glenn J.; Kalantidis, Kriton; Hornyik, Csaba

    2016-01-01

    Potato (Solanum tuberosum L) is a natural host of Potato spindle tuber viroid (PSTVd) which can cause characteristic symptoms on developing plants including stunting phenotype and distortion of leaves and tubers. PSTVd is the type species of the family Pospiviroidae, and can replicate in the nucleus and move systemically throughout the plant. It is not well understood how the viroid can affect host genes for successful invasion and which genes show altered expression levels upon infection. Our primary focus in this study is the identification of genes which can affect tuber formation since viroid infection can strongly influence tuber development and especially tuber shape. In this study, we used a large-scale method to identify differentially expressed genes in potato. We have identified defence, stress and sugar metabolism related genes having altered expression levels upon infection. Additionally, hormone pathway related genes showed significant up- or down-regulation. DWARF1/DIMINUTO, Gibberellin 7-oxidase and BEL5 transcripts were identified and validated showing differential expression in viroid infected tissues. Our study suggests that gibberellin and brassinosteroid pathways have a possible role in tuber development upon PSTVd infection. PMID:26937634

  20. Composition and physical properties of starch in microgravity-grown plants

    NASA Astrophysics Data System (ADS)

    Kuznetsov, O. A.; Brown, C. S.; Levine, H. G.; Piastuch, W. C.; Sanwo-Lewandowski, M. M.; Hasenstein, K. H.

    2001-01-01

    The effect of spaceflight on starch development in soybean ( Glycine max L., BRIC-03) and potato ( Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio Δκ/Δρ (Δκ - difference of magnetic susceptibilities, Δρ - difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm 3), the observed difference in Δκ/Δρ was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with α-amylase for 24 hours, 77±6% of the starch from the flight cotyledons was degraded compared to 58±12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and Δκ/Δρ suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, Δκ/Δρ and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

  1. Composition and physical properties of starch in microgravity-grown plants.

    PubMed

    Kuznetsov, O A; Brown, C S; Levine, H G; Piastuch, W C; Sanwo-Lewandowski, M M; Hasenstein, K H

    2001-01-01

    The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

  2. Composition and physical properties of starch in microgravity-grown plants

    NASA Technical Reports Server (NTRS)

    Kuznetsov, O. A.; Brown, C. S.; Levine, H. G.; Piastuch, W. C.; Sanwo-Lewandowski, M. M.; Hasenstein, K. H.; Sager, J. C. (Principal Investigator)

    2001-01-01

    The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  3. Polymorphism of starch pathway genes in cassava.

    PubMed

    Vasconcelos, L M; Brito, A C; Carmo, C D; Oliveira, E J

    2016-12-02

    The distribution and frequency of single nucleotide polymorphisms (SNPs) can help to understand changes associated with characteristics of interest. We aimed to evaluate nucleotide diversity in six genes involved in starch biosynthesis in cassava using a panel of 96 unrelated accessions. The genes were sequenced, aligned, and used to obtain values for nucleotide diversity (π), segregating sites (θ), Tajima's D test, and neighbor-joining (NJ) clustering. On average, one SNP per 147 and 171 bp was identified in exon and intron regions, respectively. Thirteen heterozygous loci were found. Three of seven SNPs in the exon region resulted in non-synonymous replacement or four synonymous substitutions. However, no associations were noted between SNPs and root dry-matter content. The parameter π ranged from 0.0001 (granule bound starch synthase I) to 0.0033 (α-amylase), averaging 0.0011, while θ ranged from 0.00014 (starch branching enzyme) to 0.00584 (starch synthase I), averaging 0.002353. The θ diversity value was typically double that of the π. Results of the D test did not suggest any evidence of deviance of neutrality in these genes. Among the evaluated accession, 82/96 were clustered using the NJ method but without a clear separation of the root dry-matter content, root pulp coloration, and classification of the cyanogenic compound content. High variation in genes of the starch biosynthetic pathway can be used to identify associations with the functional properties of starch for the use of polymorphisms for selection purposes.

  4. Evaluation of potato tuber moth (Lepidoptera: Gelechiidae) resistance in tubers of Bt-cry5 transgenic potato lines.

    PubMed

    Mohammed, A; Douches, D S; Pett, W; Grafius, E; Coombs, J; Liswidowati; Li, W; Madkour, M A

    2000-04-01

    The potato tuber moth, Phthorimaea operculella (Zeller), in tropical and subtropical countries, is the most destructive pest of potato, Solanum tuberosum L. The larvae attack foliage and tubers in the field and in storage. The purpose of this study was to evaluate the efficacy of a Bt-cry5 transgene to control the potato tuber moth in tuber tissues. Tuber bioassays using stored (11-12 mo old) and newly harvested tubers of Bt-cry5-Lemhi Russet and Bt-cry5-Atlantic potato lines showed up to 100% mortality of 1st instars. Mortality was lowest in the newly harvested tubers of Bt-cry5-Atlantic lines (47.1-67.6%). Potato tuber moth mortality was 100% in the Bt-cry5-Spunta lines that were transformed with Bt-cry5 gene controlled by the CaMV 35S promoter (pBIML5 vector) and in 2 of 3 lines transformed with Bt-cry5 gene controlled by the Gelvin super promoter (pBIML1 vector). The transgenic Spunta lines expressing Bt-cry5 controlled by the patatin promoter (pBMIL2 vector) showed the lowest tuber moth mortality (25.6 and 31.1%). The Bt-cry5 transgenic lines with high tuber expression of B. thuringiensis have value in an integrated pest management system to control potato tuber moth.

  5. Characterization of starch nanoparticles

    NASA Astrophysics Data System (ADS)

    Szymońska, J.; Targosz-Korecka, M.; Krok, F.

    2009-01-01

    Nanomaterials already attract great interest because of their potential applications in technology, food science and medicine. Biomaterials are biodegradable and quite abundant in nature, so they are favoured over synthetic polymer based materials. Starch as a nontoxic, cheap and renewable raw material is particularly suitable for preparation of nanoparticles. In the paper, the structure and some physicochemical properties of potato and cassava starch particles of the size between 50 to 100 nm, obtained by mechanical treatment of native starch, were presented. We demonstrated, with the aim of the Scanning Electron Microscopy (SEM) and the non-contact Atomic Force Microscopy (nc-AFM), that the shape and dimensions of the obtained nanoparticles both potato and cassava starch fit the blocklets - previously proposed as basic structural features of native starch granules. This observation was supported by aqueous solubility and swelling power of the particles as well as their iodine binding capacity similar to those for amylopectin-type short branched polysaccharide species. Obtained results indicated that glycosidic bonds of the branch linkage points in the granule amorphous lamellae might be broken during the applied mechanical treatment. Thus the released amylopectin clusters could escape out of the granules. The starch nanoparticles, for their properties qualitatively different from those of native starch granules, could be utilized in new applications.

  6. Color Blindness

    MedlinePlus

    ... rose in full bloom. If you have a color vision defect, you may see these colors differently than most people. There are three main kinds of color vision defects. Red-green color vision defects are the most ...

  7. Formulation and development of plasma volume expander using natural and modified starch from Solanum tuberosum

    PubMed Central

    Thombre, Nilima A.; Vishwakarma, Ajit V.; Jadhav, Trupti S.; Kshirsagar, Sanjay J.

    2016-01-01

    Background: To formulation and development of plasma volume expander (PVE) by using natural and modified starch from Solanum tuberosum. The function of blood circulation is to provide the needs of the body tissues and to maintain an appropriate environment in all tissue fluids of the body for the optimal survival and functions of the cells. Rapid restoration of the blood volume is necessary to decrease reduction in the amount of the blood. The PVEs are isotonic colloidal solutions, act by increasing the osmotic pressure of the intravascular compartment, which leads to the influx of the interstitial fluids through the capillary pore which, in turn, leads to the increase in the volume of the blood. Therefore, there is a need to discover the PVE with less side effects. The main aim of the present study is to use amylopectin as PVEs, fractionated from natural and modified starch obtained from S. tuberosum. Methods: The starch extracted from the normal grains and the tubers of potatoes was selected for the production of starch. Statistical analysis includes in vitro characterization that involves viscosity studies, plasma–product interaction, osmotic pressure detection, molecular weight–viscosity relationship, determination of weight average molecular weight, enzymatic interaction, and in vivo characterization such as toxicity studies and the effect of the products on the blood coagulation. The isolated starch and fractionated amylopectin were analyzed for the physicochemical characteristics. Result and Conclusion: The amylopectin fractionated from isolated starch from grains and tubers of potatoes can be used as PVE, as per the outcome of the study. PMID:28123990

  8. Cloning, expression, and characterization of soluble starch synthase I cDNA from taro (Colocasia esculenta Var. esculenta).

    PubMed

    Lin, Da-Gin; Jeang, Chii-Ling

    2005-10-05

    Soluble starch synthase I (SSSI) cDNA was isolated from taro (Colocasia esculenta var. esculenta) by RT-PCR and rapid amplification of cDNA ends reaction. The transcript of this single-copy gene is 2340 bp and encodes 642 amino acids protein containing a putative transit peptide of 54 residues. Recombinant SSSI protein displayed both primer-dependent and primer-independent activities of starch synthase. More SSSI transcript was expressed in taro leaves than in tubers, with no evident expression in petioles; and more transcript and protein were found in tubers of 597 +/- 37 g of fresh weight than in smaller or larger ones. Two forms of SSSI, i.e., 72 and 66 kDa, exist in leaves, and only the 66 kDa form was found in tubers. The taro SSSI, proposed as a novel member, was located only in the soluble fraction of tuber extract, while SSSI from other sources exist in both soluble and granule-bound forms.

  9. Genetic controls on starch amylose content in wheat and rice grains.

    PubMed

    Fasahat, Parviz; Rahman, Sadequr; Ratnam, Wickneswari

    2014-04-01

    Starch accumulates in plants as granules in chloroplasts of source organs such as leaves (transitory starch) or in amyloplasts of sink organs such as seeds, tubers and roots (storage starch). Starch is composed of two types of glucose polymers: the essentially linear polymer amylose and highly branched amylopectin. The amylose content of wheat and rice seeds is an important quality trait, affecting the nutritional and sensory quality of two of the world's most important crops. In this review, we focus on the relationship between amylose biosynthesis and the structure, physical behaviour and functionality of wheat and rice grains. We briefly describe the structure and composition of starch and then in more detail describe what is known about the mechanism of amylose synthesis and how the amount of amylose in starch might be controlled. This more specifically includes analysis of GBSS alleles, the relationship between waxy allelic forms and amylose, and related quantitative trait loci. Finally, different methods for increasing or lowering amylose content are evaluated.

  10. A mass spectrometric method for quantifying C3 and C6 phosphorylation of starch.

    PubMed

    Carpenter, Margaret; Joyce, Nigel; Butler, Ruth; Genet, Russell; Timmerman-Vaughan, Gail

    2012-12-15

    The glucosyl residues comprising starch can be phosphorylated at either the C3 or the C6 position of the molecule because of the activities of two distinct dikinase enzymes. After hydrolysis of the starch, the C6 phosphorylation is easy to measure using a routine enzyme assay for glucose 6-phosphate, but the C3 phosphorylation is more difficult to assay. A mass spectrometric (MS) method has been developed that, in a single run, can distinguish and quantify the glucose 3-phosphate and glucose 6-phosphate produced by hydrolysis of starch and can also measure the glucose content to give an accurate estimate of the starting material. The MS method involves quantification by LC/MS with external standards, using normal-phase hydrophilic interaction liquid chromatography and selective reaction monitoring. The MS method has been used to determine degrees of starch phosphorylation in a diverse group of potato lines, revealing threefold differences in phosphorylation between high- and low-phosphate lines. The method was also used to show that cold storage of potato tubers for up to 24weeks had little substantive effect on the levels of starch phosphorylation. MS provided an effective and efficient means of determining both the C6 and the C3 phosphorylation of starch.

  11. Proteome analysis of Pueraria mirifica tubers collected in different seasons.

    PubMed

    Jungsukcharoen, Jutarmas; Chokchaichamnankit, Daranee; Srisomsap, Chantragan; Cherdshewasart, Wichai; Sangvanich, Polkit

    2016-06-01

    Pueraria mirifica-derived tuberous powder has been long-term consumed in Thailand as female hormone-replacement traditional remedies. The protein profiles of tubers collected in different seasons were evaluated. Phenol extraction, 2D-PAGE, and mass spectrometry were employed for tuberous proteome analysis. Out of the 322 proteins detected, over 59% were functionally classified as being involved in metabolism. The rest proteins were involved in defense, protein synthesis, cell structure, transportation, stress, storage, and also unidentified function. The proteins were found to be differentially expressed with respect to harvest season. Importantly, chalcone isomerase, isoflavone synthase, cytochrome p450, UDP-glycosyltransferase, and isoflavone reductase, which are all involved in the biosynthesis pathway of bioactive isoflavonoids, were most abundantly expressed in the summer-collected tubers. This is the first report on the proteomic patterns in P. mirifica tubers in relevant with seasonal variation. The study enlights the understanding of variance isoflavonoid production in P. mirifica tubers.

  12. Ezrin and moesin expression within the developing human cerebrum and tuberous sclerosis-associated cortical tubers.

    PubMed

    Johnson, Michael W; Miyata, Hajime; Vinters, Harry V

    2002-08-01

    The ERM (ezrin, radixin, and moesin) proteins belong to the band-4.1 superfamily of membrane-cytoskeleton-linking proteins which bind to the actin cytoskeleton via their C-terminal sequences and bind ERM binding membrane proteins (ERMBMPs). We investigated the immunohistochemical expression of two of the ERM proteins (ezrin and moesin) in developing human cerebral cortex and in cortical tubers from patients with tuberous sclerosis (TSC), to assess possible consequences of TSC gene product malfunction or inactivation in the developing brain in relation to ERM protein expression. Ezrin is abundantly expressed within radial glia and migrating cells in the intermediate zone in the prenatal human cerebrum, while moesin is primarily expressed in vascular endothelial cells in developing and adult human brain and scattered microglia in adult brain. In addition, both ezrin and moesin are abundantly co-expressed with hamartin and tuberin within a population of abnormal cells in TSC-associated cortical tubers. The expression of these two proteins--primarily ezrin--suggests that they are developmentally regulated and abundantly expressed in germinal matrix and/or migrating cells during cerebral cortical development. In TSC-associated cortical tubers, both proteins appeared to be up-regulated and are co-localized within a population of abnormal neuroglial cells typical of those seen in tubers. Expression of these proteins and their co-localization with tuberin and hamartin in these cells may suggest a compensatory up-regulation in response to TSC gene mutation.

  13. Dormancy regulation by morphactin in aerial tubers of Begonia evansiana.

    PubMed

    Okagami, N; Esashi, Y

    1972-09-01

    The sprouting of aerial tubers of Begonia evansiana was promoted by treatment with morphactin. As with cytokinins, the promotion of sprouting occurred in both the immature and mature tubers. Unlike cytokinins, however, morphactin did not stimulate tuber enlargement. The sprout-inhibiting action of applied gibberellin (GA) was overcome by morphactin. The possible mechanism of the inhibitory action of GA is diseussed in relation to apical dominance.

  14. Oral health management implications in patients with tuberous sclerosis.

    PubMed

    Cutando, A; Gil, J A; López, J

    2000-10-01

    We report 6 cases of patients with tuberous sclerosis and concomitant dental pathosis. The multiple manifestations in tuberous sclerosis determine its impact on dental therapy. A lack of awareness of this condition may compound the possible side effects of dental treatment. Possible preventive measures by dentists are highlighted in this presentation. Medical evaluation and the control of risk factors in relation to general anesthesia and sedation are key considerations for the management of patients with tuberous sclerosis.

  15. A proteomic analysis of storage stress responses in Ipomoea batatas (L.) Lam. tuberous root.

    PubMed

    Jiang, Yusong; Chen, Cheng; Tao, Xiang; Wang, Jianxi; Zhang, Yizheng

    2012-08-01

    During post-harvest storage, tuberous roots of sweet potato (Ipomoea batatas L. Lam.) usually undergo a biotic and abiotic stress influencing protein expression pattern and substance contents. This research compared the change of total proteins and carbohydrate content in tuberous roots of sweet potato during the storage period. The result of the two-dimensional electrophoresis analysis demonstrated that there were 25 differentially expressed proteins between day 0 and day 75 during the storage. Among these proteins, 11 proteins were down-regulated and the other 14 were up-regulated. The results from MALDI-TOF-TOF/MS analyses and mascot database searching showed that 11 of the 25 differentially expressed proteins were identified as store-stress regulated proteins. It was also found that the proteins involved in the energy metabolism and the stress-response were drastically up-regulated, whereas those in biomacromolecule synthesis were markedly down-regulated. Meanwhile, under the experimental conditions, the content of the starch and the cellulose was decreased by more than a quarter and the amylase activity was increased moderately.

  16. Relationship between the electrical and rheological properties of potato tuber tissue after various forms of processing.

    PubMed

    Dejmek, Petr; Miyawaki, Osato

    2002-06-01

    The impedance at frequencies of 1-1000 kHz and dynamic bending storage modulus measured by the vibrating reed method were compared for potato tuber tissue, which had been processed by various methods. Raw potato tuber tissue strips were either heated for 30 min up to 100 degrees C or frozen-thawed. Some samples were osmotically dehydrated in a mannitol solution up to a concentration of 0.7 mol/l. The electrical reactance correlated well with the storage modulus of heated or frozen-thawed potato tissues, but not with the storage modulus of the mannitol-treated tissue. The storage modulus appeared to be strongly dependent on the turgor pressure of the cells which was drastically decreased by the heating, freezing-thawing, and osmotic treatments. The electrical properties reflect the cell integrity, and a large difference was observed between the change in impedance after heating or freezing-thawing, and that after the osmotic treatment. A significant change in the electric properties was also observed for a starch suspension at the gelatinization temperature. However, the contribution due to gelatinization did not appear to play an important role in the change of electrical properties of potato tissue by heating.

  17. Physicochemical, sensory properties and starch in vitro digestion of gluten-free breads.

    PubMed

    Carini, Eleonora; Scazzina, Francesca; Curti, Elena; Fattori, Fabio; Mazzeo, Teresa; Vittadini, Elena

    2015-01-01

    The physicochemical (volume, crumb grain and color), sensory and starch in vitro digestion properties were investigated in four gluten-free breads, produced using gluten-free commercial mixes. Different mixes' formulations and processing parameters led to the production of breads with different crumb grain, specific volume, crust and crumb color, which affected product's sensory acceptability. Generally, more heterogeneous and coarser crumb grain and darker color were more appreciated by the judges. Nutritional composition of gluten-free breads differed mainly for starch and lipids contents, due to a wide variety of ingredients used in breads formulations. Starch availability to hydrolytic enzymes in the gluten-free breads was not influenced by variation in ingredients and nutritional composition, but it was related to the physical structure in terms of specific volume. The higher was the specific volume, the higher was the starch-digested fraction.

  18. Tuberous sclerosis complex; single center experience

    PubMed Central

    Erol, İlknur; Savaş, Tülin; Şekerci, Sevda; Yazıcı, Nalan; Erbay, Ayşe; Demir, Şenay; Saygı, Semra; Alkan, Özlem

    2015-01-01

    Aim: This study was planned with the aim of retrospectively reviewing the clinical and laboratory findings and therapies of our patients diagnosed with tuberous sclerosis and redefining the patients according to the diagnostic criteria revised by the 2012 International Tuberous Sclerosis Complex Consensus Group and comparing them with the literature. Materials and Method: Twenty patients diagnosed with tuberous sclerosis complex in the Pediatric Neurology Clinic were examined retrospectively in terms of clinical findings and therapies. The diagnoses were compared again according to 1998 and 2012 criteria. Results: It was observed that the complaint at presentation was seizure in 17 of 20 patients and hypopigmented spots on the skin in 3 of 20 patients. On the initial physical examination, findings related with the disease were found in the skin in 17 of the patients, in the eye in 5, in the kidneys in 7 and in the brain with imaging in 17. No cardiac involvement was observed in the patients. Infantile spasm was observed in 7 of the patients who presented because of seizure (n=17), partial seizure was observed in 7 and multiple seizure types were observed in 3. It was found that sirolimus treatment was given to 9 of 20 patients because of different reasons, 7 of these 9 patients had epileptic seizures and sirolimus treatment had no effect on epileptic seizures. According to 2012 diagnostic criteria, no marked change occured in the diagnoses of our patients. Conclusions: It was observed that the signs and symptoms of our patients were compatible with the literature. Molecular genetic examination was planned for the patients who were being followed up because of probable tuberous sclerosis complex. It was observed that sirolimus treatment had no marked effect on the seizure frequency of our patients. PMID:26078697

  19. Defining Translational Reprogramming in Tuberous Sclerosis Complex

    DTIC Science & Technology

    2015-07-01

    programming. 2 2. KEYWORDS Tuberous sclerosis complex; mTORC1; rapamycin; mRNA; translation; ribosome; quality control; alternative translation 3...alternative TIS sites identified from human and mouse cell lines based on multiple GTI-Seq replicates. The TISdb, available at http...tisdb.human.cornell.edu, includes 6,991 TIS sites from 4,961 human genes and 9,973 TIS sites from 5,668 mouse genes. The TISdb website provides a simple browser

  20. Production of oxalic acid by some fungi infected tubers.

    PubMed

    Faboya, O; Ikotun, T; Fatoki, O S

    1983-01-01

    Oxalic acid (as oxalate) was detected in four tubers commonly used for food in Nigeria-Dioscorea rotundata (White yam), Solanum tuberosum (Irish potato), Ipomoea batatas (Sweet potato), and Manihot esculenta (cassava). Whereas healthy I. batata had the highest oxalic acid content, healthy M. esculenta contained the lowest. When all tubers were artifically inoculated with four fungi-Penicillium oxalicum CURIE and THOM, Aspergillus niger VAN TIEGH, A. flavus and A. tamarii KITA, there was an increase in oxalate content/g of tuber tissue. The greatest amount of oxalate was produced by P. oxalicum in D. rotundata tuber. Consistently higher amounts of oxalate were produced by the four fungi in infected sweet potato tuber than in any other tuber and consistently lower amounts of oxalate were produced by the four fungi in Irish potato tuber. Differences in the carbohydrate type present in the tubers and in the biosynthesis pathway are thought to be responsible for variation in the production of oxalate in the different tubers by the four fungi used.

  1. Differential cellular expression of neurotrophins in cortical tubers of the tuberous sclerosis complex.

    PubMed

    Kyin, R; Hua, Y; Baybis, M; Scheithauer, B; Kolson, D; Uhlmann, E; Gutmann, D; Crino, P B

    2001-10-01

    Neurotrophins and their receptors modulate cerebral cortical development. Tubers in the tuberous sclerosis complex (TSC) are characterized histologically by disorganized cortical cytoarchitecture and thus, we hypothesized that expression of neurotrophin mRNAs and proteins might be altered in tubers. Using in situ transcription and mRNA amplification to probe cDNA arrays, we found that neurotrophin-3 (NT3) and trkB mRNA expression were reduced whereas neurotrophin-4 (NT4) and trkC mRNA expression were increased in whole tuber sections. Alterations in mRNA abundance were defined in single microdissected dysplastic neurons (DNs) and giant cells (GCs). NT3 mRNA expression was reduced in GCs and trkB mRNA expression was reduced in DNs. NT4 mRNA expression was increased in DNs and trkC mRNA expression was increased in both DNs and GCs. In three patients, TSC2 locus mutations were confirmed and the mean tuberin mRNA expression levels was reduced across all nine cases. Consistent with these observations, NT3 mRNA expression was reduced but trkC mRNA expression was increased in vitro in human NTera2 neurons (NT2N) transfected with a tuberin antisense construct that reduced tuberin expression. Western analysis of tuber homogenates and computer-assisted densitometry of immunolabeled sections confirmed the neurotrophin mRNA expression data in whole sections and single neurotrophin immunoreactive cells. We conclude that alterations in NT4/trkB and NT3/trkC expression may contribute to tuber formation during brain development as downstream effects of the hamartin and tuberin pathway in TSC.

  2. Enzymatically hydrolysed, acetylated and dually modified corn starch: physico-chemical, rheological and nutritional properties and effects on cake quality.

    PubMed

    Sahnoun, Mouna; Ismail, Nouha; Kammoun, Radhouane

    2016-01-01

    Corn starch was treated by enzymatic hydrolysis with Aspergillus oryzae S2 α-amylase, acetylation with vinyl acetate, and dual modification. The dual modified starch displayed a higher substitution degree than the acetylated starch and lower reducing sugar content than the hydrolysed starch. The results revealed that the cooling viscosity and amylose content of those products decrease (P < 0.05). An increase in moisture, water, and oil absorption capacity was observed for the acetylated starch and, which was less pronounced for the enzymatically hydrolysed starch but more pronounced for the enzymatically hydrolysed acetylated product. The latter product underwent an increase in resistant starch content, which is induced by a rise in hydrolysis time to attain about 67 % after 1 h of reaction. The modified starch samples were added to cake formulations at 5 and 10 % concentrations on a wheat flour basis and compared to native starch. The results revealed that when applied at 5 % concentrations, the modified starches reduced the hardness, cohesion, adhesion and chewiness of baked cakes and enhanced their elasticity, volume, height, crust color, and appearance as compared to native starch. These effects were more pronounced for the cake incorporating the dually modified starch.

  3. Food microstructure and starch digestion.

    PubMed

    Singh, Jaspreet; Kaur, Lovedeep; Singh, Harjinder

    2013-01-01

    Microstructural characteristics of starch-based natural foods such as parenchyma or cotyledon cell shape, cell size and composition, and cell wall composition play a key role in influencing the starch digestibility during gastrointestinal digestion. The stability of cell wall components and the arrangement of starch granules in the cells may affect the free access of amylolytic enzymes during digestion. Commonly used food processing techniques such as thermal processing, extrusion cooking, and post-cooking refrigerated storage alter the physical state of starch (gelatinization, retrogradation, etc.) and its digestibility. Rheological characteristics (viscosity) of food affect the water availability during starch hydrolysis and, consequently, the absorption of digested carbohydrates in the gastrointestinal tract. The nonstarch ingredients and other constituents present in food matrix, such as proteins and lipids interact with starch during processing, which leads to an alteration in the overall starch digestibility and physicochemical characteristics of digesta. Starch digestibility can be controlled by critically manipulating the food microstructure, processing techniques, and food composition.

  4. Physicochemical, rheological and structural characteristics of starch in maize tortillas.

    PubMed

    Hernández-Uribe, Juan P; Ramos-López, Gonzalo; Yee-Madeira, Hernani; Bello-Pérez, Luis A

    2010-06-01

    Fresh and stored maize (white and blue) tortillas were evaluated for physicochemical, rheological and structural characteristics assessed by calorimetry, x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, dynamic viscoelastic tests, and high-performance size-exclusion chromatography. Two endotherms were found in studies of fresh and stored tortillas. The low temperature endotherm (50-56 degrees C) was due to reorganized (retrograded) amylopectin, while the high temperature endotherm (105-123 degrees C) was attributed to retrograded amylose. The enthalpy value for the lower temperature transition was minor than that of the high temperature transition. Fresh tortillas showed an amorphous starch arrangement by x-ray diffraction study. Stored samples showed the presence of peaks at 2theta = 17 masculine and 23 masculine, indicating re-crystallization of starch components. FTIR results confirmed the development of higher levels of starch crystals during storage. Differences in the viscoelastic parameters were also observed between fresh and stored samples. At the longest storage times, white tortillas were more rigid than blue tortillas. Molar mass values for starch increased for both white and blue tortillas as storage time progressed, though relatively higher values were obtained for white tortillas. More starch reorganization occurred in white tortillas, in accordance to calorimetric, x-ray diffraction, FTIR and rheological results. These results corroborate that changes occurring in tortillas during storage are related to reorganization of starch components, and the maize variety more than the color plays an important role.

  5. Physicochemical properties of kiwifruit starch.

    PubMed

    Li, Dongxing; Zhu, Fan

    2017-04-01

    Three varieties of golden kiwifruit (Actinidia chinensis) (Gold3, Gold9 and Hort16A) were collected at the commercial harvesting time, and physicochemical properties of starches from core and outer pericarp were studied. Starch contents (dry weight basis) in outer pericarp and core tissues ranged from 38.6 to 51.8% and 34.6 to 40.7%, respectively. All the kiwifruit starches showed B-type polymorph. Compared to the outer pericarp starches, amylose content and enzyme susceptibility of core starches were higher, and the degree of crystallinity, granule size and gelatinization parameters of core starches were somewhat lower. This suggests different biosynthetic properties between these two starches. The enthalpy changes of gelatinization of outer pericarp starches were high (∼21J/g). Rheological properties of outer pericarp starches were compared with normal maize and potato starches showed high yield stress of flow properties. This study revealed the unique properties of kiwifruit starch among various types of starches.

  6. Systematic analysis of potato acid invertase genes reveals that a cold-responsive member, StvacINV1, regulates cold-induced sweetening of tubers.

    PubMed

    Liu, Xun; Zhang, Chi; Ou, Yongbin; Lin, Yuan; Song, Botao; Xie, Conghua; Liu, Jun; Li, Xiu-Qing

    2011-08-01

    Acid invertase is believed to play a regulatory role during plant developmental processes and to respond to environmental stimuli. The expression profiles of the entire acid invertase family are not yet available for potato. By searching existing databases, it was determined that there are at least six acid invertase genes in potato, including four cell-wall invertase genes and two vacuolar invertase genes. They were subjected to comparative expression profiling in various organs of potato plants and in stored tubers to exploit their potential functions. The results revealed that each gene exhibited a unique expression pattern, which differed in transcript abundance or showed organ-specific features, pointing to the possible involvement of individual genes in plant development. The vacuolar invertase gene StvacINV1 had the highest expression level among three genes detected in the potato tubers. Further storage experiments showed that StvacINV1 was strongly induced by low temperatures, which is consistent with glucose accumulation in cold-stored tubers. Suppression of StvacINV1 by the antisense transformation in potato confirmed that lower StvacINV1 transcript abundance in transgenic tubers is related to lower reducing sugar content and lighter chip color in comparison with the wild type. The evidence strongly suggests that StvacINV1 is a gene involved in regulation of cold-induced sweetening of potato tubers. This provides an avenue for studying the mechanism involved in the regulation of the cold-induced sweetening trait and for agronomic enhancement.

  7. Challenges in the management of a case of tuberous sclerosis

    PubMed Central

    Rathi, Anubhav; Bhatia, Manjeet Singh; Jhanjee, Anurag

    2012-01-01

    Tuberous sclerosis complex is a multi-system disorder with autosomal dominant inheritance, which can affect the brain, heart, skin, kidneys, lungs, and retina. We hereby report therapeutic challenges faced in a case of an adolescent male suffering from tuberous sclerosis. PMID:24250049

  8. Potato tuber wounding induces responses associated with various healing processes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wounding induces an avalanche of biological responses involved in the healing and protection of internal tuber tissues exposed by mechanical damage and seed cutting. Collectively, our studies have framed a portrait of the mechanisms and regulation of potato tuber wound-healing, but much more is req...

  9. Determining Changes in Neural Circuits in Tuberous Sclerosis

    DTIC Science & Technology

    2012-05-01

    accepted models of obsessive compulsive disorder and autism , in which the corticostriatal circuit is disrupted, do not have seizures. Our mouse model lacks...mutant mice. Importantly, the early deletion of Tsc1 in the thalamus mimicked salient features of human Tuberous Sclerosis including mosaicism, autism ...neuroanatomy, Mouse model of Tuberous Sclerosis, Spatially and temporally controlled mosaicism 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  10. 605 Salad crops: Root, bulb, and tuber Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root and tuber crops (potato, cassava, sweet potato, and yams) comprise 4 of the 10 major food staples of the world and serve as a major source of energy for the poor of developing nations. Minimal strain placed on agro ecosystems by root and tuber crops highlight their welcomed contribution to the ...

  11. Color blindness

    MedlinePlus

    ... have trouble telling the difference between red and green. This is the most common type of color ... color blindness often have problems seeing reds and greens, too. The most severe form of color blindness ...

  12. Examining the role of tuber biochemistry in the development of zebra chip in stored potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zebra chip disease (ZC), associated with infection by the bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), is an emerging problem for potato growers in the United States, Mexico, and New Zealand. Although potato tubers exhibiting ZC symptoms will be rejected by processors, it remains possible...

  13. Starch biosynthesis: experiments on how starch granules grow in vivo.

    PubMed

    Mukerjea, Romila; Mukerjea, Rupendra; Robyt, John F

    2009-01-05

    Four varieties of starch granules from potato, wheat, maize, and rice were fractionated into homogeneous 10-microm-sized ranges. The size with the largest amount of granules was reacted with ADP-[(14)C]Glc, washed, and peeled into 7-9 layers, using a controlled peeling process, involving 90:10 volume proportions of Me(2)SO-H(2)O at 10 degrees C. All of the starches showed biosynthesis of starch throughout the granules. Starch synthase activities were determined for each of the layers. Three of the starches had a relatively large amount of synthase activity in the second layer, with only a small amount in the first layer. Potato starch had the largest amount of activity in the first layer. Starch synthase activity was found to alternate between higher and lower activities throughout all of the varieties of granules, showing that the synthesis was not uniform and also was not exclusively occurring at the surface of the starch granules, which had previously been hypothesized. From these results and our previous studies on the mechanism of starch chain elongation by the addition of d-glucose to the reducing end of a growing chain that is covalently attached to the active site of starch synthase, a hypothesis is proposed for how starch granules grow in vivo.

  14. Preparation of Inulin Powder from Jerusalem Artichoke (Helianthus tuberosus L.) Tuber.

    PubMed

    Srinameb, Bang-orn; Nuchadomrong, Suporn; Jogloy, Sanun; Patanothai, Aran; Srijaranai, Supalax

    2015-06-01

    The complete procedure for the production of inulin powder from Jerusalem artichoke tubers (JAT) was investigated. The procedure consists of isolation of inulin from JAT, elimination of color from the inulin extract and solidification. Washed tubers were first sliced, dried in a 60 °C oven for 10 h and then milled and sieved into a powder. Inulin was isolated from the JAT powder by hot water extraction using an accelerated solvent extractor (ASE). The effects of temperature and time for the extraction were investigated. The highest extraction efficiency was obtained at the extraction temperature of 80 °C for 20 min. The color of the extract was eliminated using ion exchange process with diethylaminoethyl cellulose as the sorbent. The inulin powder was subsequently obtained by freeze drying. Inulin content and inulin profiles were monitored to evaluate the efficiencies of the complete procedure. The inulin content was indirectly determined by spectrophotometry from free and total fructose measurements using potassium iodide. The inulin profile was monitored using high performance anion exchange chromatography equipped with integrated pulse amperometric detection (HPAEC-PAD). The proposed method provided the inulin production yield of 92.5%. The present procedure is fast, simple and effective for production of inulin powder from JAT. In addition, infrared spectra and some physico-chemical properties of the obtained inulin powder were determined and compared with the standard inulin.

  15. Thermoplastic starch-waxy maize starch nanocrystals nanocomposites.

    PubMed

    Angellier, Hélène; Molina-Boisseau, Sonia; Dole, Patrice; Dufresne, Alain

    2006-02-01

    Waxy maize starch nanocrystals obtained by hydrolysis of native granules were used as a reinforcing agent in a thermoplastic waxy maize starch matrix plasticized with glycerol. Compared to our previous studies on starch nanocrystals reinforced natural rubber (NR) [Macromolecules 2005, 38, 3783; 2005, 38, 9161], the present system presents two particularities: (i) thermoplastic starch is a polar matrix, contrarily to NR, and (ii) the chemical structures of the matrix and the filler are similar. The influence of the glycerol content, filler content, and aging on the reinforcing properties of waxy maize starch nanocrystals (tensile tests, DMA) and crystalline structure (X-ray diffraction) of materials were studied. It was shown that the reinforcing effect of starch nanocrystals can be attributed to strong filler/filler and filler/matrix interactions due to the establishment of hydrogen bonding. The presence of starch nanocrystals leads to a slowing down of the recrystallization of the matrix during aging in humid atmosphere.

  16. The neurobiology of tuberous sclerosis complex.

    PubMed

    Ess, Kevin C

    2006-03-01

    Tuberous sclerosis complex (TSC) is a multiorgan genetic disease caused by inactivation of either the TSC1 or TSC2 genes. The disorder typically has profound neurologic involvement and often presents early in life with epilepsy, developmental delay, mental retardation, and autism. These features are generally accepted to result from structural brain abnormalities that are found in patients with TSC. Although much progress has recently been made in discerning the function(s) of the TSC genes, many questions remain as to the role of these genes in brain development and homeostasis. This review will summarize recent progress and suggest future avenues of basic science research.

  17. Alkyl ferulates in wound healing potato tubers.

    PubMed

    Bernards, M A; Lewis, N G

    1992-10-01

    Seven ferulic acid esters of 1-alkanols ranging in carbon length from C16 to C28 were synthesized and an HPLC protocol for their separation developed. Extracts prepared from wound healing potato (Solanum tuberosum) tubers and analysed by HPLC indicated that alkyl ferulate esters begin to accumulate 3-7 days after wound treatment. Of the nine esters identified by EIMS, (including two esters of odd chain length alkanols) hexadecyl and octadecyl ferulates were predominant. Alkyl ferulate esters were restricted to the wound periderm.

  18. Understanding the Etiology of Tuberous Sclerosis Complex

    DTIC Science & Technology

    2011-07-01

    of tuber- ous sclerosis. Ann N Y Acad Sci. 1991;615:125–127.   2. European  Chromosome  16 Tuberous Sclerosis  Consortium. Identification and...our lesion lacks cytomegalic cells with a mixed neuron-glial or immature phenotype (e.g. immunostaining for nestin or proliferative markers ) called...circuitry of TSC and other mTOR-associated neurodevelopmental disorders. References Alexander GM, Rogan SC, Abbas AI, Armbruster BN, Pei Y

  19. The change of amyloplasts structure and composition of storage starch in potato minitubers during imitated microgravity

    NASA Astrophysics Data System (ADS)

    Nedukha, O. M.; Kordyum, E. L.; Martyn, G. M.; Schnyukova, E. I.

    Potato was designated for food production in the controlled ecological life-support system CELSS because its tubers as it is known contain starch and significant protein content and are edible food after the long-term storage We used the cultivation of potato miniplants under influence of long-term horizontal clinorotation 2 rev min which imitated microgravity as a model for the technology of potato food production in the CELSS The aim of our work was to determine content and composition storage starch as well as amyloplast ultrastructure of storage parenchyma cells in potato minitubers formed under long-term to 6 weeks slow horizontal clinorotation 2 rpm Minitubers developed from axillary buds of potato miniplants growing in the aseptic stationary conditions and under clinorotation Methods of scanning and transmission electron microscopy were used for the study of surface and ultrastructure of amyloplasts the biochemical method by Hovenkamp-Hermelink et al 1988 - for study of starch composition Some differences were observed in amyloplast structure under clinorotation namely increased volume of starch grains in plastid decreased stroma volume changed structure of envelope membranes in comparison with the stationary control Besides an appearance of fraction of gigantic amyloplasts in central layers of parenchyma was observed under clinorotation after 4 weeks of growth The total starch content increased and reached to 219 5 - 4 1 mg g FW at 6 weeks of clinorotation it was 167 5 - 5 6 mg g FW in the control minitubers A ratio of

  20. Age-induced protein modifications and increased proteolysis in potato seed-tubers

    SciTech Connect

    Kumar, G.N.M.; Knowles, N.R.; Houtz, R.L.

    1999-01-01

    Long-term aging of potato (Solanum tuberosum) seed-tubers resulted in a loss of patatin and a cysteine-proteinase inhibitor, potato multicystatin (PMC), as well as in increase in the activities of 84-, 95-, and 125-kD proteinases. Highly active, additional proteinases appeared in the oldest tubers. Over 90% of the total proteolytic activity in aged tubers was sensitive to trans-epoxysuccinyl-L-leucylamido (4-guanidino) butane or leupeptin, whereas pepstatin was the most effective inhibitor of proteinases in young tubers. Proteinases in aged tubers were also inhibited by crude extracts or purified PMC from young tubers, suggesting that the loss of PMC was responsible for the age-induced increase in proteinase activity. Nonenzymatic oxidation, glycation, and deamidation of proteins were enhanced by aging. Aged tubers developed daughter tubers that contained 3-fold more protein than mother tubers, with a polypeptide profile consistent with that of young tubers. Although PMC and patatin were absent from the older mother tubers, both proteins were expressed in the daughter tubers, indicating that aging did not compromise the efficacy of genes encoding PMC and patatin. Unlike the mother tubers, proteinase activity in daughter tubers was undetectable. Their results indicate that tuber aging nonenzymatically modifies proteins, which enhances their susceptibility to breakdown; the authors also identify a role for PMC in regulating protein turnover in potato tubers.

  1. Production of starch with antioxidative activity by baking starch with organic acids.

    PubMed

    Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

    2011-01-01

    A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

  2. Starches, resistant starches, the gut microflora and human health.

    PubMed

    Bird, A R; Brown, I L; Topping, D L

    2000-03-01

    Starches are important as energy sources for humans and also for their interactions with the gut microflora throughout the digestive tact. Largely, those interactions promote human health. In the mouth, less gelatinised starches may lower risk of cariogensis. In the large bowel, starches which have escaped small intestinal digestion (resistant starch), together with proteins, other undigested carbohydrates and endogenous secretions are fermented by the resident microflora. The resulting short chain fatty acids contribute substantially to the normal physiological functions of the viscera. Specific types of resistant starch (e.g. the chemically modified starches used in the food industry) may be used to manipulate the gut bacteria and their products (including short chain fatty acids) so as to optimise health. In the upper gut, these starches may assist in the transport of probiotic organisms thus promoting the immune response and suppressing potential pathogens. However, it appears unlikely that current probiotic organisms can be used to modulate large bowel short chain fatty acids in adults although resistant starch and other prebiotics can do so. Suggestions that starch may exacerbate certain conditions (such as ulcerative colitis) through stimulating the growth of certain pathogenic organisms appear to be unfounded. Short chain fatty acids may modulate tissue levels and effects of growth factors in the gut and so modify gut development and risk of serious disease, including colo-rectal cancer. However, information on the relationship between starches and the microflora is relatively sparse and substantial opportunities exist both for basic research and food product development.

  3. Major proteins of yam bean tubers.

    PubMed

    Gomes, A V; Sirju-Charran, G; Barnes, J A

    1997-09-01

    The tuberous roots of the Mexican yam bean, jicama, (Pachyrhizus erosus L. Urban) contained large quantities of two acidic glycoproteins which accounted for more than 70% of the total soluble proteins (about 3 g per 100 g of tuber on a dry weight basis). The two major proteins, tentatively named YBG1 and YBG2, had apparent M(r)s of 28,000 and 26,000, respectively, by SDS-PAGE. A third protein named YBP22 which accounted for 2-5% of the total soluble proteins had an M(r) of 22,000. YBG1 and YBG2 exhibited great similarity on the basis of their amino acid composition and had identical N-terminal amino acid sequences. The first 23 amino acids in the N-terminal region of YBG2 were DDLPDYVDWRDYGAVTRIKNQGQ which showed strong homology with the papain class of cysteine proteases. YBG1 and YBG2 were found to bind to a Concanavalin A-Sepharose column and were also stained positively by a sensitive glycoprotein stain. Both glycoproteins exhibited cysteine proteolytic activity. In contrast, YBP22 showed sequence homology with several known protease inhibitors, and a polyclonal antibody raised against this protein cross reacted with soybean trypsin inhibitor.

  4. Chemical characteristic and functional properties of arenga starch-taro (Colocasia esculanta L.) flour noodle with turmeric extracts addition

    NASA Astrophysics Data System (ADS)

    Ervika Rahayu N., H.; Ariani, Dini; Miftakhussolikhah, E., Maharani P.; Yudi, P.

    2017-01-01

    Arenga starch-taro (Colocasia esculanta L.) flour noodle is an alternative carbohydrate source made from 75% arenga starch and 25% taro flour, but it has a different color with commercial noodle product. The addition of natural color from turmeric may change the consumer preference and affect chemical characteristic and functional properties of noodle. This research aims to identify chemical characteristic and functional properties of arenga starch-taro flour noodle with turmeric extract addition. Extraction was performed using 5 variances of turmeric rhizome (0.06; 0.12; 0.18; 0.24; and 0.30 g (fresh weight/ml water). Then, noodle was made and chemical characteristic (proximate analysis) as well as functional properties (amylose, resistant starch, dietary fiber, antioxidant activity) were then evaluated. The result showed that addition of turmeric extract did not change protein, fat, carbohydrate, amylose, and resistant starch content significantly, while antioxidant activity was increased (23,41%) with addition of turmeric extract.

  5. Tuberous Sclerosis Associated Neuropsychiatric Disorders (TAND) and the TAND Checklist

    PubMed Central

    de Vries, Petrus J.; Whittemore, Vicky H.; Leclezio, Loren; Byars, Anna W.; Dunn, David; Ess, Kevin C.; Hook, Dena; King, Bryan H.; Sahin, Mustafa; Jansen, Anna

    2015-01-01

    BACKGROUND Tuberous sclerosis complex is a multisystem genetic disorder with a range of physical manifestations that require evaluation, surveillance, and management. Individuals with tuberous sclerosis complex also have a range of behavioral, psychiatric, intellectual, academic, neuropsychologic, and psychosocial difficulties. These may represent the greatest burden of the disease. Around 90% of individuals with tuberous sclerosis complex will have some of these difficulties during their lifetime, yet only about 20% ever receive evaluation and treatment. The Neuropsychiatry Panel at the 2012 Tuberous Sclerosis Complex International Consensus Conference expressed concern about the significant “treatment gap” and about confusion regarding terminology relating to the biopsychosocial difficulties associated with tuberous sclerosis complex. METHODS The Tuberous Sclerosis Complex Neuropsychiatry Panel coined the term TAND—tuberous sclerosis complex-associated neuropsychiatric disorders—to bring together these multidimensional manifestations of the disorder, and recommended annual screening for TAND. In addition, the Panel agreed to develop a TAND Checklist as a guide for screening. RESULTS Here, we present an outline of the conceptualization of TAND, rationale for the structure of the TAND Checklist, and include the full US English version of the TAND Checklist. CONCLUSION We hope that the unified term TAND and the TAND Checklist will raise awareness of the importance of tuberous sclerosis complex-associated neuropsychiatric disorders and of the major burden of disease associated with it, provide a shared language and a simple tool to describe and evaluate the different levels of TAND, alert clinical teams and families or individuals of the importance of screening, assessment, and treatment of TAND, and provide a shared framework for future studies of tuberous sclerosis complex-associated neuropsychiatric disorders. PMID:25532776

  6. The Calcium Solution: Developing Potato Cultivars With Enhanced Tuber Storage and Internal Quality by Genetic Improvement of Tuber Calcium Accumulation Ability Enetic Improvement of Potato for Tuber Calcium Uptake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tuber internal quality is a major limiting factor for the U.S. potato industry. Breeders invest time and money in producing advanced selections which, in the end, often fail because of tuber internal defects, tuber bruising, or storage quality issues. In-season fertilization with calcium is known to...

  7. A synthesis of fluorescent starch based on carbon nanoparticles for fingerprints detection

    NASA Astrophysics Data System (ADS)

    Li, Hongren; Guo, Xingjia; Liu, Jun; Li, Feng

    2016-10-01

    A pyrolysis method for synthesizing carbon nanoparticles (CNPs) were developed by using malic acid and ammonium oxalate as raw materials. The incorporation of a minor amount of carbon nanoparticles into starch powder imparts remarkable color-tunability. Based on this phenomenon, an environment friendly fluorescent starch powder for detecting latent fingerprints in non-porous surfaces was prepared. The fingerprints on different non-porous surfaces developed with this powder showed very good fluorescent images under ultraviolet excitation. The method using fluorescent starch powder as fluorescent marks is simple, rapid and green. Experimental results illustrated the effectiveness of proposed methods, enabling its practical applications in forensic sciences.

  8. Gene expression analysis of tuberous sclerosis complex cortical tubers reveals increased expression of adhesion and inflammatory factors

    PubMed Central

    Boer, Karin; Crino, Peter B.; Gorter, Jan A.; Nellist, Mark; Jansen, Floor E.; Spliet, Wim G.M.; van Rijen, Peter C.; Wittink, Floyd R.A.; Breit, Timo M.; Troost, Dirk; Wadman, Wytse J.; Aronica, Eleonora

    2009-01-01

    Cortical tubers in patients with tuberous sclerosis complex are associated with disabling neurological manifestations, including intractable epilepsy. While these malformations are believed to result from the effects of TSC1 or TSC2 gene mutations, the molecular mechanisms leading to tuber formation, as well as the onset of seizures remain largely unknown. We used the Affymetrix Gene Chip platform to provide the first genome wide investigation of gene expression in surgically resected tubers, compared with histological normal perituberal tissue from the same patients or autopsy control tissue. We identified 2501 differentially expressed genes in cortical tubers compared with autopsy controls. Expression of genes associated with cell adhesion e.g., VCAM1, integrins and CD44, or with the inflammatory response, including complement factors, serpinA3, CCL2 and several cytokines, was increased in cortical tubers, whereas genes related to synaptic transmission e.g., the glial glutamate transporter GLT-1, and voltage-gated channel activity, exhibited lower expression. Gene expression in perituberal cortex was distinct from autopsy control cortex suggesting that even in the absence of tissue pathology the transcriptome is altered in TSC. Changes in gene expression yield insights into new candidate genes that may contribute to tuber formation or seizure onset, representing new targets for potential therapeutic development. PMID:19912235

  9. Mycorrhization of pecan (Carya illinoinensis) with black truffles: Tuber melanosporum and Tuber brumale.

    PubMed

    Marozzi, Giorgio; Sánchez, Sergio; Benucci, Gian Maria Niccolò; Bonito, Gregory; Falini, Leonardo Baciarelli; Albertini, Emidio; Donnini, Domizia

    2017-04-01

    Pecan, Carya illinoinensis, is an economically important nut producing tree that can establish ectomycorrhizal symbiosis with a high diversity of fungi. In the southern USA, truffles (Tuber spp.) sometimes fruit prolifically in cultivated pecan orchards and regularly associate with pecan roots as ectomycorrhizae (ECMs). It has been demonstrated that some valuable European truffle species (e.g., Tuber borchii and Tuber aestivum) can form ECMs with pecan seedlings in nursery conditions. Thus, pecan may represent an attractive alternative host to forest trees for truffle growers given the potential for co-cropping truffles and pecans. To further explore the capacity of pecan to host truffle symbionts, pecan seedlings were inoculated with species of black truffles that are economically important in Europe, T. melanosporum and T. brumale. Ectomycorrhizae were characterized molecularly and their morphology was described in detail. Mycorrhization rates on pecan roots were assessed over a 2-year period. Tuber melanosporum and T. brumale produced well-formed ECMs with a level of root colonization in the first year of 37.3 and 34.5%, respectively. After 24 months, the level of mycorrhization increased for T. brumale (49.4%) and decreased for T. melanosporum (10.5%) inversely to that of non-target ECM greenhouse contaminants (e.g., Sphaerosporella brunnea, Trichophaea woolhopeia, Pulvinula constellatio). To assess whether mating types segregated in T. melanosporum as been reported for other host species, we amplified the mating-type locus from single T. melanosporum ECM belonging to different seedlings over a 2-year period. The two mating idiomorphs were nearly equally represented along the 2-year time span: MAT 1-1-1 decreased from 59.4% in the first year to 48.5% in the second year after inoculation. Data reported in this study add to knowledge on the mycorrhization of pecan trees with commercial truffles and has application to truffle and nut co-cropping systems.

  10. Morphology, structure and gelatinization properties of heterogeneous starch granules from high-amylose maize.

    PubMed

    Cai, Canhui; Zhao, Lingxiao; Huang, Jun; Chen, Yifang; Wei, Cunxu

    2014-02-15

    High-amylose cereal endosperm is rich in heterogeneous starch granules. In this paper, we investigated the morphology, structure and gelatinization properties of high-amylose maize endosperm starch. Starch had individual, aggregate and elongated heterogeneous granules. Most of individual granules were round with small size and had one central hilum. Aggregate and elongated granules consisted of many subgranules with central hila, and had irregular and rod/filamentous shapes, respectively. Iodine stained starch granules showed five types of polarization colors: blue, purple, fuchsia, dark red, and interior dark blue and exterior brown. Most of individual and aggregate granules had the color of dark red, that of elongated granules the color of interior dark blue and exterior brown. Amylose was mainly distributed in the hilum region and the circumference of starch granules. Aggregate and elongated granules had higher amylose content than individual granules. Elongated and individual granules had the highest and the lowest gelatinization resistance among high-amylose maize heterogeneous starch granules, respectively.

  11. Effect of farming systems on the yield, quality parameters and sensory properties of conventionally and organically grown potato (Solanum tuberosum L.) tubers.

    PubMed

    Brazinskiene, V; Asakaviciute, R; Miezeliene, A; Alencikiene, G; Ivanauskas, L; Jakstas, V; Viskelis, P; Razukas, A

    2014-02-15

    The objectives of this two-year research were to study the impact of two different farming types, conventional and organic, on the yield and sensory properties of five Lithuanian varieties of potato tuber. The parameters and properties examined were: phenolic acids; dry matter and starch content; and the spread and intensity of Phytophthora infestans growth. It was determined that potato yield fluctuates with the variety, but for conventional farming it is significantly (p<0.05) higher than that obtained by organic farming. The farming type has no significant effect (p>0.05) on the content of phenolic acids. No significant effect (p>0.05) of farming type on dry matter and starch content, or sensory properties was found. No significant relation (p>0.05) was found between the content of phenolic acids and P. infestans spread. The spread of P. infestans was faster and infection was heavier in organically grown potatoes.

  12. Changes in properties of starch isolated from whole rice grains with brown, black, and red pericarp after storage at different temperatures.

    PubMed

    Ziegler, Valmor; Ferreira, Cristiano Dietrich; Goebel, Jorge Tiago Schwanz; El Halal, Shanise Lisie Mello; Santetti, Gabriela Soster; Gutkoski, Luiz Carlos; Zavareze, Elessandra da Rosa; Elias, Moacir Cardoso

    2017-02-01

    The aim of this study was to evaluate the physicochemical, morphological, crystallinity, thermal, and pasting properties of starches isolated from rice grains with brown, black, and red pericarp. Starch was isolated from the rice grains at initial storage time, and after 6months of storage at different storage temperatures (16, 24, 32 and 40°C). Starch isolated from the grains stored for 6months at 40°C showed darker coloration, surface deformation of granules, and a significant reduction in the extraction yield, final viscosity, enthalpy, and crystallinity, independent of the grain pericarp coloration. The time and storage temperature not influence the swelling power and solubility of starch isolated from grains with brown pericarp, while for the grains with black and red pericarp there was reduction in swelling power and solubility of starches isolated of grains stored at 40°C. Grains stored at 16°C showed minimum changes in starch properties.

  13. Process for producing vegetative and tuber growth regulator

    NASA Technical Reports Server (NTRS)

    Stutte, Gary W. (Inventor); Yorio, Neil C. (Inventor)

    1999-01-01

    A process of making a vegetative and tuber growth regulator. The vegetative and tuber growth regulator is made by growing potato plants in a recirculating hydroponic system for a sufficient time to produce the growth regulator. Also, the use of the vegetative and growth regulator on solanaceous plants, tuber forming plants and ornamental seedlings by contacting the roots or shoots of the plant with a sufficient amount of the growth regulator to regulate the growth of the plant and one more of canopy size, plant height, stem length, internode number and presence of tubers in fresh mass. Finally, a method for regulating the growth of potato plants using a recirculating hydroponic system is described.

  14. Root architecture and root and tuber crop productivity.

    PubMed

    Villordon, Arthur Q; Ginzberg, Idit; Firon, Nurit

    2014-07-01

    It is becoming increasingly evident that optimization of root architecture for resource capture is vital for enabling the next green revolution. Although cereals provide half of the calories consumed by humans, root and tuber crops are the second major source of carbohydrates globally. Yet, knowledge of root architecture in root and tuber species is limited. In this opinion article, we highlight what is known about the root system in root and tuber crops, and mark new research directions towards a better understanding of the relation between root architecture and yield. We believe that unraveling the role of root architecture in root and tuber crop productivity will improve global food security, especially in regions with marginal soil fertility and low-input agricultural systems.

  15. Color realism and color science.

    PubMed

    Byrne, Alex; Hilbert, David R

    2003-02-01

    The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in the mind." The article has two other purposes: First, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. The first part explains the problem of color realism and makes some useful distinctions. These distinctions are then used to expose various confusions that often prevent people from seeing that the issues are genuine and difficult, and that the problem of color realism ought to be of interest to anyone working in the field of color science. The second part explains the various leading answers to the problem of color realism, and (briefly) argues that all views other than our own have serious difficulties or are unmotivated. The third part explains and motivates our own view, that colors are types of reflectances and defends it against objections made in the recent literature that are often taken as fatal.

  16. [Allelopathic effects of extracts from tuberous roots of Aconitum carmichaeli on three pasture grasses].

    PubMed

    Jiao, Yu-jie; Wang, Ya-qi; Yuan, Ling

    2015-11-01

    The tuberous roots of Aconitum carmichaeli are largely used in traditional Chinese medicine and widely grown in Jiangyou, Sichuan, China. During the growth process, this medicinal plant releases a large amount of allelochemicals into soil, which retard the growth and development of near and late crops. Therefore, a pure culture experiment was thus carried out by seed soaking to study the allelopathic effects of extracts from tuberous roots of A. carmichaeli (ETR) on the seed germination and young seedling growth of Lolium perenne, Trifolium repens, and Medicago sativa, the late pasture grasses after cultivation of A. carmichaeli. The results showed that three pasture grasses varied significantly in seed germination and young seedling growth in response to ETR concentrations. Seed germination of M. sativa was stimulated by low ERT concentration (0.01 x g(-1)), while all of pasture grass seeds germinated poorly in solution with 1.00 g x L(-1). Seed soaking with 1.00 g x L(-1) also inhibited significantly the growth of pasture young seedlings, with M. sativa showing the highest seedling height reduction of 42.05% in seeding height, followed by T. repens (40.21%) and L. perenne with about 11%. Cultivation of L. perenne could thus be beneficial to increase whole land productivity in A. carmichaeli-pasture grass cropping systems. In addition, hydrolysis of protein, starch, and inositol phosphates was blocked and free amino acids, soluble sugars and phosphorus were decreased in seeds by seed soaking with ETR, which could be one of the reason for the inhibition of seed germination. There was a significant reduction in root vigor, nitrate reductase, and chlorophyll after the seed treatment with ETR, indicating the suppression of nutrient uptake, nitrate assimilation, and photosynthesis by allelopathic chemicals in ETR, which could lead to the slow growth rate of pasture grass seedlings.

  17. A subtle case of tuberous sclerosis complex.

    PubMed

    Nakano, Hitoshi; Otsuka, Atsushi; Kinoshita, Masako

    2015-01-01

    Tuberous sclerosis complex (TSC) is known to cause severe intractable epilepsy and mental retardation; however, diagnosis can be delayed in milder cases. We report a 26-year-old right-handed female patient who started having convulsions at age 7 days. She had several focal seizures per year that were intractable to treatment with carbamazepine or phenytoin. Her two sisters had several episodes of suspected epileptic seizures but had no symptoms related to TSC. Seizure semiology of the patient comprised of visual hallucination, loss of consciousness, and convulsive movements predominantly on the right. Physical examination revealed several small scattered angiofibromas over the nose that were histologically determined by skin biopsy. Hypomelanotic macules, shagreen patches, or periungual fibromas were not seen. Neurological examination showed mental retardation (MMSE: 23/30, WAIS-III: VIQ63, PIQ59, FIQ58) and decreased vibration sensation in both legs. Interictal EEG showed slow waves and epileptiform discharges broadly over the anterior quadrants bilaterally. Brain imaging showed multiple cortical tubers and malformation of cortical development but no subependymal nodules. Interictal IMP-SPECT showed hypoperfusion in the left frontal lobe. Cardiac rhabdomyoma was not noticed by cardiac echography. Truncal CT showed sclerosis of the bilateral lumbosacral joints. There was no abnormality in the lung, major arteries, liver, or kidneys. No hamartomas or retinal achromic patches were noticed by ophthalmologic evaluation. Administration of lamotrigine was effective for her seizures. This patient fulfilled two major features of diagnostic criteria for TSC and was diagnosed as definite TSC. Patients with mental retardation and epilepsy should be carefully evaluated for the possible diagnosis of TSC.

  18. Production of Tuber-Inducing Factor

    NASA Technical Reports Server (NTRS)

    Stutte, Gary W.; Yorio, Neil C.

    2006-01-01

    A process for making a substance that regulates the growth of potatoes and some other economically important plants has been developed. The process also yields an economically important by-product: potatoes. The particular growth-regulating substance, denoted tuber-inducing factor (TIF), is made naturally by, and acts naturally on, potato plants. The primary effects of TIF on potato plants are reducing the lengths of the main shoots, reducing the numbers of nodes on the main stems, reducing the total biomass, accelerating the initiation of potatoes, and increasing the edible fraction (potatoes) of the overall biomass. To some extent, these effects of TIF can override environmental effects that typically inhibit the formation of tubers. TIF can be used in the potato industry to reduce growth time and increase harvest efficiency. Other plants that have been observed to be affected by TIF include tomatoes, peppers, radishes, eggplants, marigolds, and morning glories. In the present process, potatoes are grown with their roots and stolons immersed in a nutrient solution in a recirculating hydroponic system. From time to time, a nutrient replenishment solution is added to the recirculating nutrient solution to maintain the required nutrient concentration, water is added to replace water lost from the recirculating solution through transpiration, and an acid or base is added, as needed, to maintain the recirculating solution at a desired pH level. The growing potato plants secrete TIF into the recirculating solution. The concentration of TIF in the solution gradually increases to a range in which the TIF regulates the growth of the plants.

  19. Regulation of CDPK isoforms during tuber development.

    PubMed

    Raíces, Marcela; Gargantini, Pablo Rubén; Chinchilla, Delphine; Crespi, Martín; Téllez-Iñón, María Teresa; Ulloa, Rita María

    2003-07-01

    CDPK activities present during tuber development were analysed. A high CDPK activity was detected in the soluble fraction of early stolons and a lower one was detected in soluble and particulate fractions of induced stolons. The early and late CDPK activities displayed diverse specificity for in vitro substrates and different subcellular distribution. Western blot analysis revealed two CDPKs of 55 and 60 kDa that follow a precise spatial and temporal profile of expression. The 55 kDa protein was only detected in early-elongating stolons and the 60 kDa one was induced upon stolon swelling, correlating with early and late CDPK activities. A new member of the potato CDPK family, StCDPK3, was identified from a stolon cDNA library. Gene specific RT-PCR demonstrated that this gene is only expressed in early stolons, while the previously identified StCDPK1 is expressed upon stolon swelling. This expression profile suggests that StCDPK3 could correspond to the 55 kDa isoform while StCDPK1 could encode the 60 kDa isoform present in swelling stolons. StCDPK1 has myristoylation and palmitoylation consensus possibly involved in its dual intracellular localization. Transient expression studies with wild-type and mutated forms of StCDPK1 fused to GFP were used to show that subcellular localization of this isoform is controlled by myristoylation and palmitoylation. Altogether, our data suggest that sequential activation of StCDPK3 and StCDPK1 and the subcellular localisation of StCDPK1 might be critical regulatory steps of calcium signalling during potato tuber development.

  20. Isolation and characterization of starch obtained from Brosimum alicastrum Swarts seeds.

    PubMed

    Pérez-Pacheco, E; Moo-Huchin, V M; Estrada-León, R J; Ortiz-Fernández, A; May-Hernández, L H; Ríos-Soberanis, C R; Betancur-Ancona, D

    2014-01-30

    In this paper, the Ramon starch was isolated and its chemical composition and physical and microscopic characteristics were determined. Corn starch was used as reference. In general, the proximal composition was similar between starches studied. Ramon starch granules were oval-spherical and rounded with sizes between 6.5 and 15 μm. Starch purity was high (92.57%) with amylose content of 25.36%. The gelatinization temperature was 83.05°C and transition enthalpy was 21.423 J/g. At 90°C, solubility was 20.42%, swelling power 17.64 g water/gstarch and water absorption capacity was 13 gwater/gstarch. The pH, clarity and color (Hue angle) of Ramon starch were higher to those reported for corn starch. The results achieved suggest that Ramon starch has potential for application in food systems requiring high processing temperatures and it is also a promising option for use in the manufacture of biodegradable materials.

  1. Sensory and physicochemical evaluation of low-fat chicken mortadella with added native and modified starches.

    PubMed

    Prestes, R C; Silva, L B; Torri, A M P; Kubota, E H; Rosa, C S; Roman, S S; Kempka, A P; Demiate, I M

    2015-07-01

    The objective of this work was to evaluate the effect of adding different starches (native and modified) on the physicochemical, sensory, structural and microbiological characteristics of low-fat chicken mortadella. Two formulations containing native cassava and regular corn starch, coded CASS (5.0 % of cassava starch) and CORN (5.0 % of regular corn starch), and one formulation produced with physically treated starch coded as MOD1 (2.5 % of Novation 2300) and chemically modified starch coded as MOD2 (2.5 % of Thermtex) were studied. The following tests were performed: physicochemical characterization (moisture, ash, protein, starch and lipid contents, and water activity); cooling, freezing and reheating losses; texture (texture profile test); color coordinates (L*, a*, b*, C and h); microbiological evaluation; sensory evaluation (multiple comparison and preference test); and histological evaluation (light microscopy). There was no significant difference (p > 0.05) for ash, protein, cooling loss, cohesiveness or in the preference test for the tested samples. The other evaluated parameters showed significant differences (p < 0.05). Histological study allowed for a qualitative evaluation between the physical properties of the food and its microscopic structure. The best results were obtained for formulation MOD2 (2.5 % Thermtex). The addition of modified starch resulted in a better performance than the native starch in relation to the evaluated technological parameters, mainly in relation to reheating losses, which demonstrated the good interaction between the modified starch in the structure of the product and the possibility of the application of this type of starch in other types of functional meat products.

  2. Determining Changes in Neural Circuits in Tuberous Sclerosis

    DTIC Science & Technology

    2013-05-01

    how the mTOR pathway contributes to autism -like repetitive behavior and to seizures. Notably, this is the first TS mouse model to capture both of...that they gave themselves severe lesions. A similar overgrooming phenotype has been described in genetic mouse models of autism and obsessive compulsive...features of human Tuberous Sclerosis including mosaicism, autism and epilepsy. This research progress deepened our understanding of Tuberous Sclerosis by

  3. [FTIR and classification study on trueborn tuber dioscoreae samples].

    PubMed

    Sun, Su-qin; Tang, Jun-ming; Yuan, Zi-min; Bai, Yan

    2003-04-01

    To identify the origin of tuber dioscoreae, 45 samples were studied by soft independent modeling of class analogy (SIMCA) in this paper. The combination of Fourier transform infrared spectroscopy (FTIR) with mathematic method was used to classify the trueborn and non-trueborn samples. The samples were chosen randomly as modeling group and predicting group. The correctness of classification was 70%. This approach was proved to be a reliable and practicable method for trueborn quality analysis of tuber dioscoreae.

  4. Entropy, color, and color rendering.

    PubMed

    Price, Luke L A

    2012-12-01

    The Shannon entropy [Bell Syst. Tech J.27, 379 (1948)] of spectral distributions is applied to the problem of color rendering. With this novel approach, calculations for visual white entropy, spectral entropy, and color rendering are proposed, indices that are unreliant on the subjectivity inherent in reference spectra and color samples. The indices are tested against real lamp spectra, showing a simple and robust system for color rendering assessment. The discussion considers potential roles for white entropy in several areas of color theory and psychophysics and nonextensive entropy generalizations of the entropy indices in mathematical color spaces.

  5. Color Algebras

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    2017-01-01

    A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. We would like it to match the well-defined algebra of spectral functions describing lights and surface reflectances, but an exact correspondence is impossible after the spectra have been projected to a three-dimensional color space, because of metamerism physically different spectra can produce the same color sensation. Metameric spectra are interchangeable for the purposes of addition, but not multiplication, so any color algebra is necessarily an approximation to physical reality. Nevertheless, because the majority of naturally-occurring spectra are well-behaved (e.g., continuous and slowly-varying), color algebras can be formulated that are largely accurate and agree well with human intuition. Here we explore the family of algebras that result from associating each color with a member of a three-dimensional manifold of spectra. This association can be used to construct a color product, defined as the color of the spectrum of the wavelength-wise product of the spectra associated with the two input colors. The choice of the spectral manifold determines the behavior of the resulting system, and certain special subspaces allow computational efficiencies. The resulting systems can be used to improve computer graphic rendering techniques, and to model various perceptual phenomena such as color constancy.

  6. Color Facsimile.

    DTIC Science & Technology

    1995-02-01

    modification of existing JPEG compression and decompression software available from Independent JPEG Users Group to process CIELAB color images and to use...externally specificed Huffman tables. In addition a conversion program was written to convert CIELAB color space images to red, green, blue color space

  7. Seeing Color

    ERIC Educational Resources Information Center

    Texley, Juliana

    2005-01-01

    Colors are powerful tools for engaging children, from the youngest years onward. We hang brightly patterned mobiles above their cribs and help them learn the names of colors as they begin to record their own ideas in pictures and words. Colors can also open the door to an invisible world of electromagnetism, even when children can barely imagine…

  8. Clinical Usefulness of Aripiprazole and Lamotrigine in Schizoaffective Presentation of Tuberous Sclerosis

    PubMed Central

    Lee, Seung-Yup; Min, Jung-Ah; Lee, In Goo; Kim, Jung Jin

    2016-01-01

    Tuberous sclerosis is not as rare as once thought and has high psychiatric comorbidities. However, bipolar or psychotic features associated with tuberous sclerosis have been rarely reported. This report first presents a tuberous sclerosis patient, resembling a schizoaffective disorder of bipolar type. A patient with known tuberous sclerosis displayed mood fluctuation and psychotic features. Her symptoms did not remit along with several psychiatric medications. After hospitalization, the patient responded well with lamotrigine and aripiprazole without exacerbation. As demonstrated in this case, tuberous sclerosis may also encompass bipolar affective or psychotic features. We would like to point out the necessity to consider bipolarity in evaluating and treating tuberous sclerosis. PMID:27489387

  9. [Nutritional characterization of carbohydrates and proximal composition of cooked tropical roots and tubers produced in Costa Rica].

    PubMed

    Blanco-Metzler, Adriana; Tovar, Juscelino; Fernández-Piedra, Mireya

    2004-09-01

    Tropical roots and tubers (TRT) are important staple foods in the tropics. TRT are produced by small farmers and have received only limited attention. The objective of this paper was to evaluate nutritionally important carbohydrate fractions and proximal composition of cooked cassava (Manihot esculenta), cocoyam- or tannia- (Xantosoma sp) and yam (Dioscorea alata) grown in Costa Rica. Twenty boiled samples of each TRT were analyzed for proximal composition, following AOAC protocols. Carbohydrate fractions (dietary fiber, available and resistant starch) and alpha-amylolysis rate were assessed by enzymatic methods. All TRT analyzed consisted mainly of water and carbohydrates, representing moderate dietary fiber and energy sources. They show a low protein level and contain no fat. Moisture, protein, ashes and dietary fiber contents vary significantly (p<0.01) among the three species. In terms of their proximal composition, these locally grown TRT differ from TRTs cultivated in the South Pacific area, but appear similar to other Latin American varieties. In all samples most of the dietary fiber (84-88%) is insoluble; available starch ranges between 74 and 84% of the dry matter, whereas resistant starch content varied between 0.7 and 1.7%. Amylolysis rate was similar for cassava and cocoyam, whereas a significantly slower digestion (p<0.01) was recorded for yam. Compared to values reported in the literature for other starchy foods and to gelatinized potato starch, used as reference sample, the studied TRT showed intermediate amylolysis rates. It is concluded that consumption of these TRT may be promoted in Costa Rica and other countries with a similar nutritional situation.

  10. Post-translational regulation of acid invertase activity by vacuolar invertase inhibitor affects resistance to cold-induced sweetening of potato tubers.

    PubMed

    McKenzie, Marian J; Chen, Ronan K Y; Harris, John C; Ashworth, Matthew J; Brummell, David A

    2013-01-01

    Cold-induced sweetening (CIS) is a serious post-harvest problem for potato tubers, which need to be stored cold to prevent sprouting and pathogenesis in order to maintain supply throughout the year. During storage at cold temperatures (below 10 °C), many cultivars accumulate free reducing sugars derived from a breakdown of starch to sucrose that is ultimately cleaved by acid invertase to produce glucose and fructose. When affected tubers are processed by frying or roasting, these reducing sugars react with free asparagine by the Maillard reaction, resulting in unacceptably dark-coloured and bitter-tasting product and generating the probable carcinogen acrylamide as a by-product. We have previously identified a vacuolar invertase inhibitor (INH2) whose expression correlates both with low acid invertase activity and with resistance to CIS. Here we show that, during cold storage, overexpression of the INH2 vacuolar invertase inhibitor gene in CIS-susceptible potato tubers reduced acid invertase activity, the accumulation of reducing sugars and the generation of acrylamide in subsequent fry tests. Conversely, suppression of vacuolar invertase inhibitor expression in a CIS-resistant line increased susceptibility to CIS. The results show that post-translational regulation of acid invertase by the vacuolar invertase inhibitor is an important component of resistance to CIS.

  11. [Evaluation of the flour and starch from white and purple varieties of mapuey (Dioscorea trifida)].

    PubMed

    Bou Rached, Lizet; de Vizcarrondo, Consuelo A; Rincón, Alicia M; Padilla, Fanny

    2006-12-01

    Mapuey (Dioscorea trifida), is a tropical America tuber, which is appreciated for its taste and fine texture. It has not been fully cultivated in Venezuela, even though products like its flour and starch could replace conventional used products. In this work physical and chemical characteristic of flours from mapuey (varieties white and purple), were assessed, as well as some of their micronutrients. Physical, physicochemical and rheological properties, and chemical composition of isolated starches were also evaluated. Flours were obtained by a drying process and starches by aqueous extraction. Chemical analysis was performed following standard methodologies. The flour yield of purple mapuey was the highest, as was its protein content. The minerals content, showed significant differences between both varieties, presenting purple variety a higher content. Isolated starches showed high purity, this was corroborated by the scanning electron microscopy which showed irregular shaped granules (oval and elongated), with truncated end and smooth surfaces. Purple mapuey granules were smaller. Both varieties exhibited a B type diffraction pattern. The greater swelling power and water absorption capacity was presented by white mapuey, while the highest solubility was shown by the purple one. The white mapuey had maximum viscosity, as well as the highest value of breakdown, suggesting more fragile granules. Setback was lower in the white mapuey, suggesting lower tendency to retrogradation. The purple mapuey although, it showed a higher amylose content, presented lower consistency, even though the difference was not relevant.

  12. The expression of a recombinant glycolate dehydrogenase polyprotein in potato (Solanum tuberosum) plastids strongly enhances photosynthesis and tuber yield.

    PubMed

    Nölke, Greta; Houdelet, Marcel; Kreuzaler, Fritz; Peterhänsel, Christoph; Schillberg, Stefan

    2014-08-01

    We have increased the productivity and yield of potato (Solanum tuberosum) by developing a novel method to enhance photosynthetic carbon fixation based on expression of a polyprotein (DEFp) comprising all three subunits (D, E and F) of Escherichia coli glycolate dehydrogenase (GlcDH). The engineered polyprotein retained the functionality of the native GlcDH complex when expressed in E. coli and was able to complement mutants deficient for the D, E and F subunits. Transgenic plants accumulated DEFp in the plastids, and the recombinant protein was active in planta, reducing photorespiration and improving CO2 uptake with a significant impact on carbon metabolism. Transgenic lines with the highest DEFp levels and GlcDH activity produced significantly higher levels of glucose (5.8-fold), fructose (3.8-fold), sucrose (1.6-fold) and transitory starch (threefold), resulting in a substantial increase in shoot and leaf biomass. The higher carbohydrate levels produced in potato leaves were utilized by the sink capacity of the tubers, increasing the tuber yield by 2.3-fold. This novel approach therefore has the potential to increase the biomass and yield of diverse crops.

  13. Starch Applications for Delivery Systems

    NASA Astrophysics Data System (ADS)

    Li, Jason

    2013-03-01

    Starch is one of the most abundant and economical renewable biopolymers in nature. Starch molecules are high molecular weight polymers of D-glucose linked by α-(1,4) and α-(1,6) glycosidic bonds, forming linear (amylose) and branched (amylopectin) structures. Octenyl succinic anhydride modified starches (OSA-starch) are designed by carefully choosing a proper starch source, path and degree of modification. This enables emulsion and micro-encapsulation delivery systems for oil based flavors, micronutrients, fragrance, and pharmaceutical actives. A large percentage of flavors are encapsulated by spray drying in today's industry due to its high throughput. However, spray drying encapsulation faces constant challenges with retention of volatile compounds, oxidation of sensitive compound, and manufacturing yield. Specialty OSA-starches were developed suitable for the complex dynamics in spray drying and to provide high encapsulation efficiency and high microcapsule quality. The OSA starch surface activity, low viscosity and film forming capability contribute to high volatile retention and low active oxidation. OSA starches exhibit superior performance, especially in high solids and high oil load encapsulations compared with other hydrocolloids. The submission is based on research and development of Ingredion

  14. Characterization of potato leaf starch.

    PubMed

    Santacruz, Stalin; Koch, Kristine; Andersson, Roger; Aman, Per

    2004-04-07

    The starch accumulation-degradation process as well as the structure of leaf starch are not completely understood. To study this, starch was isolated from potato leaves collected in the early morning and late afternoon in July and August, representing different starch accumulation rates. The starch content of potato leaves varied between 2.9 and 12.9% (dry matter basis) over the night and day in the middle of July and between 0.6 and 1.5% in August. Scanning electron microscopy analyses of the four isolated starch samples showed that the granules had either an oval or a round shape and did not exceed 5 microm in size. Starch was extracted by successive washing steps with dimethyl sulfoxide and precipitated with ethanol. An elution profile on Sepharose CL-6B of debranched starch showed the presence of a material with a chain length distribution between that generally found for amylose and amylopectin. Amylopectin unit chains of low molecular size were present in a higher amount in the afternoon than in the morning samples. What remains at the end of the night is depleted in specific chain lengths, mainly between DP 15 and 24 and above DP 35, relative to the end of the day.

  15. Responsive starch-based materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch, a low-cost, annually renewable resource, is naturally hydrophilic and its properties change with relative humidity. Starch’s hygroscopic nature can be used to develop materials which change shape or volume in response to environmental changes (e.g. humidity). For example, starch-based graf...

  16. Brucite nanoplate reinforced starch bionanocomposites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper the mechanical reinforcement in a series of bionanocomposites films based on starch and nano-sized brucite, Mg(OH)2, was investigated. Brucite nanoplates with an aspect ratio of 9.25 were synthesized by wet precipitation and incorporated into starch matrices at different concentrations...

  17. Physicochemical properties of maca starch.

    PubMed

    Zhang, Ling; Li, Guantian; Wang, Sunan; Yao, Weirong; Zhu, Fan

    2017-03-01

    Maca (Lepidium meyenii Walpers) is gaining research attention due to its unique bioactive properties. Starch is a major component of maca roots, thus representing a novel starch source. In this study, the properties of three maca starches (yellow, purple and black) were compared with commercially maize, cassava, and potato starches. The starch granule sizes ranged from 9.0 to 9.6μm, and the granules were irregularly oval. All the maca starches presented B-type X-ray diffraction patterns, with the relative degree of crystallinity ranging from 22.2 to 24.3%. The apparent amylose contents ranged from 21.0 to 21.3%. The onset gelatinization temperatures ranged from 47.1 to 47.5°C as indicated by differential scanning calorimetry. Significant differences were observed in the pasting properties and textural parameters among all of the studied starches. These characteristics suggest the utility of native maca starch in products subjected to low temperatures during food processing and other industrial applications.

  18. Starch-filled polymer composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report describes the development of degradable polymer composites that can be made at room temperature without special equipments. The developed composites are made from ethyl cyanoacrylate and starch. The polymer composites produced by this procedure contain 60 wt% of starch with compressive s...

  19. Color Categories and Color Appearance

    ERIC Educational Resources Information Center

    Webster, Michael A.; Kay, Paul

    2012-01-01

    We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

  20. Color Terms and Color Concepts

    ERIC Educational Resources Information Center

    Davidoff, Jules

    2006-01-01

    In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

  1. Tuber-specific silencing of asparagine synthetase-1 reduces the acrylamide-forming potential of potatoes grown in the field without affecting tuber shape and yield.

    PubMed

    Chawla, Rekha; Shakya, Roshani; Rommens, Caius M

    2012-10-01

    Simultaneous silencing of asparagine synthetase (Ast)-1 and -2 limits asparagine (ASN) formation and, consequently, reduces the acrylamide-forming potential of tubers. The phenotype of silenced lines appears normal in the greenhouse, but field-grown tubers are small and cracked. Assessing the effects of silencing StAst1 and StAst2 individually, we found that yield drag was mainly linked to down-regulation of StAst2. Interestingly, tubers from untransformed scions grafted onto intragenic StAst1/2-silenced rootstock contained almost the same low ASN levels as those in the original silenced lines, indicating that ASN is mainly formed in tubers rather than being transported from leaves. This conclusion was further supported by the finding that overexpression of StAst2 caused ASN to accumulate in leaves but not tubers. Thus, ASN does not appear to be the main form of organic nitrogen transported from leaves to tubers. Because reduced ASN levels coincided with increased levels of glutamine, it appears likely that this alternative amide amino acid is mobilized to tubers, where it is converted into ASN by StAst1. Indeed, tuber-specific silencing of StAst1, but not of StAst2, was sufficient to substantially lower ASN formation in tubers. Extensive field studies demonstrated that the reduced acrylamide-forming potential achieved by tuber-specific StAst1 silencing did not affect the yield or quality of field-harvested tubers.

  2. Microbial starch-binding domain.

    PubMed

    Rodríguez-Sanoja, Romina; Oviedo, Norma; Sánchez, Sergio

    2005-06-01

    Glucosidic bonds from different non-soluble polysaccharides such as starch, cellulose and xylan are hydrolyzed by amylases, cellulases and xylanases, respectively. These enzymes are produced by microorganisms. They have a modular structure that is composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. Starch-binding modules are present in microbial enzymes that are involved in starch metabolism; these are classified into several different families on the basis of their amino acid sequence similarities. Such binding domains promote attachment to the substrate and increase its concentration at the active site of the enzyme, which allows microorganisms to degrade non-soluble starch. Fold similarities are better conserved than sequences; nevertheless, it is possible to notice two evolutionary clusters of microbial starch-binding domains. These domains have enormous potential as tags for protein immobilization, as well as for the tailoring of enzymes that play a part in polysaccharide metabolism.

  3. Antitranspirant-induced increases in leaf water potential increase tuber calcium and decrease tuber necrosis in water-stressed potato plants.

    PubMed

    Win, K; Berkowitz, G A; Henninger, M

    1991-05-01

    Experiments were undertaken with field-grown potato (Solanum tuberosum L.) plants to test the hypothesis that altering leaf:tuber water potential gradients within a plant subjected to low soil moisture will allow greater Ca accumulation in tubers and reverse Ca deficiency-related tuber necrosis. Antitranspirant formulations containing a wax emulsion and a spreader/sticker surfactant increased leaf water potential during a drought episode, significantly reducing the potential gradient that develops between leaf and tuber during a period of stress. Increased leaf water potential in treated plants was associated with decreased leaf Ca and increased tuber Ca. Tuber necrosis was found to be reduced in treated plants, thus increasing tuber quality.

  4. Gibberellin-induced inhibition and promotion of sprouting in aerial tubers of Begonia evansiana Andr. in relation to photoperiodic treatment and tuber stage.

    PubMed

    Okagami, N; Esashi, Y; Nagao, M

    1977-01-01

    Gibberellic-acid (GA3) treatment, when applied within a period ranging from the start of short-day (SD) treatment until about 10 SD, GA3 strongly inhibited formation of aerial tubers in response to SD and brought about sprouting of developing aerial tubers. In contrast, when applied after about 10 SD or more, GA3 hastened the completion of the dormant state in the tubers and prolonged their dormancy. The dormancy-promoting effect of GA3 on detached tubers increased with their degree of maturation. Application of growth retardants N-dimethylaminosuccinamic acid (B-9), 2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride (AMO-1618) and 2-chloroethyltrimethylammonium chloride (CCC) to the cuttings delayed the onset of dormancy in the aerial tuber. When the retardants were applied to detached aerial tubers, however, such a delay of dormancy was not observed, and GA3 application did not inhibit sprouting in aerial tubers detached from CCC-treated cuttings.

  5. Color terms and color concepts.

    PubMed

    Davidoff, Jules

    2006-08-01

    In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction are taken up in the current commentary, especially with regard to the neuropsychological evidence. Data from aphasic patients also argue for a priority for abstract thought, but nevertheless it may still be that the use of color terms is the only way in which to form color categories even if both linguistic and attentional factors play an important role.

  6. Color Analysis

    NASA Astrophysics Data System (ADS)

    Wrolstad, Ronald E.; Smith, Daniel E.

    Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

  7. Measurement of the Water Potential of Stored Potato Tubers 1

    PubMed Central

    Bland, William L.; Tanner, Champ B.

    1985-01-01

    A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential. Pressure chamber measurements, while useful for tubers with functional stolons, cannot be made on stored tubers. Measurements could be made on excised tissue pieces in a hygrometer chamber and with hygrometers implanted into tubers. We report here our evaluation of these hygrometric methods using a comparison with the pressure chamber on tubers harvested with stolons intact. In tubers of high water potential, measurements on excised tissue were as much as 0.5 megapascals lower than the pressure chamber, probably due to turgor-driven expansion of the sample when freed from constraints imposed by surrounding tissue. Good agreement (±0.05 megapascals) was found between the implanted hygrometer and the pressure chamber at potentials higher than −0.5 megapascals. At lower water potentials, both hygrometer measurements were higher than the pressure chamber. Respirational heating of the tissue contributed to the increase in the excised tissue samples, but not with the implanted hygrometers because of the hygrometer design. The osmotic pressure balanced the pressure chamber measurement of potential at −0.7 megapascals, but was too small to do so at lower potentials. At most, 25% of this discrepancy can be accounted for by dilution by apoplastic water. We believe that the pressure chamber measurement is too low at low water potentials and that the error is associated with air bubbles in the xylem. At low potentials air emerged from xylem vessels along with sap, and fewer xylem emitted sap as potentials decreased. PMID:16664511

  8. Measurement of the water potential of stored potato tubers.

    PubMed

    Bland, W L; Tanner, C B

    1985-11-01

    A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential. Pressure chamber measurements, while useful for tubers with functional stolons, cannot be made on stored tubers. Measurements could be made on excised tissue pieces in a hygrometer chamber and with hygrometers implanted into tubers. We report here our evaluation of these hygrometric methods using a comparison with the pressure chamber on tubers harvested with stolons intact.In tubers of high water potential, measurements on excised tissue were as much as 0.5 megapascals lower than the pressure chamber, probably due to turgor-driven expansion of the sample when freed from constraints imposed by surrounding tissue. Good agreement (+/-0.05 megapascals) was found between the implanted hygrometer and the pressure chamber at potentials higher than -0.5 megapascals. At lower water potentials, both hygrometer measurements were higher than the pressure chamber. Respirational heating of the tissue contributed to the increase in the excised tissue samples, but not with the implanted hygrometers because of the hygrometer design. The osmotic pressure balanced the pressure chamber measurement of potential at -0.7 megapascals, but was too small to do so at lower potentials. At most, 25% of this discrepancy can be accounted for by dilution by apoplastic water. We believe that the pressure chamber measurement is too low at low water potentials and that the error is associated with air bubbles in the xylem. At low potentials air emerged from xylem vessels along with sap, and fewer xylem emitted sap as potentials decreased.

  9. Potato tuber herbivory increases resistance to aboveground lepidopteran herbivores.

    PubMed

    Kumar, Pavan; Ortiz, Erandi Vargas; Garrido, Etzel; Poveda, Katja; Jander, Georg

    2016-09-01

    Plants mediate interactions between aboveground and belowground herbivores. Although effects of root herbivory on foliar herbivores have been documented in several plant species, interactions between tuber-feeding herbivores and foliar herbivores are rarely investigated. We report that localized tuber damage by Tecia solanivora (Guatemalan tuber moth) larvae reduced aboveground Spodoptera exigua (beet armyworm) and Spodoptera frugiperda (fall armyworm) performance on Solanum tuberosum (potato). Conversely, S. exigua leaf damage had no noticeable effect on belowground T. solanivora performance. Tuber infestation by T. solanivora induced systemic plant defenses and elevated resistance to aboveground herbivores. Lipoxygenase 3 (Lox3), which contributes to the synthesis of plant defense signaling molecules, had higher transcript abundance in T. solanivora-infested leaves and tubers than in equivalent control samples. Foliar expression of the hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and 3-hydroxy-3-methylglutaryl CoA reductase I (HMGR1) genes, which are involved in chlorogenic acid and steroidal glycoalkaloid biosynthesis, respectively, also increased in response to tuber herbivory. Leaf metabolite profiling demonstrated the accumulation of unknown metabolites as well as the known potato defense compounds chlorogenic acid, α-solanine, and α-chaconine. When added to insect diet at concentrations similar to those found in potato leaves, chlorogenic acid, α-solanine, and α-chaconine all reduced S. exigua larval growth. Thus, despite the fact that tubers are a metabolic sink tissue, T. solanivora feeding elicits a systemic signal that induces aboveground resistance against S. exigua and S. frugiperda by increasing foliar abundance of defensive metabolites.

  10. Processing of Color Words Activates Color Representations

    ERIC Educational Resources Information Center

    Richter, Tobias; Zwaan, Rolf A.

    2009-01-01

    Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

  11. Transcriptomic identification and expression of starch and sucrose metabolism genes in the seeds of Chinese chestnut (Castanea mollissima).

    PubMed

    Zhang, Lin; Lin, Qing; Feng, Yanzhi; Fan, Xiaoming; Zou, Feng; Yuan, De-Yi; Zeng, Xiaochun; Cao, Heping

    2015-01-28

    The Chinese chestnut (Castanea mollissima) seed provides a rich source of carbohydrates as food and feed. However, little is known about starch biosynthesis in the seeds. The objectives of this study were to determine seed composition profiles and identify genes involved in starch and sucrose metabolism. Metabolite analysis showed that starch was the major component and rapidly accumulated during seed endosperm development. Amylopectin was approximately 3-fold of amylose content in chestnut starch. Illumina platform-based transcriptome sequencing generated 56671 unigenes in two cDNA libraries from seed endosperms collected at 45 and 75 days after flowering (DAF). A total of 1537 unigenes showed expression differences ≥2-fold in the two stages of seeds including 570 up-regulated and 967 down-regulated unigenes. One hundred and fifty-two unigenes were identified as involved in starch and sucrose metabolism, including 1 for glycogenin glucosyltransferase, 4 for adenylate transporter (brittle1-type), 3 for ADP-glucose pyrophosphorylase (AGP, not brittle2- or shrunken2-type), 3 for starch synthase (SS), 2 for starch branching enzyme, 5 for starch debranching enzyme, 11 for sucrose synthase, and 3 for sucrose-phosphate synthase. Among them, 58 unigenes showed a ≥2-fold expression difference between the 45 and 75 DAF seeds including 11 up- and 47 down-regulated unigenes. The expression of 21 unigenes putatively coding for major enzymes in starch and sucrose metabolism was validated by qPCR using RNA from five seed stages. Expression profiles and correlation analysis indicated that the mRNA levels of AGP (large and small subunits), granule-bound SS2, and soluble SS1 and SS4 were well-correlated with starch accumulation in the seeds. This study suggests that the starch biosynthesis pathway in Chinese chestnut is similar to that of potato tuber/Arabidopsis leaf and differs from that of maize endosperm. The information provides valuable metabolite and genetic resources

  12. Modulation of the cellulose content of tuber cell walls by antisense expression of different potato (Solanum tuberosum L.) CesA clones.

    PubMed

    Oomen, Ronald J F J; Tzitzikas, Emmanouil N; Bakx, Edwin J; Straatman-Engelen, Irma; Bush, Maxwell S; McCann, Maureen C; Schols, Henk A; Visser, Richard G F; Vincken, Jean-Paul

    2004-03-01

    Four potato cellulose synthase (CesA) homologs (StCesA1, 2, 3 and 4) were isolated by screening a cDNA library made from developing tubers. Based on sequence comparisons and the fact that all four potato cDNAs were isolated from this single cDNA-library, all four StCesA clones are likely to play a role in primary cell wall biosynthesis. Several constructs were generated to modulate cellulose levels in potato plants in which the granule-bound starch synthase promoter was used to target the modification to the tubers. The StCesA3 was used for up- and down-regulation of the cellulose levels by sense (SE-StCesA3) and antisense (AS-StCesA3) expression of the complete cDNA. Additionally, the class-specific regions (CSR) of all four potato cellulose synthase genes were used for specific down-regulation (antisense) of the corresponding CesA genes (csr1, 2, 3 and 4). None of the transformants showed an overt developmental phenotype. Sections of tubers were screened for altered cell wall structure by Fourier Transform Infrared microspectroscopy (FTIR) and exploratory Principal Component Analysis (PCA), and those plants discriminating from WT plants were analysed for cellulose content and monosaccharide composition. Several transgenic lines were obtained with mainly decreased levels of cellulose. These results show that the cellulose content in potato tubers can be reduced down to 40% of the WT level without affecting normal plant development, and that constructs based on the CSR alone are specific and sufficient to down-regulate cellulose biosynthesis.

  13. Mixed biopolymer systems based on starch.

    PubMed

    Abd Elgadir, M; Akanda, Md Jahurul Haque; Ferdosh, Sahena; Mehrnoush, Amid; Karim, Alias A; Noda, Takahiro; Sarker, Md Zaidul Islam

    2012-01-09

    A binary mixture of starch-starch or starch with other biopolymers such as protein and non-starch polysaccharides could provide a new approach in producing starch-based food products. In the context of food processing, a specific adjustment in the rheological properties plays an important role in regulating production processing and optimizing the applicability, stability, and sensory of the final food products. This review examines various biopolymer mixtures based on starch and the influence of their interaction on physicochemical and rheological properties of the starch-based foods. It is evident that the physicochemical and rheological characteristics of the biopolymers mixture are highly dependent on the type of starch and other biopolymers that make them up mixing ratios, mixing procedure and presence of other food ingredients in the mixture. Understanding these properties will lead to improve the formulation of starch-based foods and minimize the need to resort to chemically modified starch.

  14. Subtilisin protein inhibitor from potato tubers.

    PubMed

    Revina, T A; Speranskaya, A S; Kladnitskaya, G V; Shevelev, A B; Valueva, T A

    2004-10-01

    A protein with molecular weight of 21 kD denoted as PKSI has been isolated from potato tubers (Solanum tuberosum L., cv. Istrinskii). The isolation procedure includes precipitation with (NH4)2SO4, gel chromatography on Sephadex G-75, and ion-exchange chromatography on CM-Sepharose CL-6B. The protein effectively inhibits the activity of subtilisin Carlsberg (Ki = 1.67 +/- 0.2 nM) by stoichiometric complexing with the enzyme at the molar ratio of 1 : 1. The inhibitor has no effect on trypsin, chymotrypsin, and the cysteine proteinase papain. The N-terminal sequence of the protein consists of 19 amino acid residues and is highly homologous to sequences of the known inhibitors from group C of the subfamily of potato Kunitz-type proteinase inhibitors (PKPIs-C). By cloning PCR products from the genomic DNA of potato, a gene denoted as PKPI-C2 was isolated and sequenced. The N-terminal sequence (residues from 15 to 33) of the protein encoded by the PKPI-C2 gene is identical to the N-terminal sequence (residues from 1 to 19) of the isolated protein PKSI. Thus, the inhibitor PKSI is very likely encoded by this gene.

  15. Sago starch and its utilisation.

    PubMed

    Abd-Aziz, Suraini

    2002-01-01

    The importance and development of industrial biotechnology processing has led to the utilisation of microbial enzymes in various applications. One of the important enzymes is amylase, which hydrolyses starch to glucose. In Malaysia, the use of sago starch has been increasing, and it is presently being used for the production of glucose. Sago starch represents an alternative cheap carbon source for fermentation processes that is attractive out of both economic and geographical considerations. Production of fermentable sugars from the hydrolysis of starches is normally carried out by an enzymatic processes that involves two reaction steps, liquefaction and saccharification, each of which has different temperature and pH optima with respect to the maximum reaction rate. This method of starch hydrolysis requires the use of an expensive temperature control system and a complex mixing device. Our laboratory has investigated the possibility of using amylolytic enzyme-producing microorganisms in the continuous single-step biological hydrolysis of sago flour for the production of a generic fermentation medium. The ability of a novel DNA-recombinated yeast, Saccharomyces cerevisiae strain YKU 107 (expressing alpha-amylase production) to hydrolyse gelatinised sago starch production has been studied with the aim of further utilizing sago starch to obtain value-added products.

  16. Quantum Color

    ScienceCinema

    Lincoln, Don

    2016-07-20

    The idea of electric charges and electricity in general is a familiar one to the science savvy viewer. However, electromagnetism is but one of the four fundamental forces and not the strongest one. The strongest of the fundamental forces is called the strong nuclear force and it has its own associated charge. Physicists call this charge “color” in analogy with the primary colors, although there is no real connection with actual color. In this video, Fermilab’s Dr. Don Lincoln explains why it is that we live in a colorful world.

  17. Polar Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 3 May 2004 This nighttime visible color image was collected on January 1, 2003 during the Northern Summer season near the North Polar Troughs.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 79, Longitude 346 East (14 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

  18. Fed-batch fermentation of Tuber melanosporum for the hyperproduction of mycelia and bioactive Tuber polysaccharides.

    PubMed

    Liu, Qiao-Ning; Liu, Rui-Sang; Wang, Yi-Hua; Mi, Zhi-Yuan; Li, Dong-Sheng; Zhong, Jian-Jiang; Tang, Ya-Jie

    2009-07-01

    For the first time, a fed-batch fermentation process of Tuber melanosporum was developed for the efficient production of bioactive mycelia and Tuber polysaccharides. Each 1.67 g/L of peptone and 8.33 g/L of yeast extract were added on day 3, 6, and 9, respectively, and sucrose was fed to maintain its concentration around 35-5 g/L when its residual level decreased to 10-5 g/L. Then, the maximal biomass, the production of extracellular polysaccharides (EPS) and intracellular polysaccharides (IPS) reached 53.72+/-2.57 g DW/L, 7.09+/-0.62 and 4.43+/-0.21 g/L, respectively. Compared with the batch culture conducted in the enriched medium, the biomass, the production of EPS and IPS were enhanced by 55.8%, 222.3% and 103.2%, respectively. Not only the cell density but also the production of EPS and IPS were the highest ever reported in truffle fermentation, and the biomass was also the highest as ever reported in mushroom fermentation.

  19. Herbicide residues and nitrate concentration in tubers of table potatoes.

    PubMed

    Zarzecka, Krystyna; Gugała, Marek; Mystkowska, Iwona

    2010-01-01

    This study examined Wiking-cultivar table potato tubers in a field experiment conducted between 2002 and 2004 using a rye complex soil. The experimental factors included (a) two methods of tillage, including traditional and simplified, as well as (b) seven methods of cultivation with the use of herbicides as follows: 1, control without herbicides; 2, Plateen 41.5 WG; 3, Plateen 41.5 WG + Fusilade Forte 150 EC; 4, Plateen 41.5 WG + Fusilade Forte 150 EC + adjuvant Atpolan 80 EC; 5, Barox 460 SL; 6, Barox 460 SL + Fusilade Forte 150 EC; and 7, Barox 460 SL + Fusilade Forte 150 EC + adjuvant Atpolan 80 EC. Determination of residues was performed using high-performance liquid and gas chromatography. Only trace quantities of bentazone (Barox 460 SL) were found in potato tubers, amounts that fell below the maximum residue limit (MRL). The nitrate content of potato tubers was determined using a nitrate ion-selective electrode and silver chloride reference electrode. The nitrate content in fresh matter of unpeeled and peeled tubers depended significantly only on weather conditions in the years of study. In contrast, agrotechnical procedures such as methods of tillage and cultivation did not significantly affect potato tuber nitrate content.

  20. Synthesis of porous starch xerogels modified with mercaptosuccinic acid to remove hazardous gardenia yellow.

    PubMed

    Bao, Liping; Zhu, Xinyi; Dai, Hongxia; Tao, Yongxin; Zhou, Xiaoying; Liu, Wenjie; Kong, Yong

    2016-08-01

    Mercaptosuccinic acid (MSA) molecules were inserted into potato starch, leading to the breaking of intrinsic H-bonds within macromolecular chains of starch and the formation of intermolecular H-bonds between MSA and starch, which could be verified by Fourier transform infrared spectroscopy (FT-TR). MSA modified porous starch xerogels (PSX/MSA) were obtained after freeze-drying the MSA modified starch, and they were characterized by field emission scanning electron microscopy (FESEM), exhibiting the intriguing porous structure due to the separation of starch chains by MSA molecules. The PSX/MSA were then used as the adsorbents to remove gardenia yellow (GY), a natural colorant with genotoxicity. Due to the porous structure of PSX and the introduced carboxyl groups from MSA, the adsorption capacity of the PSX/MSA was much higher than that of the starch xerogels alone (SX). The adsorption behaviors of GY by the PSX/MSA fitted both the Freundlich isotherm model and the pseudo-second-order kinetic model, and the efficient adsorption of GY suggested that the PSX/MSA might be potential adsorbents for the removal of dyes from contaminated aquatic systems.

  1. Effects of granule swelling on starch saccharification by granular starch hydrolyzing enzyme.

    PubMed

    Li, Zhaofeng; Cai, Liming; Gu, Zhengbiao; Shi, Yong-Cheng

    2014-08-13

    The effects of granule swelling on enzymatic saccharification of normal corn starch by granular starch hydrolyzing enzyme were investigated. After swelling, Km values for the saccharification of granular starch decreased compared with native granular starch, indicating that granule swelling caused granular starch hydrolyzing enzyme to have higher affinity for starch granules. The partial swelling of starch granules enhanced starch saccharification. Furthermore, the enhancement at an earlier stage of enzymatic reaction was much more significant than that at later stages. For granular starch pretreated at 67.5 °C for 30 min, conversions to glucose after incubation with the enzyme at 32 °C for 4 and 24 h were approximately 3-fold and 26% higher than for native granular starch, respectively. As a result, proper heat pretreatment of granular starch before simultaneous saccharification and fermentation has great potential to facilitate industrial production of ethanol by use of granular starch hydrolyzing enzyme.

  2. Biochemical properties and expression analysis of potato cytokinin oxidases during tuber dormancy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At harvest and for an indeterminate period thereafter, potato tubers are dormant and will not sprout. Tuber dormancy is lost during postharvest storage and the subsequent sprouting results in the loss of tuber processing and nutritional qualities. Endogenous cytokinins have been posited to play a p...

  3. Supplemental calcium nutrition improves tuber yield and quality of native potatoes in the Peruvian highlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tubers are known to be calcium deficient. This is because calcium moves with water and most water is transported to leaves and tubers being in soil do not have the draw for water and calcium. Calcium fertilizers are now routinely used to improve tuber quality and production in the US. Potatoe...

  4. Effect of gelatinized-retrograded and extruded starches on characteristics of cookies, muffins and noodles.

    PubMed

    Sharma, Shagun; Singh, Narpinder; Katyal, Mehak

    2016-05-01

    The effect of substitution of wheat flour with gelatinized-retrograded starch (GRS) and extruded starch (ES) at 10 and 20 % levels on characteristics of cookies, muffins and noodles was evaluated. Cookies made by substitution of flour with GRS or ES were lighter in color, showed higher spread ratio and resistant starch (RS) content. Muffins made by substitution of flour with GRS or ES were lighter in color, showed less height, specific volume and gas cells and higher RS content. Muffins containing GRS were less firm while those made by incorporating ES showed higher firmness than those made without substitution. Noodles made with substitution of flour with GRS or ES showed higher RS content and reduced water uptake, gruel solid loss, hardness and adhesiveness. Cookies and noodles prepared with and without substitution of flour with GRS or ES did not show any significant differences in terms of overall acceptability scores.

  5. Ocatin. A Novel Tuber Storage Protein from the Andean Tuber Crop Oca with Antibacterial and Antifungal Activities1

    PubMed Central

    Flores, Teresita; Alape-Girón, Alberto; Flores-Díaz, Marietta; Flores, Hector E.

    2002-01-01

    The most abundant soluble tuber protein from the Andean crop oca (Oxalis tuberosa Mol.), named ocatin, has been purified and characterized. Ocatin accounts for 40% to 60% of the total soluble oca tuber proteins, has an apparent molecular mass of 18 kD and an isoelectric point of 4.8. This protein appears to be found only in tubers and is accumulated only within the cells of the pith and peridermis layers (peel) of the tuber as it develops. Ocatin inhibits the growth of several phytopathogenic bacteria (Agrobacterium tumefaciens, Agrobacterium radiobacter, Serratia marcescens, and Pseudomonas aureofaciens) and fungi (Phytophthora cinnamomi, Fusarium oxysporum, Rhizoctonia solani, and Nectria hematococcus). Ocatin displays substantial amino acid sequence similarity with a widely distributed group of intracellular pathogenesis-related proteins with a hitherto unknown biological function. Our results showed that ocatin serves as a storage protein, has antimicrobial properties, and belongs to the Betv 1/PR-10/MLP protein family. Our findings suggest that an ancient scaffolding protein was recruited in the oca tuber to serve a storage function and that proteins from the Betv 1/PR-10/MLP family might play a role in natural resistance to pathogens. PMID:11950978

  6. Color Metric.

    ERIC Educational Resources Information Center

    Illinois State Office of Education, Springfield.

    This booklet was designed to convey metric information in pictoral form. The use of pictures in the coloring book enables the more mature person to grasp the metric message instantly, whereas the younger person, while coloring the picture, will be exposed to the metric information long enough to make the proper associations. Sheets of the booklet…

  7. Cerebellar Development and Autism Spectrum Disorder in Tuberous Sclerosis Complex.

    PubMed

    Sundberg, Maria; Sahin, Mustafa

    2015-12-01

    Approximately 50% of patients with the genetic disease tuberous sclerosis complex present with autism spectrum disorder. Although a number of studies have investigated the link between autism and tuberous sclerosis complex, the etiology of autism spectrum disorder in these patients remains unclear. Abnormal cerebellar function during critical phases of development could disrupt functional processes in the brain, leading to development of autistic features. Accordingly, the authors review the potential role of cerebellar dysfunction in the pathogenesis of autism spectrum disorder in tuberous sclerosis complex. The authors also introduce conditional knockout mouse models of Tsc1 and Tsc2 that link cerebellar circuitry to the development of autistic-like features. Taken together, these preclinical and clinical investigations indicate the cerebellum has a profound regulatory role during development of social communication and repetitive behaviors.

  8. The biosynthesis of starch granules.

    PubMed

    Smith, A M

    2001-01-01

    Although composed simply of glucose polymers, the starch granule is a complex, semicrystalline structure. Much of this complexity arises from the fact that the two primary enzymes of synthesis-starch synthase and starch-branching enzyme-exist as multiple isoforms. Each form has distinct properties and plays a unique role in the synthesis of the two starch polymers, amylose and amylopectin. The debranching enzyme isoamylase also has a profound influence on the synthesis of amylopectin. Despite much speculation, no acceptable model to explain the interactions of all of these enzymes to produce amylose and amylopectin has thus far emerged. The organization of newly synthesized amylopectin to form the semicrystalline matrix of the granule appears to be a physical process, implying the existence of complex interactions between biological and physical processes at the surface of the growing granule. The synthesis of the amylose component occurs within the amylopectin matrix.

  9. Starch granules: structure and biosynthesis.

    PubMed

    Buléon, A; Colonna, P; Planchot, V; Ball, S

    1998-08-01

    The emphasis of this review is on starch structure and its biosynthesis. Improvements in understanding have been brought about during the last decade through the development of new physicochemical and biological techniques, leading to real scientific progress. All this literature needs to be kept inside the general literature about biopolymers, despite some confusing results or discrepancies arising from the biological variability of starch. However, a coherent picture of starch over all the different structural levels can be presented, in order to obtain some generalizations about its structure. In this review we will focus first on our present understanding of the structures of amylose and amylopectin and their organization within the granule, and we will then give insights on the biosynthetic mechanisms explaining the biogenesis of starch in plants.

  10. Gastrokinetic activity of Amorphophallus paeoniifolius tuber in rats

    PubMed Central

    Dey, Yadu Nandan; Mahor, Shivani; Kumar, Dharmendra; Wanjari, Manish; Gaidhani, Sudesh; Jadhav, Ankush

    2016-01-01

    Aim: The tuber of Amorphophallus paeoniifolius (Family-Araceae), commonly called suran or jimikand, has medicinal and food value. It is used in ethnomedicinal practices for correction of gastrointestinal disturbances such as constipation and hemorrhoids. The present study evaluated the effect of A. paeoniifolius tuber on gastrointestinal motor functions. Materials and Methods: The tuber was collected in December 2011, and its methanolic extract was standardized with the major phenolic compound, betulinic acid, by high-performance liquid chromatography. Rats were orally administered methanolic (APME) or aqueous (APAE) extract (250 and 500 mg/kg, each) of tuber for 7 days. Metoclopramide (MET) (3 mg/kg, orally) was used a reference prokinetic drug. The gastrointestinal parameters viz. number of feces, wet and dry weight and moisture content of feces, gastric emptying, and intestinal transit were evaluated. The isolated tissue preparations were used to check the effect of the extracts on fundus and intestinal contractility. The glucomannan and total phenolic and flavonoid contents were determined spectrophotometrically. Results: The pre-treatment of extracts significantly increased the number of feces, wet and dry weight of feces, moisture content, gastric emptying, and intestinal transit. Results were comparable to MET. Further, APME and APAE showed a contraction of fundus and ileum in isolated preparations. APME and APAE were also found to have fair amount of glucomannan, total phenolics, and flavonoids. The results indicate the gastrokinetic potential of the tuber extracts. This may be attributed to the presence of glucomannan and betulinic acid present in the extracts. Conclusion: In conclusion, the tuber of A. paeoniifolius exhibits gastrokinetic activity and substantiates its traditional use in gastrointestinal motor disturbances. PMID:27069720

  11. The heart and tuberous sclerosis. An echocardiographic and electrocardiographic study.

    PubMed Central

    Gibbs, J L

    1985-01-01

    Cross sectional echocardiography, 12 lead electrocardiography, and 24 hour ambulatory electrocardiography were performed in eleven patients with tuberous sclerosis. Echocardiography showed single or multiple intramyocardial masses, most commonly in the ventricular septum, suggestive of rhabdomyomata in seven of the eleven cases. One patient with a normal echocardiogram showed ventricular pre-excitation on electrocardiography, with tachycardias of 180 beats per minute on ambulatory monitoring. Sinus bradycardia, sinus tachycardia, and supraventricular tachycardia were also seen, but their importance is uncertain. Echocardiography and electrocardiography should be routinely performed in the assessment of patients with tuberous sclerosis and ambulatory electrocardiography should be considered in those with seizures that respond poorly to anticonvulsants. Images PMID:4074592

  12. Phasic temperature change patterns affect growth and tuberization in potatoes

    SciTech Connect

    Cao, W.; Tibbitts, T.W. . Dept. of Horticulture)

    1994-07-01

    This study determined the response of potato (Solanum tuberosum L., cv. Norland) plants to various patterns of air temperature changes over different growth periods. In each of two experiments under controlled environments, eight treatments of temperature changes were carried out in two growth rooms maintained at 17 and 22 C and a constant vapor pressure deficit of 0.60 kPa and 14-hour photoperiod. Plants were grown for 63 days after transplanting of tissue culture plantlets in 20-liter pots containing peat-vermiculite mix. Temperature changes were imposed on days 21 and 42, which were essentially at the beginning of tuber initiation and tuber enlargement, respectively, for this cultivar. Plants were moved between two temperature rooms to obtain eight temperature change patterns: 17-17-17, 17-17-22, 17-22-17, 22-17-17, 17-22-22, 22-17-22, 22-22-17, and 22-22-22C over three 21-day growth periods. At harvest on day 63, total plant dry weight was higher for the treatments beginning with 22 C than for those beginning with 17C, with highest biomass obtained at 22-22-17 and 22-17-17C. Shoot dry weight increased with temperature increased from 17-17-17 to 22-22-22C during the three growth periods. Tuber dry weight was highest with 22-17-17C, and lowest with 17-17-22 and 17-22-22C. With 22-17-17C, both dry weights of stolons and roots were lowest. Total tuber number and number of small tubers were highest with 17-17-17 and 17-17-22C, and lowest with 17-22-22 and 22-22-22C, whereas number of medium tubers was highest with 22-17-22C, and number of large tubers was highest with 22-17-17C. This study indicates that tuber development of potatoes is optimized with a phasic pattern of high temperature during early growth and low temperature during later growth.

  13. Onychogryphosis in tuberous sclerosis complex: an unusual feature*

    PubMed Central

    Han, Xiang-chun; Zheng, Li-qiang; Zheng, Tie-gang

    2016-01-01

    Onychogryphosis is an acquired nail plate change. It often affects the toenail and is characterized by an opaque, yellow-brownish nail plate that is distorted, grossly thickened, elongated, and partly curved resembling a ram's horn. Tuberous sclerosis complex is a multisystem disorder associated with high rates of mental retardation, autism, cognitive impairment, behavioral problems, or seizures. Nail disease can also be associated, which is a concern to patients due to pain and nail distortion. We reported a typical tuberous sclerosis complex patient with distinctive clinical features of a ram's horn nails, which presented a great challenge to surgical treatment and nail restoration.

  14. Slow digestion property of native cereal starches.

    PubMed

    Zhang, Genyi; Ao, Zihua; Hamaker, Bruce R

    2006-11-01

    The slow digestion property of native cereal starches, represented by normal maize starch, was investigated. The in vitro Englyst test showed that 53.0% of the maize starch is slowly digestible starch (SDS), and scanning electron microscopy (SEM) revealed that SDS starts from an increase of pore size until almost complete fragmentation of starch granules. However, similar amounts of SDS ( approximately 50%) were shown for partially digested fragmented starch residuals, which would normally be considered resistant to digestion based on the Englyst assay. Molecularly, both amylopectin (AP) and amylose (AM) contributed to the amount of SDS as evidenced by a similar ratio of AP to AM at different digestion times. Consistently, similar degrees of crystallinity, comparable gelatinization behavior, and similar debranched profiles of starch residuals following different digestion times indicated that the crystalline and amorphous regions of starch granules were evenly digested through a mechanism of side-by-side digestion of concentric layers of semicrystalline shells of native starch granules.

  15. Quantum Color

    SciTech Connect

    Lincoln, Don

    2016-07-05

    The idea of electric charges and electricity in general is a familiar one to the science savvy viewer. However, electromagnetism is but one of the four fundamental forces and not the strongest one. The strongest of the fundamental forces is called the strong nuclear force and it has its own associated charge. Physicists call this charge “color” in analogy with the primary colors, although there is no real connection with actual color. In this video, Fermilab’s Dr. Don Lincoln explains why it is that we live in a colorful world.

  16. Improving starch for food and industrial applications.

    PubMed

    Jobling, Steve

    2004-04-01

    Progress in understanding starch biosynthesis, and the isolation of many of the genes involved in this process, has enabled the genetic modification of crops in a rational manner to produce novel starches with improved functionality. For example, potato starches have been created that contain unprecedented levels of amylose and phosphate. Amylose-free short-chain amylopectin starches have also been developed; these starches have excellent freeze-thaw stability without the need for chemical modification. These developments highlight the potential to create even more modified starches in the future.

  17. The relation of starch phosphorylases to starch metabolism in wheat.

    PubMed

    Schupp, Nicole; Ziegler, Paul

    2004-10-01

    Tissues of wheat (Triticum aestivum L., var. Star) exhibit three starch phosphorylase activity forms resolved by non-denaturing polyacrylamide gel affinity electrophoresis (P1, P2 and P3). Compartmentation analysis of young leaf tissues showed that P3 is plastidic, whereas P1 and P2 are cytosolic. P1 exhibits a strong binding affinity to immobilized glycogen upon electrophoresis, whereas P2 and the chloroplastic P3 do not. Cytosolic leaf phosphorylase was purified to homogeneity by affinity chromatography. The single polypeptide product constituted both the P1 and P2 activity forms. Probes for the detection of phosphorylase transcripts were derived from cDNA sequences of cytosolic and plastidic phosphorylases, and these-together with activity assays and a cytosolic phosphorylase-specific antiserum-were used to monitor phosphorylase expression in leaves and seeds. Mature leaves contained only plastidic phosphorylase, which was also strongly evident in the endosperm of developing seeds at the onset of reserve starch accumulation. Germinating seeds contained only cytosolic phosphorylase, which was restricted to the embryo. Plastidic phosphorylase thus appears to be associated with transitory leaf starch metabolism and with the initiation of seed endosperm reserve starch accumulation, but it plays no role in the degradation of the reserve starch. Cytosolic phosphorylase may be involved in the processing of incoming carbohydrate during rapid tissue growth.

  18. Starch grains reveal early root crop horticulture in the Panamanian tropical forest.

    PubMed

    Piperno, D R; Ranere, A J; Holst, I; Hansell, P

    2000-10-19

    Native American populations are known to have cultivated a large number of plants and domesticated them for their starch-rich underground organs. Suggestions that the likely source of many of these crops, the tropical forest, was an early and influential centre of plant husbandry have long been controversial because the organic remains of roots and tubers are poorly preserved in archaeological sediments from the humid tropics. Here we report the occurrence of starch grains identifiable as manioc (Manihot esculenta Crantz), yams (Dioscorea sp.) and arrowroot (Maranta arundinacea L.) on assemblages of plant milling stones from preceramic horizons at the Aguadulce Shelter, Panama, dated between 7,000 and 5,000 years before present (BP). The artefacts also contain maize starch (Zea mays L.), indicating that early horticultural systems in this region were mixtures of root and seed crops. The data provide the earliest direct evidence for root crop cultivation in the Americas, and support an ancient and independent emergence of plant domestication in the lowland Neotropical forest.

  19. Endometrial Adenocarcinoma Presenting in a Premenopausal Patient with Tuberous Sclerosis

    ERIC Educational Resources Information Center

    Jaffe, J. S.; Chambers, J. T.

    2005-01-01

    Background: Endometrial adenocarcinoma is very uncommon in women under 40 years of age. Case: A 39-year-old woman with tuberous sclerosis and severe intellectual disability presented with irregular bleeding unresponsive to oral contraceptive therapy. She was subsequently found to have a deeply invasive endometrial adenocarcinoma. Conclusion:…

  20. Accumulation of vitamin E in potato (Solanum tuberosum) tubers.

    PubMed

    Crowell, Elizabeth F; McGrath, J Mitchell; Douches, David S

    2008-04-01

    Vitamin E (tocopherol) is a powerful antioxidant essential for human health and synthesized only by photosynthetic organisms. The effects of over-expression of tocopherol biosynthetic enzymes have been studied in leaves and seeds, but not in a non-photosynthetic, below-ground plant organ. Genetic and molecular approaches were used to determine if increased levels of tocopherols can be accumulated in potato (Solanum tuberosum L.) tubers through metabolic engineering. Two transgenes were constitutively over-expressed in potato: Arabidopsis thaliana p-hydroxyphenylpyruvate dioxygenase (At-HPPD) and A. thaliana homogentisate phytyltransferase (At-HPT). alpha-Tocopherol levels in the transgenic plants were determined by high-performance liquid chromatography. In potato tubers, over-expression of At-HPPD resulted in a maximum 266% increase in alpha-tocopherol, and over-expression of At-HPT yielded a 106% increase. However, tubers from transgenic plants still accumulated approximately 10- and 100-fold less alpha-tocopherol than leaves or seeds, respectively. The results indicate that physiological and regulatory constraints may be the most limiting factors for tocopherol accumulation in potato tubers. Studying regulation and induction of tocopherol biosynthesis should reveal approaches to more effectively engineer crops with enhanced tocopherol content.

  1. Gene Expression Associated with Tuber Wound-Healing/Suberization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wounding of potatoes during harvest and handling operations results in tuber shrinkage, market quality defects and infection. Suberization and other wound-healing processes that mitigate these losses are of great agricultural importance. Previously, we determined that suberin poly(phenolics) and s...

  2. Potato spindle tuber viroid: the simplicity paradox resolved?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Taxonomy: Potato spindle tuber viroid (PSTVd) is the type species of the genus Posipiviroid, family Pospiviroidae. An absence of hammerhead ribozymes and the presence of a 'central conserved region' distinguish PSTVd and related viroids from members of a second viroid family, the Avsunviroidae. ...

  3. Mutational Analysis of Cell Types in Tuberous Sclerosis Complex (TSC)

    DTIC Science & Technology

    2009-01-01

    astrocytoma in tuberous sclerosis complex. Neurology 64(8):1446-9 Green, A.J., Smith, M., and Yates , J.R. (1994). Loss of heterozygosity on chromosome...128-139 Ridler K, Bullmore ET, De Vries PJ, Suckling J, Barker GJ , Meara SJ, Williams SC, Bolton PF.Widespread anatomical abnormalities of grey

  4. Halosulfuron reduced purple nutsedge (Cyperus rotundus) tuber production and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weeds persist and cause economic losses in agricultural systems because they exploit an underutilized portion of that system. Reducing the impact of weeds on agroecosystems begins with minimizing the number of propagules (e.g, seeds and tubers) that are produced and returned to the soil. Purple nu...

  5. Encoding electric signals by Gymnotus omarorum: heuristic modeling of tuberous electroreceptor organs.

    PubMed

    Cilleruelo, Esteban R; Caputi, Angel Ariel

    2012-01-24

    The role of different substructures of electroreceptor organs in signal encoding was explored using a heuristic computational model. This model consists of four modules representing the pre-receptor structures, the transducer cells, the synapses and the afferent fiber, respectively. Simulations reproduced previously obtained experimental data. We showed that different electroreceptor types described in the literature can be qualitative modeled with the same set of equations by changing only two parameters, one affecting the filtering properties of the pre-receptor, and the other affecting the transducer module. We studied the responses of different electroreceptor types to natural stimuli using simulations derived from an experimentally-obtained database in which the fish were exposed to resistive or capacitive objects. Our results indicate that phase and frequency spectra are differentially encoded by different subpopulations of tuberous electroreceptors. A different type of receptor responses to the same input is a necessary condition for encoding a multidimensional space of stimuli as in the waveform of the EOD. Our simulation analysis suggested that the electroreceptive mosaic may perform a waveform analysis of electrosensory signals. As in color vision or tactile texture perception, a secondary attribute, "electric color" may be encoded as a parallel activity of various electroreceptor types. This article is part of a Special Issue entitled Neural Coding.

  6. Rheological properties of reactive extrusion modified waxy starch and waxy starch-polyacrylamide copolymer gels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of modified waxy starch and waxy starch-polyacrylamide graft copolymers prepared by reactive extrusion were investigated. Both materials can absorb huge amount of water and form gels. The modified waxy starch and waxy starch-polyacrylamide graft copolymer gels all exhibite...

  7. Comparison of Cationic and Unmodified Starches in Reactive Extrusion of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide (PAAm) were prepared using reactive extrusion in a corotating twin screw extruder. The effect of cationic starch modification was examined using unmodified and cationic dent starch (approximately 23% amylose) and waxy maize starch (approximately 2% amyl...

  8. Starch phosphorylation: insights and perspectives.

    PubMed

    Mahlow, Sebastian; Orzechowski, Sławomir; Fettke, Joerg

    2016-07-01

    During starch metabolism, the phosphorylation of glucosyl residues of starch, to be more precise of amylopectin, is a repeatedly observed process. This phosphorylation is mediated by dikinases, the glucan, water dikinase (GWD) and the phosphoglucan, water dikinase (PWD). The starch-related dikinases utilize ATP as dual phosphate donor transferring the terminal γ-phosphate group to water and the β-phosphate group selectively to either C6 position or C3 position of a glucosyl residue within amylopectin. By the collaborative action of both enzymes, the initiation of a transition of α-glucans from highly ordered, water-insoluble state to a less order state is realized and thus the initial process of starch degradation. Consequently, mutants lacking either GWD or PWD reveal a starch excess phenotype as well as growth retardation. In this review, we focus on the increased knowledge collected over the last years related to enzymatic properties, the precise definition of the substrates, the physiological implications, and discuss ongoing questions.

  9. Psychopathology in Tuberous Sclerosis: An Overview and Findings in a Population-Based Sample of Adults with Tuberous Sclerosis

    ERIC Educational Resources Information Center

    Raznahan, A.; Joinson, C.; O'Callaghan, F.; Osborne, J. P.; Bolton, P. F.

    2006-01-01

    Background: Tuberous sclerosis (TS) is a multi- system disorder with complex genetics. The neurodevelopmental manifestations of TS are responsible for considerable morbidity. The prevalence of epilepsy and intellectual disabilities among individuals with TS have been well described. Ours is the first study that explores the prevalence and pattern…

  10. Color vision test

    MedlinePlus

    ... from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... test - color; Ishihara color vision test Images Color blindness tests References Adams AJ, Verdon WA, Spivey BE. ...

  11. Studies of Amylose Content in Potato Starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato starch is typically low in amylose (~20-25%), but high amylose starch has superior nutritional qualities. The ratio between amylose and amylopectin is the most important property influencing the physical properties of starch. There is a strong case to be made for the development of food crops...

  12. Structural and physicochemical characterisation of rye starch.

    PubMed

    Gomand, S V; Verwimp, T; Goesaert, H; Delcour, J A

    2011-12-13

    The gelatinisation, pasting and retrogradation properties of three rye starches isolated using a proteinase-based procedure were investigated and compared to those of wheat starch isolated in a comparable way. On an average, the rye starch granules were larger than those of wheat starch. The former had very comparable gelatinisation temperatures and enthalpies, but slightly lower gelatinisation temperatures than wheat starch. Under standardised conditions, they retrograded to a lesser extent than wheat starch. The lower gelatinisation temperatures and tendencies of the rye starches to retrograde originated probably from their higher levels of short amylopectin (AP) chains [degree of polymerisation (DP) 6-12] and their lower levels of longer chains (DP 13-24) than observed for wheat starch. The rapid visco analysis differences in peak and end viscosities between the rye starches as well as between rye and wheat starches were at least partly attributable to differences in the levels of AP short chains and in average amylose molecular weight. The AP average chain lengths and exterior chain lengths were slightly lower for rye starches, while the interior chain lengths were slightly higher than those for wheat starch.

  13. Esterification of Starch in Ionic Liquids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We shall discuss the use of various ionic liquids in the preparation of starch esters. Starch was reacted with vinyl acetate in different 1-butyl-3-methylimidazolium (bmim) salts as solvents in an effort to produce starches with different acetylation patterns. Overall degree of substitution (DS) w...

  14. Increased soil salinity causes elevated cadmium concentrations in field-grown potato tubers

    SciTech Connect

    McLaughlin, M.J.; Tiller, K.G.; Beech, T.A.

    1994-09-01

    Elevated Cd concentrations have been observed in potato (Solanum tuberosum L.) tubers from commercial crops in certain regions of southern Australia. Reasons for enhanced Cd uptake by tubers were investigated by a survey of commercial crops and associated soils. Eighty-nine sites were selected and paired tuber and soil samples taken. Concentration of Cd in tubers was compared to potato variety, tuber elemental composition, and chemical-physical characteristics of topsoil (0-150) and subsoil (150-300 mm). Tuber Cd concentrations were positively related to soil electrical conductivity (EC) and extractable Cl (R{sup 2} = 0.62, P < 0.001) in the topsoil, with extractable Cl accounting for more variation than EC. Tuber Cd concentrations were not strongly related (R{sup 2} = 0.23, P < 0.05) to potato variety alone. However, inclusion of variety and EDTA-extractable Zn with water-extractable Cl in a multivariate model resulted in a small but significant improvement in the variance accounted for by the model (R{sup 2} = 0.73, p < 0.001). Tuber Cd was unrelated to tuber concentrations of P or tuber but was positively related to concentrations of major cations in the tuber particularly Na. Soil pH, total C, EDTA-extractable Cd, or particle-size distribution were not correlated to tuber Cd concentrations, either singly or after inclusion in a multivariate model with soil Cl concentrations. As Cl is known to mobilize soil Cd and increase its phytoavailability, elevated Cd concentrations in potato tubers in southern Australia appear to be largely a result of the use of saline irrigation waters. 41 refs., 5 figs., 4 tabs.

  15. Color superconductivity

    SciTech Connect

    Wilczek, F.

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  16. A new method for on-line measurement of diurnal change in potato tuber growth under controlled environments.

    PubMed

    Eguchi, T

    2000-05-01

    An on-line laser micrometer system was applied to measurement of diurnal change in potato (Solanum tuberosum L.) tuber growth. Diameters of the potato tuber were scanned by moving a laser micrometer along the longitudinal axis of the tuber at constant speed, and tuber volume was evaluated as an aggregate of thin discs. A single potato tuber, without competitive sink tubers in the plant, was grown in controlled air at 20 degrees C and 80% RH, and tuber volume was measured at 30 min intervals. During the growth experiment, the potato tuber increased in size without any inhibitory effect of periodical laser beam irradiation. Greatest expansion generally occurred during the early night, and transient contraction of the tuber occurred at the beginning of the light period.

  17. Starch characteristics influencing resistant starch content of cooked buckwheat groats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzyme resistant starch (RS), owing to its health benefits such as colon cancer inhibition, reduced glycemic response, reduced cholesterol level, prevention of gall stone formation and obesity, has received an increasing attention from consumers and food manufacturers, whereas intrinsic and extrinsi...

  18. Transformation of crystalline starch nanoparticles into highly luminescent carbon nanodots: Toxicity studies and their applications.

    PubMed

    Sonthanasamy, Regina Sisika A; Ahmad, Wan Yaacob Wan; Fazry, Shazrul; Hassan, Nurul I; Lazim, Azwan Mat

    2016-02-10

    Being abundant in many tropical part of the world, Dioscorea sp. as food is limited due to its toxicity. However polysaccharides derive from these tubers could be important for other applications. Here we developed a Highly Luminescent Carbon Nanodots (C-dots) via acid hydrolysis of Gadong starch (GS). The hydrolysis rate of GS increased from 49% to 86% within 7 days while the X-ray diffraction showed the native GS particle is a C-crystalline type. The GS particles were either round or oval with diameters ranging from 50-90 nm. Further acid dehydration and surface oxidation reduced the size of GS nanoparticles to 6-25 nm. The C-dots produced a fluorescent emission at wavelength 441 nm. Toxicity tests demonstrate that zebrafish embryo were able to tolerate the C-dots for 48 h after exposure. This study has successfully demonstrated a novel approach of converting GS into excellent fluorescent C-dot.

  19. Color transparency

    SciTech Connect

    Jennings, B.K.; Miller, G.A.

    1993-11-01

    The anomously large transmission of nucleons through a nucleus following a hard collision is explored. This effect, known as color transparency, is believed to be a prediction of QCD. The necessary conditions for its occurrence and the effects that must be included a realistic calculation are discussed.

  20. Color Sense

    ERIC Educational Resources Information Center

    Johnson, Heidi S. S.; Maki, Jennifer A.

    2009-01-01

    This article reports a study conducted by members of the WellU Academic Integration Subcommittee of The College of St. Scholastica's College's Healthy Campus Initiative plan whose purpose was to determine whether changing color in the classroom could have a measurable effect on students. One simple improvement a school can make in a classroom is…

  1. Comparison between Aging of Slices and Ethylene Treatment of Whole White Potato Tubers.

    PubMed

    Janes, H W; Wiest, S C

    1980-07-01

    Cyanide-resistant O(2) consumption can be stimulated by either treating whole white potato tubers (Norchip) with ethylene, in the presence of 100% O(2), or aging slices obtained from untreated potato tubers. A comparison of alternative pathway activity elicited by either treatment was undertaken. The proportion of electrons flowing through the alternative path in the presence of intermediate concentrations of KCN and at various concentrations of salicylhydroxamic acid was identical in both cases. However, the respiration of slices from ethylene-treated tubers was in every case stimulated by KCN, whereas the aged slices never exhibited this phenomenon. Furthermore, the metabolism of d-[U-(14)C]glucose was several hundred times greater in aged slices than in fresh slices from C(2)H(4)-treated tubers. These results, along with the respiratory kinetics of aged slices from ethylene-treated tubers, suggest that aged slices and fresh slices from ethylene-treated tubers are biochemically dissimilar.

  2. Subcellular analysis of starch metabolism in developing barley seeds using a non-aqueous fractionation method

    PubMed Central

    Tiessen, Axel; Nerlich, Annika; Faix, Benjamin; Hümmer, Christine; Fox, Simon; Trafford, Kay; Weber, Hans; Weschke, Winfriede; Geigenberger, Peter

    2012-01-01

    Compartmentation of metabolism in developing seeds is poorly understood due to the lack of data on metabolite distributions at the subcellular level. In this report, a non-aqueous fractionation method is described that allows subcellular concentrations of metabolites in developing barley endosperm to be calculated. (i) Analysis of subcellular volumes in developing endosperm using micrographs shows that plastids and cytosol occupy 50.5% and 49.9% of the total cell volume, respectively, while vacuoles and mitochondria can be neglected. (ii) By using non-aqueous fractionation, subcellular distribution between the cytosol and plastid of the levels of metabolites involved in sucrose degradation, starch synthesis, and respiration were determined. With the exception of ADP and AMP which were mainly located in the plastid, most other metabolites of carbon and energy metabolism were mainly located outside the plastid in the cytosolic compartment. (iii) In developing barley endosperm, the ultimate precursor of starch, ADPglucose (ADPGlc), was mainly located in the cytosol (80–90%), which was opposite to the situation in growing potato tubers where ADPGlc was almost exclusively located in the plastid (98%). This reflects the different subcellular distribution of ADPGlc pyrophosphorylase (AGPase) in these tissues. (iv) Cytosolic concentrations of ADPGlc were found to be close to the published Km values of AGPase and the ADPGlc/ADP transporter at the plastid envelope. Also the concentrations of the reaction partners glucose-1-phosphate, ATP, and inorganic pyrophosphate were close to the respective Km values of AGPase. (v) Knock-out of cytosolic AGPase in Riso16 mutants led to a strong decrease in ADPGlc level, in both the cytosol and plastid, whereas knock-down of the ADPGlc/ADP transporter led to a large shift in the intracellular distribution of ADPGlc. (v) The thermodynamic structure of the pathway of sucrose to starch was determined by calculating the mass–action ratios

  3. Resistant starch: promise for improving human health.

    PubMed

    Birt, Diane F; Boylston, Terri; Hendrich, Suzanne; Jane, Jay-Lin; Hollis, James; Li, Li; McClelland, John; Moore, Samuel; Phillips, Gregory J; Rowling, Matthew; Schalinske, Kevin; Scott, M Paul; Whitley, Elizabeth M

    2013-11-01

    Ongoing research to develop digestion-resistant starch for human health promotion integrates the disciplines of starch chemistry, agronomy, analytical chemistry, food science, nutrition, pathology, and microbiology. The objectives of this research include identifying components of starch structure that confer digestion resistance, developing novel plants and starches, and modifying foods to incorporate these starches. Furthermore, recent and ongoing studies address the impact of digestion-resistant starches on the prevention and control of chronic human diseases, including diabetes, colon cancer, and obesity. This review provides a transdisciplinary overview of this field, including a description of types of resistant starches; factors in plants that affect digestion resistance; methods for starch analysis; challenges in developing food products with resistant starches; mammalian intestinal and gut bacterial metabolism; potential effects on gut microbiota; and impacts and mechanisms for the prevention and control of colon cancer, diabetes, and obesity. Although this has been an active area of research and considerable progress has been made, many questions regarding how to best use digestion-resistant starches in human diets for disease prevention must be answered before the full potential of resistant starches can be realized.

  4. Mechanical properties and solubility in water of corn starch-collagen composite films: Effect of starch type and concentrations.

    PubMed

    Wang, Kun; Wang, Wenhang; Ye, Ran; Liu, Anjun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana

    2017-02-01

    This study investigated the possibility of enhancing the properties of collagen with three different maize starches: waxy maize starch, normal starch, and high amylose starch. Scanning electron microscopy images revealed that starch-collagen films had a rougher surface compared to pure collagen films which became smoother upon heating. Amylose starch and normal starch increased the tensile strength of unheated collagen films in both dry and wet states, while all starches increased tensile strength of collagen film by heating. Depending upon the amylose content and starch concentrations, film solubility in water decreased with the addition of starch. DSC thermograms demonstrated that addition of all starches improved the thermal stability of the collagen film. Moreover, X-ray diffraction results indicated that except for high amylose starch, the crystallinity of both starch and collagen was significantly decreased when subject to heating. FTIR spectra indicated that intermolecular interactions between starch and collagen were enhanced upon heating.

  5. Induction of vacuolar invertase inhibitor mRNA in potato tubers contributes to cold-induced sweetening resistance and includes spliced hybrid mRNA variants.

    PubMed

    Brummell, David A; Chen, Ronan K Y; Harris, John C; Zhang, Huaibi; Hamiaux, Cyril; Kralicek, Andrew V; McKenzie, Marian J

    2011-06-01

    Cold storage of tubers of potato (Solanum tuberosum L.) compromises tuber quality in many cultivars by the accumulation of hexose sugars in a process called cold-induced sweetening. This is caused by the breakdown of starch to sucrose, which is cleaved to glucose and fructose by vacuolar acid invertase. During processing of affected tubers, the high temperatures involved in baking and frying cause the Maillard reaction between reducing sugars and free amino acids, resulting in the accumulation of acrylamide. cDNA clones with deduced proteins homologous to known invertase inhibitors were isolated and the two most abundant forms, termed INH1 and INH2, were shown to possess apoplastic and vacuolar localization, respectively. The INH2 gene showed developmentally regulated alternative splicing, so, in addition to the INH2α transcript encoding the full-length protein, two hybrid mRNAs (INH2β*A and INH2β*B) that encoded deduced vacuolar invertase inhibitors with divergent C-termini were detected, the result of mRNA splicing of an upstream region of INH2 to a downstream region of INH1. Hybrid RNAs are common in animals, where they may add to the diversity of the proteome, but are rarely described in plants. During cold storage, INH2α and the hybrid INH2β mRNAs accumulated to higher abundance in cultivars resistant to cold-induced sweetening than in susceptible cultivars. Increased amounts of invertase inhibitor may contribute to the suppression of acid invertase activity and prevent cleavage of sucrose. Evidence for increased RNA splicing activity was detected in several resistant lines, a mechanism that in some circumstances may generate a range of proteins with additional functional capacity to aid adaptability.

  6. Induction of vacuolar invertase inhibitor mRNA in potato tubers contributes to cold-induced sweetening resistance and includes spliced hybrid mRNA variants

    PubMed Central

    Brummell, David A.; Chen, Ronan K. Y.; Harris, John C.; Zhang, Huaibi; Hamiaux, Cyril; Kralicek, Andrew V.; McKenzie, Marian J.

    2011-01-01

    Cold storage of tubers of potato (Solanum tuberosum L.) compromises tuber quality in many cultivars by the accumulation of hexose sugars in a process called cold-induced sweetening. This is caused by the breakdown of starch to sucrose, which is cleaved to glucose and fructose by vacuolar acid invertase. During processing of affected tubers, the high temperatures involved in baking and frying cause the Maillard reaction between reducing sugars and free amino acids, resulting in the accumulation of acrylamide. cDNA clones with deduced proteins homologous to known invertase inhibitors were isolated and the two most abundant forms, termed INH1 and INH2, were shown to possess apoplastic and vacuolar localization, respectively. The INH2 gene showed developmentally regulated alternative splicing, so, in addition to the INH2α transcript encoding the full-length protein, two hybrid mRNAs (INH2β*A and INH2β*B) that encoded deduced vacuolar invertase inhibitors with divergent C-termini were detected, the result of mRNA splicing of an upstream region of INH2 to a downstream region of INH1. Hybrid RNAs are common in animals, where they may add to the diversity of the proteome, but are rarely described in plants. During cold storage, INH2α and the hybrid INH2β mRNAs accumulated to higher abundance in cultivars resistant to cold-induced sweetening than in susceptible cultivars. Increased amounts of invertase inhibitor may contribute to the suppression of acid invertase activity and prevent cleavage of sucrose. Evidence for increased RNA splicing activity was detected in several resistant lines, a mechanism that in some circumstances may generate a range of proteins with additional functional capacity to aid adaptability. PMID:21393382

  7. Solvent effects on starch dissolution and gelatinization.

    PubMed

    Koganti, Nagamani; Mitchell, John R; Ibbett, Roger N; Foster, Tim J

    2011-08-08

    The disruption of starch granular structure during dissolution in varying concentrations of N-methyl morpholine N-oxide (NMMO) has been studied using three maize starches with varying ratios of amylose and amylopectin. Behavior in NMMO has been characterized by differential scanning calorimetry (DSC), microscopy, rapid viscosity analysis (RVA), and rheometry. Exothermic transitions were observed for the three starches in both 78 and 70% NMMO; the transition changed to an endotherm at 60 and 50% NMMO. Consistent with DSC, hot stage microscopy showed that starch granules dissolved at NMMO concentrations of 78 and 70%, whereas in 60 and 50% NMMO, gelatinization behavior similar to that found for starch in water was observed. Mechanical spectroscopy revealed the dominant viscous behavior (G″ > G') of starch at NMMO concentrations of 70 and 78% and more elastic behavior (G' > G″) at lower concentrations. Starch solutions in 78% NMMO obey the Cox-Merz rule, suggesting that the solutions are homogeneous on a molecular level.

  8. Isolation and characterization of starch from industrial fresh pasta by-product and its potential use in sugar-snap cookie making.

    PubMed

    Ellouzi, Soumaya Zouari; Driss, Dorra; Maktouf, Sameh; Neifar, Mohamed; Kobbi, Ameni; Kamoun, Hounaida; Chaabouni, Semia Ellouze; Ghorbel, Raoudha Ellouze

    2015-09-01

    In this paper, starch was extracted from fresh pasta by-product (PS) and its chemical composition and physical and microscopic characteristics were determined. Commercial wheat starch (CS) was used as reference. In general, purity was similar between starches studied. However, others compounds such as protein, lipid and ash were significantly different. PS starch granules had large lenticular-shape (25-33 μm) and small spherical-shape (5-8 μm). The pH and color of PS starch were similar to those reported for CS starch. On the other hand, PS had higher water absorption capacity, viscosity and cooking stability than CS. The gelatinization temperature of PS was similar to that of CS (60 and 61 °C). At high temperature (90 °C) both starches had similar rheological behavior. The results achieved suggest that PS starch has potential for application in food systems requiring high processing temperatures such the manufacture of sugar snap cookie. The effects of PS starch addition on the dough making stage and the final cookie quality were analyzed. Improvements in dough cohesiveness (24 %) and springiness (10 %) were significant relative to those of CS dough. Texture profile analysis confirmed the rheological changes.

  9. Physicochemical properties of starches and proteins in alkali-treated mungbean and cassava starch granules.

    PubMed

    Israkarn, Kamolwan; Na Nakornpanom, Nantarat; Hongsprabhas, Parichat

    2014-05-25

    This study explored the influences of envelope integrity of cooked starch granules on physicochemical and thermophysical properties of mungbean and cassava starches. Alkali treatment was used to selectively leach amylose from the amorphous region of both starches and partially fragmented starch molecules into lower-molecular-weight polymers. It was found that despite the loss of 40% of the original content of amylose, both mungbean and cassava starches retained similar crystallinities, gelatinization temperature ranges, and pasting profiles compared to the native starches. However, the loss of granule-bound starch synthases during alkali treatment and subsequent alkali cooking in excess water played significant roles in determining granular disintegration. The alterations in envelope integrity due to the negative charge repulsion among polymers within the envelope of swollen granules, and the fragmentation of starch molecules, were responsible for the alterations in thermophysical properties of mungbean and cassava starches cooked under alkaline conditions.

  10. Properties of baked foams from citric acid modified cassava starch and native cassava starch blends.

    PubMed

    Pornsuksomboon, Kanlaya; Holló, Berta Barta; Szécsényi, Katalin Mészáros; Kaewtatip, Kaewta

    2016-01-20

    Starch foams from native cassava starch (NS) and citric acid modified cassava starch (CNS) were prepared using baking processes with blend ratios of 80/20, 60/40, 50/50, 40/60 and 20/80. The density, thickness, morphology, thermal stability and water absorption of the NS, CNS and blended starch foams were determined. The ratio of the two starch components had a significant influence on the density and thickness of the blended starch foams. All blended starch foams showed good water resistance. Moreover, the morphology of the blended starch foam with the NS/CNS ratio of 50/50 showed a more ordered distribution of cell sizes with thicker cell walls than for the NS and CNS foams. The thermal stability of the blended starch foams was somewhat lower than the stability of the NS foam but not to the extent that it affected any potential practical applications.

  11. Starch composites with aconitic acid.

    PubMed

    Gilfillan, William Neil; Doherty, William O S

    2016-05-05

    The aim of this project is to examine the effectiveness of using aconitic acid (AcA), a tricarboxylic acid which contains a carbon/carbon double bond (CC), to enhance the properties of starch-based films. Starch/glycerol cast films were prepared with 0, 2, 5, 10 and 15wt% AcA (starch wt% basis) and the properties analysed. It was shown that AcA acted as both a cross-linking agent and also a strong plasticising agent. The 5wt% AcA derived starch films were the most effectively cross-linked having the lowest solubility (28wt%) and decreased swelling coefficient (35vol.%) by approximately 3 times and 2.4 times respectively compared to the control film submerged in water (23°C). There was also a significant increase in the film elongation at break by approximately 35 times (compared to the control) with the addition of 15wt% AcA, emphasising the plasticising effect of AcA. However, generally there was a reduced tensile strength, softening of the film, and reduced thermal stability with increased amounts of AcA.

  12. Limiting factors of starch hydrolysis.

    PubMed

    Colonna, P; Leloup, V; Buléon, A

    1992-10-01

    Foods appear as complex structures, in which starch may be present in different forms. These, including the molecular characteristics and the crystalline organization, depend on processing conditions and compositions of ingredients. The main changes in starch macro- and microstructures are the increase of surface area to volume ratio in the solid phase, the modification of the crystallinity as affected by gelatinization and gelation, and the depolymerization of amylose and amylopectin. Starch modification may be estimated by different methodologies, which should be selected according to the level of structure considered. When amylose and amylopectin are in solution, rapid and total hydrolysis leads to the formation of a mixture of linear oligosaccharides and branched alpha-limit dextrins. However, starch usually occurs in foods as solid structures. Structural factors of starchy materials influence their enzymic hydrolysis. A better understanding of the enzymatic process enables the identification of the structural factors limiting hydrolysis: diffusion of enzyme molecules, porosity of solid substrates, adsorption of enzymes onto solid substrates, and the catalytic event. A mechanistic modelling should be possible in the future.

  13. Cellular localization of metabotropic glutamate receptors in cortical tubers and subependymal giant cell tumors of tuberous sclerosis complex.

    PubMed

    Boer, K; Troost, D; Timmermans, W; Gorter, J A; Spliet, W G M; Nellist, M; Jansen, F; Aronica, E

    2008-09-22

    Tuberous sclerosis complex (TSC) is an autosomal dominant disorder associated with cortical malformations (cortical tubers) and the development of glial tumors (subependymal giant-cell tumors, SGCTs). Expression of metabotropic glutamate receptor (mGluR) subtypes is developmentally regulated and several studies suggest an involvement of mGluR-mediated glutamate signaling in the regulation of proliferation and survival of neural stem-progenitor cells, as well as in the control of tumor growth. In the present study, we have investigated the expression and cell-specific distribution of group I (mGluR1, mGluR5), group II (mGluR2/3) and group III (mGluR4 and mGluR8) mGluR subtypes in human TSC specimens of both cortical tubers and SGCTs, using immunocytochemistry. Strong group I mGluR immunoreactivity (IR) was observed in the large majority of TSC specimens in dysplastic neurons and in giant cells within cortical tubers, as well as in tumor cells within SGCTs. In particular mGluR5 appeared to be most frequently expressed, whereas mGluR1alpha was detected in a subpopulation of neurons and giant cells. Cells expressing mGluR1alpha and mGluR5, demonstrate IR for phospho-S6 ribosomal protein (PS6), which is a marker of the mammalian target of rapamycin (mTOR) pathway activation. Group II and particularly group III mGluR IR was less frequently observed than group I mGluRs in dysplastic neurons and giant cells of tubers and tumor cells of SGCTs. Reactive astrocytes were mainly stained with mGluR5 and mGluR2/3. These findings expand our knowledge concerning the cellular phenotype in cortical tubers and in SGCTs and highlight the role of group I mGluRs as important mediators of glutamate signaling in TSC brain lesions. Individual mGluR subtypes may represent potential pharmacological targets for the treatment of the neurological manifestations associated with TSC brain lesions.

  14. A prevalence study of autism in tuberous sclerosis.

    PubMed

    Hunt, A; Shepherd, C

    1993-06-01

    An estimate of the prevalence of autism in tuberous sclerosis (TSC) was made by interviewing the parents of 21 children between ages 3 and 11 ascertained during a previous population study of the condition in the West of Scotland. Five of the children (24%) were rated autistic and a further four (19%), all of whom were girls, had socially impaired behavior categorized as pervasive developmental disorder, without fulfilling all the DSM-III-R criteria for autism. One further boy had disruptive attention-seeking behavior that had excluded him from his normal school. The estimated prevalence from this study of autism in TSC is 1 in 4 children in general, and 1 in 2 of those with mental retardation. Tuberous sclerosis could be a significant cause of autism and pervasive developmental disorders, particularly in girls.

  15. Antioxidant properties of sterilized yacon (Smallanthus sonchifolius) tuber flour.

    PubMed

    Sousa, Sérgio; Pinto, Jorge; Rodrigues, César; Gião, Maria; Pereira, Claúdia; Tavaria, Freni; Malcata, F Xavier; Gomes, Ana; Bertoldo Pacheco, M T; Pintado, Manuela

    2015-12-01

    The objective of this research work was to investigate the antioxidant properties of sterilized yacon tuber flour. The results revealed for the first time the high antioxidant activity of sterilized yacon flour. The best extract obtained by boiling 8.9% (w/v) of yacon flour in deionised water for 10 min exhibited a total antioxidant capacity of 222±2 mg (ascorbic acid equivalent)/100 g DW and a total polyphenol content of 275±3 mg (gallic acid equivalent)/100 g DW associated to the presence of four main phenolic compounds: chlorogenic acid, caffeic acid, coumaric acid and protocatechuic acid, as well as the amino acid tryptophan. The most abundant was chlorogenic acid, followed by caffeic acid. Biological assays revealed that the extract had indeed antioxidant protection, and no pro-oxidant activity. In conclusion, sterilized yacon tuber flour has the potential to be used in the food industry as a food ingredient to produce functional food products.

  16. Glioblastoma multiforme in a child with tuberous sclerosis complex.

    PubMed

    Vignoli, Aglaia; Lesma, Elena; Alfano, Rosa Maria; Peron, Angela; Scornavacca, Giulia Federica; Massimino, Maura; Schiavello, Elisabetta; Ancona, Silvia; Cerati, Michele; Bulfamante, Gaetano; Gorio, Alfredo; Canevini, Maria Paola

    2015-10-01

    Tuberous Sclerosis Complex (TSC) is characterized by the presence of benign tumors in the brain, kidneys, heart, eyes, lungs, and skin. The typical brain lesions are cortical tubers, subependimal nodules and subependymal giant-cell astrocytomas. The occurrence of malignant astrocytomas such as glioblastoma is rare. We report on a child with a clinical diagnosis of TSC and a rapidly evolving glioblastoma multiforme. Genetic analysis identified a de novo mutation in TSC2. Molecular characterization of the tumor was performed and discussed, as well as a review of the literature where cases of TSC and glioblastoma multiforme are described. Although the co-occurrence of TSC and glioblastoma multiforme seems to be rare, this possible association should be kept in mind, and proper clinical and radiological follow up should be recommended in these patients.

  17. Effect of replacement of corn starch by whey protein isolate in biodegradable film blends obtained by extrusion.

    PubMed

    Azevedo, Viviane Machado; Borges, Soraia Vilela; Marconcini, José Manoel; Yoshida, Maria Irene; Neto, Alfredo Rodrigues Sena; Pereira, Tamara Coelho; Pereira, Camila Ferreira Gonçalves

    2017-02-10

    The aim of this study was to evaluate the effect of replacing corn starch by whey protein isolated (WPI) in biodegradable polymer blends developed by extrusion. X-ray diffraction showed the presence of a Vh-type crystalline arrangement. The films were homogeneous, indicating strong interfacial adhesion between the protein and the thermoplastic starch matrix (TPS) as observed in scanning electron microscopy. The addition of WPI on TPS matrix promoted an increase in the thermal stability of the materials. It was observed 58.5% decrease in the water vapor permeability. The effect of corn starch substitution by WPI on mechanical properties resulted in a more resistant and less flexible film when compared the TPS film. The addition of WPI caused greenish yellow color and less transparent films. The substitution of corn starch by WPI made it possible to obtain polymer blends with improved properties and represents an innovation for application as a packaging material.

  18. Mutational Analysis of Cell Types in Tuberous Sclerosis Complex (TSC)

    DTIC Science & Technology

    2007-01-01

    disorder resulting from mutations in the TSC1 or TSC2 genes that is associated with epilepsy, cognitive disability, and autism . TSC1/TSC2 gene mutations...cognitive disability, and autism . TSC1/TSC2 gene mutations lead to developmental alterations in brain structure known as tubers in over 80% of TSC...TSC (Sparagana and Roach, 2000). Comorbid neuropsychological disorders such as autism , mental retardation (MR), pervasive developmental disorder

  19. Do we have a cure for tuberous sclerosis complex?

    PubMed

    Crino, Peter B

    2008-01-01

    The recent development of several mouse models for tuberous sclerosis complex (TSC) provides in vivo systems to test new therapies for the neurological manifestations of TSC. Rapamycin is known to antagonize the effects of loss of TSC protein function in vitro and in mouse TSC models, rapamycin can prevent seizures and improve learning task performance. These findings provide new hope for TSC patients suffering from intractable seizures and possibly, for those with autism and cognitive disabilities.

  20. Impact of variety type and particle size distribution on starch enzymatic hydrolysis and functional properties of tef flours.

    PubMed

    Abebe, Workineh; Collar, Concha; Ronda, Felicidad

    2015-01-22

    Tef grain is becoming very attractive in the Western countries since it is a gluten-free grain with appreciated nutritional advantages. However there is little information of its functional properties and starch digestibility and how they are affected by variety type and particle size distribution. This work evaluates the effect of the grain variety and the mill used on tef flour physico-chemical and functional properties, mainly derived from starch behavior. In vitro starch digestibility of the flours by Englyst method was assessed. Two types of mills were used to obtain whole flours of different granulation. Rice and wheat flours were analyzed as references. Protein molecular weight distribution and flour structure by SEM were also analyzed to justify some of the differences found among the cereals studied. Tef cultivar and mill type exhibited important effect on granulation, bulking density and starch damage, affecting the processing performance of the flours and determining the hydration and pasting properties. The color was darker although one of the white varieties had a lightness near the reference flours. Different granulation of tef flour induced different in vitro starch digestibility. The disc attrition mill led to higher starch digestibility rate index and rapidly available glucose, probably as consequence of a higher damaged starch content. The results confirm the adequacy of tef flour as ingredient in the formulation of new cereal based foods and the importance of the variety and the mill on its functional properties.

  1. Size of tuber propagule influences injury of 'Kennebec' potato plants by constant light

    NASA Technical Reports Server (NTRS)

    Cushman, K. E.; Tibbitts, T. W.

    1996-01-01

    Chlorosis and necrotic spotting develop on the foliage of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light. 'Kennebec', a cultivar severely injured by constant light when propagated from tissue-cultured plantlets, also was injured when plants were propagated from small tuber pieces (approximately 1 g). However, plants did not develop injury when propagated from large tuber pieces (approximately 100 g). Plants from large tuber pieces grew more rapidly than plants from small tuber pieces. The role of plant vigor and carbohydrate translocation in controlling injury development is discussed.

  2. The effects of auxin and strigolactones on tuber initiation and stolon architecture in potato

    PubMed Central

    Bachem, Christian W.B.

    2012-01-01

    Various transcriptional networks and plant hormones have been implicated in controlling different aspects of potato tuber formation. Due to its broad impact on many plant developmental processes, a role for auxin in tuber initiation has been suggested but never fully resolved. Here, auxin concentrations were measured throughout the plant prior to and during the process of tuber formation. Auxin levels increase dramatically in the stolon prior to tuberization and remain relatively high during subsequent tuber growth, suggesting a promoting role for auxin in tuber formation. Furthermore, in vitro tuberization experiments showed higher levels of tuber formation from axillary buds of explants where the auxin source (stolon tip) had been removed. This phenotype could be rescued by application of auxin on the ablated stolon tips. In addition, a synthetic strigolactone analogue applied on the basal part of the stolon resulted in fewer tubers. The experiments indicate that a system for the production and directional transport of auxin exists in stolons and acts synergistically with strigolactones to control the outgrowth of the axillary stolon buds, similar to the control of above-ground shoot branching. PMID:22689826

  3. The effects of auxin and strigolactones on tuber initiation and stolon architecture in potato.

    PubMed

    Roumeliotis, Efstathios; Kloosterman, Bjorn; Oortwijn, Marian; Kohlen, Wouter; Bouwmeester, Harro J; Visser, Richard G F; Bachem, Christian W B

    2012-07-01

    Various transcriptional networks and plant hormones have been implicated in controlling different aspects of potato tuber formation. Due to its broad impact on many plant developmental processes, a role for auxin in tuber initiation has been suggested but never fully resolved. Here, auxin concentrations were measured throughout the plant prior to and during the process of tuber formation. Auxin levels increase dramatically in the stolon prior to tuberization and remain relatively high during subsequent tuber growth, suggesting a promoting role for auxin in tuber formation. Furthermore, in vitro tuberization experiments showed higher levels of tuber formation from axillary buds of explants where the auxin source (stolon tip) had been removed. This phenotype could be rescued by application of auxin on the ablated stolon tips. In addition, a synthetic strigolactone analogue applied on the basal part of the stolon resulted in fewer tubers. The experiments indicate that a system for the production and directional transport of auxin exists in stolons and acts synergistically with strigolactones to control the outgrowth of the axillary stolon buds, similar to the control of above-ground shoot branching.

  4. Retrograded maize starch used as a medium to enrich Monascus from the air in winter.

    PubMed

    Liu, Lizeng; Wang, Danli; Lian, Xijun; Wu, Hong

    2014-06-01

    Red pigments extracted from fungus Monascus are used for food coloration in China. Wild-growing Monascus spores are usually enriched in the yeast and mold media in the air, but those media are also favorable for yeast and bacteria. In the paper, Monascus species have grown in retrograded maize starch lain in air outdoors in winter, molds, yeast or bacteria colonies have been absent. Then a medium of the retrograded maize starch for enriching Monascus in the air is explored and its physicochemical properties are determined by ordinary camera photos, NMR, SEM spectra and X-ray diffraction. The lamellar structure of frozen retrograded maize starch, whose interlamellar spacing is about 2μm, provides a favorable condition for Monascus spore to germinate and grow.

  5. Facile Precursor for Synthesis of Silver Nanoparticles Using Alkali Treated Maize Starch

    PubMed Central

    El-Rafie, M. H.; Ahmed, Hanan B.; Zahran, M. K.

    2014-01-01

    Silver nanoparticles were prepared by using alkali treated maize starch which plays a dual role as reducer for AgNO3 and stabilizer for the produced AgNPs. The redox reaction which takes a place between AgNO3 and alkali treated starch was followed up and controlled in order to obtain spherical shaped silver nanoparticles with mean size 4–6 nm. The redox potentials confirmed the principle role of alkali treatment in increasing the reducibility of starch macromolecules. The measurements of reducing sugars at the end of reaction using dinitrosalicylic acid reagent (DNS) were carried out in order to control the chemical reduction reaction. The UV/Vis spectra show that an absorption peak, occurring due to surface plasmon resonance (SPR), exists at 410 nm, which is characteristic to yellow color of silver nanoparticles solution. The samples have been characterized by transmission electron microscopy (TEM), which reveal the nanonature of the particles. PMID:27433508

  6. Generic Delimitations in Tuberous Periplocoideae (Apocynaceae) from Africa and Madagascar

    PubMed Central

    MEVE, ULRICH; LIEDE, SIGRID

    2004-01-01

    • Background and Aims The number of genera included in Apocynaceae subfamily Periplocoideae is a matter of debate. DNA sequences are used here as an independent dataset to clarify generic relationships and classification of the tuberous periplocoid genera and to address the question of the phylogenetic interpretation of pollinia formation in Schlechterella. • Methods Representatives of nearly all African and Malagasy genera of Periplocoideae possessing root tubers were analysed using ITS and plastid DNA sequence characters. • Key Results Sequence data from non‐coding molecular markers (ITS of nrDNA and the trnT‐L and trnL‐F spacers as well as the trnL intron of plastid DNA) give support for a broad taxonomic concept of Raphionacme including Pentagonanthus. Together with Schlechterella, which is sister to Raphionacme, all Raphionacme‐like taxa form a derived monophyletic group of somewhat diverse species. Sister to the Schlechterella/Raphionacme clade is a clade comprising Stomatostemma and the not truly tuberous vine Mondia. In the combined analysis, sister to these two clades combined is a clade formed by Petopentia natalensis and Periploca. • Conclusions The recent inclusion of the monotypic South African Petopentia in the monotypic Malagasy endemic Ischnolepis is to be rejected. The Malagasy Camptocarpus is sister to the remainder of Periplocoideae in the ITS and combined analyses, and a Malagasy origin for the subfamily is discussed. PMID:14980976

  7. Utilization of sorghum, rice, corn flours with potato starch for the preparation of gluten-free pasta.

    PubMed

    Ferreira, Sila Mary Rodrigues; de Mello, Ana Paula; de Caldas Rosa dos Anjos, Mônica; Krüger, Cláudia Carneiro Hecke; Azoubel, Patrícia Moreira; de Oliveira Alves, Márcia Aurelina

    2016-01-15

    The aim of this study was to evaluate the use of mixture of sorghum-rice-corn flour and potato starch in the development of gluten-free pasta for celiac disease patients. The experiment was designed according to simplex-lattice method and different types of gluten-free flours were used, such as sorghum, rice, corn, and potato starch. The fifteen formulations were subjected to sensory analysis (Mixed Structured Scale - MSS) and seven formulations were selected in respect to taste and grittiness. These formulations were subjected to Quantitative Descriptive Analysis (QDA), which evaluated the attributes: appearance, color, odor, hardness, elasticity, stickiness, grittiness, taste, residual bitterness and overall quality. Results showed significant difference in appearance, color and hardness. The formulations that showed the best sensory results were submitted to chemical analysis and cooking quality of pasta. It was observed that the best results for mixing is sorghum flour, rice flour and potato starch.

  8. Physicochemical Properties of Starch Isolated from Bracken (Pteridium aquilinim) Rhizome.

    PubMed

    Yu, Xurun; Wang, Jin; Zhang, Jing; Wang, Leilei; Wang, Zhong; Xiong, Fei

    2015-12-01

    Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X-ray diffraction analysis revealed that bracken starch exhibited a typical C-type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch.

  9. Rheological and textural properties of pulse starch gels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The properties of starch gels from black beans, chickpeas, lentils and navy beans were investigated. Differences were shown between starch sources, and effect of starch concentration was studied. Navy bean starch had the highest peak and final viscosities in pasting tests, while black bean starch h...

  10. Colorful drying.

    PubMed

    Lakio, Satu; Heinämäki, Jyrki; Yliruusi, Jouko

    2010-03-01

    Drying is one of the standard unit operations in the pharmaceutical industry and it is important to become aware of the circumstances that dominate during the process. The purpose of this study was to test microcapsulated thermochromic pigments as heat indicators in a fluid bed drying process. The indicator powders were manually granulated with alpha-lactose monohydrate resulting in three particle-size groups. Also, pellets were coated with the indicator powders. The granules and pellets were fluidized in fluid bed dryer to observe the progress of the heat flow in the material and to study the heat indicator properties of the indicator materials. A tristimulus colorimeter was used to measure CIELAB color values. Color indicator for heat detection can be utilized to test if the heat-sensitive API would go through physical changes during the pharmaceutical drying process. Both the prepared granules and pellets can be used as heat indicator in fluid bed drying process. The colored heat indicators give an opportunity to learn new aspects of the process at real time and could be exploded, for example, for scaling-up studies.

  11. Shelf-life extension of fresh Tuber aestivum and Tuber melanosporum truffles by modified atmosphere packaging with microperforated films.

    PubMed

    Rivera, Carmen Susana; Blanco, Domingo; Salvador, María Luisa; Venturini, María Eugenia

    2010-05-01

    The aim of this study was to design a modified atmosphere packaging suitable for Tuber melanosporum and Tuber aestivum truffles that extend their shelf life and their availability as a fresh product. Their respiration rates were determined by O(2) depletion and CO(2) formation in closed systems performed at different temperatures: 4, 10, and 23 degrees C. The results were fitted by exponential equations and derivatives of these equations were used to obtain the experimental respiration rates. Our results revealed high respiration rates in both species of truffles and respiratory quotients (RQ) higher than 1 in all the cases studied. A linear dependence of respiration rate, both R(O2) and R(CO2), on O(2) concentration was revealed. A mathematical model was used to predict the evolution of the gaseous composition at 4 degrees C in the interior of polypropylene trays (250 mL) heat sealed with 4 microperforated films of different transmission rates. A microperforated film with 2 holes (90 x 50 microm) was selected to produce an internal atmosphere of 15%CO(2)/7%O(2) at 4 degrees C. The predicted atmosphere composition was confirmed by the experimental results. The quality and microbiological characteristics of fresh truffles, packaged in these conditions, revealed that the microbial counts of pseudomonads and Enterobacteriaceae were decreased, the weight loss was reduced, the typical hard texture was maintained, and the development of mycelium growth was delayed, enabling good scores for aroma and flavor, and therefore prolonging the shelf life of T. melanosporum and T. aestivum truffles to 28 and 21 d, respectively. Practical Application: This study describes the benefits of using MAP with microperforated films in the postharvest storage of Tuber melanosporum and Tuber aestivum fresh truffles. The shelf life of T. aestivum is prolonged to 21 d and of T. melanosporum to beyond 28 d increasing the possibilities for a foreign market.

  12. Purification and properties of lectin from potato tubers and leaves; interaction with acid phosphatase from potato tuber.

    PubMed

    Wierzba-Arabska, E; Morawiecka, B

    1987-01-01

    The haemagglutination activity of lectin, (STA) was determined during vegetation of potatoes (Solanum tuberosum var. Uran). Traces of haemagglutination activity were found in young stalks and first leaves. In the next leaves the maximal activity appeared after 6-8 weeks of vegetation and, simultaneously with the decrease in leaves it appeared in young tubers (at the time of their differentiation from stolons), reaching the maximum in the 18th week of vegetation. Lectins from potato tubers and leaves were extracted with acetate buffer, pH 3.6, salted out with ammonium sulphate, and purified alternatively by affinity chromatography on GlcNAc-Spheron or by adsorption on trypsinated and glutaraldehyde-fixed rabbit erythrocytes. Chromatography on Sephadex G-200 was used for preparative separation of isomeric forms. In the tubers four isolectins were found, differeing in molecular mass, pI values, content of sugars and haemagglutination activity. Two of these forms were isolated in homogeneous form: a heavy dimeric form, Mr 130,000-142,000 containing 59.6% of sugars (including 28.8% arabinose, 6.9% galactose, 16.5% glucose, 1.6% xylose and 3.1% mannose), and a light monomeric form. of Mr 21,000-22,000, containing 20% of neutral sugars (2.5% of pentoses and 17.5% of hexoses). From leaves, a single heavy dimeric lectin of Mr 136,000, containing 14.3% of neutral sugars was isolated. The effect of tuber isolectin on the activity, pH optima and heat-stability of the potato acid phosphatase has been described.

  13. Thermal and rheological properties of breadfruit starch.

    PubMed

    Wang, Xueyu; Chen, Ling; Li, Xiaoxi; Xie, Fengwei; Liu, Hongshen; Yu, Long

    2011-01-01

    The thermal and rheological properties of breadfruit starch were studied using DSC and 2 different rheometers. It was found that the gelatinization temperature of starch with excess moisture content (>70%) was at approximately 75 °C. A new endotherm was detected at about 173 °C when the moisture content was lower than required for full gelatinization of the starch. A detailed examination revealed that this endotherm represented the melting of amylose-lipid complexes. Breadfruit starch paste exhibited shear-thinning fluid characteristics, and good thermal and pH stability. The setback viscosity of the breadfruit starch was lower than that of potato and corn starches. The rheological properties of the breadfruit starch paste was well described by the Herschel-Bulkley model at a shear rate of 0 to 100 s(-1), where R(2) is greater than 0.95, and it behaved like a yield-pseudoplastic fluid. Both the storage modulus and loss modulus of the paste initially increased sharply, then dropped after reaching the gelatinization peak. Breadfruit starch gel showed both flexibility and viscosity. Suspension with 6% starch content exhibited very weak gel rigidity; however, this increased significantly at starch contents above 20%.

  14. Molecular disassembly of starch granules during gelatinization and its effect on starch digestibility: a review.

    PubMed

    Wang, Shujun; Copeland, Les

    2013-11-01

    Starch is the most important glycemic carbohydrate in foods. The relationship between the rate and extent of starch digestion to produce glucose for absorption into the bloodstream and risk factors for diet-related diseases is of considerable nutritional interest. Native starch is attacked slowly by enzymes, but after hydrothermal processing its susceptibility to enzymatic breakdown is greatly increased. Most starch consumed by humans has undergone some form of processing or cooking, which causes native starch granules to gelatinize, followed by retrogradation on cooling. The extent of gelatinization and retrogradation are major determinants of the susceptibility of starch to enzymatic digestion and its functional properties for food processing. The type and extent of changes that occur in starch as a result of gelatinization, pasting and retrogradation are determined by the type of the starch, processing and storage conditions. A mechanistic understanding of the molecular disassembly of starch granules during gelatinization is critical to explaining the effects of processing or cooking on starch digestibility. This review focuses on the molecular disassembly of starch granules during starch gelatinization over a wide range of water levels, and its consequential effect on in vitro starch digestibility and in vivo glycemic index.

  15. Introduction To Color Vision

    NASA Astrophysics Data System (ADS)

    Thorell, Lisa G.

    1983-08-01

    Several human cognitive studies have reported that color facilitates certain learning, memory and search tasks. Consideration of the color-opponent organization of human color vision and the spatial modulation transfer function for color suggests several simple sensory explanations.

  16. 75 FR 879 - National Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-06

    ... Employment and Training Administration National Starch and Chemical Company Specialty Starches Division..., applicable to workers of National Starch and Chemical Company, Specialty Starches Division, Island Falls.... The workers were engaged in the production of drum dried and modified food starches. New...

  17. QTL mapping of potato chip color and tuber traits within an autotetraploid family

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated potato (Solanum tuberosum L.) is a highly heterozygous autotetraploid crop species, and this presents challenges for traditional line development and molecular breeding. Recent availability of a single nucleotide polymorphism (SNP) array with 8303 features and software packages for linkag...

  18. Mutations Affecting Starch Synthase III in Arabidopsis Alter Leaf Starch Structure and Increase the Rate of Starch Synthesis1

    PubMed Central

    Zhang, Xiaoli; Myers, Alan M.; James, Martha G.

    2005-01-01

    The role of starch synthase (SS) III (SSIII) in the synthesis of transient starch in Arabidopsis (Arabidopsis thaliana) was investigated by characterizing the effects of two insertion mutations at the AtSS3 gene locus. Both mutations, termed Atss3-1 and Atss3-2, condition complete loss of SSIII activity and prevent normal gene expression at both the mRNA and protein levels. The mutations cause a starch excess phenotype in leaves during the light period of the growth cycle due to an apparent increase in the rate of starch synthesis. In addition, both mutations alter the physical structure of leaf starch. Significant increases were noted in the mutants in the frequency of linear chains in amylopectin with a degree of polymerization greater than approximately 60, and relatively small changes were observed in chains of degree of polymerization 4 to 50. Furthermore, starch in the Atss3-1 and Atss3-2 mutants has a higher phosphate content, approximately two times that of wild-type leaf starch. Total SS activity is increased in both Atss3 mutants and a specific SS activity appears to be up-regulated. The data indicate that, in addition to its expected direct role in starch assembly, SSIII also has a negative regulatory function in the biosynthesis of transient starch in Arabidopsis. PMID:15908598

  19. Effect of the incorporation of antimicrobial/antioxidant proteins on the properties of potato starch films.

    PubMed

    Moreno, Olga; Atarés, Lorena; Chiralt, Amparo

    2015-11-20

    Glycerol plasticized potato starch films containing bioactive proteins (lactoferrin (LF) and/or lysozyme (LZ), at 0.1 and 0.2 ratio with respect to starch) were obtained by casting method and characterized as to their microstructural, thermal and physical (water content, mechanical, water and oxygen barrier, optical) properties. The bioactive properties, named antioxidant and antimicrobial, of the proteins and the films were also characterized. The incorporation of proteins affected the structural and physical properties of potato starch films, while modifying their thermal behavior and increasing the glass transition temperature. Both proteins showed a certain degree of compatibility with starch chains through the bond formations (increase in Tg), while a part is separated and migrates to the film surface. Their incorporation, especially that of lactoferrin, greatly increased the film's brittleness, regardless of the films water content, although they enhance the water vapor and oxygen barrier properties, whatever the age of the film. Protein also reduced the film's transparency and gloss, while lactoferrin induced color changes. The thermal degradation of blend films and isolated proteins occurred at temperatures of over 250°C, which means that blend starch films can be thermoprocessed, according to their thermoplastic properties and following the usual practices of the plastics industries. A synergistic antimicrobial action against Escherichia coli and coliforms was observed when both LZ and LF were simultaneously applied. Both of these exhibited antioxidant capacity.

  20. Starch gelatinization in coiled heaters.

    PubMed

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  1. Characterisation and disintegration properties of irradiated starch.

    PubMed

    De Kerf, M; Mondelaers, W; Lahorte, P; Vervaet, C; Remon, J P

    2001-06-19

    Irradiation treatment could provide a quick and simple way to modify the physical, chemical and pharmaceutical properties of biopolymers such as starch. Corn, potato and drum dried corn starch were exposed to X-ray and electron beam (e-beam) irradiation treatment at doses of 10, 50 and 100 kGy. The disintegration properties of these starches were compared using alpha-lactose monohydrate tablets containing 5% (w/w) starch as disintegrant. Starch solubility increased, while its swelling capacity decreased with increasing irradiation dose. The irradiation treatment caused fragmentation of the amylopectin fraction. Irradiation modified the different starches thoroughly, showing remarkable differences in disintegration properties after X-ray treatment and e-beam modification. The e-beam modification resulted in significantly higher disintegration times of the tablets.

  2. The effects of starches on mechanical properties of paracetamol tablet formulations. I. Pregelatinization of starch binders.

    PubMed

    Alebiowu, Gbenga; Itiola, Oludele Adelanwa

    2003-09-01

    A study has been made of the effects of pregelatinization of native sorghum and plantain starches on the mechanical properties of a paracetamol tablet formulation in comparison with corn starch BP. The mechanical properties tested, viz. tensile strength (T) and brittle fracture index (BFI) of the paracetamol tablets were affected by pregelatinization of the starch. The results suggest that pregelatinized starches may be useful as binders when a particular degree of bond strength and brittleness is desired.

  3. Structural and functional properties of C-type starches.

    PubMed

    Cai, Jinwen; Cai, Canhui; Man, Jianmin; Zhou, Weidong; Wei, Cunxu

    2014-01-30

    This study investigated the structural and functional properties of C-type starches from pea seeds, faba bean seeds, yam rhizomes and water chestnut corms. These starches were mostly oval in shape with significantly different sizes and contents of amylose, damaged starch and phosphorus. Pea, faba bean and water chestnut starches had central hila, and yam starch had eccentric hilum. Water chestnut and yam starches had higher amylopectin short and long chain, respectively. Water chestnut and faba bean starches showed CA-type crystallinities, and pea and yam starches had C-type crystallinities. Water chestnut starch had the highest swelling power, granule swelling and pasting viscosity, lowest gelatinization temperatures and enthalpy. Faba bean starch had the lowest pasting viscosity, whereas yam starch had the highest gelatinization temperatures. Water chestnut and yam starches possessed significantly higher and lower susceptibility to acid and enzyme hydrolysis, the highest and lowest RDS contents, and the lowest and highest RS contents, respectively.

  4. Insights into molecular structure and digestion rate of oat starch.

    PubMed

    Xu, Jinchuan; Kuang, Qirong; Wang, Kai; Zhou, Sumei; Wang, Shuo; Liu, Xingxun; Wang, Shujun

    2017-04-01

    The in vitro digestibility of oat starch and its relationship with starch molecular structure was investigated. The in vitro digestion results showed that the first-order kinetic constant (k) of oat starches (OS-1 and OS-2) was lower than that of rice starch. The size of amylose chains, amylose content and degree of branching (DB) of amylopectin in oat starch were significantly higher than the corresponding parameters in rice starch. The larger molecular size of oat starch may account for its lower digestion rate. The fine structure of amylopectin showed that oat starch had less chains of DP 6-12 and DP>36, which may explain the small difference in digestion rate between oat and rice starch. The biosynthesis model from oat amylopectin fine structure data suggested a lower starch branching enzyme (SBE) activity and/or a higher starch synthase (SS) activity, which may decrease the DB of oat starch and increase its digestion rate.

  5. The Involvement of Gibberellins in 1,8-Cineole-Mediated Inhibition of Sprout Growth in Russet Burbank Tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The involvement of gibberellins in 1,8-cineole-mediated inhibition of tuber sprout growth was investigated in non-dormant field- and greenhouse-grown tubers of Russet Burbank. Continuous exposure of tubers to cineole in the vapor-phase resulted in a dose-dependent inhibition of sprout growth. Comp...

  6. Issues of Starch in Sugarcane Processing and Prospects of Breeding for Low Starch Content in Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch is a sugarcane impurity that adversely affects the quantity and quality of sugar processes and products. The increased production of combine and green harvested sugarcane has increased delivery of starch to sugarcane factories. Starch occurs as granules composed of amylose and amylopectin p...

  7. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.

    PubMed

    Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends.

  8. Starch aerogel beads obtained from inclusion complexes prepared from high amylose starch and sodium palmitate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch aerogels are a class of low density highly porous renewable materials currently prepared from retrograded starch gels and are of interest for their good surface area, porosity, biocompatibility, and biodegradability. Recently, we have reported on starches containing amylose-fatty acid salt h...

  9. Do focal colors look particularly "colorful"?

    PubMed

    Witzel, Christoph; Franklin, Anna

    2014-04-01

    If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

  10. The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development.

    PubMed

    Pasare, Stefania A; Ducreux, Laurence J M; Morris, Wayne L; Campbell, Raymond; Sharma, Sanjeev K; Roumeliotis, Efstathios; Kohlen, Wouter; van der Krol, Sander; Bramley, Peter M; Roberts, Alison G; Fraser, Paul D; Taylor, Mark A

    2013-06-01

    · Strigolactones (SLs) are a class of phytohormones controlling shoot branching. In potato (Solanum tuberosum), tubers develop from underground stolons, diageotropic stems which originate from basal stem nodes. As the degree of stolon branching influences the number and size distribution of tubers, it was considered timely to investigate the effects of SL production on potato development and tuber life cycle. · Transgenic potato plants were generated in which the CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) gene, key in the SL biosynthetic pathway, was silenced by RNA interference (RNAi). · The resulting CCD8-RNAi potato plants showed significantly more lateral and main branches than control plants, reduced stolon formation, together with a dwarfing phenotype and a lack of flowering in the most severely affected lines. New tubers were formed from sessile buds of the mother tubers. The apical buds of newly formed transgenic tubers grew out as shoots when exposed to light. In addition, we found that CCD8 transcript levels were rapidly downregulated in tuber buds by the application of sprout-inducing treatments. · These results suggest that SLs could have an effect, solely or in combination with other phytohormones, in the morphology of potato plants and also in controlling stolon development and maintaining tuber dormancy.

  11. The pink eye syndrome does not impair tuber fresh cut wound-related responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato tuber pink eye (PE) syndrome is a costly physiological disorder that results in corruption of the native periderm, susceptibility to infection, water vapor loss and associated shrinkage, roughened and cracked tuber surfaces, and various related blemishes and defects. PE results in aberra...

  12. Cover crops alter the soil microbial community and increase potato tuber yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An on-going study at a commercial farm operation in the San Luis Valley, CO is examining the effect of various summer cover crops (mustard, canola, sorghum-sudangrass, and a wet fallow control) on potato tuber yield and quality. In four of the five years, potato tuber yield and quality has shown si...

  13. Variation for tuber greening in the diploid wild potato Solanum microdontum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greening of the tuber skin is an undesirable defect in fresh and processed potato. Tubers of 92 Solanum microdontum families represented by 12 individuals each were generated in the winter greenhouse in 2009-2010. These were evaluated in two trials of family bulks after four days of exposure to 200 ...

  14. Advances and Future Directions for Tuberous Sclerosis Complex Research: Recommendations From the 2015 Strategic Planning Conference.

    PubMed

    Sahin, Mustafa; Henske, Elizabeth P; Manning, Brendan D; Ess, Kevin C; Bissler, John J; Klann, Eric; Kwiatkowski, David J; Roberds, Steven L; Silva, Alcino J; Hillaire-Clarke, Coryse St; Young, Lisa R; Zervas, Mark; Mamounas, Laura A

    2016-07-01

    On March 10 to March 12, 2015, the National Institute of Neurological Disorders and Stroke and the Tuberous Sclerosis Alliance sponsored a workshop in Bethesda, Maryland, to assess progress and new opportunities for research in tuberous sclerosis complex with the goal of updating the 2003 Research Plan for Tuberous Sclerosis (http://www.ninds.nih.gov/about_ninds/plans/tscler_research_plan.htm). In addition to the National Institute of Neurological Disorders and Stroke and Tuberous Sclerosis Alliance, participants in the strategic planning effort and workshop included representatives from six other Institutes of the National Institutes of Health, the Department of Defense Tuberous Sclerosis Complex Research Program, and a broad cross-section of basic scientists and clinicians with expertise in tuberous sclerosis complex along with representatives from the pharmaceutical industry. Here we summarize the outcomes from the extensive premeeting deliberations and final workshop recommendations, including (1) progress in the field since publication of the initial 2003 research plan for tuberous sclerosis complex, (2) the key gaps, needs, and challenges that hinder progress in tuberous sclerosis complex research, and (3) a new set of research priorities along with specific recommendations for addressing the major challenges in each priority area. The new research plan is organized around both short-term and long-term goals with the expectation that progress toward specific objectives can be achieved within a five to ten year time frame.

  15. Regulatory control of high levels of carotenoid accumulation in potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato (Solanum tuberosum L.) tubers contain a wide range of carotenoid content. To decipher the key factors controlling carotenoid levels in tubers, four potato lines (Atlantic, Désirée, 91E22, and POR03) were examined by a combination of biochemical, molecular, and genomics approaches. These lines...

  16. Monitoring and predicting shrink potential and future processing quality of potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term storage of potato tubers increases risks, which are often attributed to shrink and quality loss. To minimize shrink and ensure high quality tubers, producers must closely monitor the condition of the crop during storage and make necessary adjustments to management plans. Evaluation procedu...

  17. Assessing potato tuber diel growth by means of X-ray computed tomography.

    PubMed

    Pérez-Torres, Eduardo; Kirchgessner, Norbert; Pfeifer, Johannes; Walter, Achim

    2015-11-01

    The formation and development of belowground organs is difficult to study. X-ray computed tomography (CT) provides the possibility to analyse and interpret subtle volumetric changes of belowground organs such as tubers, storage roots and nodules. Here, we report on the establishment of a method based on a voxel dimension of 240 μm and precision (standard deviation) of 30 μL that allows interpreting growth differences among potato tubers happening within 3 h. Plants were not stressed by the application of X-ray radiation, which was shown both by morphological comparison with control plants and by analysis of lipid peroxidation as a measure of oxidative stress. Diel (24 h) tuber growth fluctuations of three potato genotypes were monitored in soil-filled pots of 10 L. In contrast to the results from previous reports, most tubers grew at similar rates during day and night. Tuber growth was not related to the developmental stage of plants and tubers. Pronounced differences were observed between average growth rates in different tubers within a plant. These results are discussed in the context of restrictions of past methods to study tuber growth and in the context of their potential for the characterization of the formation and development of other belowground plant organs.

  18. Epitope mapping for monoclonal antibodies recognizing tuber necrotic isolates of Potato virus Y

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato virus Y (PVY) is an important viral pathogen of potato responsible for reducing tuber yield and quality across the globe. The PVYN and PVYNTN strains, the latter of which induces potato tuber necrotic ringspot disease (PTNRD), are regulated for international potato trade, and have been routin...

  19. Physical modification of food starch functionalities.

    PubMed

    BeMiller, James N; Huber, Kerry C

    2015-01-01

    Because, in general, native starches do not have properties that make them ideally suited for applications in food products, most starch is modified by dervatization to improve its functionality before use in processed food formulations, and because food processors would prefer not to have to use the modified food starch label designation required when chemically modified starches are used, there is considerable interest in providing starches with desired functionalities that have not been chemically modified. One investigated approach is property modification via physical treatments, that is, modifications of starches imparted by physical treatments that do not result in any chemical modification of the starch. Physical treatments are divided into thermal and nonthermal treatments. Thermal treatments include those that produce pregelatinized and granular cold-water-swelling starches, heat-moisture treatments, annealing, microwave heating, so-called osmotic pressure treatment, and heating of dry starch. Nonthermal treatments include ultrahigh-pressure treatments, instantaneous controlled pressure drop, use of high-pressure homogenizers, dynamic pulsed pressure, pulsed electric field, and freezing and thawing.

  20. Development of a certified reference material for genetically modified potato with altered starch composition.

    PubMed

    Broothaerts, Wim; Corbisier, Philippe; Emons, Hendrik; Emteborg, Håkan; Linsinger, Thomas P J; Trapmann, Stefanie

    2007-06-13

    The presence of genetically modified organisms (GMOs) in food and feed products is subject to regulation in the European Union (EU) and elsewhere. As part of the EU authorization procedure for GMOs intended for food and feed use, reference materials must be produced for the quality control of measurements to quantify the GMOs. Certified reference materials (CRMs) are available for a range of herbicide- and insect-resistant genetically modified crops such as corn, soybean, and cotton. Here the development of the first CRM for a GMO that differs from its non-GMO counterpart in a major compositional constituent, that is, starch, is described. It is shown that the modification of the starch composition of potato (Solanum tuberosum L.) tubers, together with other characteristics of the delivered materials, have important consequences for the certification strategy. Moreover, the processing and characterization of the EH92-527-1 potato material required both new and modified procedures, different from those used routinely for CRMs produced from genetically modified seeds.

  1. Seasonal adaptations of the tuberous roots of Ranunculus asiaticus to desiccation and resurrection by changes in cell structure and protein content.

    PubMed

    Kamenetsky, Rina; Peterson, R Larry; Melville, Lewis H; Machado, Cibele F; Bewley, J Derek

    2005-04-01

    The annual developmental cycle of tuberous roots of Ranunculus asiaticus was studied with respect to structure and content of their cells, to understand how these roots are adapted to desiccation, high temperature and rehydration. Light microscopy, histochemical analysis, and protein analyses by SDS-PAGE were employed at eight stages of annual root development. During growth and maturation of the roots, cortical cells increased in size and their cell walls accumulated pectin materials in a distinct layer to the inside of the primary walls, with pits between adjoining cells. The number of starch granules and protein bodies also increased within the cells. Several discrete proteins accumulated. Following quiescence and rehydration of the roots there was a loss of starch and proteins from the cells, and cell walls decreased in thickness. The resurrection geophyte R. asiaticus possesses desiccation-tolerant annual roots. They store carbon and nitrogen reserves within their cells, and pectin within the walls to support growth of the plant following summer quiescence and rehydration.

  2. Can loss of apical dominance in potato tuber serve as a marker of physiological age?

    PubMed Central

    Eshel, Dani; Teper-Bamnolker, Paula

    2012-01-01

    The potato tuber constitutes a model system for the study of dormancy release and sprouting, suggested to be regulated by endogenous plant hormones and their balance inside the tuber. During dormancy, potato tubers cannot be induced to sprout without some form of stress or exogenous hormone treatment. When dormancy is released, sprouting of the apical bud may be inhibited by sprout control agents or cold temperature. Dominance of the growing apical bud over other lateral buds decreases during storage and is one of the earliest morphophysiological indicators of the tuber's physiological age. Three main types of loss of apical dominance (AD) affect sprouting shape. Hallmarks of programmed cell death (PCD) have been identified in the tuber apical bud meristem (TAB-meristem) during normal growth, and are more extensive when AD is lost following extended cold storage or chemical stress. Nevertheless, the role of hormonal regulation in TAB-meristem PCD remains unclear. PMID:22899056

  3. Polyphenol oxidase expression in potato (Solanum tuberosum) tubers inhibited to sprouting by treatment with iodine atmosphere.

    PubMed

    Eolini, Francesco; Hochkoeppler, Alejandro; Credi, Andrea; Rodríguez, Antonio Gonzàlez Vara Y; Poggi, Valeria

    2004-08-01

    Iodine-saturated atmosphere was found to inhibit the sprouting of potato (Solanum tuberosum L.) tubers. The iodine concentration in tuber tissues increased as a function of exposure length, and the onset of inhibition of sprouting was found to depend on tubers genotype. During the time-course of the treatment, the transcription of polyphenol oxidases (EC 1.10.3.1 and EC 1.14.18.1) was undetectable in tuber peel, whereas in bud tissues featured an increase, followed by a decrease occurring simultaneously with the suppression of sprouting. The treatment of tubers with iodine strongly affected the expression of polyphenol oxidases at the transcriptional level. Polyphenol oxidase activity in buds poorly reflected the corresponding level of transcription; similarly, little differences were found among the enzyme isoforms expressed in buds as a function of length of exposure to iodine. These findings suggest that the induction of polyphenol oxidases mRNAs transcription could probe the inhibition of sprouting by iodine.

  4. The ABC Transporter ABCG1 Is Required for Suberin Formation in Potato Tuber Periderm[W

    PubMed Central

    Landgraf, Ramona; Smolka, Ulrike; Altmann, Simone; Eschen-Lippold, Lennart; Senning, Melanie; Sonnewald, Sophia; Weigel, Benjamin; Frolova, Nadezhda; Strehmel, Nadine; Hause, Gerd; Scheel, Dierk; Böttcher, Christoph; Rosahl, Sabine

    2014-01-01

    The lipid biopolymer suberin plays a major role as a barrier both at plant-environment interfaces and in internal tissues, restricting water and nutrient transport. In potato (Solanum tuberosum), tuber integrity is dependent on suberized periderm. Using microarray analyses, we identified ABCG1, encoding an ABC transporter, as a gene responsive to the pathogen-associated molecular pattern Pep-13. Further analyses revealed that ABCG1 is expressed in roots and tuber periderm, as well as in wounded leaves. Transgenic ABCG1-RNAi potato plants with downregulated expression of ABCG1 display major alterations in both root and tuber morphology, whereas the aerial part of the ABCG1-RNAi plants appear normal. The tuber periderm and root exodermis show reduced suberin staining and disorganized cell layers. Metabolite analyses revealed reduction of esterified suberin components and hyperaccumulation of putative suberin precursors in the tuber periderm of RNA interference plants, suggesting that ABCG1 is required for the export of suberin components. PMID:25122151

  5. Starch, inulin and maltodextrin as encapsulating agents affect the quality and stability of jussara pulp microparticles.

    PubMed

    Lacerda, Ellen Cristina Quirino; Calado, Verônica Maria de Araújo; Monteiro, Mariana; Finotelli, Priscilla Vanessa; Torres, Alexandre Guedes; Perrone, Daniel

    2016-10-20

    The influence of encapsulating carbohydrates (EC) with varying properties on the technological and functional properties of jussara pulp microparticles produced by spray drying were evaluated using experimental design. Microparticles produced with sodium octenyl succinate (OSA) starch at 0.5 core to EC ratio and with mixtures of inulin and maltodextrin at 1.0 and 2.0 core to EC ratio showed darker color, and higher anthocyanins contents and antioxidant activity. Seven microparticles showing high water solubility and desirable surface morphology. Hygroscopicity (10.7% and 11.5%) and wettability (41s and 43s) were improved when OSA starch and mixtures of inulin and maltodextrin were used. The anthocyanins contents and color of the microparticles did not change when exposed to light at 50°C for 38days. Finally, microparticles produced at 1.0 core to EC ratio with 2/3 OSA starch, 1/6 inulin and 1/6 maltodextrin were selected. These microparticles may be applied as colorant in numerous foods, whilst adding prebiotic fiber and anthocyanins.

  6. Treatment of Renal Angiomyolipoma and Other Hamartomas in Patients with Tuberous Sclerosis Complex.

    PubMed

    Samuels, Joshua A

    2017-03-16

    Tuberous sclerosis complex is an autosomal dominant genetic disease characterized by growth of benign tumors (hamartomas) in multiple organs, especially the kidneys, brain, heart, lungs, and skin. Tuberous sclerosis complex is usually caused by a mutation in either the tuberous sclerosis complex 1 or tuberous sclerosis complex 2 gene, resulting in constitutive activation of mammalian target of rapamycin signaling. Currently, mammalian target of rapamycin inhibitors are recommended in adult patients with tuberous sclerosis complex for the treatment of asymptomatic, growing renal angiomyolipoma that are >3 cm in diameter and pediatric or adult patients with brain lesions (subependymal giant cell astrocytoma) that either are growing or are not amenable to surgical resection. Clinical evidence suggests that systemic administration of a mammalian target of rapamycin inhibitor may provide concurrent improvements in multiple lesions and symptoms of tuberous sclerosis complex. With the major paradigm shift in consensus guidelines toward screening at diagnosis and ongoing monitoring and with the recent availability of an effective oral treatment, it is important that nephrologists have a thorough understanding of our role in the management of patients with tuberous sclerosis complex. Because the various manifestations of tuberous sclerosis complex typically emerge at different periods during patients' lifetimes, patients will need to be followed throughout their lives. Unlike brain and cardiac lesions, renal lesions are more likely to emerge as patients age and can grow at any time. Considerations regarding long-term medication administration for the potential control of multiple tuberous sclerosis complex manifestations will need to be addressed; these include the most appropriate starting dose, appropriate doses for tumor shrinkage versus prevention of regrowth, and management of adverse events. Best practices and potential obstacles for nephrologists treating patients

  7. Localization of the Epileptogenic Foci in Tuberous Sclerosis Complex: A Pediatric Case Report

    PubMed Central

    Hunold, Alexander; Haueisen, Jens; Ahtam, Banu; Doshi, Chiran; Harini, Chellamani; Camposano, Susana; Warfield, Simon K.; Grant, Patricia Ellen; Okada, Yoshio; Papadelis, Christos

    2014-01-01

    Tuberous sclerosis complex (TSC) is a rare disorder of tissue growth and differentiation, characterized by benign hamartomas in the brain and other organs. Up to 90% of TSC patients develop epilepsy and 50% become medically intractable requiring resective surgery. The surgical outcome of TSC patients depends on the accurate identification of the epileptogenic zone consisting of tubers and the surrounding epileptogenic tissue. There is conflicting evidence whether the epileptogenic zone is in the tuber itself or in abnormally developed surrounding cortex. Here, we report the localization of the epileptiform activity among the many cortical tubers in a 4-year-old patient with TSC-related refractory epilepsy undergoing magnetoencephalography (MEG), electroencephalography (EEG), and diffusion tensor imaging (DTI). For MEG, we used a prototype system that offers higher spatial resolution and sensitivity compared to the conventional adult systems. The generators of interictal activity were localized using both EEG and MEG with equivalent current dipole (ECD) and minimum norm estimation (MNE) methods according to the current clinical standards. For DTI, we calculated four diffusion scalar parameters for the fibers passing through four ROIs defined: (i) at a large cortical tuber identified at the right quadrant, (ii) at the normal appearing tissue contralateral to the tuber, (iii) at the cluster formed by ECDs fitted at the peak of interictal spikes, and (iv) at the normal appearing tissue contralateral to the cluster. ECDs were consistently clustered at the vicinity of the large calcified cortical tuber. MNE and ECDs indicated epileptiform activity in the same areas. DTI analysis showed differences between the scalar values of the tracks passing through the tuber and the ECD cluster. In this illustrative case, we provide evidence from different neuroimaging modalities, which support the view that epileptiform activity may derive from abnormally developed tissue

  8. Localization of the epileptogenic foci in tuberous sclerosis complex: a pediatric case report.

    PubMed

    Hunold, Alexander; Haueisen, Jens; Ahtam, Banu; Doshi, Chiran; Harini, Chellamani; Camposano, Susana; Warfield, Simon K; Grant, Patricia Ellen; Okada, Yoshio; Papadelis, Christos

    2014-01-01

    Tuberous sclerosis complex (TSC) is a rare disorder of tissue growth and differentiation, characterized by benign hamartomas in the brain and other organs. Up to 90% of TSC patients develop epilepsy and 50% become medically intractable requiring resective surgery. The surgical outcome of TSC patients depends on the accurate identification of the epileptogenic zone consisting of tubers and the surrounding epileptogenic tissue. There is conflicting evidence whether the epileptogenic zone is in the tuber itself or in abnormally developed surrounding cortex. Here, we report the localization of the epileptiform activity among the many cortical tubers in a 4-year-old patient with TSC-related refractory epilepsy undergoing magnetoencephalography (MEG), electroencephalography (EEG), and diffusion tensor imaging (DTI). For MEG, we used a prototype system that offers higher spatial resolution and sensitivity compared to the conventional adult systems. The generators of interictal activity were localized using both EEG and MEG with equivalent current dipole (ECD) and minimum norm estimation (MNE) methods according to the current clinical standards. For DTI, we calculated four diffusion scalar parameters for the fibers passing through four ROIs defined: (i) at a large cortical tuber identified at the right quadrant, (ii) at the normal appearing tissue contralateral to the tuber, (iii) at the cluster formed by ECDs fitted at the peak of interictal spikes, and (iv) at the normal appearing tissue contralateral to the cluster. ECDs were consistently clustered at the vicinity of the large calcified cortical tuber. MNE and ECDs indicated epileptiform activity in the same areas. DTI analysis showed differences between the scalar values of the tracks passing through the tuber and the ECD cluster. In this illustrative case, we provide evidence from different neuroimaging modalities, which support the view that epileptiform activity may derive from abnormally developed tissue

  9. Asada-Halliwell pathway maintains redox status in Dioscorea alata tuber which helps in germination.

    PubMed

    Sharma, Shruti; Sehrawat, Ankita; Deswal, Renu

    2016-09-01

    Reactive Oxygen Species (ROS) are important regulatory molecules governing physiological processes. In the present study a biochemical and proteome level comparison of two contrasting growth stages of Dioscorea alata tuber namely germinating and mature tuber was performed in order to understand the tuber physiology and biochemistry. Existence of all the component enzymes [APx (ascorbate peroxidase), GR (glutathione reductase), DHAR (dehydroascorbate reductase), MDHAR (mono-dehydroascorbate reductase)] and major products [ascorbate (ASC) and glutathione (GSH)] of the cycle showed an operational Asada-Halliwell cycle in the tuber. A 2.65 fold increase in ASC content & a 3.8 fold increase in GR activity fortified the redox milieu during germination. In contrast a 5 fold higher H2O2 content (due to 3.08 fold lower APx activity) and accumulation of reactive nitrogen species (RNS) such as nitric oxide (NO, 2.4-fold) and S-nitrosothiol (SNO, 2.08 fold) contributed to overall oxidative conditions in the mature tuber. The carbonic anhydrase (CA, 7.5 fold), DHAR (5.31 fold) and MDHAR (7 fold) activities were higher in the germinating tuber in comparison with the mature tuber. GSNO negatively regulated the CA (3.6 & 3.95 fold), MDHAR (7.5 & 1.5 fold) and APx (2.3 & 1.81 fold) while another NO donor, CysNO negatively regulated the DHAR (2.24 & 1.32 fold) activity in the mature and germinating stages respectively indicating again that the lesser inhibition by NO (via nitrosylation) may be because of overall reducing environment in the germinating tuber. Increased SNO leading to S-nitrosylation of dioscorin was confirmed by Biotin switch assay. This is the first report showing dioscorin nitrosylation. The present analysis showed differential redox regulation and also suggests the physiological relevance of CA, DHAR, MDHAR, APx & GR in tuber germination for the first time. These enzymes may be used as potential markers of tuber germination in future.

  10. [Wound healing and induced resistance in potato tubers].

    PubMed

    Ozeretskovskaia, O L; Vasiukova, N I; Chalenko, G I; Gerasimova, N G; Revina, T A; Valueva, T A

    2009-01-01

    It was demonstrated that biogenic elicitors, arachidonic acid and chitosan, locally and systemically stimulated wound healing in potato tuber tissues by increasing the number of wound periderm layers, accelerating the development of cork cambium (phellogen), and inducing proteinase inhibitors. The signal molecules, jasmonic and salicylic acids, had different effects on the development of wound periderm: jasmonic acid locally and systemically stimulated potato wound healing and elevated the level of proteinase inhibitors, whereas salicylic acid did not have any effect on wound healing and even blocked the formation of proteinase inhibitors.

  11. Scalp fibroma: a rare cutaneous manifestation of tuberous sclerosis

    PubMed Central

    Sharma, Bhawna; Prakash, Swayam; Sannegowda, Raghavendra Bakki; Panagariya, Ashok

    2014-01-01

    We report a case of a 23-year-old woman with a history of generalised tonic–clonic seizures, reddish brown maculopapular swelling over the face and an enlarging swelling over the scalp. Physical examinations revealed angiofibroma of the face and other typical cutaneous lesions of tuberous sclerosis, for example, shagreen patch and periungual fibroma. Scalp swelling was labelled as fibroma by dermatologists, which was further supported by the histopathological findings. Fibroma of the face is one of the commonest lesions, however, fibroma of the scalp is a rarely described entity. PMID:24748136

  12. Starch-branching enzymes preferentially associated with A-type starch granules in wheat endosperm.

    PubMed

    Peng, M; Gao, M; Båga, M; Hucl, P; Chibbar, R N

    2000-09-01

    Two starch granule-bound proteins (SGP), SGP-140 and SGP-145, were preferentially associated with A-type starch granules (>10 microm) in developing and mature wheat (Triticum aestivum) kernels. Immunoblotting and N-terminal sequencing suggested that the two proteins were different variants of SBEIc, a 152-kD isoform of wheat starch-branching enzyme. Both SGP-140 and SGP-145 were localized to the endosperm starch granules but were not found in the endosperm soluble fraction or pericarp starch granules younger than 15 d post anthesis (DPA). Small-size starch granules (<10 microm) initiated before 15 DPA incorporated SGP-140 and SGP-145 throughout endosperm development and grew into full-size A-type starch granules (>10 microm). In contrast, small-size starch granules harvested after 15 DPA contained only low amounts of SGP-140 and SGP-145 and developed mainly into B-type starch granules (<10 microm). Polypeptides of similar mass and immunologically related to SGP-140 and/or SGP-145 were also preferentially incorporated into A-type starch granules of barley (Hordeum vulgare), rye (Secale cereale), and triticale (x Triticosecale Wittmack) endosperm, which like wheat endosperm have a bimodal starch granule size distribution.

  13. Characterisation of corn starch-based films reinforced with taro starch nanoparticles.

    PubMed

    Dai, Lei; Qiu, Chao; Xiong, Liu; Sun, Qingjie

    2015-05-01

    Taro starch nanoparticles (TSNPs) obtained by hydrolysis with pullulanase and the recrystallisation of gelatinised starch were used as reinforcing agents in corn starch films. The influence of TSNPs contents (0.5-15%) on the physical, mechanical, thermal, and structural properties of starch films was investigated. An increase in the concentration of TSNPs led to a significant decrease in the water vapour permeability (WVP) of films. The addition of TSNPs increased the tensile strength (TS) of films from 1.11 MPa to 2.87 MPa. Compared with pure starch films, the surfaces of nanocomposite films became uneven. The onset temperature (To) and melting temperature (Tm) of films containing TSNPs were higher than those of pure starch films. The addition of TSNPs improved the thermal stability of starch films.

  14. A starch-accumulating mutant of Arabidopsis thaliana deficient in a chloroplastic starch-hydrolysing enzyme.

    PubMed

    Zeeman, S C; Northrop, F; Smith, A M; Rees, T

    1998-08-01

    The aim of this work was to identify enzymes that participate in the degradation of transitory starch in Arabidopsis. A mutant line was isolated by screening leaves at the end of the night for the presence of starch. The mutant had a higher starch content than the wild-type throughout the diurnal cycle. This accumulation was due to a reduction in starch breakdown, leading to an imbalance between the rates of synthesis and degradation. No reduction in the activity of endo-amylase (alpha-amylase), beta-amylase, starch phosphorylase, maltase, pullulanase or D-enzyme could be detected in crude extracts of leaves of the mutant. However, native PAGE in gels containing amylopectin revealed that a starch-hydrolysing activity, putatively identified as an endo-amylase and present in wild-type chloroplasts, was absent or appreciably reduced in the mutant. This is the first time that a specific enzyme required for starch degradation has been identified in leaves.

  15. Production and physicochemical characterization of resistant starch type III derived from pea starch.

    PubMed

    Lehmann, Undine; Rössler, Christine; Schmiedl, Detlef; Jacobasch, Gisela

    2003-02-01

    Smooth pea starch was used for the production of physiological important resistant starch type III. For reduction of the molecular weight of the starch, different strategies including enzymatic debranching and acid hydrolysis (lintnerization), were tested to obtain an optimal starting material for retrogradation. The resulting polymer chain lengths were analyzed by high-performance anion-exchange chromatography. Temperature regimes and starch concentrations in gel were optimized during the retrogradation with the aim to obtain a high yield of resistant starch. Optimal conditions led to resistant starch contents up to 74%. The products were thermostable and showed no loss of resistant structures after autoclaving. The peak temperatures of the thermal transition were at approximately 147 degrees C. The resulting resistant starch products are suitable for the generation of functional foods.

  16. Effect of sorghum flour addition on in vitro starch digestibility, cooking quality, and consumer acceptability of durum wheat pasta.

    PubMed

    Khan, Imran; Yousif, Adel M; Johnson, Stuart K; Gamlath, Shirani

    2014-08-01

    Whole grain sorghum is a valuable source of resistant starch and polyphenolic antioxidants and its addition into staple food like pasta may reduce the starch digestibility. However, incorporating nondurum wheat materials into pasta provides a challenge in terms of maintaining cooking quality and consumer acceptability. Pasta was prepared from 100% durum wheat semolina (DWS) as control or by replacing DWS with either wholegrain red sorghum flour (RSF) or white sorghum flour (WSF) each at 20%, 30%, and 40% incorporation levels, following a laboratory-scale procedure. Pasta samples were evaluated for proximate composition, in vitro starch digestibility, cooking quality, and consumer acceptability. The addition of both RSF and WSF lowered the extent of in vitro starch digestion at all substitution levels compared to the control pasta. The rapidly digestible starch was lowered in all the sorghum-containing pastas compared to the control pasta. Neither RSF or WSF addition affected the pasta quality attributes (water absorption, swelling index, dry matter, adhesiveness, cohesiveness, and springiness), except color and hardness which were negatively affected. Consumer sensory results indicated that pasta samples containing 20% and 30% RSF or WSF had acceptable palatability based on meeting one or both of the preset acceptability criteria. It is concluded that the addition of wholegrain sorghum flour to pasta at 30% incorporation level is possible to reduce starch digestibility, while maintaining adequate cooking quality and consumer acceptability.

  17. Acetylation and characterization of banana (Musa paradisiaca) starch.

    PubMed

    Bello-Pérez, L A; Contreras-Ramos, S M; Jìmenez-Aparicio, A; Paredes-López, O

    2000-01-01

    Banana native starch was acetylated and some of its functional properties were evaluated and compared to corn starch. In general, acetylated banana starch presented higher values in ash, protein and fat than corn acetylated starch. The modified starches had minor tendency to retrogradation assessed as % transmittance of starch pastes. At high temperature acetylated starches presented a water retention capacity similar to their native counterpart. The acetylation considerably increased the solubility of starches, and a similar behavior was found for swelling power. When freeze-thaw stability was studied, acetyl banana starch drained approximately 60% of water in the first and second cycles, but in the third and fourth cycles the percentage of separated water was low. However, acetyl corn starch showed lower freeze-thaw stability than the untreated sample. The modification increased the viscosity of banana starch pastes.

  18. Amylose content decreases during tuber development in potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato starch is composed of amylopectin and amylose in an approximately three to one ratio. Amylose is considered to be nutritionally desirable, so there is interest in finding strategies to increase the amylose content of potatoes. There is also interest in marketing “baby” potatoes, which are har...

  19. Color Relationalism and Relativism.

    PubMed

    Byrne, Alex; Hilbert, David R

    2017-01-01

    This paper critically examines color relationalism and color relativism, two theories of color that are allegedly supported by variation in normal human color vision. We mostly discuss color relationalism, defended at length in Jonathan Cohen's The Red and the Real, and argue that the theory has insuperable problems.

  20. Primary Theme Club. Colors.

    ERIC Educational Resources Information Center

    Walmsley, Bonnie Brown; Camp, Anne-Marie

    1997-01-01

    Presents a cross-curricular theme unit on colors that includes a pullout poster and a resource list. Social studies activities highlight flags of the world. Science activities teach about colors of animals and the science of color. Language arts activities describe colorful language. Mathematics activities involve sorting and graphing colors. (SM)

  1. Activities: Some Colorful Mathematics.

    ERIC Educational Resources Information Center

    DeTemple, Duane W.; Walker, Dean A.

    1996-01-01

    Describes three activities in discrete mathematics that involve coloring geometric objects: counting colored regions of overlapping simple closed curves, counting colored triangulations of polygons, and determining the number of colors required to paint the plane so that no two points one inch apart are the same color. (MKR)

  2. Production of PLA-Starch Fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Composites of polylactic acid (PLA) with starch have been prepared previously in an effort to reduce cost as well as to modify other properties such as biodegradation rate. However, strength and elongation both decrease on addition of starch due to poor adhesion and stress concentration at the inte...

  3. Pasting characteristics of starch-lipid composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch-lipid composites (SLC) have been used as fat replacers and stabilizers in beef patties, dairy products, and baked goods. The SLC are produced by mixing aqueous starch slurry with a lipid source, and steam jet-cooking. The SLC may be dried using a drum drier and then milled in a Retch mill. ...

  4. Properties of corn starch subjected hydrothermal modification

    NASA Astrophysics Data System (ADS)

    Gryszkin, Artur; Zięba, Tomasz; Kapelko-Żeberska, Małgorzata

    2017-01-01

    The objective of this study was to determine the effect of heating a water dispersion of corn starch to various temperatures, followed by its freezing and defrosting, on selected properties of re-formed starch pastes. A suspension of starch was heated to various temperatures ranging from 59 to 94°C, and afterwards frozen and defrosted. The differential scanning calorimetry (Mettler Toledo, 822E) thermal characteristics of starch pre-heated to temperatures not inducing complete pasting revealed transitions of: (I) retrograded amylopectin, (II) non-pasted starch, (III) amylose-lipid complexes, (IV) retrograded amylose, and (V) highly thermostable starch structures. The application of higher temperatures during heating caused disappearance of transitions II and V. The increase of pre-heating temperature induced firstly a decrease and then stabilization of the swelling power as well as a successive decrease in starch solubility. Pastes pre-heated to temperatures over 79°C contained large macroparticles that were increasing viscosity of the re-formed starch paste (their size was positively correlated with viscosity value).

  5. Starch nanoparticles formation via high power ultrasonication.

    PubMed

    Bel Haaj, Sihem; Magnin, Albert; Pétrier, Christian; Boufi, Sami

    2013-02-15

    Nano-sized starch particles (NSP) were prepared from starch granules using a purely physical method of high-intensity ultrasonication. Particle size distribution, Field Effect Scanning Electron Microscopy (FE-SEM), Raman spectroscopy, and Wide-Angle X-ray Diffraction (WAXD) were used to characterize the morphology and crystal structure of the ensuing nanoparticles. The results revealed that ultrasound treatment of the starch suspension in water and at low temperature for 75 min results in the formation of starch nanoparticles between 30 and 100 nm in size. An attempt to explain the generation of starch nanoparticles was made on the basis of WAXD, Raman analysis and FE-SEM observation. Compared to acid hydrolysis, which is the most commonly adopted process, the present approach has the advantage of being quite rapid, presenting a higher yield and not requiring any chemical treatment.

  6. Understanding starch gelatinization: The phase diagram approach.

    PubMed

    Carlstedt, Jonas; Wojtasz, Joanna; Fyhr, Peter; Kocherbitov, Vitaly

    2015-09-20

    By constructing a detailed phase diagram for the potato starch-water system based on data from optical microscopy, synchrotron X-ray scattering and differential scanning calorimetry, we show that gelatinization can be interpreted in analogy with a eutectic transition. The phase rule explains why the temperature of the gelatinization transition (G) is independent on water content. Furthermore, the melting (M1) endotherm observed in DSC represents a liquidus line; the temperature for this event increases with increasing starch concentration. Both the lamellar spacing and the inter-helix distance were observed to decrease with increasing starch content for starch concentrations between approximately 65 wt% and 75 wt%, while the inter-helix distance continued decreasing upon further dehydration. Understanding starch gelatinization has been a longstanding challenge. The novel approach presented here shows interpretation of this phenomenon from a phase equilibria perspective.

  7. Preparation and characterization of octenylsuccinylated plantain starch.

    PubMed

    Bello-Flores, Christopher A; Nuñez-Santiago, Maria C; San Martín-Gonzalez, María F; BeMiller, James N; Bello-Pérez, Luis A

    2014-09-01

    Plantain starch was esterified with octenylsuccinic anhydride (OSA) at two concentrations (3 and 15% w/w) of OSA. The morphology, granule size distribution, pasting, gelatinization, swelling, and solubility of granules and structural features of the starch polymers were evaluated. Granules of the OSA-modified starches increased in size during cooking more than did the granules of the native starch, and the effect was greater at the higher OSA concentration. Pasting viscosities also increased, but gelatinization and pasting temperatures and enthalpy of gelatinization decreased in the OSA-modified starches. It was concluded that insertion of OS groups effected disorder in the granular structure. Solubility, weight average molar mass, Mw¯, and z-average radius of gyration, RGz, of the amylopectin decreased as the OSA concentration increased, indicating a decrease in molecular size.

  8. Nootropic activity of tuber extract of Pueraria tuberosa (Roxb).

    PubMed

    Rao, N Venkata; Pujar, Basavaraj; Nimbal, S K; Shantakumar, S M; Satyanarayana, S

    2008-08-01

    Nootropic effect of alcoholic (ALE; 50, 75, 100 mg/kg) and aqueous (AQE; 100, 200, 400 mg/kg) extracts of P. tuberosa was evaluated by using Elevated Plus Maze (EPM), scopolamine-induced amnesia (SIA), diazepam-induced amnesia (DIA), clonidine-induced (NA-mediated) hypothermia (CIH), lithium-induced (5-HT mediated) head twitches (LIH) and haloperidol-induced (DA- mediated) catalepsy (HIC) models. Piracetam was used as the standard drug. A significant increase in inflexion ratio (IR) was recorded in EPM, SIA and DIA models. A significant reversal effect was observed on rectal temperature in CIH model, reduction of head twitches in LIH models. However no significant reduction in catalepsy scores in HIC models were observed with test extracts and standard piracetam. The results indicate that nootropic activity observed with ALE and AQE of tuber extracts of P. tuberosa could be through improved learning and memory either by augmenting the noradrenaline (NA) transmission or by interfering with 5-hydroxytryptamine (5-HT) release. Further, the extracts neither facilitated nor blocked release of the dopamine (DA). Thus ALE and AQE elicited significant nootropic effect in mice and rats by interacting with cholinergic, GABAnergic, adrenergic and serotonergic systems. Phytoconstituents like flavonoids have been reported for their nootropic effect and these are present in both ALE and AQE extracts of tubers of P. tuberosa (Roxb) and these active principles may be responsible for nootropic activity.

  9. Antimicrobial activity of the solvent fractions from Bulbine natalensis Tuber.

    PubMed

    Yakubu, M T; Mostafa, M; Ashafa, A O T; Afolayan, A J

    2012-01-01

    Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent.

  10. Imaging of tuberous sclerosis complex: a pictorial review

    PubMed Central

    von Ranke, Felipe Mussi; Faria, Igor Murad; Zanetti, Gláucia; Hochhegger, Bruno; Souza Jr., Arthur Soares; Marchiori, Edson

    2017-01-01

    Tuberous sclerosis complex (TSC) is a genetically determined hamartomatous neurocutaneous disease with high phenotypic variability. TSC is characterized by widespread hamartomas and benign, or rarely malignant, neoplasms distributed in several organs throughout the body, especially in the brain, skin, retina, kidney, heart, and lung. Common manifestations include cortical tubers, subependymal nodules, white matter abnormalities, retinal abnormalities, cardiac rhabdomyoma, lymphangioleiomyomatosis, renal angiomyolipoma, and skin lesions. The wide range of organs affected by the disease implies that TSC1 and TSC2 genes play important roles in the regulation of cell proliferation and differentiation. Although recent advances in treatment have improved morbidity, the prognosis remains quite poor and nearly 40% of patients die by the age of 35 years. Imaging is important in the evaluation of TSC because of its role not only in presumptive diagnosis, but also in defining the full extent of involvement. This information allows a better understanding of the behavioural phenotype, as related to lesion location. Imaging also contributes to treatment planning. This pictorial review describes common and uncommon imaging manifestations of TSC. PMID:28298732

  11. Imaging of tuberous sclerosis complex: a pictorial review.

    PubMed

    von Ranke, Felipe Mussi; Faria, Igor Murad; Zanetti, Gláucia; Hochhegger, Bruno; Souza, Arthur Soares; Marchiori, Edson

    2017-01-01

    Tuberous sclerosis complex (TSC) is a genetically determined hamartomatous neurocutaneous disease with high phenotypic variability. TSC is characterized by widespread hamartomas and benign, or rarely malignant, neoplasms distributed in several organs throughout the body, especially in the brain, skin, retina, kidney, heart, and lung. Common manifestations include cortical tubers, subependymal nodules, white matter abnormalities, retinal abnormalities, cardiac rhabdomyoma, lymphangioleiomyomatosis, renal angiomyolipoma, and skin lesions. The wide range of organs affected by the disease implies that TSC1 and TSC2 genes play important roles in the regulation of cell proliferation and differentiation. Although recent advances in treatment have improved morbidity, the prognosis remains quite poor and nearly 40% of patients die by the age of 35 years. Imaging is important in the evaluation of TSC because of its role not only in presumptive diagnosis, but also in defining the full extent of involvement. This information allows a better understanding of the behavioural phenotype, as related to lesion location. Imaging also contributes to treatment planning. This pictorial review describes common and uncommon imaging manifestations of TSC.

  12. Toughing It Out--Disease-Resistant Potato Mutants Have Enhanced Tuber Skin Defenses.

    PubMed

    Thangavel, Tamilarasan; Tegg, Robert S; Wilson, Calum R

    2016-05-01

    Common scab, a globally important potato disease, is caused by infection of tubers with pathogenic Streptomyces spp. Previously, disease-resistant potato somaclones were obtained through cell selections against the pathogen's toxin, known to be essential for disease. Further testing revealed that these clones had broad-spectrum resistance to diverse tuber-invading pathogens, and that resistance was restricted to tuber tissues. The mechanism of enhanced disease resistance was not known. Tuber periderm tissues from disease-resistant clones and their susceptible parent were examined histologically following challenge with the pathogen and its purified toxin. Relative expression of genes associated with tuber suberin biosynthesis and innate defense pathways within these tissues were also examined. The disease-resistant somaclones reacted to both pathogen and toxin by producing more phellem cell layers in the tuber periderm, and accumulating greater suberin polyphenols in these tissues. Furthermore, they had greater expression of genes associated with suberin biosynthesis. In contrast, signaling genes associated with innate defense responses were not differentially expressed between resistant and susceptible clones. The resistance phenotype is due to induction of increased periderm cell layers and suberization of the tuber periderm preventing infection. The somaclones provide a valuable resource for further examination of suberization responses and its genetic control.

  13. Resistance to Multiple Tuber Diseases Expressed in Somaclonal Variants of the Potato Cultivar Russet Burbank

    PubMed Central

    Thangavel, Tamilarasan; Steven Tegg, Robert; Wilson, Calum Rae

    2014-01-01

    Multiple disease resistance is an aim of many plant breeding programs. Previously, novel somatic cell selection was used to generate potato variants of “Russet Burbank” with resistance to common scab caused by infection with an actinomycete pathogen. Coexpression of resistance to powdery scab caused by a protozoan pathogen was subsequently shown. This study sought to define whether this resistance was effective against additional potato tuber diseases, black scurf, and tuber soft rot induced by fungal and bacterial pathogens. Pot trials and in vitro assays with multiple pathogenic strains identified significant resistance to both tuber diseases across the potato variants examined; the best clone A380 showed 51% and 65% reductions in disease severity to tuber soft rot and black scurf, respectively, when compared with the parent line. The resistance appeared to be tuber specific as no enhanced resistance was recorded in stolons or stem material when challenged Rhizoctonia solani that induces stolon pruning and stem canker. The work presented here suggests that morphological characteristics associated with tuber resistance may be the predominant change that has resulted from the somaclonal cell selection process, potentially underpinning the demonstrated broad spectrum of resistance to tuber invading pathogens. PMID:24523639

  14. Visual Evoked Potentials as a Readout of Cortical Function in Infants With Tuberous Sclerosis Complex.

    PubMed

    Varcin, Kandice J; Nelson, Charles A; Ko, Jordan; Sahin, Mustafa; Wu, Joyce Y; Jeste, Shafali Spurling

    2016-02-01

    Tuberous sclerosis complex is an autosomal dominant genetic disorder that confers a high risk for neurodevelopmental disorders, such as autism spectrum disorder and intellectual disability. Studies have demonstrated specific delays in visual reception skills that may predict the development of autism spectrum disorder and intellectual disability. Based on evidence for alterations in the retinogeniculate pathway in animal models of tuberous sclerosis complex, we asked whether children with tuberous sclerosis complex demonstrate alterations in early visual processing that may undermine the development of higher-level visual behaviors. Pattern-reversal visual evoked potentials were recorded in infants with tuberous sclerosis complex (n = 16) and typically developing infants (n = 18) at 12 months of age. Infants with tuberous sclerosis complex demonstrated remarkably intact visual evoked potentials even within the context of intellectual disability and epilepsy. Infants with tuberous sclerosis complex show intact visual cortical processing, suggesting that delays in visually mediated behaviors in tuberous sclerosis complex may not be rooted in early visual processing deficits.

  15. [Microscopic anatomy of abnormal structure in root tuber of Pueraria lobata].

    PubMed

    Duan, Hai-yan; Cheng, Ming-en; Peng, Hua-sheng; Zhang, He-ting; Zhao, Yu-jiao

    2015-11-01

    Puerariae Lobatae Radix, also known as Gegen, is a root derived from Pueraria lobata. Based on field investigation and the developmental anatomy of root tuber, we have elucidated the relationship between the growth of root tuber and the anomalous structure. The results of analysis showed that the root system of P. lobata was developed from seed and adventitious root and there existed root tuber, adventitious root and conductive root according to morphology and function. The root tuber was developed from adventitious root, its secondary structure conformed to the secondary structure of dicotyledon's root. With the development of root, the secondary phloem of root tuber appeared abnormal vascular tissue, which was distributed like ring in the outside of secondary vascular tissue. The root tuber might have 4-6 concentric circular permutation abnormal vascular tissuelobate, and was formed by the internal development of abnormal vascular tissue. The xylem and phloem of abnormal vascular tissue were the main body of the root tuber. The results reveal the abnormal anatomical structure development of P. lobata, also provides the theoretical basis for reasonable harvest medicinal parts and promoting sustainable utilization of resources of P. lobata.

  16. Color vision and color formation in dragonflies.

    PubMed

    Futahashi, Ryo

    2016-10-01

    Dragonflies including damselflies are colorful and large-eyed insects, which show remarkable sexual dimorphism, color transition, and color polymorphism. Recent comprehensive visual transcriptomics has unveiled an extraordinary diversity of opsin genes within the lineage of dragonflies. These opsin genes are differentially expressed between aquatic larvae and terrestrial adults, as well as between dorsal and ventral regions of adult compound eyes. Recent topics of color formation in dragonflies are also outlined. Non-iridescent blue color is caused by coherent light scattering from the quasiordered nanostructures, whereas iridescent color is produced by multilayer structures. Wrinkles or wax crystals sometimes enhances multilayer structural colors. Sex-specific and stage-specific color differences in red dragonflies is attributed to redox states of ommochrome pigments.

  17. Urine - abnormal color

    MedlinePlus

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  18. Tooth - abnormal colors

    MedlinePlus

    ... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

  19. LED Color Characteristics

    SciTech Connect

    2012-01-01

    Color quality is an important consideration when evaluating LED-based products for general illumination. This fact sheet reviews the basics regarding light and color and summarizes the most important color issues related to white-light LED systems.

  20. Color Blindness Simulations

    MedlinePlus

    ... Coordinator Color blindness Simulations Normal Color Vision Deuteranopia Color blindness marked by confusion of purplish red and green Tritanopia A dichromatism in which the spectrum is seen in tones of red and green. ...

  1. Preparation of metallic nanoparticles by irradiation in starch aqueous solution

    SciTech Connect

    Nemţanu, Monica R. Braşoveanu, Mirela Iacob, Nicuşor

    2014-11-24

    Colloidal silver nanoparticles (AgNPs) were synthesized in a single step by electron beam irradiation reduction of silver ions in aqueous solution containing starch. The nanoparticles were characterized by spectrophotocolorimetry and compared with those obtained by chemical (thermal) reduction method. The results showed that the smaller sizes of AgNPs were prepared with higher yields as the irradiation dose increased. The broadening of particle size distribution occurred by increasing of irradiation dose and dose rate. Chromatic parameters such as b* (yellow-blue coordinate), C* (chroma) and ΔE{sub ab} (total color difference) could characterize the nanoparticles with respect of their concentration. Hue angle h{sup o} was correlated to the particle size distribution. Experimental data of the irradiated samples were also subjected to factor analysis using principal component extraction and varimax rotation in order to reveal the relation between dependent variables and independent variables and to reduce their number. The radiation-based method provided silver nanoparticles with higher concentration and narrower size distribution than those produced by chemical reduction method. Therefore, the electron beam irradiation is effective for preparation of silver nanoparticles using starch aqueous solution as dispersion medium.

  2. Characterization of the major proteins of tubers of yam bean (Pachyrhizus ahipa).

    PubMed

    Forsyth, Jane L; Shewry, Peter R

    2002-03-27

    Tubers of six accessions of ahipa (Pachyrhizus ahipa) contained between 0.77 and 1.34% nitrogen on a dry weight basis. This corresponds to 4.8 to 8.4% crude protein based on a nitrogen to protein conversion factor of 6.25; but detailed analysis of AC230 showed that although 93% of the total N was extracted with buffer containing 1.0 M NaCl, about a third of this was lost on dialysis. It was calculated, therefore, that salt-soluble proteins comprise about 60% of the total tuber nitrogen, with low-molecular-mass nitrogenous components comprising a further 30%. Electophoretic analysis of the salt-soluble proteins showed similar patterns of components in the six accessions, with none being present in amounts sufficiently high to suggest a role as storage proteins. Furthermore, light microscopy failed to show significant deposits of protein within the tuber cells. Five "major" protein bands, which together accounted for about 19% of the total salt-soluble protein fraction were purified and subjected to N-terminal amino acid sequencing. Comparison of these with sequences in protein databases revealed similarities to alpha-amylases, chitinases and chitin binding proteins, cysteine proteinases (including major components from P. erosus tubers), a tuberization-specific protein from potato, and proteins induced in soybean and pea by stress or the plant hormone abscisic acid, respectively. It was concluded that the primary roles of these proteins are probably in aspects of tuber metabolism and development and/or conferring protection to pests and pathogens, and that true storage proteins are not present. The absence of storage proteins is consistent with the biological role of the tubers as storage organs for carbohydrates (cf cassava tuberous roots) rather than as propagules (cf yam and potato tubers).

  3. Molecular disassembly of rice and lotus starches during thermal processing and its effect on starch digestibility.

    PubMed

    Wang, Shujun; Sun, Yue; Wang, Jinrong; Wang, Shuo; Copeland, Les

    2016-02-01

    The molecular disassembly of starch during thermal processing is a major determinant for the susceptibility of starch to enzymatic digestion. In the present study, the effects of thermal processing on the disassembly of the granular structure and the in vitro enzymatic digestibility of rice and lotus starches were investigated. After heating at 50 °C, rice and lotus starches did not show significant changes in granular morphology, long-range crystallinity and short-range molecular order. As the temperature increased to 60 °C, rice starch underwent a partial gelatinization followed by an incomplete disruption of granular morphology, crystallites and molecular order. In contrast, lotus starch was almost completely gelatinized at 60 °C. At 70 °C or higher, both starches were fully gelatinized with complete disruption of the micro and macro structures. Our results show that gelatinization greatly increased the in vitro enzymatic digestibility of both starches, but that the degree of disassembly of the starch structure during thermal processing was not a major determinant of the digestibility of gelatinized starch.

  4. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  5. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  6. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  7. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Industrial starch-modified. 178.3520 Section 178... § 178.3520 Industrial starch-modified. Industrial starch-modified may be safely used as a component of..., transporting, or holding food, subject to the provisions of this section. (a) Industrial starch-modified...

  8. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  9. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  10. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  11. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  12. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Food starch-modified. 172.892 Section 172.892 Food... starch-modified. Food starch-modified as described in this section may be safely used in food. The... insure safe use of the food starch-modified, the label of the food additive container shall bear the...

  13. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  14. Mycorrhization of pecan trees (Carya illinoinensis) with commercial truffle species: Tuber aestivum Vittad. and Tuber borchii Vittad.

    PubMed

    Benucci, Gian Maria Niccolò; Bonito, Gregory; Baciarelli Falini, Leonardo; Bencivenga, Mattia

    2012-07-01

    Pecan (Carya illinoinensis) is an economically important nut tree native to the Mississippi basin and cultivated worldwide. In North America, species of truffles are regularly found fruiting in productive pecan orchards and the truffle genus Tuber appears to be abundant in pecan ectomycorrhizal (EM) communities. As an initial step to determine the feasibility of co-cropping European truffle species with pecan, we evaluated whether mycorrhizae of highly esteemed European truffle species (Tuber aestivum Vittad. T. borchii and T. macrosporum) could be formed on pecan seedlings. Seedlings were inoculated with truffle spores and were grown in a greenhouse for 10 months. Levels of EM colonization were estimated visually and quantified by counting EM tips. Ectomycorrhizae were identified both morphologically and molecularly with species-specific amplification and by sequencing of the ITS region of the nuclear ribosomal DNA (nrDNA). Both T. borchii and T. aestivum spores produced well-formed ectomycorrhizae on pecan seedlings with average root colonization levels of about 62% and 42%, respectively, whereas no ectomycorrhizae of T. macrosporum were formed. The anatomy and morphology of these truffle ectomycorrhizae on pecan was characterized. The co-cropping of T. aestivum and T. borchii may hold promise as an additional stream of revenue to pecan growers, although, further studies are needed to assess whether this symbiosis is maintained after planting in the field and whether truffle production can be supported by this host species.

  15. Increasing of Food and Bioenergy Potato Resources by Microbial Influence on Tubers Phytohormonal Status

    NASA Astrophysics Data System (ADS)

    Kiprushkina, Elena I.; Baranenko, Denis A.

    2014-12-01

    Potato and its by-products became a promising both food and bioenergy resource. The determination of the bacteriaantagonists influence on phytohormone status and productivity of potato tubers was studied. The indole-3-acetic acid content during the dormancy end and germinating in the tubers treated with Bacillus subtilis Ch-13 was fewer than in the control samples. L-tryptophan significant quantity compared to the control was found in the treated tubers in a state of physiological dormancy (more than 2-fold) and especially during active germination (43 times greater). Average potato yield increase at treated fields was of 18.8 %.

  16. Model approach to starch functionality in bread making.

    PubMed

    Goesaert, Hans; Leman, Pedro; Delcour, Jan A

    2008-08-13

    We used modified wheat starches in gluten-starch flour models to study the role of starch in bread making. Incorporation of hydroxypropylated starch in the recipe reduced loaf volume and initial crumb firmness and increased crumb gas cell size. Firming rate and firmness after storage increased for loaves containing the least hydroxypropylated starch. Inclusion of cross-linked starch had little effect on loaf volume or crumb structure but increased crumb firmness. The firming rate was mostly similar to that of control samples. Presumably, the moment and extent of starch gelatinization and the concomitant water migration influence the structure formation during baking. Initial bread firmness seems determined by the rigidity of the gelatinized granules and leached amylose. Amylopectin retrogradation and strengthening of a long-range network by intensifying the inter- and intramolecular starch-starch and possibly also starch-gluten interactions (presumably because of water incorporation in retrograded amylopectin crystallites) play an important role in firming.

  17. Native starch in tablet formulations: properties on compaction.

    PubMed

    Bos, C E; Bolhuis, G K; Van Doorne, H; Lerk, C F

    1987-10-16

    Maize, potato, rice and tapioca (cassava) starch were evaluated with respect to their properties on direct compression. Rice starch showed much better compactibility as compared to maize, potato and tapioca starch. Moreover, its binding capacity proved to be almost insensitive to mixing with magnesium stearate. This in contrast to the dramatic decrease in crushing strength of potato starch tablets containing the lubricant. The compactibility of the starches was found to be strongly affected by the equilibrium moisture content of the starches, which is dependent on the relative humidity of the atmosphere under which the powders were stored. All starches showed adequate capacity for water uptake to act as a disintegrant. Rice starch exhibited worst flowability, caused by its fine particle size as compared to the other starches. Granulation of rice starch changed it into a potential filler-binder in tablets prepared by direct compression.

  18. Plant-crafted starches for bioplastics production.

    PubMed

    Sagnelli, Domenico; Hebelstrup, Kim H; Leroy, Eric; Rolland-Sabaté, Agnès; Guilois, Sophie; Kirkensgaard, Jacob J K; Mortensen, Kell; Lourdin, Denis; Blennow, Andreas

    2016-11-05

    Transgenically-produced amylose-only (AO) starch was used to manufacture bioplastic prototypes. Extruded starch samples were tested for crystal residues, elasticity, glass transition temperature, mechanical properties, molecular mass and microstructure. The AO starch granule crystallinity was both of the B- and Vh-type, while the isogenic control starch was mainly A-type. The first of three endothermic transitions was attributed to gelatinization at about 60°C. The second and third peaks were identified as melting of the starch and amylose-lipid complexes, respectively. After extrusion, the AO samples displayed Vh- and B-type crystalline structures, the B-type polymorph being the dominant one. The AO prototypes demonstrated a 6-fold higher mechanical stress at break and 2.5-fold higher strain at break compared to control starch. Dynamic mechanical analysis showed a significant increase in the storage modulus (E') for AO samples compared to the control. The data support the use of pure starch-based bioplastics devoid of non-polysaccharide fillers.

  19. Diffractive parameric colors.

    PubMed

    Orava, Joni; Heikkila, Noora; Jaaskelainen, Timo; Parkkinen, Jussi

    2008-12-01

    A method of producing inkless parameric color pairs is studied. In this method, colors are formed additively using diffraction gratings with differing grating periods as primary colors. Gratings with different grating periods reflect different spectral radiance peaks of a fluorescent lamp to the desired viewing angle, according to the grating equation. Four spectral peaks of a 4000 K fluorescent lamp--red, green, cyan, and blue-are used as the primary colors. The colors are mixed additively by fixing the relative areas of different grating periods inside a pixel. With four primary colors it is possible to mix certain colors with different triplets of primary colors. Thus, it is theoretically possible to produce metameric colors. In this study, three parameric color pairs are fabricated using electron beam lithography, electroplating, and hot embossing. The radiance spectra of the color pairs are measured by spectroradiometer from hot-embossed plastic samples. The CIELAB DeltaE(ab) and CIEDE2000 color differences between radiance spectra of the color pairs are calculated. The CIEDE2000 color differences of color pairs are between 2.6 and 7.2 units in reference viewing conditions. The effects of viewing angle and different light sources are also evaluated. It is found that both the viewing angle and the light source have very strong influences on the color differences of the color pairs.

  20. Saffron and beetroot extracts encapsulated in maltodextrin, gum Arabic, modified starch and chitosan: Incorporation in a chewing gum system.

    PubMed

    Chranioti, Charikleia; Nikoloudaki, Aspasia; Tzia, Constantina

    2015-08-20

    Maltodextrin (MD-21DE), gum Arabic (GA), gum Arabic-modified starch (GA-MS), modified starch-chitosan (MS-CH) and modified starch-maltodextrin-chitosan (MS-MD-CH) were used as agents for beetroot and saffron coloring-extracts microencapsulation by freeze drying. The produced powders were evaluated in terms of coloring strength (E) during storage at 40°C for 10 weeks and a first-order kinetic was applied. Color parameters (L(*), a(*), b(*), C(*) and ΔE(*)) and water sorption behavior was also studied. Moreover, incorporation of the powders in a chewing gum model system was conducted. The type of encapsulating agent significantly (P<0.05) affected the studied parameters with the order of protection in both extracts being as follows: MD>GA>GA-MS>MS-CH>MS-MD-CH. The water sorption study revealed that MD and GA kept their structural integrity up to water activities of 0.66 and 0.82, respectively. The chewing gum samples produced with coloring extracts encapsulated in GA-MS showed the greatest a(*)(for beetroot) and b(*) (for saffron) values indicating a better protection.

  1. Effect of pressure and temperature on the gelatinization of starch at various starch concentrations.

    PubMed

    Baks, Tim; Bruins, Marieke E; Janssen, Anja E M; Boom, Remko M

    2008-01-01

    The effects of pressure, temperature, and treatment time on the degree of gelatinization were determined with differential scanning calorimetry measurements for wheat starch-water mixtures with starch concentrations varying between 5 and 80 w/w %. Although simple models could be used to describe the degree of starch gelatinization as a function of pressure or temperature, a more complex model based on the Gibbs energy difference had to be used to describe the degree of gelatinization as a function of both pressure and temperature. The experimental and model data were used to construct a phase diagram for 5, 30, and 60 w/w % wheat starch-water mixtures. Data obtained from literature were in accordance with our phase diagrams. These phase diagrams can be used to estimate the degree of gelatinisation after applying a certain pressure and temperature on a starch-water mixture with starch concentrations in the range of 5 and 60 w/w %.

  2. Applicability, Commercial Utility and Recent Patents on Starch and Starch Derivative as Pharmaceutical Drug Delivery Carrier.

    PubMed

    Pandey, Shreya; Malviya, Rishabha; Sharma, Pramod K

    2015-01-01

    Natural polymers are widely utilized in pharmaceutical and food industries. Starch, a major carbohydrate is a staple food in human and animal diets which is simply extractable from various sources, like potato, maize, corn, wheat, etc. It is widely used as a raw material in various food and non food industries as well as in paper, textile and other industries. This article summarizes the starch and modification of starch and to produce a novel molecule with various applications in industries including number of advances in pharmaceutical industry. The unique characteristics of starch and their modified form can be successfully used as drug delivery carriers in various pharmaceutical preparations. It is widely used as controlled and sustained release polymer, tablet disintegrant, drug delivery carrier, plasma volume expander and also finds its applicability in bone tissue engineering and in artificial red cells. It also includes the patents related to starch and modified starch based products and their commercial utility.

  3. Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.

    PubMed

    Liu, Zhongdong; Liu, Boxiang; Li, Mengxing; Wei, Min; Li, Hua; Liu, Peng; Wan, Tuo

    2013-10-15

    Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials.

  4. Effects of salts on the gelatinization and retrogradation properties of maize starch and waxy maize starch.

    PubMed

    Wang, Wei; Zhou, Hongxian; Yang, Hong; Zhao, Siming; Liu, Youming; Liu, Ru

    2017-01-01

    The objective of this study was to evaluate the effects of salts on the gelatinization and retrogradation of maize and waxy maize starch. Experimental results showed that the salting-out or structure-making ions, such as F(-) and SO4(2-), decreased the swelling power, solubility and transparency of both starches, but increased the gelatinization temperature, enthalpy, and syneresis, due to the tendency of these ions to protect the hydrogen bond links among starch molecules. On the other hand, the salting-in or structure-breaking ions, such as I(-) and SCN(-), exhibited the opposite effects. Microscopic observations confirmed such effects of salts on both starches. Furthermore, the effects of salts were more significant on waxy maize and on normal maize starch. Generally, salts could significantly influence on the gelatinization and retrogradation of maize and waxy maize starch, following the order of the Hofmeister series.

  5. Starch synthesis in Arabidopsis. Granule synthesis, composition, and structure.

    PubMed

    Zeeman, Samuel C; Tiessen, Axel; Pilling, Emma; Kato, K Lisa; Donald, Athene M; Smith, Alison M

    2002-06-01

    The aim of this work was to characterize starch synthesis, composition, and granule structure in Arabidopsis leaves. First, the potential role of starch-degrading enzymes during starch accumulation was investigated. To discover whether simultaneous synthesis and degradation of starch occurred during net accumulation, starch was labeled by supplying (14)CO(2) to intact, photosynthesizing plants. Release of this label from starch was monitored during a chase period in air, using different light intensities to vary the net rate of starch synthesis. No release of label was detected unless there was net degradation of starch during the chase. Similar experiments were performed on a mutant line (dbe1) that accumulates the soluble polysaccharide, phytoglycogen. Label was not released from phytoglycogen during the chase indicating that, even when in a soluble form, glucan is not appreciably degraded during accumulation. Second, the effect on starch composition of growth conditions and mutations causing starch accumulation was studied. An increase in starch content correlated with an increased amylose content of the starch and with an increase in the ratio of granule-bound starch synthase to soluble starch synthase activity. Third, the structural organization and morphology of Arabidopsis starch granules was studied. The starch granules were birefringent, indicating a radial organization of the polymers, and x-ray scatter analyses revealed that granules contained alternating crystalline and amorphous lamellae with a periodicity of 9 nm. Granules from the wild type and the high-starch mutant sex1 were flattened and discoid, whereas those of the high-starch mutant sex4 were larger and more rounded. These larger granules contained "growth rings" with a periodicity of 200 to 300 nm. We conclude that leaf starch is synthesized without appreciable turnover and comprises similar polymers and contains similar levels of molecular organization to storage starches, making Arabidopsis

  6. New data on ectomycorrhizae and soils of the Chinese truffles Tuber pseudoexcavatum and Tuber indicum, and their impact on truffle cultivation.

    PubMed

    García-Montero, Luis G; Di Massimo, Gabriella; Manjón, José L; García-Abril, Antonio

    2008-12-01

    Chinese truffles serve as a good complement to the market for Tuber melanosporum (Périgord black truffle). However, Chinese truffles could be introduced accidentally or fraudulently into the plantations of Mediterranean truffles, and they could have a negative effect on truffle production and natural ecosystems. The study of Tuber species from China which are commercialized in Europe began 14 years ago. Tuber pseudoexcavatum was proposed as a new species, and this has been validated by some authors based on molecular and phylogenetic studies. We synthesize their ectomycorrhizae using samples from the type collection, and we compare T. pseudoexcavatum and Tuber indicum ectomycorrhizae. The ectomycorrhizae of these species have a morphology which is related to the ectomycorrhizae of T. melanosporum. We provide useful information for the rapid screening of the above-mentioned Chinese truffles ectomycorrhizae, for the quality control of commercial plants mycorrhized with Tuber. Moreover, we analyze the soil tolerance and the host plant affinity of T. pseudoexcavatum and T. indicum, in order to assess the capacity of both Chinese truffles to penetrate T. melanosporum plantations and habitats.

  7. Effects of processing moisture on the physical properties and in vitro digestibility of starch and protein in extruded brown rice and pinto bean composite flours.

    PubMed

    Sumargo, Franklin; Gulati, Paridhi; Weier, Steven A; Clarke, Jennifer; Rose, Devin J

    2016-11-15

    The influence of pinto bean flour and processing moisture on the physical properties and in vitro digestibility of rice-bean extrudates has been investigated. Brown rice: pinto bean flour (0%, 15%, 30%, and 45% bean flour) were extruded under 5 moisture conditions (17.2%, 18.1%, 18.3%, 19.5%, and 20.1%). Physical properties [bulk density, unit density, radial expansion, axial expansion, overall expansion, specific volume, hardness, color, water solubility index, and water absorption index] and in vitro starch and protein digestibilities were determined. Increasing bean flour and processing moisture increased density and hardness while decreasing expansion. Rapidly digestible starch decreased and resistant starch increased as bean substitution and processing moisture increased. In vitro protein digestibility increased with increasing bean flour or with decreasing processing moisture. Incorporating bean flour into extruded snacks can negatively affect physical attributes (hardness, density, and expansion) while positively affecting in vitro starch (decrease) and protein (increase) digestibilities.

  8. Microwave-accelerated methylation of starch.

    PubMed

    Singh, Vandana; Tiwari, Ashutosh

    2008-01-14

    A novel microwave-accelerated method for methylating soluble starch is described. Soluble starch could be fully methylated in 72% yield within 4.66 min using iodomethane and 30% potassium hydroxide under microwave irradiation. The completely methylated starch thus obtained was hydrolyzed with 60% HCO(2)H for 1.5 min under 80% MW power, followed by 0.05 M H(2)SO(4) for 2.0 min under 100% MW power. The partially methylated monosaccharides were separated by preparative paper chromatography and identified by their melting points and optical rotations.

  9. Response of Potato Tuber Number and Spatial Distribution to Plant Density in Different Growing Seasons in Southwest China

    PubMed Central

    Zheng, Shun-Lin; Wang, Liang-Jun; Wan, Nian-Xin; Zhong, Lei; Zhou, Shao-Meng; He, Wei; Yuan, Ji-Chao

    2016-01-01

    The aim of this study was to explore the effects of different density treatments on potato spatial distribution and yield in spring and fall. Plant density influenced yield and composition, horizontal, and vertical distribution distances between potato tubers, and spatial distribution position of tuber weights. The results indicated that: (1) Spring potato yield had a convex quadratic curve relationship with density, and the highest value was observed at 15.75 × 104 tubers per hectare. However, the yield of fall potatoes showed a linear relationship with plant density, and the highest value was observed at 18 × 104 tubers per hectare; (2) Density had a greater influence on the tuber weight of spring potatoes and fruit number of single fall potatoes; (3) The number of potato tubers in the longitudinal concentration exhibited a negative linear relationship with density, whereas the average vertical distribution distance of tubers exhibited a positive incremental hyperbolic relationship. For spring and fall potato tubers, the maximum distances were 8.4152 and 6.3316 cm, and the minimum distances 8.7666 and 6.9366 cm, respectively; and (4) Based on the artificial neural network model of the spatial distribution of tuber weight, density mainly affected the number and spatial distribution of tubers over 80 g. Tubers over 80 g were mainly distributed longitudinally (6–10 cm) and transversely (12–20 cm) within the high density treatment, and the transverse distribution scope and number of tubers over 80 g were reduced significantly. Spring potato tubers over 80 g grown at the lowest density were mainly distributed between 12 and 20 cm, whereas those at the highest density were primarily distributed between 10 and 15 cm. PMID:27092146

  10. Uniform color space based on color matching

    NASA Astrophysics Data System (ADS)

    Liao, Shih-Fang; Yang, Tsung-Hsun; Lee, Cheng-Chung

    2007-09-01

    This research intends to explore with a uniform color space based on the CIE 1931 x-y chromatic coordinate system. The goal is to improve the non-uniformity of the CIE 1931 x-y chromaticity diagram such as to approach the human color sensation as possible; however, its simple methodology still can be kept. In spite of the existence of various kinds of the uniform color coordinate systems built up early (CIE u'-v', CIE Lab, CIE LUV, etc.), the establishment of a genuine uniform color space is actually still an important work both for the basic research in color science and the practical applications of colorimetry, especially for recent growing request in illumination engineering and in display technology. In this study, the MacAdam ellipses and the Munsell color chips are utilized for the comparison with the human color sensation. One specific linear transformation matrix is found for the CIE 1931 color matching functions (see manuscript) to become the novel uniform ones. With the aid of the optimization method, the transformation matrix can be easily discovered and makes the 25 MacAdam ellipses are similar to each other in the novel uniform color space. On the other hand, the perfectiveness of the equal-hue curves and the equal-chroma contours from the Mnusell color chips evaluates for the best optimization conditions among several different definitions for the similarity of all the MacAdam ellipses. Finally, the color difference between any two colors can be simply measured by the Euclidean distance in the novel uniform color space and is still fitted to the human color sensation.

  11. Study on the stability of β-carotene microencapsulated with pinhão (Araucaria angustifolia seeds) starch.

    PubMed

    Spada, Jordana Corralo; Noreña, Caciano Pelayo Zapata; Marczak, Ligia Damasceno Ferreira; Tessaro, Isabel Cristina

    2012-08-01

    Native and hydrolyzed pinhão starches were used as coating materials for β-carotene microencapsulation by freeze-drying. The purpose of the present study was to evaluate the stability of β-carotene encapsulated under three different conditions: in the presence of ultraviolet light at 25±2 °C, in the dark at 25±2 °C and in the dark at 10.0±0.2 °C. The color of the samples was also analyzed. Microcapsules prepared with native starch showed the lowest stability during storage. In contrast, microcapsules encapsulated with 12 dextrose equivalent (DE) hydrolyzed starch exhibited the highest stability. First-order kinetic and Weibull models were applied to describe the degradation of β-carotene over time. The R(2) values of the Weibull model were greater than those of the first-order kinetic model. Moreover, multivariate analyses (principal component and cluster analyses) were also conducted.

  12. Stability and physicochemical properties of model salad dressings prepared with pregelatinized potato starch.

    PubMed

    Bortnowska, Grażyna; Balejko, Jerzy; Schube, Violetta; Tokarczyk, Grzegorz; Krzemińska, Natalia; Mojka, Katarzyna

    2014-10-13

    The effects of pregelatinized potato starch concentration (PSC) ranged from 0 to 5 wt% on the physical stability, color, rheological, textural, and sensory properties of model salad dressings prepared with 2 wt% dried egg yolk (DEY) or sodium caseinate (SC) were explored. All dressings showed shear-thinning behavior with yield stress. Raising PSC increased storage (G') and loss (G") moduli decreasing loss tangent (tanδ) and samples containing ≥ 3 wt% starch showed a weak gel-like (tanδ<1) response. A generalized Cox-Merz rule was applicable to indicate shear/strain sensitivity of the dressings structures. Rheological characterization based on Bohlin's parameters (A, z) was useful for distinguishing physical stability of dressings made with different formulations. Changes in color were generally very small and mainly PSC-dependent. Correlation analyses revealed that sensory descriptors could be satisfactory modeled with the appropriate instrumental data. Overall, the results proved that pregelatinized potato starch may be suitable ingredient in low-fat dressings applications.

  13. Alternative oxidase expression in aged potato tuber slices

    SciTech Connect

    Hiser, C.; Herdies, L.; McIntosh, L. )

    1989-04-01

    Higher plant mitochondria posses a cyanide-resistant, hydroxamate-sensitive alternative pathway of electron transport that does not conserve energy. Aging of potato tuber slices for 24 hours leads to the development of an alternative pathway capacity. We have shown that a monoclonal antibody raised against the alternative pathway terminal oxidase of Sauromatum guttatum crossreacts with a protein of similar size in aged potato slice mitochondria. This protein was partially purified and characterized by two-dimensional gel electrophoresis, and its relative levels parallel the rise in cyanide-resistant respiration. We are using a putative clone of the S. guttatum alternative oxidase gene to isolate the equivalent gene from potato and to examine its expression.

  14. Isolation and biochemical characterization of Apios tuber lectin.

    PubMed

    Kenmochi, Eri; Kabir, Syed Rashel; Ogawa, Tomohisa; Naude, Ryno; Tateno, Hiroaki; Hirabayashi, Jun; Muramoto, Koji

    2015-01-09

    Apios tuber lectin, named ATL, was isolated from Apios americana Medikus by two chromatography steps, hydrophobic chromatography and anion-exchange chromatography. The minimum concentration required for the hemagglutination activity toward rabbit erythrocytes of ATL was 4 μg/mL. ATL was composed of a homodimer of 28.4 kDa subunits. The amino acid sequence of ATL was similar to those of other legume lectins. The lectin showed moderate stability toward heating and acidic pH, and the binding affinity against several monosaccharides, such as D-glucosamine and D-galactosamine. ATL also bound to desialylated or agalactosylated glycoproteins such as asialo and agalacto transferrin. ATL decreased the transepithelial electrical resistance across human intestinal Caco-2 cell monolayers, suggesting the effect on the tight junction-mediated paracellular transport.

  15. Rapamycin for treating Tuberous Sclerosis and Autism Spectrum Disorders

    PubMed Central

    Ehninger, Dan; Silva, Alcino J.

    2010-01-01

    Tuberous sclerosis (TSC) is a genetic disorder caused by heterozygous mutations in the TSC1 or TSC2 genes and is associated with autism spectrum disorders (ASD) in 20–60% of cases. In addition, altered TSC/mTOR signaling is emerging as a feature common to a subset of ASD. Recent findings, in animal models, show that restoration of the underlying molecular defect can improve neurological dysfunction in several of these models, even if treatment is initiated in adult animals, suggesting that pathophysiological processes in the mature brain contribute significantly to the overall neurological phenotype in these models. These findings suggest that windows for therapeutic intervention in ASD may be wider than thought previously. PMID:21115397

  16. Tuberous sclerosis complex: everything old is new again.

    PubMed

    Ess, Kevin C

    2009-06-01

    Tuberous Sclerosis Complex (TSC) is a multiorgan genetic disease caused by loss of function of either the TSC1 (encodes hamartin) or TSC2 (encodes tuberin) genes. Patients with TSC have benign tumors (hamartomas) in multiple organs though brain involvement is typically the most disabling aspect of the disease as very high rates of neurodevelopmental disorders are seen. While first described well over 120 years ago, recent advances have transformed TSC into a prototypical disorder that exemplifies the methods and potential of molecular medicine. This review will detail historical aspects of TSC and its strong associations with neurodevelopmental disorders focusing on epilepsy and autism. Finally, promising new approaches for the treatment of epilepsy and autism in patients with TSC as well as those in the general population will be discussed.

  17. [Chymotrypsin and trypsin inhibitor isolated from potato tubers].

    PubMed

    Revina, T A; Parfenov, I A; Gvozdeva, E L; Gerasimova, N G; Valueva, T A

    2011-01-01

    Potato Kunitz-type chymotrypsin inhibitor (PKCI-23) was isolated from potato tubers (Solanum tuberosum L., Zhukov's Jubilee breed) and purified to a homogenous state. The protein was purified by gel-filtration chromatography and ion-exchange chromatography using Sephadex G-75 and CM-Sepharose CL-6B, respectively. PKCI-23 protein has been shown to inhibit both chymotrypsin and trypsin with equal efficacy, forming equimolar complexes with these enzymes. However, much weaker inhibitory effect of PKCI-23 has been observed for Carlsberg subtilisin. The N-terminal 20 amino acid sequence of PKCI-23 has been sequenced. PKCI-23 has been shown to suppress, with different efficacy, the growth and development of pathogenic microorganisms Fusarium culmorum (Wm. G. Sm.) Sacc. and Phytophtora infestans (Mont.) de Bary that infect potato.

  18. Hepatotoxicity of tubers of Indian Kudzu (Pueraria tuberosa) in rats.

    PubMed

    Santosh, Nagwani; Mohan, Kumar; Royana, Singh; Yamini, Tripathi B

    2010-04-01

    Methanolic extract of tubers of Pueraria tuberosa Linn. (Fabaceae) (PTME) has been tested for hepatoxicity in rats. In acute study, PTME (100-400 mg/100 g BW, given orally) showed LD(50) at 227.5 mg. For sub-chronic study, its repeated doses (5-100 mg/100 g BW, for 30 days), significantly increased hepatic enzymes in blood, sinusoidal congestion, disruption of central vein, inflammatory cell infiltration and hepatocellular necrosis in liver in dose dependent manner, with increase in NO, iNOS and ROS levels. In a kinetic study (single dose 227.5 mg/100 g BW), there was sequential decrease in GSH and enhanced NO suggesting free-radical generation as the primary cause of cell damage. It is concluded that the higher dosing of PTME or its continuous use for longer period (even in low doses) is hepatotoxicity by inducing oxidative stress.

  19. Precocious puberty produced by an osteolipoma of the tuber cinereum.

    PubMed

    Vivanco-Allende, Ana; García-González, Mónica; González-Jiménez, David; Pérez-Guirado, Alejandro; Fernández, Isela; Gómez-Illan, Rafael

    2012-01-01

    Central precocious puberty (CPP) is fairly common in girls. In most girls, the etiology for the CPP is unknown. Among the more rare causes of CPP in girls are central nervous system tumors and hamartomas. Osteolipoma of the tuber cinereum, which is the most commonly diagnosed at autopsy, has been reported as a cause of CPP. We describe an 8-year-old girl with central precocious puberty in whom MRI demonstrated a lesion compatible with osteolipoma. Her symptom was breast development that begun at age 7 years and 9 months. Her case history, laboratory studies and imaging are presented. Her puberty was rapidly progressive. She was treated successfully with a GnRHa (Triptorelin 3.75 mg IM q 4 weeks). Her case brings to the forefront the need to perform an MRI in children with rapidly progressing puberty.

  20. Pulmonary choriostoma in a case of tuberous sclerosis complex

    PubMed Central

    Spalgais, S; Gothi, D; Verma, AK

    2015-01-01

    A 52 years old lady was diagnosed to have Tuberous Sclerosis Complex (TSC) on the basis of 2 major and one minor criterion. She had family history of similar complaints in her sister and two sons. There was involvement of kidney in the form of angiomyolipoma, skin in the form of facial angiofibroma and teeth with a dental pit. She had an unusual lung involvement in the form of multiple small choristomas. Choristoma was diagnosed on transbronchial lung biopsy and was present in the form of disorganised striated muscles. The reported pulmonary manifestations of TCS i.e. lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH) are types of hamartomas. Hamartomas and choristomas are both types of disorganized tissue. ‘Choristoma’of lung in TSC however is not reported. Clinopathological correlation of pulmonary hamartoma and choristoma, and treatment in TSC has been discussed. PMID:26119439

  1. Enzymatic browning and after-cooking darkening of Jerusalem artichoke tubers (Helianthus tuberosus L.).

    PubMed

    Bach, Vibe; Jensen, Sidsel; Clausen, Morten R; Bertram, Hanne C; Edelenbos, Merete

    2013-11-15

    Jerusalem artichoke tubers (Helianthus tuberosus L.) undergo enzymatic browning when peeled or cut, and turn grey after boiling, due to after-cooking darkening reactions between iron and phenolic acids. In an attempt to reveal the components responsible for these discolouration reactions, sensory evaluation and instrumental colour measurements were related to contents of total phenolics, phenolic acids, organic acids and iron in three varieties of raw and boiled Jerusalem artichoke tubers harvested in the autumn and the spring. No differences were found between varieties in sensory evaluated enzymatic browning, but Rema and Draga had higher scores than Mari in after-cooking darkening. Jerusalem artichoke tubers had higher contents of total phenolics, phenolic acids and citric acid in the autumn and low contents in the spring, while it was the opposite for malic acid. None of the chemical parameters investigated could explain the discolouration of the Jerusalem artichoke tubers.

  2. The Or gene enhances carotenoid accumulation and stability during post-harvest storage of potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Provitamin A carotenoids in staple crops are not very stable during storage and their loss compromises nutritional quality. To elucidate the fundamental mechanisms underlying carotenoid accumulation and stability, we investigated transgenic potato tubers that express the cauliflower Orange (Or) gene...

  3. Pseudoaneurysm After Spontaneous Rupture of Renal Angiomyolipoma in Tuberous Sclerosis: Successful Treatment with Percutaneous Thrombin Injection

    SciTech Connect

    Corso, Rocco Carrafiello, Gianpaolo; Rampoldi, Antonio; Leni, Davide; Ticca, Cristiana; Vercelli, Ruggero; Vanzulli, Angelo

    2005-04-15

    We report a case of a large perinephric pseudoaneurysm due to spontaneous rupture of renal angiomyolipoma, occluded by percutaneous thrombin injection under ultrasound guidance in a young woman affected by tuberous sclerosis.

  4. In vitro analyses of resistant starch in retrograded waxy and normal corn starches.

    PubMed

    Zhou, Xing; Chung, Hyun-Jung; Kim, Jong-Yea; Lim, Seung-Taik

    2013-04-01

    Gelatinized waxy and normal corn starches (40% starch) were subjected to temperature cycling between 4 and 30°C (1 day at each temperature) or isothermal storage (4°C) to induce retrogradation. The in vitro analysis methods that are currently used for the measurement of resistant starch (RS), i.e. Englyst, AACC 32-40 and Goni methods, were compared with homogenized retrograded starch gels and freeze-dried powders of the gels. RS contents obtained by the three analysis methods were in the following order: Goni>Englyst>AACC. Although different RS values were obtained among the analysis methods, similar trends in regards to the starch type and storage conditions could be observed. Little or no RS was found in freeze-dried powders of the retrograded starch gels and storage conditions had no effect, indicating that the physical state for RS analysis is important. More RS was found in normal corn starch gels than in waxy corn starch gels under identical storage conditions and in the gels stored under temperature cycling than those under isothermal storage (4°C), indicating that the presence of amylose inhibits starch digestion and the level of crystalline structure of re-crystallized amylopectin also affects the RS formation during retrogradation.

  5. Electron microscopy and composition of raw acorn starch in relation to in vivo starch digestibility.

    PubMed

    Cappai, Maria Grazia; Alesso, Giuseppe Andrea; Nieddu, Giuseppa; Sanna, Marina; Pinna, Walter

    2013-06-01

    The structure and composition of starch play an important role as co-factors affecting raw starch digestibility: such features were investigated in raw acorn starch from the most diffused oak trees in the Mediterranean basin. A total of 620 whole ripe acorns from Holm (Quercus ilex L., n = 198), Downy (Quercus pubescens Willd., n = 207) and Cork (Quercus suber L., n = 215) oaks sampled on the Sardinia Isle (40° 56' 0'' N; 9° 4' 0'' E; 545 m above the mean sea level) in the same geographical area, were analyzed for their chemical composition. The starch contents ranged between 51.2% and 53.5% of dry matter. The starch granules displayed a spheroid/ovoid and cylindrical shape; on scanning electron microscopic (SEM) analyses, a bimodal distribution of starch granule size was observed both for Holm and Cork oak acorns, whereas the starch granules of Downy oak acorns showed diameters between 10.2 and 13.8 μm. The specific amylose to amylopectin ratio of acorn starch was 25.8%, 19.5% and 34.0% in the Holm, Downy and Cork oaks, respectively. The (13)C Nuclear Magnetic Resonance (NMR) signal analysis displayed a pivotal spectrum for the identification of the amylose peaks in raw acorn starch, as a basis for the amylose to amylopectin ratio determination.

  6. Distribution of branches in whole starches from maize mutants deficient in starch synthase III.

    PubMed

    Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

    2014-05-21

    An earlier study explored the possibility of analyzing the distribution of branches directly in native, whole starch without isolating the amylopectin component. The aim of this study was to explore if this approach can be extended to include starch mutants. Whole starches from du1 maize mutants deficient in starch synthase III (SSIII) with amylose content of ∼30-40% were characterized and compared with the wild type of the common genetic background W64A. Clusters were produced from whole starch by hydrolysis with α-amylase of Bacillus amyloliquefaciens. Their compositions of building blocks and chains were analyzed further by complete α-amylolysis and by debranching, respectively, whereafter the products were subjected to gel permeation and anion exchange chromatography. The size and structure of the clusters were compared with those of their isolated amylopectin component. Whereas the whole starch of the wild type sample had a branched structure similar to that of its amylopectin component, the results showed that the du1 mutation resulted in more singly branched building blocks in the whole starch compared to the isolated amylopectin. This suggested that amylose and/or intermediate materials in whole du1 starches likely contributed to the composition of branches. This study explored an alternative procedure to characterize the composition of branches in the whole starch without fractionating the components.

  7. Resistant starch improvement of rice starches under a combination of acid and heat-moisture treatments.

    PubMed

    Hung, Pham Van; Vien, Ngo Lam; Lan Phi, Nguyen Thi

    2016-01-15

    The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1-39.0%, significantly higher than those of native rice starches (6.3-10.2%) and those of heat-moisture treated rice starches (18.5-23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application.

  8. Dilute solution properties of canary seed (Phalaris canariensis) starch in comparison to wheat starch.

    PubMed

    Irani, Mahdi; Razavi, Seyed M A; Abdel-Aal, El-Sayed M; Hucl, Pierre; Patterson, Carol Ann

    2016-06-01

    Dilute solution properties of an unknown starch are important to understand its performance and applications in food and non-food industries. In this paper, rheological and molecular properties (intrinsic viscosity, molecular weight, shape factor, voluminosity, conformation and coil overlap parameters) of the starches from two hairless canary seed varieties (CO5041 & CDC Maria) developed for food use were evaluated in the dilute regime (Starch dispersions in DMSO (0.5g/dl)) and compared with wheat starch (WS). The results showed that Higiro model is the best among five applied models for intrinsic viscosity determination of canary seed starch (CSS) and WS on the basis of coefficient of determination (R(2)) and root mean square error (RMSE). WS sample showed higher intrinsic viscosity value (1.670dl/g) in comparison to CSS samples (1.325-1.397dl/g). Berry number and the slope of master curve demonstrated that CSS and WS samples were in dilute domain without entanglement occurrence. The shape factor suggested spherical and ellipsoidal structure for CO5041 starch and ellipsoidal for CDC Maria starch and WS. The molecular weight, coil radius and coil volume of CSSs were smaller than WS. The behavior and molecular characterization of canary seed starch showed its unique properties compared with wheat starch.

  9. Color identification testing device

    NASA Technical Reports Server (NTRS)

    Brawner, E. L.; Martin, R.; Pate, W.

    1970-01-01

    Testing device, which determines ability of a technician to identify color-coded electric wires, is superior to standard color blindness tests. It tests speed of wire selection, detects partial color blindness, allows rapid testing, and may be administered by a color blind person.

  10. Color Me Understood.

    ERIC Educational Resources Information Center

    Harris, Judy J.

    2000-01-01

    Describes the "color system" as a way of grouping children into different personality types based on a certain color: orange, blue, green, and gold. Lists stress producers for specific color people. Asserts that, through making groups of different colors, children begin to see the various specialties others can bring to the group and learn to…

  11. Digital Color Image Restoration

    DTIC Science & Technology

    1975-08-01

    color image recording system is derived and the equations representing the model and the equations of colorimetry are expressed in matrix form. Computer ... algorithms are derived which correct color errors introduced by imperfections in the color recording system. The sources of color error which are

  12. The Potato Tuber Mitochondrial Proteome1[W][OPEN

    PubMed Central

    Salvato, Fernanda; Havelund, Jesper F.; Chen, Mingjie; Rao, R. Shyama Prasad; Rogowska-Wrzesinska, Adelina; Jensen, Ole N.; Gang, David R.; Thelen, Jay J.; Møller, Ian Max

    2014-01-01

    Mitochondria are called the powerhouses of the cell. To better understand the role of mitochondria in maintaining and regulating metabolism in storage tissues, highly purified mitochondria were isolated from dormant potato tubers (Solanum tuberosum ‘Folva’) and their proteome investigated. Proteins were resolved by one-dimensional gel electrophoresis, and tryptic peptides were extracted from gel slices and analyzed by liquid chromatography-tandem mass spectrometry using an Orbitrap XL. Using four different search programs, a total of 1,060 nonredundant proteins were identified in a quantitative manner using normalized spectral counts including as many as 5-fold more “extreme” proteins (low mass, high isoelectric point, hydrophobic) than previous mitochondrial proteome studies. We estimate that this compendium of proteins represents a high coverage of the potato tuber mitochondrial proteome (possibly as high as 85%). The dynamic range of protein expression spanned 1,800-fold and included nearly all components of the electron transport chain, tricarboxylic acid cycle, and protein import apparatus. Additionally, we identified 71 pentatricopeptide repeat proteins, 29 membrane carriers/transporters, a number of new proteins involved in coenzyme biosynthesis and iron metabolism, the pyruvate dehydrogenase kinase, and a type 2C protein phosphatase that may catalyze the dephosphorylation of the pyruvate dehydrogenase complex. Systematic analysis of prominent posttranslational modifications revealed that more than 50% of the identified proteins harbor at least one modification. The most prominently observed class of posttranslational modifications was oxidative modifications. This study reveals approximately 500 new or previously unconfirmed plant mitochondrial proteins and outlines a facile strategy for unbiased, near-comprehensive identification of mitochondrial proteins and their modified forms. PMID:24351685

  13. Cooking behavior and starch digestibility of NUTRIOSE® (resistant starch) enriched noodles from sweet potato flour and starch.

    PubMed

    Menon, Renjusha; Padmaja, G; Sajeev, M S

    2015-09-01

    The effect of a resistant starch source, NUTRIOSE® FB06 at 10%, 15% and 20% in sweet potato flour (SPF) and 5% and 10% in sweet potato starch (SPS) in reducing the starch digestibility and glycaemic index of noodles was investigated. While NUTRIOSE (10%) significantly reduced the cooking loss in SPF noodles, this was enhanced in SPS noodles and guar gum (GG) supplementation reduced CL of both noodles. In vitro starch digestibility (IVSD) was significantly reduced in test noodles compared to 73.6g glucose/100g starch in control SPF and 65.9 g in SPS noodles. Resistant starch (RS) was 54.96% for NUTRIOSE (15%)+GG (1%) fortified SPF noodles and 53.3% for NUTRIOSE (5%)+GG (0.5%) fortified SPS noodles, as against 33.8% and 40.68%, respectively in SPF and SPS controls. Lowest glycaemic index (54.58) and the highest sensory scores (4.23) were obtained for noodles with 15% NUTRIOSE+1% GG.

  14. Biochemical Characterisation of TSC1 and TSC2 Variants Identified in Patients with Tuberous Sclerosis Complex

    DTIC Science & Technology

    2010-07-01

    B) TSC2 5069-47ins34 variant. Sequence (forward strand only) of the repeat region in TSC2 exon 38 and intron 38. Exonic nucleotides are represented...novel missense mutation in the GTPase activating protein homology region of TSC2 in two large families with tuberous sclerosis complex. J Med Genet 38...Thiele E, Franz D, Kwiatkowski DJ. 2010. Ultra deep sequencing detects a low rate of mosaic mutations in Tuberous Sclerosis Complex. Hum Genet 127

  15. Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides.

    PubMed

    Olszyk, David; Pfleeger, Thomas; Lee, E Henry; Plocher, Milton

    2010-01-01

    The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plants were treated with herbicides (cloransulam, dicamba, glyphosate, imazapyr, primsulfuron, sulfometuron, or tribenuron) at simulated drift levels [tubers and shoot dry weight were determined at approximately 28 DAT. Imazapyr, sulfometuron, and tribenuron caused significant reductions in tuber fresh weight, with the effective concentrations producing a 25% potato tuber fresh weight (EC25) of 0.00038, 0.0016, and 0.0021 x f.a.r. of 1,124, 52, and 9 g active ingredient hectare(-1) (g a.i. HA(-1)), respectively. Primisulfuron, dicamba, and cloransulam also significantly reduced tuber fresh weight, but with higher EC25 values of 0.011, 0.07, and 0.010 to 0.2 x f.a.r. of 40, 558, and 18 g a.i. HA(-1), respectively. Glyphosate had little effect on tuber fresh weight, with a significant reduction in only one experiment. Sulfometuron reduced tuber fresh weight at an EC25 value lower than the EC25 values for shoot dry weight or plant height. For other herbicides, the reduction in tuber fresh weight occurred within the range of EC25 values for other responses. Although additional experiments are required to develop further a phytotoxicity test, these results indicated that tuber production in young potato plants (harvested approximately 42 DAE) may be an effective assay for below-ground asexual reproductive responses to herbicides, especially acetolactate synthase inhibitors.

  16. Age-induced loss of wound-healing ability in potato tubers is partly regulated by ABA.

    PubMed

    Kumar, G N Mohan; Lulai, Edward C; Suttle, Jeffrey C; Knowles, N Richard

    2010-11-01

    Wounding of potato (Solanum tuberosum L.) tubers induces the development of a suberized closing layer and wound periderm that resists desiccation and microbial invasion. Wound-healing ability declines with tuber age (storage period). The mechanism of loss in healing capacity with age is not known; however, upregulation of superoxide production, increased ABA biosynthesis and phenylalanine ammonia lyase (PAL) activity in response to wounding are processes critical to the development of a suberized closing layer and wound periderm. Therefore, the role of ABA in modulating the age-induced loss of wound-healing ability of tubers was examined. Non-wounded older tubers had 86% less ABA (dry matter basis) than younger tubers. PAL transcript increased in younger tubers within 24 h of wounding, but transcription was delayed by 5 days in older tubers. Wound-induced PAL activity increased more rapidly in younger than older tubers. ABA treatment increased PAL expression and activity in tissue from both ages of tubers and restored the 24 h transcription time line in older tubers. Moreover, ABA treatment of wounded older tubers enhanced their resistance to water vapor loss following a 6-day wound-healing period. Wound-induced accumulation of suberin poly(phenolic(s)) (SPP) and suberin poly(aliphatic(s)) (SPA) was measurably slower in older versus younger tubers. ABA treatment hastened SPP accumulation in older tubers to match that in younger tubers, but only enhanced SPA accumulations over the initial 4 days of healing. Age-induced loss of wound-healing ability is thus partly due to reduced ability to accumulate ABA and modulate the production of SPP through PAL in response to wounding and to dysfunction in the downstream signaling events that couple SPA biosynthesis and/or deposition to ABA. ABA treatment partly restored the healing ability of older tubers by enhancing the accumulation of SPP without restoring wound-induced superoxide forming ability to the level of younger

  17. Production of modified starches by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

    1999-04-01

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch.

  18. [Characterisation of Dioscorea bulbifera native starch].

    PubMed

    Araujo de Vizcarrondo, Consuelo; Rincón, Alicia Mariela; Padilla, Fanny

    2004-06-01

    A non conventional source of starch, bulbs of Dioscorea bulbifera, was evaluated. Giving a yield of 28.48 g/100 g on dry weight, chemical composition, physical, physico-chemical and morphological characteristics were assessed, as well as its rheological properties. Chemical analysis showed a amylose content of 29.37%. Micrographies showed that most of the starch granules were of irregular shape, similar to a pyramid with rounded vertices, and a smaller number were elongated with smooth surface. Dioscorea starch showed a gelatinization temperature of 70.8 degrees C and maximum viscosity at 88.6 degrees C of 435 Brabender units (BU). It presented a relatively stable consistency to the cooking process and a low tendency to retrogradation; which suggest the starch possible use in food products that need a fast viscosity and a gel with a stable consistency.

  19. Starch-Poly(Hydroxylalkanoate) Composites and Blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper summarizes research on starch-polyhydroxyalkanoate (PHA) blends and composites. Efforts to increase compatibility, characterize mechanical and biodegradation properties are described. A range of blend products have been prepared including molded plastics, films and foams. Finally, futu...

  20. Rheological behaviour of heated potato starch dispersions

    NASA Astrophysics Data System (ADS)

    Juszczak, L.; Witczak, M.; Ziêba, T.; Fortuna, T.

    2012-10-01

    The study was designed to investigate the rheological properties of heated potato starch dispersions. Water suspensions of starch were heated at 65, 80 or 95°C for 5, 15, 30 or 60 min. The dispersions obtained were examined for granule size distribution and rheology. It was found that the starch dispersions significantly differed in both respects. The mean diameters of starch granules were largest for the dispersion heated at 65°C and smallest for that heated at 95°C. As the heating temperature was raised, the yield stresses and consistency coefficients decreased, while the flow behaviour indexes and Casson plastic viscosities increased. There were also differences in the viscoelastic properties of the dispersions: for those heated at 65°C the storage and loss moduli increased with heating time whereas for those heated at 80°C both moduli decreased.

  1. Biotechnological relevance of starch-degrading enzymes

    SciTech Connect

    Stewart, G.G.

    1987-01-01

    Traditional enzymes, such as the amylases and the proteases, have been improved, novel applications have been found and new and valuable products have been marketed. The enzymatic hydrolysis of starch is described in some detail. (Refs. 8).

  2. Formation of starch in plant cells.

    PubMed

    Pfister, Barbara; Zeeman, Samuel C

    2016-07-01

    Starch-rich crops form the basis of our nutrition, but plants have still to yield all their secrets as to how they make this vital substance. Great progress has been made by studying both crop and model systems, and we approach the point of knowing the enzymatic machinery responsible for creating the massive, insoluble starch granules found in plant tissues. Here, we summarize our current understanding of these biosynthetic enzymes, highlighting recent progress in elucidating their specific functions. Yet, in many ways we have only scratched the surface: much uncertainty remains about how these components function together and are controlled. We flag-up recent observations suggesting a significant degree of flexibility during the synthesis of starch and that previously unsuspected non-enzymatic proteins may have a role. We conclude that starch research is not yet a mature subject and that novel experimental and theoretical approaches will be important to advance the field.

  3. Temperature cycling periods affect growth and tuberization in potatoes under continuous irradiation

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1992-01-01

    Plants of the potato (Solanum tuberosum L.) cultivars Denali, Norland, Haig and Kennebec were grown for 42 days under three temperature cycling periods (thermoperiods) with continuous irradiation in two repeated experiments to help determine if temperature cycling might be varied to optimize tuber development of potatoes in controlled environments. Thermoperiods of 6/6 hours, 12/12 hours and 24/24 hours were established with the same temperature change of 22/14C and same controlled vapor pressure deficit of 0.60 kPa. The thermoperiod of 24/24 hours significantly promoted tuber initiation but slowed tuber enlargement in all four cultivars, compared to the thermoperiods of 6/6 hours and 12/12 hours. Denali' produced the highest tuber and total dry weights under the 6/6 hours thermoperiod. Kennebec' produced the highest tuber dry weight under the 12/12 hours thermoperiod. Thermoperiods had no significant effect on shoot and root dry weights of any cultivars. The major effect of thermoperiods was on initiation and enlargement of tubers.

  4. DNA barcoding of tuberous Orchidoideae: a resource for identification of orchids used in Salep.

    PubMed

    Ghorbani, Abdolbaset; Gravendeel, Barbara; Selliah, Sugirthini; Zarré, Shahin; de Boer, Hugo

    2017-03-01

    Tubers of terrestrial orchids are harvested and traded from the eastern Mediterranean to the Caspian Sea for the traditional product Salep. Overexploitation of wild populations and increased middle-class prosperity have escalated prices for Salep, causing overharvesting, depletion of native populations and providing an incentive to expand harvesting to untapped areas in Iran. Limited morphological distinctiveness among traded Salep tubers renders species identification impossible, making it difficult to establish which species are targeted and affected the most. In this study, a reference database of 490 nrITS, trnL-F spacer and matK sequences of 133 taxa was used to identify 150 individual tubers from 31 batches purchased in 12 cities in Iran to assess species diversity in commerce. The sequence reference database consisted of 211 nrITS, 158 trnL-F and 121 matK sequences, including 238 new sequences from collections made for this study. The markers enabled unambiguous species identification with tree-based methods for nrITS in 67% of the tested tubers, 58% for trnL-F and 59% for matK. Species in the genera Orchis (34%), Anacamptis (27%) and Dactylorhiza (19%) were the most common in Salep. Our study shows that all tuberous orchid species in this area are threatened by this trade, and further stresses the urgency of controlling illegal harvesting and cross-border trade of Salep tubers.

  5. Comparison of ectomycorrhizal communities in natural and cultivated Tuber melanosporum truffle grounds.

    PubMed

    Belfiori, Beatrice; Riccioni, Claudia; Tempesta, Sabrina; Pasqualetti, Marcella; Paolocci, Francesco; Rubini, Andrea

    2012-09-01

    Truffles are hypogeous ectomycorrhizal (EM) fungi belonging to the genus Tuber. Although outplanting of truffle-inoculated host plants has enabled the realization of productive orchards, truffle cultivation is not yet standardized. Therefore, monitoring the distribution of fungal species in different truffle fields may help us to elucidate the factors that shape microbial communities and influence the propagation and fruiting of Tuber spp. In this study, we compared the fungal biodiversity in cultivated and natural Tuber melanosporum truffle fields located in Central Italy. To this end, ectomycorrhizas (ECM) and soil samples were molecularly analyzed, and an inventory of the fungi associated with Quercus pubescens plants colonized by T. melanosporum, Tuber aestivum or Tuber brumale was compiled. T. melanosporum and T. aestivum were dominant on the cultivated plants, and the number of EM species was markedly lower in the cultivated sites than in the natural sites. However, in the same site, EM biodiversity was higher in T. brumale-colonized plants than in T. melanosporum-colonized plants. These results suggest that different Tuber spp. may have different competitive effects on the other mycobionts. Additionally, in keeping with our previous findings, we found that the number of T. melanosporum genotypes recovered from the soil samples was higher than that of the underlying ECM.

  6. Rapamycin reverses impaired social interaction in mouse models of tuberous sclerosis complex.

    PubMed

    Sato, Atsushi; Kasai, Shinya; Kobayashi, Toshiyuki; Takamatsu, Yukio; Hino, Okio; Ikeda, Kazutaka; Mizuguchi, Masashi

    2012-01-01

    Impairment of reciprocal social interaction is a core symptom of autism spectrum disorder. Genetic disorders frequently accompany autism spectrum disorder, such as tuberous sclerosis complex caused by haploinsufficiency of the TSC1 and TSC2 genes. Accumulating evidence implicates a relationship between autism spectrum disorder and signal transduction that involves tuberous sclerosis complex 1, tuberous sclerosis complex 2 and mammalian target of rapamycin. Here we show behavioural abnormalities relevant to autism spectrum disorder and their recovery by the mammalian target of rapamycin inhibitor rapamycin in mouse models of tuberous sclerosis complex. In Tsc2(+/-) mice, we find enhanced transcription of multiple genes involved in mammalian target of rapamycin signalling, which is dependent on activated mammalian target of rapamycin signalling with a minimal influence of Akt. The findings indicate a crucial role of mammalian target of rapamycin signalling in deficient social behaviour in mouse models of tuberous sclerosis complex, supporting the notion that mammalian target of rapamycin inhibitors may be useful for the pharmacological treatment of autism spectrum disorder associated with tuberous sclerosis complex and other conditions that result from dysregulated mammalian target of rapamycin signalling.

  7. Life histories and fitness of two tuber moth species feeding on native Andean potatoes.

    PubMed

    Horgan, F G; Quiring, D T; Lagnaoui, A; Pelletier, Y

    2012-08-01

    In the inter-Andean valleys of central Perú, two species of tuber moth, Phthorimaea operculella (Zeller) and Symmetrischema tangolias (Gyen), often occur simultaneously in stored potatoes. Traditional farming communities in the region produce a variety of native potatoes for local consumption. These include Solanum tuberosum subsp. andigena, the presumed predecessor of commercial potatoes, S. tuberosum subsp. tuberosum. In this study, we examined resistance against P. operculella in ten native Peruvian potato varieties (Casa blanca, Chispiadita, Madre de vaca, Mamaco negro, Misha, Chorisa, Mamaco rosado, Occa papa, Vacapa jayllo, and Yana tornasol). We also compared resistance in the first five of these varieties against S. tangolias. Varieties with pigmented periderms showed moderate resistance (30-40% against P. operculella in Mamaco negro, Mamaco rosado, and Yana tornasol and 55% against S. tangolias in Mamaco negro). All the other varieties were susceptible to both moth species. Small tubers tended to be the most resistant to the attack by both moths; however, this was not related to the availability of food for developing larvae, since pupal weight and development time were unaffected by the size of tubers. Similar responses by the two moths to native potatoes indicate that tuber resistance could be used to control the complex of tuber moths that damage potatoes in the Andes. We suggest that native potatoes, which are often easily introgressed with commercial potatoes, are a potential source of resistance against tuber moths.

  8. Yellow nutsedge (Cyperus esculentus L. ) control with herbicides: the role of tuberization

    SciTech Connect

    Pereira, W.

    1985-01-01

    Trials were carried out under greenhouse, growth chamber, laboratory, outdoor pot, and field conditions to characterize stages of yellow nutsedge tuberization and to investigate the influence of herbicides. The effects of herbicides on tuberization and phytotoxicity at several growth stages, as well as on sprouting, growth characteristics, and survival of new tubers were determined. Tuberization was a continuous process, but was modulated by plant age and environmental conditions. The growth stage that included the time of first tuber initiation was the best for applying glyphosate (N-(phosphonomethyl)glycine) and oxyfluorfen (2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluromethyl)benzene). Plant-age and length of period after spraying influenced glyphosate and oxyfluorfen absorption and translocation. Addition of unlabelled oxyfluorfen as a tank mixture can glyphosate increased absorption of /sup 14/C-glyphosate to 27% after 1 day and 46% after 8 days and increased translocation into other plant parts. Timing of postemergence herbicide applications relative to tuberization is crucial for overall control of yellow nutsedge. When soil applied herbicides were compared in the field, consecutive applications of dichlobenil (2,6-dichlorobenzonitrile) and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide) for two years provided the best control of nutsedge.

  9. Roots and Tuber Crops as Functional Foods: A Review on Phytochemical Constituents and Their Potential Health Benefits

    PubMed Central

    Josheph Kumar, Thamilini

    2016-01-01

    Starchy roots and tuber crops play a pivotal role in the human diet. There are number of roots and tubers which make an extensive biodiversity even within the same geographical location. Thus, they add variety to the diet in addition to offering numerous desirable nutritional and health benefits such as antioxidative, hypoglycemic, hypocholesterolemic, antimicrobial, and immunomodulatory activities. A number of bioactive constituents such as phenolic compounds, saponins, bioactive proteins, glycoalkaloids, and phytic acids are responsible for the observed effects. Many starchy tuber crops, except the common potatoes, sweet potatoes, and cassava, are not yet fully explored for their nutritional and health benefits. In Asian countries, some edible tubers are also used as traditional medicinal. A variety of foods can be prepared using tubers and they may also be used in industrial applications. Processing may affect the bioactivities of constituent compounds. Tubers have an immense potential as functional foods and nutraceutical ingredients to be explored in disease risk reduction and wellness. PMID:27127779

  10. Roots and Tuber Crops as Functional Foods: A Review on Phytochemical Constituents and Their Potential Health Benefits.

    PubMed

    Chandrasekara, Anoma; Josheph Kumar, Thamilini

    2016-01-01

    Starchy roots and tuber crops play a pivotal role in the human diet. There are number of roots and tubers which make an extensive biodiversity even within the same geographical location. Thus, they add variety to the diet in addition to offering numerous desirable nutritional and health benefits such as antioxidative, hypoglycemic, hypocholesterolemic, antimicrobial, and immunomodulatory activities. A number of bioactive constituents such as phenolic compounds, saponins, bioactive proteins, glycoalkaloids, and phytic acids are responsible for the observed effects. Many starchy tuber crops, except the common potatoes, sweet potatoes, and cassava, are not yet fully explored for their nutritional and health benefits. In Asian countries, some edible tubers are also used as traditional medicinal. A variety of foods can be prepared using tubers and they may also be used in industrial applications. Processing may affect the bioactivities of constituent compounds. Tubers have an immense potential as functional foods and nutraceutical ingredients to be explored in disease risk reduction and wellness.

  11. Physicochemical properties and digestibility of hydrothermally treated waxy rice starch.

    PubMed

    Zeng, Feng; Ma, Fei; Kong, Fansheng; Gao, Qunyu; Yu, Shujuan

    2015-04-01

    Waxy rice starch was subjected to annealing (ANN) and heat-moisture treatment (HMT). These starches were also treated by a combination of ANN and HMT. The impact of single and dual modifications (ANN-HMT and HMT-ANN) on the molecular weight (M(w)), crystalline structure, thermal properties, and the digestibility were investigated. The relative crystallinity and short-range order on the granule surface increased on ANN, whereas decreased on HMT. All treated starches showed lower M(w) than that of the native starch. Gelatinization onset temperature, peak temperature and conclusion temperature increased for both single and dual treatments. Increased slowly digestible starch content was found on HMT and ANN-HMT. However, resistant starch levels decreased in all treated starches as compared with native starch. The results would imply that hydrothermal treatment induced structural changes in waxy rice starch significantly affected its digestibility.

  12. Morphological features and physicochemical properties of waxy wheat starch.

    PubMed

    Zhang, Huanxin; Zhang, Wei; Xu, Chunzhong; Zhou, Xing

    2013-11-01

    Morphological features, granule composition, and physicochemical properties of waxy wheat starch were compared with those of normal wheat starch. The morphologies and granule populations were found to be similar for the two starches. However, waxy wheat starch contained a smaller proportion of B-type granules, had a larger average granule diameter, and a higher degree of crystallinity than normal wheat starch, as measured by particle size analysis and differential scanning calorimetry. These differences resulted in a higher gelatinization temperature, transition enthalpy, peak viscosity, breakdown, swelling power, lower peak viscosity temperature and final viscosity in waxy wheat starch. These points suggest that waxy wheat starch should have greater resistance to retrogradation during cooling and higher water-holding capacity under dry conditions. Highlighting the differences in physicochemical properties of waxy and normal wheat starches should help point toward effective applications of waxy wheat starch in the food industry.

  13. Phosphoglucan phosphatase function sheds light on starch degradation.

    PubMed

    Silver, Dylan M; Kötting, Oliver; Moorhead, Greg B G

    2014-07-01

    Phosphoglucan phosphatases are novel enzymes that remove phosphates from complex carbohydrates. In plants, these proteins are vital components in the remobilization of leaf starch at night. Breakdown of starch is initiated through reversible glucan phosphorylation to disrupt the semi-crystalline starch structure at the granule surface. The phosphoglucan phosphatases starch excess 4 (SEX4) and like-SEX4 2 (LSF2) dephosphorylate glucans to provide access for amylases that release maltose and glucose from starch. Another phosphatase, LSF1, is a putative inactive scaffold protein that may act as regulator of starch degradative enzymes at the granule surface. Absence of these phosphatases disrupts starch breakdown, resulting in plants accumulating excess starch. Here, we describe recent advances in understanding the biochemical and structural properties of each of these starch phosphatases.

  14. Preparation of indigestible pyrodextrins from different starch sources.

    PubMed

    Laurentin, Alexander; Cárdenas, Marité; Ruales, Jenny; Pérez, Elevina; Tovar, Juscelino

    2003-08-27

    Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl. The enzymatically available starch content of all preparations decreased by 55-65% after modification. Thus, pyrodextrinization seems to be an effective way to produce indigestible glucans from different starches. Pyrodextrins obtained were complex mixtures of starch derivatives with a wide range of molecular weight as estimated by gel filtration chromatography. Both their molecular weight profiles and contents of indigestible fractions varied with starch source. Experiments with lentil and cassava starches showed that changing dextrinization conditions also affects the susceptibility to enzymatic hydrolysis of the product.

  15. Extraction and application of starch-based coagulants from sago trunk for semi-aerobic landfill leachate treatment.

    PubMed

    Aziz, Hamidi Abdul; Sobri, Nur Izzati Mohamad

    2015-11-01

    Malaysia is one of the highest starch producers. In this study, sago starch was utilized as a natural coagulant aid to reduce the dosage of aluminum-based coagulant in leachate treatment. The potential of native sago trunk starch (NSTS) and commercial sago starch (CSS) was evaluated as sole coagulant and coagulant aid in the presence of polyaluminum chloride (PACl) in the removal of color, suspended solids (SS), NH3-N, turbidity, chemical oxygen demand, organic UV254, Cd, and Ni. Leachate was sampled from Pulau Burung Landfill Site, one of the semi-aerobic landfills in Malaysia. The optimum dosage for PACl in the presence of NSTS or CSS as coagulant aid was reduced from 3100 to 2000 mg/L. In the presence of 2000 mg/L PACl with 6000 mg/L NSTS and 2000 mg/L PACl with 5000 mg/L CSS, the removal performance for color, SS, and turbidity are 94.7, 99.2, and 98.9%, respectively. Similar results were obtained with the use of 3100 mg/L PACl alone. Therefore, CSS and NSTS can be used as coagulant aid.

  16. Intelligent pH indicator film composed of agar/potato starch and anthocyanin extracts from purple sweet potato.

    PubMed

    Choi, Inyoung; Lee, Jun Young; Lacroix, Monique; Han, Jaejoon

    2017-03-01

    A new colorimetric pH indicator film was developed using agar, potato starch, and natural dyes extracted from purple sweet potato, Ipomoea batatas. Both agar and potato starch are solid matrices used to immobilize natural dyes, anthocyanins. The ultraviolet-visible (UV-vis) spectrum of anthocyanin extract solutions and agar/potato starch films with anthocyanins showed color variations to different pH values (pH 2.0-10.0). Fourier transform infrared (FT-IR) and UV-vis region spectra showed compatibility between agar, starch, and anthocyanin extracts. Color variations of pH indicator films were measured by a colorimeter after immersion in different pH buffers. An application test was conducted for potential use as a meat spoilage sensor. The pH indicator films showed pH changes and spoilage point of pork samples, changing from red to green. Therefore, the developed pH indicator films could be used as a diagnostic tool for the detection of food spoilage.

  17. Heat expanded starch-based compositions.

    PubMed

    Glenn, Gregory M; Klamczynski, Artur K; Holtman, Kevin M; Shey, Justin; Chiou, Bor-Sen; Berrios, Jose; Wood, Delilah; Orts, William J; Imam, Syed H

    2007-05-16

    A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period.

  18. The Other Double Helix--The Fascinating Chemistry of Starch

    NASA Astrophysics Data System (ADS)

    Hancock, Robert D.; Tarbet, Bryon J.

    2000-08-01

    Current textbooks deal only briefly with the chemistry of starch. A short review with 21 references is presented, describing the structure of starch and indicating the double helix structure of A-type and B-type starch. The structure of the starch granule is examined, pointing out the existence of growth rings of alternating crystalline and noncrystalline starch, with growing amylopectin molecules extending from the hilum (point of origin) to the surface of the starch granule. The swelling of starch granules in water, above the gelatinization temperature of about 60 °C, is discussed. The process of gelatinization involves unraveling of the starch helix and a manyfold increase in volume of the starch granule as water is imbibed and bound to the unraveled starch polymer by hydrogen bonding. Baking bread or pastries causes unraveling of the starch helix, and the process by which these products become stale corresponds primarily to the re-forming of the starch helix. The importance of this phenomenon in food science is discussed. The absorption of nonpolar linear molecules such as I2, or linear nonpolar portions of molecules such as n-butanol or fats and phospholipids, by the C-type helix of starch is examined. The way in which starch is structurally modified to retard staling is discussed in relation to food technology.

  19. Engineering Potato Starch with a Higher Phosphate Content

    PubMed Central

    Xu, Xuan; Huang, Xing-Feng; Visser, Richard G. F.

    2017-01-01

    Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a carbohydrate-binding module and a dual-specificity phosphatase domain, is involved in the dephosphorylation of glycogen. To modify phosphate content and better understand starch (de)phosphorylation in storage starch, laforin was engineered and introduced into potato (cultivar Kardal). Interestingly, expression of an (engineered) laforin in potato resulted in significantly higher phosphate content of starch, and this result was confirmed in amylose-free potato genetic background (amf). Modified starches exhibited altered granule morphology and size compared to the control. About 20–30% of the transgenic lines of each series showed red-staining granules upon incubation with iodine, and contained higher phosphate content than the blue-stained starch granules. Moreover, low amylose content and altered gelatinization properties were observed in these red-stained starches. Principle component and correlation analysis disclosed a complex correlation between starch composition and starch physico-chemical properties. Ultimately, the expression level of endogenous genes involved in starch metabolism was analysed, revealing a compensatory response to the decrease of phosphate content in potato starch. This study provides a new perspective for engineering starch phosphate content in planta by making use of the compensatory mechanism in the plant itself. PMID:28056069

  20. The Effect of Nitrogen Rate on Vine Kill, Tuber Skinning Injury, Tuber Yield and Size Distribution, and Tuber Nutrients and Phytonutrients in two Potato Cultivars grown for Early Potato Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early potatoes are typically produced using less nitrogen than a full season potato crop as high rates of nitrogen may delay tuber set and lead to excessive vine growth that is difficult to terminate prior to harvest. Bintje and Ciklamen potato cultivars were grown with preplant soil nitrogen levels...