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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

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...

3

Isolation and characterization of starch from Cyperus esculentus tubers  

Microsoft Academic Search

Starch was extracted from the tubers of Cyperus esculentus with a yield of 20.51% on a dry weight basis. The starch, which was pure white in colour, was characterized in terms of granule size, cold water extracts, moisture and ash contents, paste stability, clarity, adhesive strength and line-spread at 50°C. The granule sizes compared well with those of rice starch,

S. C. Umerie; N. A. N. Obi; E. O. Okafor

1997-01-01

4

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

5

Studies on tuber starches. II. Molecular structure, composition and physicochemical properties of yam ( Dioscorea sp.) starches grown in Sri Lanka  

Microsoft Academic Search

Starch from varieties of Dioscorea esculenta (Lour.) Burkill (kukulala, java-ala, nattala) and Dioscorea alata L. (hingurala, raja-ala) tubers grown in Sri Lanka was isolated and its morphology, composition, structure and physicochemical properties were studied. The yield of starch was in the range 12.2–18.0% on a whole tuber basis. The shape and size of D. esculenta and D. alata starch granules

L. Jayakody; R. Hoover; Q. Liu; E. Donner

2007-01-01

6

Expression of different glucansucrases in potato tubers: implications for starch biosynthesis  

Microsoft Academic Search

This thesis describes the production of dextran (polymers with -(1?6)-linked glucosyl residues), mutan (polymers with -(1?3)-linked glucosyl residues) and alternan (polymers with alternating -(1?3)\\/ -(1?6)-linked glucosyl residues) in potato tubers. Modifications of the physicochemical properties of potato starch were  investigated as well as the possibilities to introduce novel linkage types in starch. The most pronounced alterations at the tuber and

G. A. Kok-Jacon

2005-01-01

7

Differential Cold Tolerance, Starch, Sugar, Protein, and Lipid of Yellow and Purple Nutsedge Tubers 1  

PubMed Central

From measurements of viability after exposure of tubers to natural overwintering in the soil and 6 weeks exposure at 2 C, species cold tolerance of the tubers was ranked in decreasing order: yellow nutsedge `I' (Cyperus esculentus L.), an ecotype originating in Illinois; yellow nutsedge `G', an ecotype originating in Georgia; and purple nutsedge (Cyperus rotundus L.). The ratios of unsaturated-saturated fatty acids in tuber triglycerides, tuber polar lipids, and leaf polar lipids followed the same order as the cold tolerance rankings, with the most cold-hardy species having the highest ratios. Lipid content was less than 1% of dry weight in purple nutsedge tubers, but was from 5 to 7% in both yellow nutsedge tubers. Starch, sugar, and lipid contents increased significantly in the hardy yellow nutsedge `I' tubers during a 6-week exposure to 2 C, but did not change in the susceptible purple nutsedge tubers; only sugar increased in yellow nutsedge `G' tubers after this treatment. Protein content was not altered by the 2 C treatment in any of the tubers. Apparently, several factors involving starch, sugar, lipids, and fatty acids are related to the differences in tolerance to cold in these species. PMID:16659181

Stoller, Edward W.; Weber, Evelyn J.

1975-01-01

8

Differential cold tolerance, starch, sugar, protein, and lipid of yellow and purple nutsedge tubers.  

PubMed

From measurements of viability after exposure of tubers to natural overwintering in the soil and 6 weeks exposure at 2 C, species cold tolerance of the tubers was ranked in decreasing order: yellow nutsedge ;I' (Cyperus esculentus L.), an ecotype originating in Illinois; yellow nutsedge ;G', an ecotype originating in Georgia; and purple nutsedge (Cyperus rotundus L.). The ratios of unsaturated-saturated fatty acids in tuber triglycerides, tuber polar lipids, and leaf polar lipids followed the same order as the cold tolerance rankings, with the most cold-hardy species having the highest ratios. Lipid content was less than 1% of dry weight in purple nutsedge tubers, but was from 5 to 7% in both yellow nutsedge tubers. Starch, sugar, and lipid contents increased significantly in the hardy yellow nutsedge ;I' tubers during a 6-week exposure to 2 C, but did not change in the susceptible purple nutsedge tubers; only sugar increased in yellow nutsedge ;G' tubers after this treatment. Protein content was not altered by the 2 C treatment in any of the tubers. Apparently, several factors involving starch, sugar, lipids, and fatty acids are related to the differences in tolerance to cold in these species. PMID:16659181

Stoller, E W; Weber, E J

1975-05-01

9

Tuber starch amylose content is associated with cold-induced sweetening in potato  

PubMed Central

Cold-induced sweetening (CIS) is the accumulation of reducing sugars in potato tubers at low storage temperatures. It is undesirable because it results in dark fry products. Our study evaluated the relationship between genetic resistance to CIS and two starch parameters, amylose content and starch granule size. We found that the amylose content in four CIS-resistant varieties was higher than that in five susceptible varieties. Amylose content was influenced not only by variety but also storage, production year, and field location. However, interactions between amylose content and environmental variables were not detected. In contrast, starch granule size was not associated with CIS resistance. No effect of storage on starch granule size was detected, and interactions among variety, production year, and field location were observed. Tuber starch amylose content should be considered a source of variability for CIS. PMID:25493178

Jansky, Shelley H; Fajardo, Diego A

2014-01-01

10

Tuber starch amylose content is associated with cold-induced sweetening in potato.  

PubMed

Cold-induced sweetening (CIS) is the accumulation of reducing sugars in potato tubers at low storage temperatures. It is undesirable because it results in dark fry products. Our study evaluated the relationship between genetic resistance to CIS and two starch parameters, amylose content and starch granule size. We found that the amylose content in four CIS-resistant varieties was higher than that in five susceptible varieties. Amylose content was influenced not only by variety but also storage, production year, and field location. However, interactions between amylose content and environmental variables were not detected. In contrast, starch granule size was not associated with CIS resistance. No effect of storage on starch granule size was detected, and interactions among variety, production year, and field location were observed. Tuber starch amylose content should be considered a source of variability for CIS. PMID:25493178

Jansky, Shelley H; Fajardo, Diego A

2014-11-01

11

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

PubMed

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. PMID:25477633

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

2014-12-01

12

Purification and properties of a starch granule-degrading a-amylase from potato tubers  

Microsoft Academic Search

An a-amylase (EC 3.2.1.1) was purified to apparent electrophoretic homogeneity from potato (Solanum tuberosum L.) tubers by affinity chromatography on a starch granule column, Q-Sepharose chromatography, and gel filtration. The enzyme was purified 24 300-fold over the crude extract of soluble proteins with a yield of 13.2% to a specific activity of 824 \\/\\/mol min\\

Wolfgang Witt; Jorg J. Sauter

2009-01-01

13

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

14

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

PubMed

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. PMID:17147423

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

2006-12-13

15

Comparative transcriptome analysis coupled to X-ray CT reveals sucrose supply and growth velocity as major determinants of potato tuber starch biosynthesis  

Microsoft Academic Search

BACKGROUND: Even though the process of potato tuber starch biosynthesis is well understood, mechanisms regulating biosynthesis are still unclear. Transcriptome analysis provides valuable information as to how genes are regulated. Therefore, this work aimed at investigating transcriptional regulation of starch biosynthetic genes in leaves and tubers of potato plants under various conditions. More specifically we looked at gene expression diurnally

Stephanus J Ferreira; Melanie Senning; Sophia Sonnewald; Petra-Maria Keßling; Ralf Goldstein; Uwe Sonnewald

2010-01-01

16

Immunological Comparison of the Starch Branching Enzymes from Potato Tubers and Maize Kernels 1  

PubMed Central

Starch branching enzyme was purified from potato (Solanum tuberosum L.) tubers as a single species of 79 kilodaltons and specific antibodies were prepared against both the native enzyme and against the gel-purified, denatured enzyme. The activity of potato branching enzyme could only be neutralized by antinative potato branching enzyme, whereas both types of antibodies reacted with denatured potato branching enzyme. Starch branching enzymes were also isolated from maize (Zea mays L.) kernels. All of the denatured forms of the maize enzyme reacted with antidenatured potato branching enzyme, whereas recognition by antinative potato branching enzyme was limited to maize branching enzymes I and IIb. Antibodies directed against the denatured potato enzyme were unable to neutralize the activity of any of the maize branching enzymes. Antinative potato branching enzyme fully inhibited the activity of maize branching enzyme I; the neutralized maize enzyme was identified as a 82 kilodalton protein. It is concluded that potato branching enzyme (Mr = 79,000) shares a high degree of similarity with maize branching enzyme I (Mr = 82,000), in the native as well as the denatured form. Cross-reactivity between potato branching enzyme and the other forms of maize branching enzyme was observed only after denaturation, which suggests mutual sequence similarities between these species. Images Figure 1 Figure 2 Figure 5 Figure 8 Figure 9 PMID:16666772

Vos-Scheperkeuter, Greetje H.; de Wit, Janny G.; Ponstein, Anne S.; Feenstra, Will J.; Witholt, Bernard

1989-01-01

17

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

PubMed

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. PMID:20620253

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

2010-07-19

18

Tuber starch amylose content is associated with cold-induced sweetening in potato  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cold induced sweetening (CIS) is the accumulation of reducing sugars in potato tubers due to cold storage. It is undesirable because it results in dark fry products. Potato varieties vary in resistance to CIS. Research efforts have focused on enzymes that contribute to the accumulation of reducing s...

19

The Sucrose Analog Palatinose Leads to a Stimulation of Sucrose Degradation and Starch Synthesis When Supplied to Discs of Growing Potato Tubers1  

PubMed Central

In the present paper we investigated the effect of the sucrose (Suc) analog palatinose on potato (Solanum tuberosum) tuber metabolism. In freshly cut discs of growing potato tubers, addition of 5 mm palatinose altered the metabolism of exogenously supplied [U-14C]Suc. There was slight inhibition of the rate of 14C-Suc uptake, a 1.5-fold increase in the rate at which 14C-Suc was subsequently metabolized, and a shift in the allocation of the metabolized label in favor of starch synthesis. The sum result of these changes was a 2-fold increase in the absolute rate of starch synthesis. The increased rate of starch synthesis was accompanied by a 3-fold increase in inorganic pyrophosphate, a 2-fold increase in UDP, decreased UTP/UDP, ATP/ADP, and ATP/AMP ratios, and decreased adenylate energy charge, whereas glycolytic and Krebs cycle intermediates were unchanged. In addition, feeding palatinose to potato discs also stimulated the metabolism of exogenous 14C-glucose in favor of starch synthesis. In vitro studies revealed that palatinose is not metabolized by Suc synthases or invertases within potato tuber extracts. Enzyme kinetics revealed different effects of palatinose on Suc synthase and invertase activities, implicating palatinose as an allosteric effector leading to an inhibition of Suc synthase and (surprisingly) to an activation of invertase in vitro. However, measurement of tissue palatinose levels revealed that these were too low to have significant effects on Suc degrading activities in vivo. These results suggest that supplying palatinose to potato tubers represents a novel way to increase starch synthesis. PMID:11299376

Fernie, Alisdair R.; Roessner, Ute; Geigenberger, Peter

2001-01-01

20

High-Temperature Perturbation of Starch Synthesis Is Attributable to Inhibition of ADP-Glucose Pyrophosphorylase by Decreased Levels of Glycerate3Phosphate in Growing Potato Tubers  

Microsoft Academic Search

To investigate the short-term effect of elevated temperatures on carbon metabolism in growing potato (Solanum tuberosum L.) tu- bers, developing tubers were exposed to a range of temperatures between 19°C and 37°C. Incorporation of (14C)glucose (Glc) into starch showed a temperature optimum at 25°C. Increasing the temperature from 23°C or 25°C up to 37°C led to decreased label- ing of

Peter Geigenberger; Michael Geiger; Mark Stitt

1998-01-01

21

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

PubMed

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 (?=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. PMID:23987322

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

22

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

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

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

1999-01-01

23

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...

24

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

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. PMID:23064409

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

2012-12-01

25

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...

26

Swelling behaviour of cell wall and starch in potato ( Solanum tuberosum L.) tuber cells — II. Permeability and swelling in macerates  

Microsoft Academic Search

The permeability and swelling behaviour in macerates of potato tuber cells were studied, because of their role in determining the texture of potato products. Chromatography of globular proteins on a column of macerate of boiled potato cells indicated cell wall (CW) pore dimensions smaller than the protein molecular size of 600 kDa. Swelling of boiled and dried potato tuber cells,

Ilan Shomer; Rosa Vasiliver; Pinhas Lindner

1995-01-01

27

Expression of Escherichia coli glycogen synthase in the tubers of transgenic potatoes (Solanum tuberosum) results in a highly branched starch  

Microsoft Academic Search

A chimeric gene containing the patatin promoter and the transit- peptide region of the small-subunit carboxylase gene was utilized to direct expression of Escherichia coli glycogen synthase (glgA) to potato (Solanum tuberosum) tuber amyloplasts. Expression of the glgA gene produd in tuber amyloplasts was between 0.007 and 0.028% of total protein in independent potato lines as determined by immunoblot analysis.

Christine K. Shewmaker; Charles D. Boyer; Dennis P. Wiesenborn; Donald B. Thompson; Micheal R. Boersig; Janette V. Oakes; David M. Stalker

1994-01-01

28

Potato Tuber Callus  

PubMed Central

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

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

1976-01-01

29

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 Dependent1[W][OA  

PubMed Central

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. PMID:23064409

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

2012-01-01

30

Structure of potato tubers formed during spaceflight  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

31

Structure function relationships of transgenic starches with engineered phosphate substitution and starch branching  

Microsoft Academic Search

Potato tuber starch was genetically engineered in the plant by the simultaneous antisense suppression of the starch branching enzyme (SBE) I and II isoforms. Starch prepared from 12 independent lines and three control lines were characterised with respect to structural and physical properties. The lengths of the amylopectin unit chains, the concentrations of amylose and monoesterified phosphate were significantly increased

Andreas Blennow; Bente Wischmann; Karen Houborg; Tina Ahmt; Kirsten Jørgensen; Søren Balling Engelsen; Ole Bandsholm; Peter Poulsen

2005-01-01

32

Physicochemical and binder properties of starch obtained from Cyperus esculentus.  

PubMed

The purpose of this study was to isolate starch from the tubers of Cyperus esculentus L. and evaluate its physicochemical and binder properties. Extraction of starch using sodium metabisulfite yielded 37 g of starch per 100 g of the tubers. Scanning electron microscopy indicated that Cyperus starch consists of oval to elliptical particles with a smooth surface. Cyperus starch demonstrates a narrow particle size distribution with a mean of 8.25 ?m. Cyperus starch conforms well to United States Pharmacopeia standards established for widely used starches like maize and potato. The X-ray powder diffraction pattern and moisture sorption profile of Cyperus starch were comparable to that of maize starch. Cyperus starch had lower swelling power than maize and potato starch, indicative of stronger associative forces within the granules. Carr's index and Hausner ratio indicate that Cyperus starch should have comparable flow properties with respect to maize and potato starch. Cyperus starch was employed as binder for the formulation of metronidazole tablets. Formulations containing 5%, 7.5%, and 10% Cyperus starch were compared with those containing 10% potato starch. At 10% binder concentration, the tablets containing Cyperus starch exhibited better hardness and negligible friability as compared with those with potato starch. Although the binder concentration had a significant effect on the disintegration time of the tablets, it did not seem to affect the dissolution profile. These results indicate that Cyperus starch provides excellent binding properties without compromising drug release characteristics and should be explored in pharmaceutical formulations. PMID:22350737

Manek, Rahul V; Builders, Philip F; Kolling, William M; Emeje, Martins; Kunle, Olobayo O

2012-06-01

33

Nature of Crystallinity in Native and Acid Modified Starches  

Microsoft Academic Search

Crystalline characteristics of natural and acid modified starches (cereals, millets, pulses, root, and tuber) were examined by X-ray diffraction studies. The (hkl) planes were identified using A-, B- and C- type starch cell parameters. The size of crystallite along the direction [hkl] was calculated for all the reflections in the starches. Smallest crystallites (35 to 56 Å) are observed for

V. Singh; S. Z. Ali; R. Somashekar; P. S. Mukherjee

2006-01-01

34

Starch Metabolism in Arabidopsis  

PubMed Central

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

Streb, Sebastian; Zeeman, Samuel C.

2012-01-01

35

Acid degradation of starch. The effect of acid and starch type  

Microsoft Academic Search

Starch from cereals (wheat, maize and finger millet) pulses (chick pea and green gram), tuber (potato) and root (tapioca) was modified with different acids (0.5N, 1.5h, 50°C). Molecular weight (number average, M?n) of these starches decreased after modification, H3PO4 causing the least and HCl and HNO3 the highest reduction. Gel permeation chromatography of native starches using Sepharose CL 4B gave

V. Singh; S. Z. Ali

2000-01-01

36

Color  

NSDL National Science Digital Library

Using this project will expose you to concepts of color, color wheels, color combinations, and techniques of using color. Use the following links, follow the directions to define color terms, create color schemes and explore the use of color in creating designs. Color Scheme Generator 2 This site identifiesbasic terms related to color, using acolor wheeland making color schemes. Color Theory This site explains terminology of color. Color Theory Tutorial This site gives excellent examples and information about ...

Dent, Mrs.

2010-03-23

37

Color  

NSDL National Science Digital Library

This project will be used to teach the importance of color. Watch the following video about color Primary Colors Click on the link Exploration of Color. When you get into the website select the different colors to see what secondary colors are made from the primary colors. Review the following siteColor Theory and then design and paint a color wheel. ...

JoLene

2008-09-29

38

Modelling the yield and texture of comminuted pork products using color and temperature. Effect of fat/lean ratio and starch.  

PubMed

Practices to control the processing of finely comminuted meat products are proposed. The objective was to test the practical value of both temperature and light reflection measurements made during emulsification as potential indicators of cooking losses and resulting gel texture in pork sausages emulsified within a wide range of temperatures and starch and fat levels. Prior to cooking, pork batters were chopped for different times to ensure final emulsion temperatures ranging from 5 to 50°C. The effects of the fat/lean ratio (0.25 and 0.67) and starch addition (0.8 and 3.2% w:w) on temperature and optical reflection were also investigated. The chopping increased the temperature and decreased the light reflection of fresh meat emulsion. There was no relevant loss of emulsifying capacity at emulsion temperature below 30°C and lightness values over 70 CIE units. The losses and textural parameters of cooked emulsions could be predicted by means of non-linear regression equations based on the temperature and color of the raw emulsion. The determination coefficients obtained ranged from 0.89 to 0.99. The prediction models needed to be fitted to each batter formulation, especially in the presence of reduced levels of gelation agents (meat protein and starch). Lightness was a better predictor than chromaticity, since it decreased constantly with chopping in the range of final emulsion temperatures studied (5-50°C). This confirms previous studies that lightness could be used for monitoring emulsion stability in meat batters. PMID:22063577

Bañón, S; Díaz, P; Nieto, G; Castillo, M; Alvarez, D

2008-11-01

39

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...

40

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...

41

Potato tuber dormancy  

Technology Transfer Automated Retrieval System (TEKTRAN)

The date that potato tubers begin to sprout must be carefully managed to maximize crop value. Spouting of fresh, chip and fry processing tubers during storage can decrease crop value, increase water loss and pressure bruising, and may promote pathogen entry. A lack of uniform sprouting in seed potat...

42

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

PubMed

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. PMID:17617825

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

2007-08-01

43

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

PubMed

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. PMID:18293922

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

2008-03-26

44

Changing Colors  

NSDL National Science Digital Library

In this challenge, learners have to figure out in what order to combine five solutions to change the color from clear, to yellow, to blue, and back to clear. The five chemicals are potassium iodide, sodium thiosulfate, sodium hypochlorite (Clorox bleach), soluble starch (Niagara spray starch), and water. The color changes indicate chemical reactions, and the lesson includes some background information about the reactions that create different colors. Suggestions are given for guiding learners through systematic approaches to making the different combinations and observing the results, and for explaining to different age groups what happens when the solutions are combined.

Sciencenter

2014-08-27

45

In situ observation of crystallinity disruption patterns during starch gelatinization.  

PubMed

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. PMID:23218322

Cai, Canhui; Wei, Cunxu

2013-01-30

46

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...

47

COLORS!  

NSDL National Science Digital Library

In this project, students will learn about primary, secondary, and complementary colors. After exploring a few sites and participating in a few deep questions as a class, they will create an optical illusion using complimentary colors. Younger students who are learning this unit will need to do this activity with a parent or as a class with a teacher or aide. INTRODUCTION: Questions to discuss with the students: 1. What colors do you see in this room? 2. What are some jobs that use colors? An Artist? Decorator? ...

Sarah

2009-09-28

48

Starch Slime  

NSDL National Science Digital Library

Learners mix liquid water with solid cornstarch. They investigate the slime produced, which has properties of both a solid and a liquid. When they press hard on the starch slime with their fingers, the slime acts like a solid. Starch in water is a suspension of solid particles in water. When learners leave the starch slime alone, it flows like a liquid. A great opportunity to discuss states of matter. This activity is currently used in the Nature of Matter Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.

Oregon Museum of Science and Industry

1997-01-01

49

Cloning and Bioinformatics Analysis of Genomic DNA Sequences of Gastrodia Tuber  

Microsoft Academic Search

Gastrodia tuber has many pharmacological effects. DNA fingerprints of Gastrodia tuber were determined using randomly amplified polymorphic DNA (RAPD) technique, of which the desired DNA segments were selected and recovered. Positive DNA clones were obtained through ligation techniques, transformation, blue\\/white color screenings, cloning and identifying. Novelty of the cloned DNA and its potential importance were confirmed by sequencing DNA and

Jun Tao; Yan Wang; Li Wen; Zhi-cheng Wang; Bi-Jun Tan

2009-01-01

50

Improved method for detection of starch hydrolysis  

SciTech Connect

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).

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

1982-09-01

51

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

PubMed

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. PMID:15695443

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

2005-04-01

52

Changes in main nutrients and medicinal composition of Chinese yam (Dioscorea opposita) tubers during storage.  

PubMed

The changes in the main nutrient and medicinal components during the storage of the Chinese yam (Dioscorea opposita) tubers were studied. The harvested tubers were stored under ambient conditions (10 °C to 18 °C, 60 % to 80 % Relative Humidity) and cold temperature and packaged conditions (4 °C, 60 % to 65 % Relative Humidity) for 45 day. The allantoin, starch, total alcohol-soluble sugar, reducing sugar, protein, and moisture contents of the samples were evaluated. Their amylase activities were also investigated. Results of ambient conditions indicated that, during storage, moisture decreased by 67.96 % to 56.51 %, and total sugars, reducing sugars, and protein increased by 6.49 % to 9.81 %, 1.7 % to 2.27 %, and 13.02 % to 14.55 %, respectively. Starch and enzyme activities increased during the early days of storage and progressively decreased, and the content of allantoin changed in volatility. The changes were more significant at cold temperatures and packaged conditions than at ambient conditions. This result suggests that after-ripening occurred in the early stages of Chinese yam tubers, which positively affected the nutritional potential of the tubers by a marked increase in nutrients. Low-temperature sweetening greatly affects the nutritional potential of tubers by a series of complicated interactions between starch and sugars at 4 °C. PMID:25328193

Zhang, Zhidan; Gao, Wenyuan; Wang, Renfang; Huang, Luqi

2014-10-01

53

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

PubMed

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. PMID:24767057

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

2014-09-15

54

Structure function relationships of transgenic starches with engineered phosphate substitution and starch branching.  

PubMed

Potato tuber starch was genetically engineered in the plant by the simultaneous antisense suppression of the starch branching enzyme (SBE) I and II isoforms. Starch prepared from 12 independent lines and three control lines were characterised with respect to structural and physical properties. The lengths of the amylopectin unit chains, the concentrations of amylose and monoesterified phosphate were significantly increased in the transgenically engineered starches. Size exclusion chromatography with refractive index detection (SEC-RI) indicated a minor decrease in apparent molecular size of the amylose and the less branched amylopectin fractions. Differential scanning calorimetry (DSC) revealed significantly higher peak temperatures for gelatinisation and retrogradation of the genetically engineered starches whereas the enthalpies of gelatinisation were lower. Aqueous gels prepared from the transgenic starches showed increased gel elasticity and viscosity. Principle component analysis (PCA) of the data set discriminated the control lines from the transgenic lines and revealed a high correlation between phosphate concentration and amylopectin unit chain length. The PCA also indicated that the rheological characteristics were primarily influenced by the amylose concentration. The phosphate and the amylopectin unit chain lengths had influenced primarily the pasting and rheological properties of the starch gels. PMID:16024070

Blennow, Andreas; Wischmann, Bente; Houborg, Karen; Ahmt, Tina; Jørgensen, Kirsten; Engelsen, Søren Balling; Bandsholm, Ole; Poulsen, Peter

2005-08-01

55

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...

56

Starch biosynthetic genes and enzymes are expressed and active in the absence of starch accumulation in sugar beet tap-root  

PubMed Central

Background Starch is the predominant storage compound in underground plant tissues like roots and tubers. An exception is sugar beet tap-root (Beta vulgaris ssp altissima) which exclusively stores sucrose. The underlying mechanism behind this divergent storage accumulation in sugar beet is currently not fully known. From the general presence of starch in roots and tubers it could be speculated that the lack in sugar beet tap-roots would originate from deficiency in pathways leading to starch. Therefore with emphasis on starch accumulation, we studied tap-roots of sugar beet using parsnip (Pastinaca sativa) as a comparator. Results Metabolic and structural analyses of sugar beet tap-root confirmed sucrose as the exclusive storage component. No starch granules could be detected in tap-roots of sugar beet or the wild ancestor sea beet (Beta vulgaris ssp. maritima). Analyses of parsnip showed that the main storage component was starch but tap-root tissue was also found to contain significant levels of sugars. Surprisingly, activities of four main starch biosynthetic enzymes, phosphoglucomutase, ADP-glucose pyrophosphorylase, starch synthase and starch branching enzyme, were similar in sugar beet and parsnip tap-roots. Transcriptional analysis confirmed expression of corresponding genes. Additionally, expression of genes involved in starch accumulation such as for plastidial hexose transportation and starch tuning functions could be determined in tap-roots of both plant species. Conclusion Considering underground storage organs, sugar beet tap-root upholds a unique property in exclusively storing sucrose. Lack of starch also in the ancestor sea beet indicates an evolved trait of biological importance. Our findings in this study show that gene expression and enzymatic activity of main starch biosynthetic functions are present in sugar beet tap-root during storage accumulation. In view of this, the complete lack of starch in sugar beet tap-roots is enigmatic. PMID:24758347

2014-01-01

57

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

PubMed

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. PMID:23132522

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

58

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

PubMed

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. PMID:22944425

Ghosh Dastidar, Trina; Netravali, Anil N

2012-11-01

59

Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner  

ERIC Educational Resources Information Center

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.

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

2004-01-01

60

Tuber Storage Proteins  

PubMed Central

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

SHEWRY, PETER R.

2003-01-01

61

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

PubMed

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 ?-amylase StAmy23, ?-amylases StBAM1 and StBAM9. SbAI could inhibit the activities of both ?-amylase and ?-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. PMID:24985879

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

2014-09-01

62

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

PubMed Central

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

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

2012-01-01

63

Effect of processing on potato starch: in vitro availability and glycaemic index.  

PubMed

The content of digestible starch (DS) and resistant starch (RS) in processed potatoes was assessed. In addition, the effect of domestic cooking on the in vitro digestibility of starch in this tuber, which may influence the glycaemic response, was studied. Resistant starch in raw potato is high, however different RS values were obtained when processed, ranging from 1.18% in boiled potatoes to 10.38% in retrograded flour. In general, cooked potatoes have high levels of DS. Starch digestibility is improved after processing and it is affected by the cooking methods. Boiled and mashed potatoes showed the highest rate of digestion, on the contrary raw potato was hardly digested. The estimated Glycaemic Index (GI) from the degree of starch hydrolysis within 90 min was in accordance with the reported GI values, for potatoes processed in the same way. PMID:10702994

García-Alonso, A; Goñi, I

2000-02-01

64

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

PubMed

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 ?m conformed by several starch granules of wedge shape that range from 2 to 7 ?m. 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. PMID:24463263

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

65

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

PubMed

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. PMID:25173632

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

2014-10-16

66

Tuberous sclerosis and autistic behavior.  

PubMed

A patient with evidence of both infantile autism and tuberous sclerosis syndrome is presented. A possible relationship between the 2 syndromes is discussed. Examination of the skin of young, very disturbed children is recommended. PMID:762036

Mansheim, P

1979-02-01

67

Changes in Lipid Peroxidation and Lipolytic and Free-Radical Scavenging Enzyme Activities during Aging and Sprouting of Potato (Solanum tuberosum) Seed-Tubers.  

PubMed Central

Previous research has shown that cell membranes of potato (Solanum tuberosum L. cv Russet Burbank) seed-tubers lose integrity between 7 and 26 months of storage (4[deg]C, 95% relative humidity), and this loss coincides with a significant decrease in growth potential. The age-induced decline in membrane integrity is apparently due to increased peroxidative damage of membrane lipids. Malondialdehyde (MDA) and ethane concentrations (sensitive markers of lipid peroxidation and membrane damage) increased in seed-tuber tissues with advancing age. Moreover, in vivo ethane production from discs of cortex tissue from 13- and 25-month-old seed-tubers was 87% greater (on average) than that from discs from 1-month-old tubers. Calcium suppressed ethane production from all ages of tissue discs, and the effect was concentration dependent. Linoleic acid enhanced ethane production from 5- and 17-month-old tubers by 61 and 228%, respectively, suggesting that older tissue may contain a higher free-radical (FR) titer and/or lower free polyunsaturated fatty acid content. In addition, throughout plant establishment, the internal ethane concentration of older seed-tubers was 54% higher than that of younger seed-tubers. MDA concentration of tuber tissue declined by about 65% during the initial 7 months of storage and then increased 267% as tuber age advanced to 30 months. The age-induced trend in tuber reducing sugar concentration was similar to that of MDA, and the two were linearly correlated. The age-dependent increase in reducing sugars may thus reflect peroxidative degeneration of the amyloplast membrane, leading to increased starch hydrolysis. Compared with 5-month-old seed tubers, 17- and 29-month-old seed-tubers had significantly higher levels of lipofuscin-like fluorescent compounds (FCs), which are produced when MDA reacts with free amino acids. Age-dependent increases in MDA, ethane, and FCs were not associated with higher activities of phospholipase and lipoxygenase in tissue from older tubers. In fact, 8-month-old seed-tubers had significantly higher activities of these enzymes than 20-month-old seed-tubers. However, the activities of superoxide dismutase, peroxidase, and catalase in 20-month-old tubers were substantially higher out of storage, and increased at a faster rate during plant establishment, than in 8-month-old seed-tubers. Collectively, these results suggest that a gradual build-up of FRs leads to peroxidative damage of membrane lipids during aging of potato seed-tubers. PMID:12231802

Kumar, GNM.; Knowles, N. R.

1993-01-01

68

Colors, Colors?  

NSDL National Science Digital Library

In this activity related to the famous "Stroop Effect," learners explore how words influence what we see and how the brain handles "mixed messages." Learners read colored words and are asked to say the color of the word, not what the word says. Learners use a data table to keep track of where they have trouble reading the colors. They analyze this data by answering questions and drawing conclusions. Learners can also take this test using the online version.

Susan Songstad

2009-01-01

69

Microbial starch-binding domains as a tool for targeting proteins to granules during starch biosynthesis.  

PubMed

Modification of starch biosynthesis pathways holds an enormous potential for tailoring granules or polymers with new functionalities. In this study, we explored the possibility of engineering artificial granule-bound proteins, which can be incorporated in the granule during biosynthesis. The starch-binding domain (SBD)-encoding region of cyclodextrin glycosyltransferase from Bacillus circulans was fused to the sequence encoding the transit peptide (amyloplast entry) of potato granule-bound starch synthase I (GBSS I). The synthetic gene was expressed in the tubers of two potato cultivars (cv. Kardal and cv. Karnico) and one amylose-free (amf) potato mutant. SBDs accumulated inside starch granules, not at the granule surface. Amylose-free granules contained 8 times more SBD (estimated at ca. 1.6% of dry weight) than the amylose-containing ones. No consistent differences in physicochemical properties between transgenic SBD starches and their corresponding controls were found, suggesting that SBD can be used as an anchor for effector proteins without having side-effects. To test this, a construct harbouring the GBSS I transit peptide, the luciferase reporter gene, a PT-linker, and the SBD (in frame), and a similar construct without the linker and the SBD, were introduced in cv. Kardal. The fusion protein accumulated in starch granules (with retainment of luciferase activity), whereas the luciferase alone did not. Our results demonstrate that SBD technology can be developed into a true platform technology, in which SBDs can be fused to a large choice of effector proteins to generate potato starches with new or improved functionalities. PMID:12678563

Ji, Qin; Vincken, Jean-Paul; Suurs, Luc C J M; Visser, Richard G F

2003-03-01

70

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

PubMed

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. PMID:16190656

Lin, Da-Gin; Jeang, Chii-Ling

2005-10-01

71

Investigating Starch in Foods  

NSDL National Science Digital Library

This activity is a classroom experiment where students gather data on which foods contain starch. They use observation and develop their own hypothesis to create a question they would like to discover about starches.

72

Ectopic expression of anthocyanin 5-o-glucosyltransferase in potato tuber causes increased resistance to bacteria.  

PubMed

The principal goal of this paper was to investigate the significance of anthocyanin 5-O-glucosyltransferase (5-UGT) for potato tuber metabolism. The ectopic expression of a 5-UGT cDNA in the tuber improved the plant's defense against pathogen infection. The resistance of transgenic lines against Erwinia carotovora subsp. carotovora was about 2-fold higher than for nontransformed plants. In most cases the pathogen resistance was accompanied by a significant increase in tuber yield. To investigate the molecular basis of transgenic potato resistance, metabolic profiling of the plant was performed. In tuber extracts, the anthocyanin 3,5-O-substituted level was significantly increased when compared to that of the control plant. Of six anthocyanin compounds identified, the highest quantity for pelargonidin 3-rutinoside-5-glucoside acylated with p-coumaric acid and peonidin 3-rutinoside-5-glucoside acylated with p-coumaric acid was detected. A significant increase in starch and a decrease in sucrose level in transgenic tubers have been detected. The level of all other metabolites (amino acids, organic acids, polyamines, and fatty acids) was quite the same as in nontransformants. The plant resistance to bacterial infection correlates with anthocyanin content and sucrose level. The properties of recombinant glucosyltransferase were analyzed in in vitro experiments. The enzyme kinetics and its biochemical properties were similar to those from other sources. PMID:15656661

Lorenc-Kuku?a, Katarzyna; Jafra, Sylwia; Oszmia?ski, Jan; Szopa, Jan

2005-01-26

73

Crystallinity in starch bioplastics  

Microsoft Academic Search

Thermoplastic starch (TPS) materials have been prepared by kneading, extrusion, compression moulding and injection moulding of several native starches with the addition of glycerol as a plasticizer. Two types of crystallinity can be distinguished in TPS directly after processing: (i) residual crystallinity: native A-, B- or C-type crystallinity caused by incomplete melting of starch during processing; (ii) processing-induced crystallinity: amylose

Jeroen J. G. van Soest; S. H. D. Hulleman; D. de Wit; J. F. G. Vliegenthart

1996-01-01

74

Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

75

Regulation of potato tuber sprouting.  

PubMed

Following tuber induction, potato tubers undergo a period of dormancy during which visible bud growth is inhibited. The length of the dormancy period is under environmental, physiological and hormonal control. Sucrose availability is one prerequisite for bud break. In the absence of sucrose, no bud break occurs. Thus, sucrose is likely to serve as nutrient and signal molecule at the same time. The mode of sucrose sensing is only vaguely understood, but most likely involves trehalose-6-phosphate and SnRK1 signalling networks. This conclusion is supported by the observation that ectopically manipulation of trehalose-6-phosphate levels influences the length of the dormancy period. Once physiological competence is achieved, sprouting is controlled by the level of phytohormones. Two phytohormones, ABA and ethylene, are supposed to suppress tuber sprouting; however, the exact role of ethylene remains to be elucidated. Cytokinins and gibberellins are required for bud break and sprout growth, respectively. The fifth classical phytohormone, auxin, seems to play a role in vascular development. During the dormancy period, buds are symplastically isolated, which changes during bud break. In parallel to the establishment of symplastic connectivity, vascular tissue develops below the growing bud most likely to support the outgrowing sprout with assimilates mobilised in parenchyma cells. Sprouting leads to major quality losses of stored potato tubers. Therefore, control of tuber sprouting is a major objective in potato breeding. Although comparative transcriptome analysis revealed a large number of genes differentially expressed in growing versus dormant buds, no master-regulator of potato tuber sprouting has been identified so far. PMID:24100410

Sonnewald, Sophia; Sonnewald, Uwe

2014-01-01

76

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

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. PMID:20356303

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

2010-04-28

77

Extraction of RNA from fresh, frozen, and lyophilized tuber and root tissues.  

PubMed

A method for isolating transcriptionally competent RNA from fresh, frozen, and lyophilized plant storage tissues containing high levels of starch and phenolics is described. The protocol avoids the use of guanidium salts, which often lead to the formation of a viscous gel during extraction of high starch-containing tissues, and instead uses a borate-Tris buffer in combination with high concentrations of NaCl, Na2SO3, and sodium dodecyl sulfate in the extraction medium. RNA was extracted from fresh, frozen, and lyophilized tissues of potato tubers, storage roots of sweet potato, radish, and turnip, and rhizomes of ginger. The yield of RNA from potato tubers averaged 281 microg g fresh weight(-1) and 1584 microg g dry weight(-1) from frozen and lyophilized samples, respectively. A260/A230 ratios of potato RNA extracts were 2.2 or greater, indicating minimal contamination by polyphenols and carbohydrates. Similarly, A260/A280 ratios exceeded 1.9, demonstrating minimal contamination of the RNA by tuber protein. While A260/A280 ratios of extracts from the other plant species were somewhat lower than those for potato (average = 1.56 and 1.80 for fresh and lyophilized samples, respectively), A260/A230 ratios averaged more than 2.0, and the RNA extracted from fresh and lyophilized samples of all species was intact, as demonstrated by denaturing agarose-formaldehyde gel electrophoresis. The protocol yielded RNA suitable for downstream molecular applications involving reverse transcription-polymerase chain reaction from all five species. Transcriptionally competent RNA was also recovered from lyophilized potato tuber tissue stored for 6 years (ambient temperature) by a simple modification to the protocol involving extraction in cold acetone. Lyophilization can thus be used to preserve RNA in high starch- and phenolic-containing plant tissues for studies on gene expression. PMID:17288445

Kumar, G N Mohan; Iyer, Suresh; Knowles, N Richard

2007-03-01

78

[Effect of ambiol and 2-chloroethylphosphonic acid on the content of phytohormones in potato leaves and tubers].  

PubMed

The effects of the antioxidant Ambiol and 2-chlorethylphosphonic acid (2-CEPA) on individual concentrations and concentration ratios of phytohormones, photosynthesis and photophosphorylation rates, sucrose and starch content in tubers, and plant productivity were studied in potato (Solanum tuberosum L). Ambiol increased the ratio of indoleacetic acid (IAA) to abscisic acid (ABA), IAA/ABA, and that of zeatin (Z) and zeatin riboside (ZR) to ABA, (Z + ZR)/ABA. These effects were underlain by an increase in the content of auxins and cytokinins and a decrease in ABA. Unlike Ambiol, 2-CEPA increased the level of ABA, the effect being the most pronounced in the tubers. Ambiol increased the rates of photosynthesis and noncyclic photophosphorylation in chloroplasts isolated from potato leaves. The relation of this phenomenon to auxin and cytokinin accumulation, Ambiol- and 2-CEPA-induced changes in the hormonal balance of potato tubers, carbon metabolism, and plant productivity is discussed. PMID:12722661

Kirillova, I G; Evsiunina, A S; Puzina, T I; Korableva, N P

2003-01-01

79

CORRELATION BETWEEN AERIAL SHOOT AND TUBER CALCIUM ACCUMULATION IN SOLANUM GENOTYPES SEGREGATING FOR TUBER CALCIUM UPTAKE EFFICIENCY  

Technology Transfer Automated Retrieval System (TEKTRAN)

INCREASING tuber calcium concentration improves tuber quality and increases resistance to biotic and abiotic stresses. Genetic variability for tuber calcium efficiency has been reported. We investigated the relationship between stem, leaf, and tuber calcium in three F2 families segregating for tuber...

80

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

PubMed

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. PMID:19153833

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

81

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

PubMed Central

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

Odeku, Oluwatoyin A.; Akinwande, Babatunde L.

2011-01-01

82

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

SciTech Connect

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.

Saxon, E.C.

1981-04-01

83

Graft polymerization of methacrylic acid on starch and hydrolyzed starches  

Microsoft Academic Search

Hydrolysis of maize starch with HCl was studied under various conditions with a view to obtaining starches having different molecular sizes. To this end, the original starches and hydrolyzed starches derived from them were indepen-dently graft-copolymerized with methacrylic acid (MAA) using KMnO4\\/citric acid as initiator. Thus the molecular weight of the polymeric backbone of starch and the substituents present on

Kh. M. Mostafa

1995-01-01

84

Intracellular starch formation in corynebacteria.  

PubMed

Carrier, E. Bernard (Louisiana State University, Baton Rouge, La.) and C. S. McCleskey. Intracellular starch formation in cor-yne bacteria. J. Bacteriol. 83:1029-1036. 1962.-Cor-ynebacterium tritici, C. striatum, C. renale, and C. pseudodiphtheriticum produce an intracellular starch-like material when grown on native starches; glucose-1-phosphate, mono-, di-, and trisaccharides do not serve as substrates for intracellular starch formation. C. pseudotuberculosis and C. kutscheri produce intracellular starch from starch substrates and glucose-1-phosphate. C. diphtheriae produces starch from glucose-1-phosphate only. PMID:13876866

CARRIER, E B; McCLESKEY, C S

1962-05-01

85

INTRACELLULAR STARCH FORMATION IN CORYNEBACTERIA  

PubMed Central

Carrier, E. Bernard (Louisiana State University, Baton Rouge, La.) and C. S. McCleskey. Intracellular starch formation in cor-yne bacteria. J. Bacteriol. 83:1029–1036. 1962.—Cor-ynebacterium tritici, C. striatum, C. renale, and C. pseudodiphtheriticum produce an intracellular starch-like material when grown on native starches; glucose-1-phosphate, mono-, di-, and trisaccharides do not serve as substrates for intracellular starch formation. C. pseudotuberculosis and C. kutscheri produce intracellular starch from starch substrates and glucose-1-phosphate. C. diphtheriae produces starch from glucose-1-phosphate only. Images PMID:13876866

Carrier, E. Bernard; McCleskey, C. S.

1962-01-01

86

Characterization of starch nanoparticles  

NASA Astrophysics Data System (ADS)

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.

Szymo?ska, J.; Targosz-Korecka, M.; Krok, F.

2009-01-01

87

An unusual case of perinatal tuberous sclerosis.  

PubMed

We report a case of a neonate who presented to us with multiple rhabdomyomas of heart, cortical tubers in the brain and skeletal anomalies such as Pierre Robin sequence, bilateral clubfoot and lower small bowel obstruction. Though a diagnosis of neonatal tuberous sclerosis was made, the association of skeletal anomalies and intestinal obstruction was a rare and unusual finding. PMID:25024981

Hegde, Deeparaj Ganapati; Mondkar, Jayashree; Panchal, Harshad

2014-04-01

88

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...

89

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

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. PMID:15770485

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

2005-08-01

90

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

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. PMID:12721851

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

2003-05-01

91

Low-fat sodium-reduced sausages: Effect of the interaction between locust bean gum, potato starch and ?-carrageenan by a mixture design approach  

Microsoft Academic Search

A mixture design approach was used to evaluate interactions between potato starch, locust bean gum and ?-carrageenan and their effect on cooking yield, expressible moisture, texture and color in low-fat sodium-reduced sausages formulated with potassium and calcium chloride. Starch had a notable influence on cooking yield and texture, increasing product hardness and resilience as starch proportion increased. The added salt

Elizabeth García-García; Alfonso Totosaus

2008-01-01

92

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

PubMed

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. PMID:18421582

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

93

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

NASA Astrophysics Data System (ADS)

Cyclodextrins (CDs) are cyclic oligasaccharides composed by d-glucose monomers joined by ?-1,4-d glicosidic linkages. The main types of CDs are ?-, ?- and ?-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 ?-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 ?/?/?. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

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

94

Variation in amylose fine structure of starches from different botanical sources.  

PubMed

The molecular structures of amylose and amylopectin have an impact on functional properties of starch-containing food. This is the first study comparing amylose size distributions from various plant sources. Chain-length distributions (CLDs) of amylose and amylopectin branches ("fine structure") are characterized using size-exclusion chromatography [sometimes termed gel permeation chromatography (GPC)] and parametrized by both biosynthesis-based and empirical fits, to understand the starch biosynthesis mechanism and identify associations with starch digestibility. All starches show bimodal amylose weight CLDs, varying with plant sources, with potato tuber and sweet potato root starch having relatively longer branches than the others. The digestograms of all starches fit first-order kinetics. Unlike what has been seen in cooked grains/flours, amylose and amylopectin fine structures have no association with the digestibility of freshly gelatinized starch. This suggests that the observed effect in cooked grains/flours arises from a secondary interaction between amylose fine structure and higher order structural features. PMID:24758598

Wang, Kai; Hasjim, Jovin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

2014-05-14

95

Tuberous Sclerosis Complex Consensus Conference: Revised Clinical Diagnostic Criteria  

Microsoft Academic Search

At the recent tuberous sclerosis complex consensus conference, the clinical diagnostic criteria for tuberous sclerosis complex were simplified and revised to reflect both new clinical information about tuberous sclerosis complex and an improved understanding of the disorder derived from molecular genetic studies. Based on this new information, some clinical signs once regarded as pathognomonic for tuberous sclerosis complex are now

E. S. Roach; Manuel R. Gomez; Hope Northrup

1998-01-01

96

Influence of cell turgor on sucrose partitioning in potato tuber storage tissues.  

PubMed

Sucrose uptake and partitioning in potato (Solanum tuberosum L.) tuber discs were examined under a range of mannitol and ethylene-glycol concentrations. Mannitol caused the same changes in turgor over a wide range of incubation periods (90 min-6 h), indicating that it did not penetrate the tissue. In comparison, ethylene glycol reduced turgor losses but did not eliminate them, even after 6 h. Between 100 mM and 300 mM mannitol, turgor fell by 350 kPa, compared with 35 kPa in ethylene glycol. Uptake experiments in mannitol alone showed that total sucrose uptake was strongly correlated with both osmotic potential and with turgor potential. In subsequent experiments sucrose uptake and partitioning were examined after 3 h equilibration in 100 mM and 300 mM concentrations of mannitol and ethylene glycol. Total sucrose uptake and the conversion of sucrose to starch were enhanced greatly only at 300 mM mannitol, indicating an effect of turgor, rather than osmotic potential on sucrose partitioning. The inhibitors p-chloromercuribenzenesulfonic acid and carbonylcyanide m-chlorophenylhydrazone (CCCP) both reduced sucrose uptake, but in quite different ways. p-Chloromercuribenzenesulfonic acid reduced total sucrose uptake but did not affect the partitioning of sucrose to starch. By contrast, CCCP inhibited total uptake and virtually eliminated the conversion of sucrose to starch. Despite this, sucrose uptake in the presence of CCCP continued to increase as the mannitol concentration increased, indicating an increase in passive transport at higher mannitol concentrations. Increased sucrose uptake above 400 mM mannitol was shown to be the result of uptake into the free space. The data show that starch synthesis is optimised at low but positive turgors and the relation between sucrose partitioning and the changing diurnal water relations of the tuber are discussed. PMID:24221935

Oparka, K J; Wright, K M

1988-10-01

97

Composition and physical properties of starch in microgravity-grown plants  

NASA Astrophysics Data System (ADS)

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 ??/?? (?? - difference of magnetic susceptibilities, ?? - 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 ??/?? 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 ?-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 ??/?? 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, ??/?? and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

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

2001-01-01

98

Composition and physical properties of starch in microgravity-grown plants  

NASA Technical Reports Server (NTRS)

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.

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

99

In vitro tuberization of potato clones from different maturity groups.  

PubMed

In vitro tuberization on shoot cultures of early, mid-season, late and very late potatoes was compared. Shoots were grown at 12, 16, or 20 h photoperiods; tuberization was then induced at 0, 8 or 16 h light. In the dark, shoots from early plants initially grown at 16 h consistently set tubers earlier than the other types, whereas the very late line tuberized later and produced significantly fewer tubers. Tuber setting of mid-season plants could not be distinguished from the late type. Tuberization of the very late line was significantly hastened by shortening the photoperiod from 20 h to 12 h during the shoot growth period. Light during tuber induction delayed tuberization. This system may be useful to screen callus-derived plants for maturity, and may also be suitable for in vitro study of the photoperiodic control of tuberization. PMID:24213695

Lentini, Z; Earle, E D

1991-04-01

100

Inhibition of the Plastidic ATP/ADP Transporter Protein Primes Potato Tubers for Augmented Elicitation of Defense Responses and Enhances Their Resistance against Erwinia carotovora  

PubMed Central

Tubers of transgenic potato (Solanum tuberosum) plants with decreased activity of the plastidic ATP/ADP transporter AATP1 display reduced levels of starch, modified tuber morphology, and altered concentrations of primary metabolites. Here, we demonstrate that the spontaneous production of hydrogen peroxide, the endogenous content of salicylic acid, and the levels of mRNAs of various defense-related genes are similar in tuber discs of wild-type and AATP1(St) antisense plants. However, upon challenging the tissue with fungal elicitors or culture supernatants of the soft rot-causing pathogen Erwinia carotovora subsp. atroseptica, the AATP1(St) antisense tubers exhibit highly potentiated activation of defense responses when compared with wild-type tissue. The augmented defense responses comprise enhanced accumulation of transcripts of five defense-related genes (?-1,3-GLUCANASE B2 and A1, CHITINASE B3 and A2, and Phe AMMONIA-LYASE) and enhanced elicitation (up to 21-fold) of the early hydrogen peroxide burst. The potentiated activation of cellular defense responses in AATP1(St) antisense tubers is not accompanied by a precedent increase in endogenous salicylic acid levels, but is associated with a strongly enhanced resistance of the tissue to E. carotovora. From these results, we conclude that inhibition of primary metabolic reactions induces a primed state that sensitizes the potato tubers for improved elicitation of various cellular defense responses, which likely contribute to enhanced E. carotovora resistance. PMID:12177473

Linke, Christoph; Conrath, Uwe; Jeblick, Wolfgang; Betsche, Thomas; Mahn, Andreas; Düring, Klaus; Neuhaus, H. Ekkehard

2002-01-01

101

Inhibition of the plastidic ATP/ADP transporter protein primes potato tubers for augmented elicitation of defense responses and enhances their resistance against Erwinia carotovora.  

PubMed

Tubers of transgenic potato (Solanum tuberosum) plants with decreased activity of the plastidic ATP/ADP transporter AATP1 display reduced levels of starch, modified tuber morphology, and altered concentrations of primary metabolites. Here, we demonstrate that the spontaneous production of hydrogen peroxide, the endogenous content of salicylic acid, and the levels of mRNAs of various defense-related genes are similar in tuber discs of wild-type and AATP1(St) antisense plants. However, upon challenging the tissue with fungal elicitors or culture supernatants of the soft rot-causing pathogen Erwinia carotovora subsp. atroseptica, the AATP1(St) antisense tubers exhibit highly potentiated activation of defense responses when compared with wild-type tissue. The augmented defense responses comprise enhanced accumulation of transcripts of five defense-related genes (beta-1,3-GLUCANASE B2 and A1, CHITINASE B3 and A2, and Phe AMMONIA-LYASE) and enhanced elicitation (up to 21-fold) of the early hydrogen peroxide burst. The potentiated activation of cellular defense responses in AATP1(St) antisense tubers is not accompanied by a precedent increase in endogenous salicylic acid levels, but is associated with a strongly enhanced resistance of the tissue to E. carotovora. From these results, we conclude that inhibition of primary metabolic reactions induces a primed state that sensitizes the potato tubers for improved elicitation of various cellular defense responses, which likely contribute to enhanced E. carotovora resistance. PMID:12177473

Linke, Christoph; Conrath, Uwe; Jeblick, Wolfgang; Betsche, Thomas; Mahn, Andreas; Düring, Klaus; Neuhaus, H Ekkehard

2002-08-01

102

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...

103

Comparative disintegrant activities of breadfruit starch and official corn starch  

Microsoft Academic Search

A Comparative evaluation of starch powder extracted from breadfruit (Artocarpus communis, Frost) as tablet disintegrant was made with corn starch BP using a 2×4 factorial experiment in a randomized complete block design. Two factors (type of starch: 2 i.e. breadfruit and corn) at four levels (concentrations of starch disintegrant: 4 i.e. 2.5%, 5%, 7.5% and 10%) were studied. One (1)

Sarafadeen A. Adebayo; Eugenie Brown-Myrie; Oludele A. Itiola

2008-01-01

104

Starch mutants of Chlamydomonas  

SciTech Connect

Wild type Chlamydomonas accumulates starch and triglycerides when grown under nitrogen limiting conditions. Toward elucidation of the mechanisms for control of starch biosynthesis, we isolated mutants impaired int he accumulation of storage carbohydrates. Chlamydomonas reinhardtii (strain ya-12) was mutagenized by UV irradiation and colonies were screened by iodine staining after growth in darkness. Mutants, denoted ais for altered in iodine staining, have been characterized by electron microscopy and assays for starch synthease, ADPG-pyrophosphorylase, phosphoglucose isomerase (PGI), phosphoglucomutase and fructose 1,6-bisphosphatase, and amylase activities. Transcript analysis of wild type and mutant RNAs with PGI, ADPG-pyrophosphorylase, and waxy probes have also been carried out. No deficiencies of any of these components have been detected. Furthermore, long-term cultures of ya-12 and ais-1d in nitrogen-limited chemostats have been studied; starch also does not accumulate in ais-1d under these conditions. Thus, the lesion affects an essential factor of unknown identity that is required for starch synthesis.

Berry-Lowe, S.L.; Schmidt, G.W. (Univ. of Georgia, Athens (USA))

1990-05-01

105

[Effects of potassium fertilization period on photosynthetic characteristics and storage root starch accumulation of edible sweetpotato].  

PubMed

Abstract: In this study, same amount of potassium (240 kg . hm-2) was applied as basal dressing (treatment 1) and as 1/2 basal dressing + 1/2 top-dressing at day 75 after planting (treatment 2), aimed to investigate the effects of potassium fertilization period on the photosynthetic characteristics of edible sweetpotato and the starch accumulation in storage root. As compared with treatment 1, treatment 2 improved the leaf photosynthetic rate and sucrose-phosphate synthase activity and the storage root's adenosine diphosphate glucose pyrophosphortlase activity, enhanced the starch accumulation rate in storage root (with an average increment of 6. 7%), and increased the root tuber yield significantly by 8. 2%. Both of the potassium fertilization treatments improved the synthesis of sucrose in leaf and the transformation from sucrose to starch in storage root, as compared with no potassium fertilization. PMID:23755492

Chen, Xiao-Guang; Shi, Chun-Yu; Li, Hong-Min; Zhang, Ai-Jun; Shi, Xin-Min; Tang, Zhong-Hou; Wei, Meng

2013-03-01

106

Changes in potato phenylpropanoids during tuber development  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phenylpropanoid metabolite and transcript expression during different developmental stages were examined in field grown potatoes. Carbohydrate and shikimic acid metabolism was assessed to determine how tuber primary metabolism influences phenylpropanoid metabolism. Phenylpropanoid concentrations wer...

107

Potato plant poisoning - green tubers and sprouts  

MedlinePLUS

Potato plant poisoning occurs when someone eats the green tubers or new sprouts of the potato plant. ... is found throughout the plant, but especially in green potatoes and new sprouts. Never eat potatoes that ...

108

Malt caramel from tubers of Cyperus esculentus  

Microsoft Academic Search

This work was done to ascertain the feasibility of obtaining caramel from malted tubers of Cyperus esculentus. The tubers of C. esculentus were partially germinated for 10 days and sun-dried for 24 h. The sun-dried samples were then kilned at 70°C for 24 h and at 120°C for 5 h for further caramelization. The kilned samples were finely crushed, infused

S. C. Umerie; J. N. Enebeli

1996-01-01

109

Volatile monoterpenes inhibit potato tuber sprouting  

Microsoft Academic Search

Several volatile monoterpenes, which are among the major constituents of several easily obtainable essential oils, were phytotoxic\\u000a in the gaseous phase to emerged potato tuber sprouts. Analyses of the more phytotoxic monoterpenes were conducted using a\\u000a continuous-flow system in which the compounds were released as volatiles into the headspace surrounding the tubers. Several\\u000a of these compounds, which have low mammalian

Steven F. Vaughn; Gayland F. Spencer

1991-01-01

110

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

PubMed

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. PMID:24840849

Fasahat, Parviz; Rahman, Sadequr; Ratnam, Wickneswari

2014-04-01

111

RECENT RESEARCH PROGRESS ON POTATO TUBER WOUND-HEALING/SUBERIAZTION AND SKIN-SET.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The suberization of tuber wounds and the development of resistance to tuber excoriation (resistance to tuber skinning injury) are important physiological processes that directly impact tuber market quality. However, critical portions of the biochemical processes responsible for suberization and res...

112

Development of maize starch granules  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize kernels of self-pollinated inbred line B73 harvested on various days after pollination (DAP) were subjected for starch granule development studies. Starch in endosperms was first observed on 6 DAP. A small amount of starch granules (<2% of dry weight) was found in the endosperm on 12 DAP. S...

113

Tuberous Sclerosis Complex Diagnostic Criteria Update: Recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference  

PubMed Central

BACKGROUND Tuberous sclerosis complex is highly variable in clinical presentation and findings. Disease manifestations continue to develop over the lifetime of an affected individual. Accurate diagnosis is fundamental to implementation of appropriate medical surveillance and treatment. Although significant advances have been made in the past 15 years in the understanding and treatment of tuberous sclerosis complex, current clinical diagnostic criteria have not been critically evaluated or updated since the last clinical consensus conference in 1998. METHODS The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important diagnostic implications and was charged with reviewing prevalence and specificity of disease-associated clinical findings and their impact on suspecting and confirming the diagnosis of tuberous sclerosis complex. RESULTS Clinical features of tuberous sclerosis complex continue to be a principal means of diagnosis. Key changes compared with 1998 criteria are the new inclusion of genetic testing results and reducing diagnostic classes from three (possible, probable, and definite) to two (possible, definite). Additional minor changes to specific criterion were made for additional clarification and simplification. CONCLUSIONS The 2012 International Tuberous Sclerosis Complex Diagnostic Criteria provide current, updated means using best available evidence to establish diagnosis of tuberous sclerosis complex in affected individuals. PMID:24053982

Northrup, Hope; Krueger, Darcy A.

2014-01-01

114

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...

115

SURFACE PROPERTIES OF WATER SOLUBLE STARCH, STARCH ACETATES AND STARCH ACETATES/ALKENYLSUCCINATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Surface and interfacial tensions with hexadecane were measured for starch and water soluble starch ester solutions in order to determine their potential as stabilizers or emulsifiers. The surface tension for an acid hydrolysed starch (maltodextrin) initially declined with concentration and then rea...

116

Physicochemical and functional characteristics of lentil starch.  

PubMed

The physicochemical properties of lentil starch were measured and linked up with its functional properties and compared with those of corn and potato starches. The amylose content of lentil starch was the highest among these starches. The crystallinity and gelatinization enthalpy of lentil starch were the lowest among these starches. The high amylose: amylopectin ratio in lentil starch resulted into low crystallinity and gelatinization enthalpy. Gelatinization and pasting temperatures of lentil starch were in between those of corn and potato starches. Lentil starch gels showed the highest storage modulus, gel strength and pasting viscosity than corn and potato starch gels. Peleg's model was able to predict the stress relaxation data of these starches well (R(2)>0.98). The elastic modulus of lentil starch gel was less frequency dependent and higher in magnitude at high temperature (60 °C) than at lower temperature (10 °C). Lentil starch is suitable where higher gel strengthened pasting viscosity are desired. PMID:23399180

Joshi, M; Aldred, P; McKnight, S; Panozzo, J F; Kasapis, S; Adhikari, R; Adhikari, B

2013-02-15

117

Effect of tuber skin on the thermal properties of whole tubers of potato and sweet potato  

NASA Astrophysics Data System (ADS)

Temperature-dependent thermal coefficients of mathematical models of the postharvest storage process play an important role in determining the models accuracy. Thermal properties of tubers under storage available in literature are generally of those in semi processed form (skinless) such as those having undergone peeling, dicing and cutting actions. This study investigates the effect of tuber skin on the thermal properties of whole tubers of potato and sweet potato. A direct approach was used to measure the tubers' density and thermal conductivity and thermal diffusivity by the transient heat transfer method. Indirect approach was used to measure the tubers' specific heat. Experimental data were used to develop empirical models of the thermal coefficients as a function of temperature. Results of the study should find great use in the modeling of potato and sweet potato storage process.

Oluwo, A. A.; Khan, R. M.; Salami, M. J. E.

2013-12-01

118

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

PubMed

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. PMID:16190660

Lin, Da-Gin; Jeang, Chii-Ling

2005-10-01

119

QTL analysis of potato tuber dormancy.  

PubMed

The potential loss of chemical sprout inhibitors because of public concern over the use of pesticides underscores the desirability of breeding for long dormancy of potato (Solanum tuberosum L.) tubers. Quantitative trait locus (QTL) analyses were performed in reciprocal backcrosses between S. tuberosum and S. berthaultii toward defining the complexity of dormancy. S. berthaultii is a wild Bolivian species characterized by a short-day requirement for tuberization, long tuber dormancy, and resistance to several insect pests. RFLP alleles segregating from the recurrent parents as well as from the interspecific hybrid were monitored in two segregating progenies. We detected QTLs on nine chromosomes that affected tuber dormancy, either alone or through epistatic interactions. Alleles from the wild parent promoted dormancy, with the largest effect at a QTL on chromosome 2. Long dormancy appeared to be recessive in the backcross to S. berthaultii (BCB). In BCB the additive effects of dormancy QTLs accounted for 48% of the measured phenotypic variance, and adding epistatic effects to the model explained only 4% more. In contrast, additive effects explained only 16% of the variance in the backcross to S. tuberosum (BCT), and an additional 24% was explained by the inclusion of epistatic effects. In BCB variation at all QTLs detected was associated with RFLP alleles segregating from the hybrid parent; in BCT all QTLs except for two found through epistasis were detected through RFLP alleles segregating from the recurrent parent. At least three dormancy QTLs mapped to markers previously found to be associated with tuberization in these crosses. PMID:24162286

van den Berg, J H; Ewing, E E; Plaisted, R L; McMurry, S; Bonierbale, M W

1996-08-01

120

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

PubMed

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. PMID:24594397

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

2014-03-15

121

The relation of infantile spasms, tubers, and intelligence in tuberous sclerosis complex  

PubMed Central

Background: The aetiology of the learning difficulty in tuberous sclerosis is debated. It may be related to the amount of tubers in the brain or caused by the infantile spasms that occur in early life. Aims: To examine the relative contributions to final intelligence (IQ) made by both cerebral tubers and infantile spasms. Methods: As part of an epidemiological study of tuberous sclerosis in the south of England, patients were recruited who were able to undergo magnetic resonance imaging (MRI) without the need for an anaesthetic. Epilepsy history was determined by interview and review of clinical records. IQ was assessed using either Wechsler intelligence scales or Raven's matrices. Results: A total of 41 patients consented to have an MRI scan. IQ scores were normally distributed about a mean of 91. Twenty six patients had a positive history of epilepsy, and 11 had suffered from infantile spasms. There was a significant relation between the number of tubers and IQ. Infantile spasm status partly confounded the relation between tubers and IQ, but did not render the relation statistically insignificant. The relation between infantile spasms and learning difficulty remained strong even when controlling for the number of tubers. PMID:15155396

O'Callaghan, F; Harris, T; Joinson, C; Bolton, P; Noakes, M; Presdee, D; Renowden, S; Shiell, A; Martyn, C; Osborne, J

2004-01-01

122

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...

123

Role of metabolism in ABA homeostasis during potato tuber dormancy  

Technology Transfer Automated Retrieval System (TEKTRAN)

Endogenous hormones play a essential role in the regulation of potato tuber dormancy. Abscisic acid has been shown to be critically involved in tuber dormancy induction and maintenance. Genes encoding enzymes catalyzing the terminal steps of ABA synthesis and metabolism have been cloned from tuber...

124

Parental Understanding of Tuberous Sclerosis Complex.  

PubMed

Tuberous sclerosis complex is a genetic disorder with multisystem involvement that poses significant challenges to the affected child and family. Caregiver knowledge in the South African population has not previously been reported. A prospective study of the parents of 21 children with tuberous sclerosis complex was undertaken. Median parental age was 38 (interquartile range 34.5-45) years. Parents were randomly allocated to receive written information about the condition, or to receive verbal counseling already established in clinic. A significant difference (P = .001) was observed in the change in the mean knowledge scores for the parent group that received written information (34.2 at baseline, 51.7 at the second visit. This impact was higher in parents with an education level of at least grade 8 (P = .003). Parental understanding of tuberous sclerosis complex can be improved by provision of written information and should be routinely available in a readily understandable format. PMID:25414235

Samia, Pauline; Donald, Kirsten A; Schlegel, Birgit; Wilmshurst, Jo M

2014-11-20

125

Isolation and characterization of polysaccharides with the antitumor activity from Tuber fruiting bodies and fermentation system.  

PubMed

Fifty-two polysaccharides were isolated from the fermentation systems of Tuber melanosporum, Tuber indicum, Tuber sinense, Tuber aestivum and the fruiting bodies of Tuber indicum, Tuber himalayense, Tuber sinense by elution with an activated carbon column. Polysaccharides from Tuber fermentation system exhibited relatively higher in vitro antitumor activity against HepG2, A549, HCT-116, SK-BR-3, and HL-60 cells than those from Tuber fruiting bodies. All polysaccharides were mainly composed of D-mannose, D-glucose, and D-galactose, which suggested that the polysaccharides from Tuber fruiting bodies and fermentation system have identical chemical compositions. The results of antitumor activity and structural identification indicated that the polysaccharide fractions could promote antitumor activity. Tuber polysaccharides from Tuber fermentation system exhibited relatively higher than that from Tuber fruiting bodies. These results confirm the potential of Tuber fermentation mycelia for use as an alternative resource for its fruiting bodies. PMID:24272369

Zhao, Wei; Wang, Xiao-Hua; Li, Hong-Mei; Wang, Shi-Hua; Chen, Tao; Yuan, Zhan-Peng; Tang, Ya-Jie

2014-03-01

126

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

Microsoft Academic Search

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

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

2008-01-01

127

Oospore Formation by Phytophthora infestans in Potato Tubers.  

PubMed

ABSTRACT The ability of Phytophthora infestans, the causal agent of potato and tomato late blight, to produce oospores in potato tuber tissue was studied in the field and under laboratory conditions. In 1998 and 2000 field experiments, the canopy of potato cvs. Alpha and Mondial, respectively, were coinoculated with A1 + A2 sporangia of the fungus, and the infected tubers collected at harvest were examined for the presence of oospores. In 1998, only 2 of 90 infected tubers had oospores, whereas none of the 90 tubers examined in 2000 had any oospores. In the latter experiment, infected tubers kept in storage up to 12 weeks after harvest had no oospores. Artificial co-inoculations of whole tubers with A1 + A2 sporangia resulted only rarely in the formation of oospores inside the tubers. Co-inoculations of potato tuber discs taken from dormant tubers 0 to 16 weeks after harvest failed to support any oospore production, whereas discs taken from sprouting tubers of >/=18 weeks after harvest allowed oospores to form. Tuber discs showed enhanced oospore formation when treated before inoculation with either sugars, amino acids, casein hydrolysate, beta-sitosterol, or chloroethylphosphonic acid. In contrast, reducing airflow into the petri dishes where potato tuber discs were incubated reduced the number of oospores produced. The number of oospores produced in tuber tissue was lower compared with that in leaf tissue regardless of the origin of isolates used. The data show that the ability of Phytophthora infestans to produce oospores in potato tuber tissue is very limited and increases with tuber aging. PMID:18943947

Levin, A; Baider, A; Rubin, E; Gisi, U; Cohen, Y

2001-06-01

128

Color Theory  

NSDL National Science Digital Library

This project will be used to teach the importance of color. Watch the following video about color Primary Colors Click on the link Exploration of Color. When you get into the website select the different colors to see what secondary colors are made from the primary colors. Review the following siteColor Theory and then design and paint a color wheel. ...

Mr. Sturgell

2009-12-02

129

Starch digestion capacity of poultry.  

PubMed

Starch is quantitatively the most important nutrient in poultry diets and will to a large extent be present as intact starch granules due to very limited extent of gelatinization during pelleting. Although native starch is difficult to digest due to a semi-crystalline structure, even fast-growing broiler chickens appears to be able to digest this starch more or less completely during passage through the jejunum. However, reduced starch digestibility has been observed, particularly in pelleted diets containing large quantities of wheat. Although properties of the starch granule such as size and components on the granule surface may affect digestibility, the entrapment of starch granules in cell walls and a protein matrix may be even more important factors impeding starch digestion. In that case, this and the fact that amylase secretion is normally very high in poultry may explain the lack of convincing effects of exogenous ?-amylase added to the diet. However, few well-designed experiments assessing mechanisms of starch digestion and the effect of ?-amylase supplementation have been carried out, and thus more research is needed in this important area. PMID:25012853

Svihus, B

2014-09-01

130

Phylogenetic study of two truffles, Tuber formosanum and Tuber furfuraceum, identified from Taiwan.  

PubMed

Truffles are one of the most valuable edible fungi and have drawn extensive research interests worldwide. In Taiwan, two species of truffle, Tuber formosanum and Tuber furfuraceum, have been identified and reported. Although the morphological features of these two truffles have been described, lack of molecular identification has led to difficulties with firmly establishing their relatedness to other truffles. In this study, we utilized the internal transcribed spacer (ITS) and beta-tubulin gene sequences to generate the phylogenetic relationship of T. formosanum and T. furfuraceum with other taxonomic relatives. Our analysis revealed five/three major phylogenetic clades according to the 5.8S-ITS2/beta-tubulin gene sequences and corroborated with their morphological characterization. Tuber formosanum highly resembles the Tuber indicum B complex, while T. furfuraceum is most similar to Tuber huidongense. Based on a molecular clock, we estimated that T. furfuraceum and T. formosanum would have diverged from their close relatives in mainland China between 10.2 and 4.1 Ma, respectively. Based on the results, we propose that these two Tuber species found in Taiwan might originate from the common ancestors with some truffle species in China. However, due to a long divergence time and geographical separation, they have evolved into indigenous species of Taiwan. PMID:19341392

Huang, Jing-Yang; Hu, Hung-Tao; Shen, Wei-Chiang

2009-05-01

131

Review on tropical root and tuber crops. II. Physiological disorders in freshly stored roots and tubers.  

PubMed

Tropical root and tubers, including cassava, sweet potato, yams and aroids, have been reported to show an increase in respiratory activity after harvest and injury and subsequent storage in association with their deterioration. This leads to loss of water and carbohydrate. Cassava roots often show discoloration of the tissue with development of pigments in the xylem vessels (vascular streaking or primary/physiological deterioration). This has been established to be enzymatic in nature. Pruning the cassava stem, leaving about a 20- to 30-cm stub prior to harvest, could delay the onset of primary deterioration. Sweet potato roots and yam tubers show a peak respiratory activity immediately or 1 d after harvest. The respiratory rate, however, declines during the subsequent storage period. Yam tubers show a further increase in respiratory activity at the breakage of dormancy occurring at the time of sprouting. Dormancy in yam tubers has been studied in some detail. Different species of yams vary in their dormancy period, a major factor that accounts for the variation in their storage life. Little information is available on the dormancy of sweet potato and aroids. Tropical roots and tubers exhibit "chilling injury" when stored at temperatures below a critical level. The critical cold-storage temperatures range between 10 and 15 degrees C for different tropical root and tuber crops. PMID:8922896

Ravi, V; Aked, J

1996-10-01

132

Tuberous Sclerosis Complex Surveillance and Management: Recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference  

PubMed Central

BACKGROUND Tuberous sclerosis complex is a genetic disorder affecting every organ system, but disease manifestations vary significantly among affected individuals. The diverse and varied presentations and progression can be life-threatening with significant impact on cost and quality of life. Current surveillance and management practices are highly variable among region and country, reflective of the fact that last consensus recommendations occurred in 1998 and an updated, comprehensive standard is lacking that incorporates the latest scientific evidence and current best clinical practices. METHODS The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 separate subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important clinical management implications and was charged with formulating key clinical questions to address within its focus area, reviewing relevant literature, evaluating the strength of data, and providing a recommendation accordingly. RESULTS The updated consensus recommendations for clinical surveillance and management in tuberous sclerosis complex are summarized here. The recommendations are relevant to the entire lifespan of the patient, from infancy to adulthood, including both individuals where the diagnosis is newly made as well as individuals where the diagnosis already is established. CONCLUSIONS The 2012 International Tuberous Sclerosis Complex Consensus Recommendations provide an evidence-based, standardized approach for optimal clinical care provided for individuals with tuberous sclerosis complex. PMID:24053983

Krueger, Darcy A.; Northrup, Hope

2014-01-01

133

Genetics Home Reference: Tuberous sclerosis complex  

MedlinePLUS

... tumors can cause serious or life-threatening complications. Kidney tumors are common in people with tuberous sclerosis complex; these growths can cause severe problems with kidney function and may be life-threatening in some cases. Additionally, tumors can develop in the heart, lungs, and the ...

134

Cell orientation in potato tuber parenchyma tissue  

NASA Astrophysics Data System (ADS)

The paper presents the results of the research of the size and shape of parenchyma tissue cells in potato tubers depending on the direction and site of sampling in tubers. An optical confocal microscope was used to observe samples in their natural state. The investigation was carried out for 1 mm thick samples cut from cylindrical samples (10x10 mm)taken in two mutually perpendicular directions of the inner and outer core of each variety. The analysis was done ten times.The methods developed for the composition and image analysis ensure obtaining a sufficient number of cells to determine tissue structure parameters (surface, shape, elongation and number of cells per 1 mm2) and decays of these parameters were obtained. Statistical analysis was performed using the ?-Kolmogorov-Smirnov compliance test.Arelationship between the direction of sampling and the size and shape of the inner core of cells was found. Greater surface area and elongation of the inner core cells for the longitudinal direction in the tuber (stolon - top) was demonstrated. There was no such a correlation for the outer core in the tubers of the cultivars examined.

Gancarz, Marek; Konstankiewicz, Krystyna; Zgórska, Kazimiera

2014-03-01

135

Steroidal glycosides from tubers of Ophiopogon japonicus.  

PubMed

A new steroidal saponin, named ophiopogonin E (1), has been isolated from the tubers of Ophiopogon japonicus, along with five known steroidal saponins (2-6). The structure of the new steroidal glycoside was characterized by spectroscopic analysis and acid-catalyzed hydrolysis as pennogenin 3-O-beta-D-xylopyranosyl (1 --> 4)-beta-D-glucopyranoside (1). PMID:16931432

Cheng, Z-H; Wu, T; Yu, B-Y

2006-09-01

136

Signals Involved in Tuber Wound-Healing  

Technology Transfer Automated Retrieval System (TEKTRAN)

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. Recen...

137

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

PubMed

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. PMID:24507325

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

2014-02-15

138

Starch — Value Addition by Modification  

Microsoft Academic Search

Starch is one of the most important but flexible food ingredients possessing value added attributes for innumerable industrial applications. Its various chemically modified derivatives offer a great scope of high technological value in both food and non-food industries. Modified starches are designed to overcome one or more of the shortcomings, such as loss of viscosity and thickening power upon cooking

Rudrapatnam N. Tharanathan

2005-01-01

139

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...

140

Damaged starch characterisation by ultracentrifugation  

Microsoft Academic Search

The relative molecular size distributions of a selection of starches (waxy maize, pea and maize) that had received differing amounts of damage from ball milling (as quantified by susceptibility to ?-amylase) were compared using analytical ultracentrifugation. Starch samples were solubilised in 90% dimethyl sulfoxide, and relative size distributions were determined in terms of the apparent distribution of sedimentation coefficients g?(s)

Richard F. Tester; Trushar Patel; Stephen E. Harding

2006-01-01

141

Starch Applications for Delivery Systems  

NASA Astrophysics Data System (ADS)

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 ?-(1,4) and ?-(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.

Li, Jason

2013-03-01

142

Starch-Lignin Baked Foams  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-kraft lignin foams were prepared by a baking process. Replacing up to 20% of the starch with lignin has no effect on foam density or overall morphology. At 10% replacement, lignin marginally increases water resistance and modulus of elasticity but decreases strain at maximum stress. At 20% re...

143

Comparative performance of Cassava Starch to PAC as Fluid Loss Control Agent in Water Based Drilling Mud  

E-print Network

Cassava starch was extracted from 46.5kg of TMS 98/0505 species of fresh cassava tubers and characterized to establish the physicochemical properties The analytical results showed the following; moisture content (4.11%), pH (7), dispersion (poly dispersed), bulk density (617.34kg/m 33) and particle size distribution (fine). It was also compared to the standard Polyanionic Cellulose (PAC) used in the oil and Gas industry for water based mud (WBM) formulation. The result also indicated closer similarity between TMS 98/0505 and PAC. It was therefore employed in the production of drilling mud. Different ratios (100:0 and 100:0) of cassava starch and PAC and used to formulate standard drilling mud. The fluid loss properties of the different drilling mud samples were tested. The filtrate volume (fluid loss) obtained for various samples using a concentration of 2g/bbl of starch/PAC were 9.2 ml and 4.2ml, while that obtained at 4g/bbl,6g/bbl, 8g/bbl of Cassava starch (100:0) were 8.0ml,7.2ml and 6.0 ml. The result also showed that the amount of cassava starch used is indirectly proportional to the filtrate volume. Conclusively, cassava starch could be used as a fluid loss additive and improved to yield a better performance in terms of its water retention capability.

Egun Il; Achadu M Abah

144

Starches, Sugars and Obesity  

PubMed Central

The rising prevalence of obesity, not only in adults but also in children and adolescents, is one of the most important public health problems in developed and developing countries. As one possible way to tackle obesity, a great interest has been stimulated in understanding the relationship between different types of dietary carbohydrate and appetite regulation, body weight and body composition. The present article reviews the conclusions from recent reviews and meta-analyses on the effects of different starches and sugars on body weight management and metabolic disturbances, and provides an update of the most recent studies on this topic. From the literature reviewed in this paper, potential beneficial effects of intake of starchy foods, especially those containing slowly-digestible and resistant starches, and potential detrimental effects of high intakes of fructose become apparent. This supports the intake of whole grains, legumes and vegetables, which contain more appropriate sources of carbohydrates associated with reduced risk of cardiovascular and other chronic diseases, rather than foods rich in sugars, especially in the form of sugar-sweetened beverages. PMID:22254101

Aller, Erik E. J. G.; Abete, Itziar; Astrup, Arne; Martinez, J. Alfredo; van Baak, Marleen A.

2011-01-01

145

Resistant-starch formation in high-amylose maize starch  

Microsoft Academic Search

A new public high-amylose maize line, GEMS-0067, has been developed by USDA-ARS Germplasm Enhancement of Maize (GEM) Project. GEMS-0067 maize line is a homozygous mutant of amylose-extender (ae) gene and high-amylose modifier (HAM) gene(s). GEMS-0067 starches consist of 83.1-85.6% apparent amylose and 39.4%-43.2% resistant starch (RS), which are larger than the ae single-mutant starches (61.7-67.7% and 11.5%-19.1%, respectively) and normal

Hongxin Jiang

2010-01-01

146

Physiological effects of consumption of resistant starch  

Microsoft Academic Search

Resistant starch (RS) is defined as the sum of starch and products of starch degradation not absorbed in the small intestine of healthy individuals. Thus, RS enters the colon where it may be fermented. In this respect, RS resembles some types of dietary fibre. Three types of RS are being discerned: RS 1<\\/sub> , physically entrapped starch; RS 2<\\/sub> ,

M. L. Heijnen

1997-01-01

147

Starch Graft Copolymers: Novel Applications in Industry  

Microsoft Academic Search

Starch, which is a natural carbohydrate biopolymer, has been the subject of academic and industrial studies for many decades, basically due to its low cost, biodegradability and versatility of use. Chemical modification of starch by grafting various monomers onto it imparts increased hydrophilicity, hydrophobicity or polyelectrolyte nature to starch depending on the reagent and conditions used. The starch graft copolymers

A. N. Jyothi

2010-01-01

148

Brew wort from Cyperus esculentus tubers  

Microsoft Academic Search

Evaluation of waste grits of Cyperus esculentus tubers and a mashing trial of the grits using the commercial enzymes ‘Termamyl’ (?-amylase), ‘Cereflo’ (?-glucanase) and ‘Neutrase’ (proteinases) to ascertain their suitability for brewing and related industries, were carried out. The grits had a carbohydrate content of 75·88%, crude fibre 12·88% and fat 4·05%. The cold water extract was 19·69% and reducing

S. C. Umerie; A. S. Uka

1998-01-01

149

Reversed Halo Sign in Tuberous Sclerosis Complex  

PubMed Central

We describe a reversed halo sign in a teenage girl with tuberous sclerosis complex (TSC). Lung manifestations of TSC include lung cysts corresponding to lymphangioleiomyomatosis and small nodules indicating multifocal micronodular pneumocyte hyperplasia (MMPH). However, a reversed halo sign in TSC has never been reported. The lesion was microscopically consistent with MMPH. Immunohistological findings also supported the notion that the lesion is associated with TSC. PMID:24159404

Seyama, Kuniaki; Hayashi, Takuo; Yamashiro, Yuki; Shiraishi, Akihiko; Kuwatsuru, Ryohei

2013-01-01

150

Transcriptomic Identification and Expression of Starch and Sucrose Metabolism Genes in the Seeds of Chinese Chestnut (Castanea mollissima).  

PubMed

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 for future research in starch and sucrose metabolism in Chinese chestnut tree. PMID:25537355

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

2015-01-28

151

Color Blindness  

MedlinePLUS

... three color cone cells to determine our color perception. Color blindness can occur when one or more ... Anyone who experiences a significant change in color perception should see an ophthalmologist (Eye M.D.). Next ...

152

Phases of Dormancy in Yam Tubers (Dioscorea rotundata)  

PubMed Central

• Background and Aims The control of dormancy in yam (Disocorea spp.) tubers is poorly understood and attempts to shorten the long dormant period (i.e. cause tubers to sprout or germinate much earlier) have been unsuccessful. The aim of this study was to identify and define the phases of dormancy in Dioscorea rotundata tubers, and to produce a framework within which dormancy can be more effectively studied. • Methods Plants of ‘TDr 131’ derived from tissue culture were grown in a glasshouse simulating temperature and photoperiod at Ibadan (7°N), Nigeria to produce tubers. Tubers were sampled on four occasions: 30?d before shoot senescence (149 days after planting, DAP), at shoot senescence (179 DAP), and twice during storage at a constant 25?°C (269 and 326 DAP). The development of the apical shoot bud was described from tissue sections. In addition, the responsiveness of shoot apical bud development to plant growth regulators (gibberellic acid, 2-chloroethanol and thiourea) applied to excised tuber sections was also examined 6 and 12?d after treatment. • Key Results and Conclusions Three phases of tuber dormancy are proposed: Phase I, from tuber initiation to the appearance of the tuber germinating meristem; Phase II, from the tuber germinating meristem to initiation of foliar primordium; and Phase III, from foliar primordium to appearance of the shoot bud on the surface of the tuber. Phase I is the longest phase (approx. 220?d in ‘TDr 131’), is not affected by PGRs and is proposed to be an endo-dormant phase. Phases II and III are shorter (<70?d in total), are influenced by PGRs and environmental conditions, and are therefore endo-/eco-dormant phases. To manipulate dormancy to allow off-season planting and more than one generation per year requires that the duration of Phase I is shortened. PMID:16446288

ILE, E. I.; CRAUFURD, P. Q.; BATTEY, N. H.; ASIEDU, R.

2006-01-01

153

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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 meristems isolated from field-g...

154

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...

155

GENETIC MANIPULATION FOR ENHANCING CALCIUM CONTENT IN POTATO TUBER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increased calcium (Ca) in potatoes may increase the production rate by enhancing tuber quality and storability. Additionally, increased Ca levels in important agricultural crops may help ameliorate the incidence of osteoporosis. However, the capacity to alter Ca levels in potato tubers through genet...

156

RENAL LESION GROWTH IN CHILDREN WITH TUBEROUS SCLEROSIS COMPLEX  

Microsoft Academic Search

PurposeRenal lesions, including angiomyolipoma, renal cysts (simple and polycystic kidney disease) and renal cell carcinoma, develop in patients with tuberous sclerosis complex. While there is limited information that these lesions may grow in adults with tuberous sclerosis complex, the incidence, characterization and growth rate in children have not been reported. Also, the age at which these lesions first appear, thus

DAVID H. EWALT; EUGENE SHEFFIELD; STEVEN P. SPARAGANA; MAURICIO R. DELGADO; E. STEVE ROACH

1998-01-01

157

Neuroepileptic Correlates of Autistic Symptomatology in Tuberous Sclerosis  

ERIC Educational Resources Information Center

Tuberous sclerosis is a genetic condition that is strongly associated with the development of an autism spectrum disorder. However, there is marked variability in expression, and only a subset of children with tuberous sclerosis develop autism spectrum disorder. Clarification of the mechanisms that underlie the association and variability in…

Bolton, Patrick F.

2004-01-01

158

Microbial Control of the Potato Tuber Moth (Lepidoptera: Gelechiidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

In tropical and subtropical agroecosystems, the potato tuber moth (PTM) (Phthorimaea operculella Zeller) is considered the most damaging potato pest. Larvae mine both leaves and tubers, in the field and in storage making the pest difficult to control. Over reliance on broad spectrum insecticides has...

159

75 FR 879 - National Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers...  

Federal Register 2010, 2011, 2012, 2013

...Administration [TA-W-62,282] National Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers...13, 2007, applicable to workers of National Starch and Chemical Company, Specialty Starches...

2010-01-06

160

Enzyme-catalyzed synthesis of hydrophobically modified starch  

Microsoft Academic Search

The reaction of starch and alkyl or alkenyl ketene dimer and starch gave a novel type of hydrophobically modified starch. The reaction was facilitated with the use of an enzyme, which gave products with higher degrees of substitution (DS) at lower temperatures. The starch used included maltodextrin, amylose, cationic starch, and pre-gelatinised starch, with molecular weights ranging from several hundreds

Lei Qiao; Qu-Ming Gu; H. N. Cheng

2006-01-01

161

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

PubMed

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. PMID:24128562

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

2014-02-15

162

Neurosurgical treatment of tuberous sclerosis complex lesions  

Microsoft Academic Search

Background  Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited syndrome. Renal disease is the main cause of death.\\u000a Brain disorders are the origin of more frequent and severe problems, such as tumors, epilepsy, and mental retardation. Participation\\u000a of neurosurgeons in the study and especially in the treatment of TSC patients is often required.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Two types of pathological conditions

Ignacio Pascual-Castroviejo

2011-01-01

163

Colored Shadows  

NSDL National Science Digital Library

In this optics activity, learners discover that not all shadows are black. Learners explore human color perception by using colored lights to make additive color mixtures. With three colored lights, learners can make shadows of seven different colors. They can also explore how to make shadows of individual colors, including black. Use this activity demonstrate how receptors in the retina of the eye work to see color.

Exploratorium, The

2011-10-31

164

Changes in GA 20-oxidase gene expression strongly affect stem length, tuber induction and tuber yield of potato plants.  

PubMed

Gene StGA20ox1 encoding potato GA 20-oxidase is expressed to relatively high levels in leaves and regulated by daylength. To investigate whether this gene is involved in photoperiodic regulation of tuber formation, we have obtained transgenic potato plants expressing sense and antisense copies of the StGA20ox1 cDNA. Over-expression of this cDNA resulted in taller plants that required a longer duration of a short day photoperiod (SD) to tuberize. Tubers from these plants had a decreased time of dormancy and developed sprouts with elongated internodes. Plants expressing antisense copies of the StGA20ox1 cDNA had shorter stems, a decreased length of the internodes and tuberized earlier than control plants, showing increased tuber yields. Antisense inhibition of this gene had no visible effect on the time of dormancy of the tubers, although at the end of dormancy these formed sprouts with shortened internodes. Decreased levels of endogenous GA20 and GA1 were detected in the apex and first leaves of the antisense lines. These results demonstrate the involvement of the GA 20-oxidase activity encoded by StGA20ox1 in the control of stem elongation and in tuber induction but not in tuber dormancy, indicating that the latter may be regulated by another member of the gene family. PMID:10849342

Carrera, E; Bou, J; García-Martínez, J L; Prat, S

2000-05-01

165

Brucite nanoplates reinforced starch bionanocomposites.  

PubMed

In this paper the mechanical reinforcement of nano-sized brucite, Mg(OH)(2) in a series of bionanocomposite films based on starch was investigated. Brucite nanoplates with an aspect ratio of 9.25 were synthesized by wet precipitation and incorporated into starch matrices at different concentrations (0-7.5 wt.%). Scanning electron microscopy revealed a high degree of nanoplate dispersion within the starch bionanocomposites and good interfacial adhesion between the filler and matrix. The brucite nanoplates formed agglomerates at high concentrations. The reinforcement factor values of the bionanocomposites were higher than the values predicted from the Halphin-Tsai model, which was attributed mainly to the high surface area of the nanoplates. Brucite (1 wt.%) nearly doubled the elastic modulus of starch films. Thermogravimetric analyses indicated some interaction between starch and the brucite that modified their decomposition profiles. Mechanical tests of glycerol plasticized bionanocomposites showed that the reinforcing efficiency of brucite remained high even at 10 wt.% and 20 wt.% of plasticizer. PMID:23399215

Moreira, Francys K V; Pedro, Daniel C A; Glenn, Gregory M; Marconcini, José M; Mattoso, Luiz H C

2013-02-15

166

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...

167

Laboratory scale production of maltodextrins and glucose syrup from banana starch.  

PubMed

Banana starch was isolated to obtain maltodextrin by enzymatic hydrolysis with a heat-stable alpha-amylase. The maltodextrin obtained had a dextrose equivalent (DE) between 7-11 and showed suitable chemical characteristics for food application. Additionally, banana maltodextrin had a greater white color value and total color difference (delta E) than a sample of commercial maltodextrin. Further saccharification of the maltodextrins was carried out with amyloglucosidase and pullulanase at 60 degrees C during 24 h obtaining a glucose syrup. Chemical characteristics of banana glucose syrup were compared with those of a commercial syrup obtaining similar results. Nevertheless, the color of banana glucose syrup was clearer than the one of a sample of commercial syrup. However, it showed lower color stability than the commercial sample, i.e., the color of banana glucose syrup changed as a function of storage time. Banana starch may be used to obtain maltodextrins and glucose syrups with similar chemical characteristics of those obtained from maize starch. Particularly, the color of banana maltodextrin is adequate for its use in food products. PMID:12216499

Bello-Pérez, Luis Arturo; Sánchez-Hernández, Laura; Moreno-Damían, Esther; Toro-Vazquez, Jorge F

2002-01-01

168

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

Microsoft Academic Search

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,

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

1994-01-01

169

Physical properties of cryomilled rice starch  

Microsoft Academic Search

Cryomilling of rice starch was evaluated as a non-chemical way to modify starch structure and properties. Cryomilling in a liquid nitrogen bath (63–77.2K) was done to Quest (10.80% amylose) and Pelde (20.75% amylose) rice starch at five different time frames (0, 15, 30, 45, and 60min). The viscosity of the cryomilled rice starch decreased significantly (p<0.05) with increasing milling duration,

A. F. Devi; K. Fibrianto; P. J. Torley; B. Bhandari

2009-01-01

170

Color Thieves  

NSDL National Science Digital Library

This story poses a challenge to its readers to solve the mystery of light, color, and how we see color. It also asks the question, "What is color?" After investigating the phenomena of color and color filters, students should realize that light is made up

Richard Konicek-Moran

2009-04-01

171

Structure of Porous Starch Microcellular Foam Particles  

Technology Transfer Automated Retrieval System (TEKTRAN)

A relatively new starch product with various novel applications is a porous microcellular foam. The foam product is made by dehydrating a starch hydrogel in a solvent such as ethanol and then removing the solvent to form a foam product. The process involves heating an aqueous slurry of starch (8% w/...

172

TRIBOLOGICAL PROPERTIES OF CHEMICALLY MODIFIED STARCH  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch is one of the most abundantly available plant-based biopolymer. It is a major component of such high volume commodity crops as corn, potato, and rice. Starch is a highly crystalline, high molecular weight poly(glucose) biopolymer. Starch is insoluble in water in its native state. Various ...

173

DEVELOPMENTS OF STARCH GRANULES IN MAIZE KERNELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maize kernels of self-pollinated inbred line B73, grown in Ames IA, were harvested on 0, 5, 6, 8, 10 12, 14, 20 and 30 days after pollination (DAP). The kernels were used for starch granule development studies. Starch in the endosperm was first observed on 6 DAP. Starch granules in the kernels th...

174

Rice functionality, starch structure and the genes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Through collaborative efforts among USDA scientists at Beaumont, Texas, we have gained in-depth knowledge of how rice functionality, i.e. the texture of the cooked rice, rice processing properties, and starch gelatinization temperature, are associated with starch-synthesis genes and starch structure...

175

LUBRICATION WITH STARCH-OIL COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aqueous starch-oil composites consist of uniformly suspended starch-coated oil droplets (1-10 µm in diameter), and find use in a wide variety of industrial, food, and agricultural applications. One of the main benefits of these starch-oil composites is that they can be drum dried and milled into a ...

176

Properties of retrograded and acetylated starch produced via starch extrusion or starch hydrolysis with pullulanase.  

PubMed

The aim of the present study was to determine the impact of serial modifications of starch, including firstly starch extrusion or hydrolysis with pullulanase, followed by retrogradation (through freezing and defrosting of pastes) and acetylation (under industrial conditions), on its susceptibility to amylolysis. The method of production had a significant effect on properties of the resultant preparations, whilst the direction and extent of changes depended on the type of modification applied. In the produced starch esters, the degree of substitution, expressed by the per cent of acetylation, ranged from 3.1 to 4.4 g/100 g. The acetylation had a significant impact on contents of elements determined with the atomic emission spectrometry, as it contributed to an increased Na content and decreased contents of Ca and K. The DSC thermal characteristics enabled concluding that the modifications caused an increase in temperatures and a decrease in heat of transition (or its lack). The acetylation of retrograded starch preparations increased their solubility in water and water absorbability. The modifications were found to exert various effects on the rheological properties of pastes determined based on the Brabender's pasting characteristics and flow curves determined with the use of an oscillatory-rotating viscosimeter. All starch acetates produced were characterized by ca. 40% resistance to amylolysis. PMID:23911484

Kapelko, M; Zi?ba, T; Gryszkin, A; Styczy?ska, M; Wilczak, A

2013-09-12

177

Ethanol breaks dormancy of the potato tuber apical bud.  

PubMed

Growing potato tubers or freshly harvested mature tubers have a dormant apical bud. Normally, this dormancy is spontaneously broken after a period of maturation of the tuber, resulting in the growth of a new sprout. Here it is shown that in in vitro-cultured growing and maturing tubers, ethanol can rapidly break this dormancy and re-induce growth of the apical bud. The in vivo promoter activity of selected genes during this secondary growth of the apical bud was monitored, using luciferase as a reporter. In response to ethanol, the expression of carbohydrate-storage, protein-storage, and cell division-related genes are rapidly down-regulated in tuber tissue. It was shown that dormancy was broken by primary but not by secondary alcohols, and the effect of ethanol on sprouting and gene expression in tuber tissue was blocked by an inhibitor of alcohol dehydrogenase. By contrast, products derived from alcohol dehydrogenase activity (acetaldehyde and acetic acid) did not induce sprouting, nor did they affect luciferase reporter gene activity in the tuber tissue. Application of an inhibitor of gibberellin biosynthesis had no effect on ethanol-induced sprouting. It is suggested that ethanol-induced sprouting may be related to an alcohol dehydrogenase-mediated increase in the catabolic redox charge [NADH/(NADH+NAD+)]. PMID:16043450

Claassens, Margo M J; Verhees, John; van der Plas, Linus H W; van der Krol, Alexander R; Vreugdenhil, Dick

2005-09-01

178

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...

179

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...

180

Regulation of Bud Rest in Tubers of Potato, Solanum tuberosum L  

PubMed Central

The rest period of the potato tuber was studied in relation to certain biochemical changes that are induced by gibberellic acid (GA3). The concentration of reducing sugars in excised plugs with buds treated with 10?4m GA3 decreased in the first 4 hours after treatment and then rapidly increased up to 70 hours. The pattern in control buds was similar, but the changes occurred more slowly. The response to GA3 is temperature-dependent and is not limited to any particular tissue of the tuber. The concentration of reducing sugars in excised buds increased proportionally to the log of the concentration of GA3 in a range from 10?8 to 10?4m. At 10?3m, GA3 slightly inhibited production of reducing sugars. Malonate inhibits the initial decrease and the subsequent increase in reducing sugars in control buds, but not the increase induced by GA3. Total protein in buds was not influenced by 10?4m GA3 over a period of 40 hours, nor did activity of ?-amylase increase significantly until 20 hours after beginning of treatment. Invertase activity was present initially and, in the presence of GA3, increased after 20 hours. GA3 had no effect on starch phosphorylase activity, which was always present and remained steady over the 20-hour test period. In short term experiments the rate of protein synthesis and synthesis of specific protein fractions were not affected by 10?4m GA3, as measured by the incorporation of l-phenylalanine-U-14C or by experiments with 14C- and 3H- labeled l-phenylalanine or l-leucine. PMID:16657283

Clegg, M. D.; Rappaport, Lawrence

1970-01-01

181

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

PubMed Central

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

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

182

Improved resolution of major clades within Tuber and taxonomy of species within the Tuber gibbosum complex.  

PubMed

Tuber gibbosum Harkn., described from northern California, originally was thought to be a single, variable species that fruited from autumn through winter to spring. It has become popular as a culinary truffle in northwestern USA, where it is commercially harvested. Morphological studies suggested it might be a complex that includes at least two species. We conducted morphological and phylogenetic studies of the complex to determine how many species it might contain and how they differed morphologically, geographically and seasonally. We also provide the first LSU phylogeny for the genus Tuber. Phylogenetic analyses resolve nine major clades in the genus with high bootstrap support and distinguish the Gibbosum clade from the Aestivum, Excavatum, Macrosporum, Magnatum, Melanosporum, Puberulum, Rufum and Spinoreticulatum clades. Further analyses of ITS and LSU regions revealed four distinct species in the Gibbosum complex. Although morphologically similar the four species differ in spore size and shape and in peridial anatomy. These species share the synapomorphy of having suprapellis hyphae with distinctive, irregular wall swellings at maturity; we have not seen this hyphal type in any other Tuber spp. worldwide. The three new species are named and described as T. bellisporum Bonito & Trappe, T. castellanoi Bonito & Trappe and T. oregonense Trappe, Bonito & Rawlinson. PMID:20943504

Bonito, Gregory; Trappe, James M; Rawlinson, Pat; Vilgalys, Rytas

2010-01-01

183

Color realism and color science  

E-print Network

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, ...

Byrne, Alex

184

Schematic Models for Potato Tuber Blight Infection Based on Foliar Blight Severity, Cultivar Resistance, Soil and Atmospheric Variables  

Technology Transfer Automated Retrieval System (TEKTRAN)

Potato tuber blight caused by Phytophthora infestans accounts for significant losses in storage tubers. Despite research on infection and management of tuber blight, there is limited published data on models predicting tuber blight infection or development. We modeled the dynamics of tuber blight in...

185

In vitro digestibility of gamma-irradiated corn starches  

Microsoft Academic Search

The digestibility of gamma-irradiated corn starches was investigated. Gamma-irradiation (5–20kGy) decreased the average molecular size of waxy and normal corn starches, but increased the proportions of both rapidly digestible (RDS) starch and enzyme-resistant starch (RS). The residual moisture in starch affected the susceptibility of the starches to the irradiation. Waxy corn starch was more susceptible to the irradiation than normal

H.-S. Yoon; J.-Y. Yoo; J.-H. Kim; J.-W. Lee; M.-W. Byun; B.-K. Baik; S.-T. Lim

2010-01-01

186

ELECTROACTIVE POLYMERS COMPOSED OF STARCH  

Technology Transfer Automated Retrieval System (TEKTRAN)

Extruded films of plasticized starch were doped with metal halides in order to produce solid polymer electrolytes. The electrical conductance of the material was increased from 10 exp(-11) S/cm to 10 exp(-6) S/cm. The type and amount of dopant affects the conductance of the material. Although the...

187

Mechanical, barrier and morphological properties of starch nanocrystals-reinforced pea starch films.  

PubMed

To characterize the pea starch films reinforced with waxy maize starch nanocrystals, the mechanical, water vapor barrier and morphological properties of the composite films were investigated. The addition of starch nanocrystals increased the tensile strength of the composite films, and the value of tensile strength of the composite films was highest when starch nanocrystals content was 5% (w/w). The moisture content (%), water vapor permeability, and water-vapor transmission rate of the composite films significantly decreased as starch nanocrystals content increased. When their starch nanocrystals content was 1-5%, the starch nanocrystals dispersed homogeneously in the composite films, resulting in a relatively smooth and compact film surface and better thermal stability. However, when starch nanocrystals content was more than 7%, the starch nanocrystals began to aggregate, which resulted in the surface of the composite films developing a longitudinal fibrous structure. PMID:25659684

Li, Xiaojing; Qiu, Chao; Ji, Na; Sun, Cuixia; Xiong, Liu; Sun, Qingjie

2015-05-01

188

New roles for Notch in tuberous sclerosis.  

PubMed

Tuberous sclerosis complex (TSC) is a dominantly inherited disease that is characterized by the growth of multiple benign tumors that are often difficult to treat. TSC is caused by mutations that inactivate the TSC1 or TSC2 genes, which normally function to inhibit activation of mammalian target of rapamycin signaling. In this issue of the JCI, two studies reported by Karbowniczek et al. and Ma et al. link TSC inactivation with activated Notch signaling (see the related articles beginning on pages 93 and 103, respectively). Using a variety of approaches, both studies show that inactivation of TSC leads to Notch1 activation. Furthermore, studies in tumor cells suggest that inhibiting Notch slows growth of the tumor cells. Although much remains to be learned about the precise mechanisms by which TSC loss leads to Notch activation, the newly identified link of TSC to Notch provides the rationale for testing Notch inhibitors in TSC-associated tumors. PMID:20038806

Pear, Warren S

2010-01-01

189

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

PubMed

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. PMID:24605946

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

2014-08-01

190

Production of Tuber-Inducing Factor  

NASA Technical Reports Server (NTRS)

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.

Stutte, Gary W.; Yorio, Neil C.

2006-01-01

191

New North American truffles (Tuber spp.) and their ectomycorrhizal associations.  

PubMed

Recent surveys of belowground fungal biodiversity in México and USA have revealed many undescribed truffle species, including many in the genus Tuber. Here we describe seven new species: Tuber beyerlei, T. castilloi, T. guevarai, T. lauryi, T. mexiusanum, T. miquihuanense and T. walkeri. Phylogenetic analyses place these species within the Maculatum group, an understudied clade of small truffles with little apparent economic value. These species are among the more taxonomically challenge-ing in the genus. We collected Tuber castilloi, T. mexiusanum and T. guevarai as fruit bodies and ectomycorrhizae on Quercus spp. in forests of eastern México. Tuber mexiusanum has a particularly broad geographic range, being collected in eastern USA under Populus deltoides and in Minnesota and Iowa in mixed hardwood forests. T. walkeri is described from the upper midwestern USA, and T. lauryi and T. beyerlei occur in the western USA. PMID:22962353

Guevara, Gonzalo; Bonito, Gregory; Trappe, James M; Cázares, Efren; Williams, Gwendolyn; Healy, Rosanne A; Schadt, Christopher; Vilgalys, Rytas

2013-01-01

192

Process for producing vegetative and tuber growth regulator  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

193

Cloning and functional analysis of a cDNA encoding a starch synthase from potato (Solanum tuberosum L.) that is predominantly expressed in leaf tissue.  

PubMed

Three isoforms of starch synthase (SS) were shown to be present in soluble potato tuber extracts by activity staining after native gel electrophoresis. A cDNA encoding SSI from rice was used as a probe to clone a corresponding cDNA from potato. The deduced amino acid sequence identified the protein as an SS from potato with an M(r) of 70.6 kDa for the immature enzyme including its transit peptide. This novel isoform was designated SSI. An analysis of the expression pattern of the gene indicated that SSI is predominantly expressed in sink and source leaves, and, to a lower extent in tubers. In several independent transgenic potato lines, where the expression of SSI was repressed using the antisense approach, the activity of a specific SS isoform was reduced to non-detectable levels as determined through activity staining after native gel electrophoresis. The reduction in the amount of this isoform of SS did not lead to any detectable changes in starch structure, probably due to the fact that this isoform only represents a minor activity in potato tubers. PMID:10420646

Kossmann, J; Abel, G J; Springer, F; Lloyd, J R; Willmitzer, L

1999-06-01

194

Color Addition  

NSDL National Science Digital Library

This activity is inquiry in that students do not know how colors are combined. They likely think that the primary colors are red, yellow, and blue. In fact, there are two sets of primary colors: red, green, and blue for additive colors of light, and cyan,

Horton, Michael

2009-05-30

195

Color Blindness  

MedlinePLUS

... looking at a lush green lawn or a red 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 common. ...

196

Color Mixing  

NSDL National Science Digital Library

This is an online activity where learners can virtually mix different colors of light or paint (you can switch between them) and see how the colors combine. It demonstrates how millions of colors are created on computer monitors and TVs, and in art and printing. Learners can try to match a given target color ("Mix to Match"), or simply play around with mixtures ("Mix for Fun"). Background information explains how light is additive (more colors tends towards white), whereas paint absorbs color and is subtractive (more colors tends towards black). There's also information about how the human eye works.

Industry, Oregon M.

2002-01-01

197

Comparison of lipid content and fatty acid composition between Tuber fermentation mycelia and natural fruiting bodies.  

PubMed

A comparison of lipid content and fatty acid (FA) composition between Tuber fermentation mycelia and natural fruiting bodies indicates that the lipid content in Tuber fermentation mycelia is higher than that in fruiting bodies. Unsaturated FAs (particularly linoleic acid and oleic acid) were the predominant constituents in total FAs in both Tuber fermentation mycelia and fruiting bodies. A total of 23 FAs, including arachidonic, eicosapentaenoic, docosahexaenoic, and ?-linolenic acids, were first identified in the Tuber species. A hierarchical clustering analysis showed that the FA profile of fermentation mycelia was quite similar, regardless of Tuber species. However, the FA profile of the fruiting bodies was significantly influenced by its species and habitat environments. Interestingly, the FA profile of the Tuber indicum and Tuber aestivum fruiting bodies was nearly identical to that of the Tuber fermentation mycelia, which partially confirms the similarity between the Tuber fermentation mycelia and the fruiting bodies. PMID:21449542

Tang, Yang; Li, Yuan-Yuan; Li, Hong-Mei; Wan, Duan-Ji; Tang, Ya-Jie

2011-05-11

198

Multiple pulmonary artery aneurysms in tuberous sclerosis complex  

PubMed Central

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterised by multiple hamartomas, caused by inactivating mutations of the TSC1/TSC2 tumour suppressor genes. Classical pulmonary involvement in tuberous sclerosis complex (TSC) consists of lymphangioleiomyomatosis and/or multiple micronodular pneumocyte hyperplasia (MMPH). Association of TSC with pulmonary artery aneurysm (PAA) has been only exceptionally described. We report here the first case of TSC with multiple PAA in combination with MMPH, cardiac rhabdomyomas and bone, skin and brain involvement. PMID:23341583

Dunet, Vincent; Qanadli, Salah Dine; Lazor, Romain; Beigelman-Aubry, Catherine

2013-01-01

199

Associations between electroencephalographic and magnetic resonance imaging findings in tuberous sclerosis complex.  

PubMed

Nearly 90% of patients with tuberous sclerosis complex (TSC) develop epilepsy; however the mechanisms of epileptogenesis remain unclear. Some cortical tubers are thought to be epileptogenic while others are not. This study aimed to evaluate whether tuber burden, size or type seen on magnetic resonance imaging (MRI) co-registers with interictal epileptiform discharges on electroencephalogram (EEG). EEG and MRI data from 69 patients with TSC were reviewed by dividing the cerebrum into four quadrants. Quadrants containing greatest tuber burden, largest tuber, calcified tubers, cyst-like tubers, and no tubers were identified on MRI. For EEG analysis, spikes and sharp waves were counted and averaged to a value per minute, and each quadrant was assigned a score. MRI and EEG findings were compared in each patient. The presence of a cyst-like tuber in a quadrant correlated with a higher incidence of epileptiform activity in the same quadrant (p=0.002). This finding supports the notion that cyst-like cortical tubers may contribute to the more severe epilepsy profile seen in TSC patients with these lesions. Quadrants containing greatest tuber burden, largest tubers, and calcified tubers were not predictive of regional interictal epileptiform activity. Furthermore, quadrants without any apparent tuber co-registered with interictal epileptiform discharges in two patients, suggesting a multifactorial component of epileptogenicity in TSC. PMID:19783123

Gallagher, Anne; Chu-Shore, Catherine J; Montenegro, Maria A; Major, Philippe; Costello, Daniel J; Lyczkowski, David A; Muzykewicz, David; Doherty, Colin; Thiele, Elizabeth A

2009-12-01

200

Effect of granular characteristics on pasting properties of starch blends.  

PubMed

Pasting and morphology properties of starch blends composed of waxy (waxy rice and waxy corn) and non-waxy (normal corn, tapioca and potato) starches at various ratios were investigated for elucidating effect of granular characteristics on pasting of blends. Pasting profiles of blends were between those of the component starches alone, while the changes varied with starch source. Results reveal obvious water competition during pasting for blends composed of waxy starch and highly swelling non-waxy (tapioca or potato) starch. On the contrary, starch blends composed of waxy starch and non-waxy (normal corn) starch with restricted swelling showed less water competition during pasting, and the pasting attributes could be estimated from those of the component starches following the mixing ratio. Results indicate that the pasting properties of starch blends composed of waxy and non-waxy starches depend on not only the mixing ratio, but also the granular characteristics of component starch. PMID:24053839

Lin, Jheng-Hua; Kao, Wen-Tsu; Tsai, You-Che; Chang, Yung-Ho

2013-11-01

201

Cyperus Tubers Protect Meloidogyne incognita from 1,3-Dichloropropene.  

PubMed

Meloidogyne incognita-infected and noninfected tubers of yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) were treated with 56 L/ha 1,3-dichloropropene (1,3-D) in microplots and subsequently examined for tuber and nematode viability in the greenhouse using a chile pepper (Capsicum annuum) bioassay system. The study was conducted three times. Nutsedge tuber viability and M. incognita harbored in both yellow and purple nutsedge tubers were unaffected by 1,3-D treatment. Nematode reproduction on nutsedges and associated chile pepper plants varied among years, possibly due to differing levels of tuber infection or soil temperature, but was not affected by fumigation. The presence of M. incognita resulted in greater yellow nutsedge tuber germination and reproduction. The efficacy of 1,3-D for management of M. incognita in chile pepper production is likely to be reduced when nutsedges are present in high numbers, reinforcing the importance of managing these weeds and nematodes simultaneously. PMID:19262797

Thomas, S H; Schroeder, J; Murray, L W

2004-06-01

202

Cyperus Tubers Protect Meloidogyne incognita from 1,3-Dichloropropene  

PubMed Central

Meloidogyne incognita-infected and noninfected tubers of yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) were treated with 56 L/ha 1,3-dichloropropene (1,3-D) in microplots and subsequently examined for tuber and nematode viability in the greenhouse using a chile pepper (Capsicum annuum) bioassay system. The study was conducted three times. Nutsedge tuber viability and M. incognita harbored in both yellow and purple nutsedge tubers were unaffected by 1,3-D treatment. Nematode reproduction on nutsedges and associated chile pepper plants varied among years, possibly due to differing levels of tuber infection or soil temperature, but was not affected by fumigation. The presence of M. incognita resulted in greater yellow nutsedge tuber germination and reproduction. The efficacy of 1,3-D for management of M. incognita in chile pepper production is likely to be reduced when nutsedges are present in high numbers, reinforcing the importance of managing these weeds and nematodes simultaneously. PMID:19262797

Thomas, S. H.; Schroeder, J.; Murray, L. W.

2004-01-01

203

Starch and cellulose nanocrystals together into thermoplastic starch bionanocomposites.  

PubMed

In the present work, thermoplastic maize starch based bionanocomposites were prepared as transparent films, plasticized with 35% of glycerol and reinforced with both waxy starch (WSNC) and cellulose nanocrystals (CNC), previously extracted by acidic hydrolysis. The influence of the nanofiller content was evaluated at 1 wt.%, 2.5 wt.% and 5 wt.% of WSNC. The effect of adding the two different nanoparticles at 1 wt.% was also investigated. As determined by tensile measurements, mechanical properties were improved at any composition of WSNC. Water vapour permeance values maintained constant, whereas barrier properties to oxygen reduced in a 70%, indicating the effectiveness of hydrogen bonding at the interphase. The use of CNC or CNC and WSNC upgraded mechanical results, but no significant differences in barrier properties were obtained. A homogeneous distribution of the nanofillers was demonstrated by atomic force microscopy, and a shift of the two relaxation peaks to higher temperatures was detected by dynamic mechanical analysis. PMID:25498612

González, Kizkitza; Retegi, Aloña; González, Alba; Eceiza, Arantxa; Gabilondo, Nagore

2015-03-01

204

REACTIVE EXTRUSION OF STARCH-POLYACRYLAMIDE GRAFT COPOLYMERS USING VARIOUS STARCHES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Graft copolymers of polyacrylamide and various substrates were prepared by reactive extrusion in a twin screw extruder using ammonium persulfate as initiator. Substrates included unmodified starches (corn, waxy maize, wheat, and potato), cationic starches, dextrin, dextran, and polyvinyl alcohol (P...

205

Starch-based lightweight concrete: effect of starch source, processing method, and aggregate geometry  

Microsoft Academic Search

One potential new use for starch is in making lightweight (<2 g\\/cm3) concrete. Lightweight concrete is important commercially because of its low sound and thermal conductivity and its low plastic, cured, and oven-dried densities. Lightweight concrete was made containing wheat, corn and high amylose corn starches. The starches were used as either hydrated raw starch or aquagels (semi-rigid gels of

G. M Glenn; G. M Gray; W. J Orts; D. W Wood

1999-01-01

206

Structural and functional properties of C-type starches.  

PubMed

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. PMID:24299776

Cai, Jinwen; Cai, Canhui; Man, Jianmin; Zhou, Weidong; Wei, Cunxu

2014-01-30

207

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...

208

Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.  

PubMed

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 ?-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the ?-limit dextrin from the OS starch with a low DS was close to that of the ?-limit dextrin from native starch but lower than that of the ?-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. PMID:24491720

Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

2014-06-15

209

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...

210

Tuberous Sclerosis Complex: A Brave New World?  

PubMed Central

Purpose of review Tuberous sclerosis complex (TSC) is a multiorgan genetic disease caused by mutations in the TSC1 or TSC2 genes. TSC has been recognized for many years as an important cause of severe neurological disease with patients suffering from epilepsy, developmental delay, autism, and psychiatric problems. During the last year there has been enormous advances in basic and translational research pertaining to TSC. Recent findings In this review, I discuss the basic science findings that position the TSC1 and TSC2 genes as critical regulators of the mTOR kinase within mTORC1. In addition, I will discuss the development of new animal models, translational data, and recent clinical trials using mTORC1 inhibitors such as rapamycin. Summary The past few years have seen spectacular advances that have energized TSC related research and challenged existing symptomatic treatments. While it remains to be seen whether use of mTORC1 inhibitors will revolutionize the care of patients with TSC, the application of basic and translational research towards a specific clinical disorder emphasizes the potential and promise of molecular medicine. PMID:20087180

Ess, Kevin C.

2010-01-01

211

Seeing Color  

ERIC Educational Resources Information Center

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…

Texley, Juliana

2005-01-01

212

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

PubMed

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. PMID:19303769

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

2009-07-01

213

Starch-Branching Enzymes Preferentially Associated with A-Type Starch Granules in Wheat Endosperm1  

PubMed Central

Two starch granule-bound proteins (SGP), SGP-140 and SGP-145, were preferentially associated with A-type starch granules (>10 ?m) 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 ?m) initiated before 15 DPA incorporated SGP-140 and SGP-145 throughout endosperm development and grew into full-size A-type starch granules (>10 ?m). 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 ?m). 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 (× Triticosecale Wittmack) endosperm, which like wheat endosperm have a bimodal starch granule size distribution. PMID:10982441

Peng, Mingsheng; Gao, Ming; Båga, Monica; Hucl, Pierre; Chibbar, Ravindra N.

2000-01-01

214

Characterisation of corn starch-based films reinforced with taro starch nanoparticles.  

PubMed

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 1.11MPa to 2.87MPa. 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. PMID:25529655

Dai, Lei; Qiu, Chao; Xiong, Liu; Sun, Qingjie

2015-05-01

215

Age-Induced Loss of Wound-Healing Ability in Potato Tubers is Regulated by ABA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wounding of potato tubers stimulates the development of a suberized wound periderm that resists desiccation and microbial invasion. Wound-healing ability declines with advancing tuber age (storage period). The mechanism of age-induced loss in healing capacity is not known; however, older tubers ha...

216

Stereospecific Analysis of Fatty Acid Composition of Chufa ( Cyperus esculentus L . ) Tuber Oil  

Microsoft Academic Search

We determined the positional fatty acid distribution of chufa tuber at stereospecific positions; the sn-1, sn-2, and sn-3 positions in the triacylglycerols of chufa tuber oil. Chufa tubers were washed with water, and oven dried to a moisture content of 20%. The total lipid (TL) was extracted in a Soxhlet apparatus using a mixture of chloroform and methanol at 40

Moonjung Kim; Siwon No; Suk Hoo Yoon

2007-01-01

217

Control of Dematophora necatrix on Cyperus esculentus tubers by hot-water treatment  

Microsoft Academic Search

Dematophora necatrix causes a tuber rot of cultivated Cyperus esculentus in eastern Spain. The disease is spread through infected tubers. To overcome this problem, the use of a hot-water treatment (HWT) of C. esculentus tubers was studied. Isolates of D. necatrix from C. esculentus showed sensitivity to temperatures above 34°C, indicating HWT could be used as a practical way of

J. Garc??a-Jiménez; J. Busto; A. Vicent; J. Armengol

2004-01-01

218

Color Terms and Color Concepts  

ERIC Educational Resources Information Center

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…

Davidoff, Jules

2006-01-01

219

Color Categories and Color Appearance  

ERIC Educational Resources Information Center

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…

Webster, Michael A.; Kay, Paul

2012-01-01

220

Friction Properties of Chemically Modified Starch  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch is a high molecular weight polyglucose biopolymer that, in its native state, is insoluble in water at room temperature. One way of improving its water solubility is by esterification of its free hydroxyl groups. Waxy maize, normal corn, and high amylose corn starches were esterified with ac...

221

POLYBLENDS CONTAINING STARCH AND VINYL POLYMERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The viscosity and gel formation in the tricomponent system, starch/poly(acrylic acid)/poly(vinyl pyrrolidone-iodine), are studied in this work. Starch and poly(acrylic acid) at 5% aqueous solution form a synergistic mixture at 60/40 ratio. The addition of a small amount of poly(vinyl pyrrolidone)-...

222

Changes in starch grain morphologies from cooking  

Microsoft Academic Search

One of the three main plant microfossils, starch grains are increasingly used as markers of diet, plant domestication, tool use and site organization, because their morphology and features provide a means to identify the plant that produced them. However, starch grains are susceptible to damage when they are exposed to heat in the presence of water, as in cooking. We

Amanda G. Henry; Holly F. Hudson; Dolores R. Piperno

2009-01-01

223

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

PubMed Central

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

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

2002-01-01

224

Polycystic kidney disease and chronic renal failure in tuberous sclerosis.  

PubMed

Tuberous sclerosis is a rare genetic disease which leads to formation of benign tumours in the brain and other organs of the body. It is a multisystem disease with various clinical manifestations. Renal angiomyolipomas are the most common renal manifestations whereas renal cell carcinoma is the least. Renal cysts are found in around 20% of the patients but polycystic kidney disease is present in less than 2% cases and is relatively rare manifestation of the disease. We present a case of tuberous sclerosis in a 60-year-old man who presented to the medicine outpatient department for routine evaluation of his hypertension. He was diagnosed as tuberous sclerosis. His ultrasound and CT scan of abdomen revealed polycystic kidney disease. His kidney function test and urine analysis were suggestive of chronic kidney disease. PMID:24092520

Dhakal, Mona; Dhakal, O P; Bhandari, Dhurba

2013-01-01

225

Renal cell carcinoma in tuberous sclerosis complex.  

PubMed

Renal cell carcinoma (RCC) occurs in 2% to 4% of patients with tuberous sclerosis complex (TSC). Previous reports have noted a variety of histologic appearances in these cancers, but the full spectrum of morphologic and molecular features has not been fully elucidated. We encountered 46 renal epithelial neoplasms from 19 TSC patients and analyzed their clinical, pathologic, and molecular features, enabling separation of these 46 tumors into 3 groups. The largest subset of tumors (n=24) had a distinct morphologic, immunologic, and molecular profile, including prominent papillary architecture and uniformly deficient succinate dehydrogenase subunit B (SDHB) expression prompting the novel term "TSC-associated papillary RCC (PRCC)." The second group (n=15) were morphologically similar to a hybrid oncocytic/chromophobe tumor (HOCT), whereas the last 7 renal epithelial neoplasms of group 3 remained unclassifiable. The TSC-associated PRCCs had prominent papillary architecture lined by clear cells with delicate eosinophilic cytoplasmic thread-like strands that occasionally appeared more prominent and aggregated to form eosinophilic globules. All 24 (100%) of these tumors were International Society of Urological Pathology (ISUP) nucleolar grade 2 or 3 with mostly basally located nuclei. Tumor cells from 17 of 24 TSC-associated PRCCs showed strong, diffuse labeling for carbonic anhydrase IX (100%), CK7 (94%), vimentin (88%), and CD10 (83%) and were uniformly negative for SDHB, TFE3, and AMACR. Gains of chromosomes 7 and 17 were found in 2 tumors, whereas chromosome 3p deletion and TFE3 translocations were not detected. In this study, we reported a sizable cohort of renal tumors seen in TSC and were able to identify them as different morphotypes, which may help to expand the morphologic spectrum of TSC-associated RCC. PMID:24832166

Yang, Ping; Cornejo, Kristine M; Sadow, Peter M; Cheng, Liang; Wang, Mingsheng; Xiao, Yu; Jiang, Zhong; Oliva, Esther; Jozwiak, Sergiusz; Nussbaum, Robert L; Feldman, Adam S; Paul, Elahna; Thiele, Elizabeth A; Yu, Jane J; Henske, Elizabeth P; Kwiatkowski, David J; Young, Robert H; Wu, Chin-Lee

2014-07-01

226

Functional Characteristics of Extruded Blends of Whey Protein Concentrate and Corn Starch  

Microsoft Academic Search

Cereal Chem. 84(2):195-201 The aim of this work was to study the effects of extrusion barrel tem- perature (70-180°C), feed moisture (18-30%), pH (3-8), different propor- tions of corn starch (75-95%), and whey protein concentrate (WPC, 80% protein concentration) (25-5%) on the preparation of functional blends. Expansion index (EI), bulk density (BD), compression force (CF), color, water absorption index (WAI),

S. L. Amaya-Llano; N. Morales Hernández; E. Castaño Tostado; F. Martínez-Bustos

2007-01-01

227

Sorption of organics and water on starch  

SciTech Connect

Starch is a well-established adsorption agent for drying ethanol. This work examines its potential for other gas-phase drying applications. Results from gas chromatography studies confirm that starch separates water from organic acids, alcohols, ketones, ethers, and aromatics, many of which form azeotropes with water. Trends in organics with respect to size and functional group show that the efficiency of this separation is related to both transport properties and strength of interaction between the organic components and starch. Small, polar molecules such as methanol and formic acid that have rapid mass-transfer characteristics and relatively strong interactions with starch are retained to a greater degree and are more difficult to separate from water than either compounds of higher molecular weight or decreased polarity. The large number of possible separations indicates that starch is a versatile material for use in sorbents for vapor-phase separations.

Westgate, P.J.; Ladisch, M.R. (Purdue Univ., West Lafayette, IN (United States). Lab. of Renewable Resources Engineering)

1993-08-01

228

Preparation and characterization of octenylsuccinylated plantain starch.  

PubMed

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. PMID:25036604

Bello-Flores, Christopher A; Nuñez-Santiago, Maria C; San Martín-Gonzalez, María F; BeMiller, James N; Bello-Pérez, Luis A

2014-09-01

229

Phasic temperature change patterns affect growth and tuberization in potatoes  

SciTech Connect

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.

Cao, W.; Tibbitts, T.W. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Horticulture)

1994-07-01

230

Familial bilateral periventricular nodular heterotopia mimics tuberous sclerosis.  

PubMed Central

A mother and daughter with an initial diagnosis of tuberous sclerosis are described. The daughter presented with partial seizures at the age of 8 months. Computed tomography showed uncalcified periventricular nodules which on magnetic resonance imaging were ovoid, almost contiguous, of grey matter density, and did not enhance with gadolinium. Brain imaging of her asymptomatic mother was similar. Absence of severe mental retardation, extracranial hamartomas, and depigmented patches distinguishes familial bilateral periventricular nodular heterotopia (FNH) from tuberous sclerosis. FNH is probably inherited as an X linked dominant with lethality in males. Images Figure 1 Figure 2 PMID:8787433

Jardine, P E; Clarke, M A; Super, M

1996-01-01

231

Involvement of endogenous gibberellins in potato tuber dormancy and early sprout growth: a critical assessment.  

PubMed

The role of endogenous gibberellins (GAs) in the regulation of potato (Solanum tuberosum) tuber dormancy was examined by determining: 1. changes in endogenous GA levels during natural dormancy progression, 2. the effects of GA biosynthesis inhibitors on tuber dormancy duration and 3. the dormancy status and tuber GA levels in a dwarf mutant of potato. The tubers (cv. Russet Burbank) used in these studies were still completely dormant after 98 days of storage. Between 98 and 134 days of storage, dormancy began to end and tubers exhibited limited (< 2 mm) sprout growth. Tuber dormancy weakened with further storage and tubers exhibited greater rates of sprout growth after 187 days of storage. Tubers stored for 212 days or longer were completely non-dormant and exhibited vigorous sprout growth. Immediately after harvest, the endogenous contents of GA19, GA20, and GA1 were relatively high (0.48-0.62 ng g fresh weight(-1)). The content of these GAs declined between 33 and 93 days of storage. Internal levels of GA19, GA20, and GA, rose slightly between 93 and 135 days of storage reaching levels comparable to those found in highly dormant tubers immediately after harvest. Levels of GA19, GA20, and GA1 continued to increase as sprout growth became more vigorous. Neither GA4 nor GA8 was detected in any tuber sample regardless of dormancy status. Dormant tubers exhibited a time-dependent increase in apparent GA sensitivity. Freshly harvested tubers were completely insensitive to exogenous GAs. As postharvest storage continued, exogenous GAs promoted premature dormancy release with GA1 and GA20 eliciting the greatest response. Injection of up to 5 microg tuber(-1) of kaurene, GA12, GA19 or GA8 had no effect on dormancy release. Sprout growth from non-dormant tubers was also promoted by exogenous GA in the following sequence of activity: GA1 = GA20 > GA19. Kaurene, GA12, and GA8 were inactive. Continuous exposure of developing tubers to inhibitors of GA biosynthesis (AMO-1618, ancymidol, or tetcyclasis) did not extend tuber dormancy but rather hastened dormancy release. Comparison of tuber dormancy and GA1 content in tubers of a wild-type and dwarf mutant of S. tuberosum ssp. andigena revealed a near-identical pattern of dormancy progression in spite of the absence of detectable levels of GA1 in tubers of the dwarf sibling at any time during dormancy progression. Collectively, these results do not support a role for endogenous GA in potato tuber dormancy release but are consistent with a role for GAs in the regulation of subsequent sprout growth. PMID:15022829

Suttle, Jeffrey C

2004-02-01

232

Acceleration of potato tuber sprouting by the expression of a bacterial pyrophosphatase.  

PubMed

Potato is a globally important crop. Unfortunately, potato farming is plagued with problems associated with the sprouting behavior of seed tubers. The data presented here demonstrate that using transgenic technology can influence this behavior. Transgenic tubers cytosolically expressing an inorganic pyrophosphatase gene derived from Escherichia coli under the control of the tuber-specific patatin promoter display significantly accelerated sprouting. The period of presprouting dormancy for transgenic tubers planted immediately after harvest is reduced by six to seven weeks when compared to wild-type tubers. This study demonstrates a method with which to regulate dormancy, an important aspect of potato crop management. PMID:11231562

Farré, E M; Bachmann, A; Willmitzer, L; Trethewey, R N

2001-03-01

233

Development of a certified reference material for genetically modified potato with altered starch composition.  

PubMed

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. PMID:17508757

Broothaerts, Wim; Corbisier, Philippe; Emons, Hendrik; Emteborg, Håkan; Linsinger, Thomas P J; Trapmann, Stefanie

2007-06-13

234

Infectivity of metalaxyl-sensitive and -resistant isolates of Phytophthora infestans to whole potato tubers as affected by tuber aging and storage  

Microsoft Academic Search

Potato tubers (cv. Alpha) were harvested at various time intervals after planting, or removed from storage at various times\\u000a after harvest, and inoculated with different sporangial concentrations of three metalaxyl-sensitive (MS) and three metalaxyl-resistant\\u000a (MR) isolates ofPhytophthora infestans. Disease parameters recorded were: (a) percentage of infected tubers; (b) percentage of blighted tuber surface area; and (c) depth of lesions. Blight

Masha Grinberger; David Kadish; Yigal Cohen I

1995-01-01

235

PHYSICOCHEMICAL PROPERTIES OF PERICARP AND ENDOSPERM STARCHES DURING MAIZE DEVELOPMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Endosperm starch and pericarp starch were isolated from maize (B73) kernels at different developmental stages. Starch granules, with small size (2-4 'm diameter), were first observed in the endosperm on 5 days after pollination (DAP). The size of endosperm-starch granules remained similar until 12DA...

236

Adsorption of Polyethylene from Solution onto Starch Film Surfaces  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since starch adsorbs onto polyethylene (PE) surfaces from cooled solutions of jet cooked starch, this study was carried out to determine whether adsorption of PE onto hydrophilic starch film surfaces would also take place if starch films were placed in hot solutions of PE in organic solvents, and th...

237

Preparation and characterization of biodegradable copolyester–starch based foams  

Microsoft Academic Search

Regular (25% amylose) and waxy corn starches blended to various ratios with Eastar Bio Copolyester® 14766 (EBC) were extruded into loose-fill foams using a twin screw extruder. Included in this study were two types of corn starch, three levels of EBC content, and three levels of starch moisture content. Waxy starch produced foams with greater radial expansions and lower unit

Qi Fang; Milford A. Hanna

2001-01-01

238

Effect of octenylsuccinic anhydride modification on ?-amylolysis of starch.  

PubMed

The effects of octenylsuccinic anhydride (OSA) modification of waxy maize and sorghum starches on subsequent ?-amylolysis are examined. Hydrolysis with ?-amylase is a method by which OSA starches may be structurally modified for industrial purposes. The hydrolysis of both granular and gelatinised forms of both starches follows first-order kinetics regardless of the OSA used as a percent of starch mass (0-24%). The highest hydrolysis rate coefficients for granular starches are at modification with 6% OSA/starch. The largest molecular sizes of ?-amylase hydrolysed OSA-modified gelatinised starches are found at modification with 24% OSA/starch. The results suggest that octenylsuccinyl groups have an action-blocking effect on ?-amylolysis of gelatinised starch, but the effect of semi-crystalline granular structure is more pronounced than that of OSA modification. Hence ?-amylolysis can be used under appropriate conditions to modify the structure of gelatinised OSA-modified starches. PMID:23769510

Sweedman, Michael C; Hasjim, Jovin; Tizzotti, Morgan J; Schäfer, Christian; Gilbert, Robert G

2013-08-14

239

Formation of resistant corn starches induced by gamma-irradiation.  

PubMed

The effect of gamma-irradiation on formation of resistant starch (RS) in corn starch with different amylose content was examined. Normal corn starch, waxy corn starch, and high amylose corn starch (Hylon V and Hylon VII) were irradiated at 5, 10, 25 and 50 kGy. Gamma-irradiation at 5 kGy increased the amylose-like molecules in starches and thus significantly enhanced the RS content (p<0.05). Highest RS content was produced by 50 kGy irradiated in all the starch samples (p<0.05). The irradiation-induced RS was more evident in waxy corn starch, followed by high amylose corn starch and normal corn starch. PMID:23911492

Lee, Jau-Shya; Ee, Min-Lee; Chung, Kok-Heung; Othman, Zainon

2013-09-12

240

Synthesis of poly(acrylamide)-starch and hydrolyzed starch graft copolymers as a size base material for cotton textiles  

Microsoft Academic Search

Rice starch was hydrolyzed with HCl to obtain starch with different molecular sizes. The original starch and hydrolyzed starches derived from it were independently graft copolymerized with acrylamide (Aam) using potassium permanganate\\/citric acid as initiator under different conditions of initiator and monomer concentration, polymerization time and temperature. The newly synthesized products were applied to sizing of cotton textiles to see

Kh. M. Mostafa

1997-01-01

241

Preparation of metallic nanoparticles by irradiation in starch aqueous solution  

NASA Astrophysics Data System (ADS)

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 ?Eab (total color difference) could characterize the nanoparticles with respect of their concentration. Hue angle ho 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.

Nemţanu, Monica R.; Bra?oveanu, Mirela; Iacob, Nicu?or

2014-11-01

242

Tuber symptoms associated with tobacco ratle virus infections  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tobacco rattle virus (TRV) is a soil-borne pathogen that is transmitted by stubby root nematodes. In the Columbia Basin of Washington and Oregon the only nematode positively shown to transmit the virus is Paratrichodorus allius. When the virus is transmitted to young tubers by the nematode, variou...

243

MICROBIAL CONTROL OF THE POTATO TUBER MOTH (LEPIDOPTERA: GELECHIIDAE)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Potato tuber moth (PTM) is a serious pest of stored potato in most countries where potatoes are grown. Pathogens that are specific to insects offer promise as alternatives to broad spectrum insecticides for management of this pest. A diverse spectrum of microscopic and multicellular organisms (bact...

244

Ultrastructural organization of vegetative hyphae of Tuber Albidum Pico  

Microsoft Academic Search

The ultrastructural organization of vegetative hyphae ofTuber albidum, an ectomycorrhizal fungus is described. Three zones are recognized: 1) an apical zone with cytoplasmic vesicles; 2) a subapical zone with protoplasmic organelles; 3) a vacuolated zone. This organization corresponds in its main features to the pattern just described for rapidly growing fungi.

Paola Fasolo Bonfante; Silvano Scannerini

1975-01-01

245

Regulatory involvement of ABA in potato tuber wound-healing  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rapid wound-healing is crucial in protecting potato tubers from infection and dehydration. Wound-induced suberization and the accumulation of hydrophobic barriers to reduce water vapor conductance/loss are principle protective wound-healing processes. However, little is known about the biological ...

246

Involvement of ABA in potato tuber wound-healing  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rapid suberization of tubers wounded during harvest, handling and seed cutting is crucial in protecting against infections, dehydration and defect development. Research at this laboratory is directed at determining the biological factors that regulate wound-healing and which may facilitate the deve...

247

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. ...

248

An Overview of Microbial Control of the Potato Tuber Moth  

Technology Transfer Automated Retrieval System (TEKTRAN)

Over reliance on broad spectrum insecticides has resulted in the development of resistance in potato tuber moth populations, safety risks to farm workers, the food supply, and the environment. An integrated pest management (IPM) strategy, in which natural enemies of pest arthropods and other alterna...

249

Soluble Sugar Concentrations Associated with Tuber and Winter Bud Sprouting  

Microsoft Academic Search

Many aquatic weeds rely on vegetative structures for surviv- al and propagation, rather than seeds. American pondweed ( Potamogeton nodosus Poiret) winter buds , and hydrilla ( Hydril- la verticillata (L.f.) Royle, monoecious and dioecious types) tubers were allowed to sprout in water in the dark. At two-to- three day intervals individual propagules and dependent shoots were analyzed for soluble

D. F. SPENCER; F. J. RYAN; L. AUNG; G. G. KSANDER

2001-01-01

250

A prevalence study of autism in tuberous sclerosis  

Microsoft Academic Search

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, has socially impaired

Ann Hunt; Charles Shepherd

1993-01-01

251

Endometrial Adenocarcinoma Presenting in a Premenopausal Patient with Tuberous Sclerosis  

ERIC Educational Resources Information Center

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:…

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

2005-01-01

252

Five new homoisoflavonoids from the tuber of Ophiopogon japonicus.  

PubMed

Five new homoisoflavonoids, ophiopogonanone C (1), ophiopogonanone D (2), ophiopogonone C (3), ophiopogonanone E (4) and ophiopogonanone F (5), and six known compounds were isolated from an ethanol extract of the tubers of Ophiopogon japonicus (Thunb) Ker-Gawl. Spectroscopic analyses were used to elucidate the structures of these compounds. PMID:12444717

Chang, Jin-Ming; Shen, Chien-Chang; Huang, Yu-Ling; Chien, Mei-Yin; Ou, Jun-Chih; Shieh, Bor-Jinn; Chen, Chien-Chih

2002-11-01

253

Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.  

PubMed

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. PMID:23987357

Liu, Zhongdong; Liu, Boxiang; Li, Mengxing; Wei, Min; Li, Hua; Liu, Peng; Wan, Tuo

2013-10-15

254

Effects of starch synthase IIa gene dosage on grain, protein and starch in endosperm of wheat  

Microsoft Academic Search

Starch synthases (SS) are responsible for elongating the ?-1,4 glucan chains of starch. A doubled haploid population was generated\\u000a by crossing a line of wheat, which lacks functional ssIIa genes on each genome (abd), and an Australian wheat cultivar, Sunco, with wild type ssIIa alleles on each genome (ABD). Evidence has been presented previously indicating that the SGP-1 (starch granule

Christine Konik-Rose; Jenny Thistleton; Helene Chanvrier; Ihwa Tan; Peter Halley; Michael Gidley; Behjat Kosar-Hashemi; Hong Wang; Oscar Larroque; Joseph Ikea; Steve McMaugh; Ahmed Regina; Sadequr Rahman; Matthew Morell; Zhongyi Li

2007-01-01

255

Molecular tools for the identification of Tuber melanosporum in agroindustry.  

PubMed

Tuber melanosporum Vitt., Tuber magnatum Pico, and Tuber uncinatum Chat. can be differentiated by their morphological characters. Fraud problems have arisen recently with the importation to Europe of truffles from China. T. melanosporum is morphologically very close, but distinct from the Chinese species [Tuber indicum (Cooke and Massee) and T. himalayense BC (Zhang and Winter)]. We have optimized molecular tools to unequivocally identify T. melanosporum. DNA extraction from ascocarps of black truffles is not straightforward. Problems to obtain pure DNA are due to high contents of phenolic compounds, melanine, and various polymers (proteins, polysaccharides, etc). These compounds coprecipitate with the DNA during extraction and strongly inhibit the PCR reaction. We have developed an efficient and reliable protocol for DNA extraction from truffle ascocarps. It was used successfully for DNA extraction from mycorrhizal root tips as well as from canned preparations of T. melanosporum. Several approaches to identify T. melanosporum by PCR were developed. Two specific primers for T. melanosporum were designed after comparison of the ITS region of this species with those of three Chinese fungi. They proved to be efficient to specifically detect the presence of T. melanosporum by PCR. The mycorrhizal status of trees inoculated with T. melanosporum but unable to produce truffles was confirmed in a single-step PCR reaction. A multiplex PCR approach was also developed with three sets of primers (including a specific one for Chinese truffles) to detect, in one PCR reaction, the presence of any other Tuber species mixed with T. melanosporum ascocarps. This optimized protocol, in association with the specific primers we designed, is applicable to quality control in the truffle industry from the production stages to final commercial products. PMID:10888592

Séjalon-Delmas, N; Roux, C; Martins, M; Kulifaj, M; Bécard, G; Dargent, R

2000-06-01

256

In vitro analyses of resistant starch in retrograded waxy and normal corn starches.  

PubMed

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. PMID:23291029

Zhou, Xing; Chung, Hyun-Jung; Kim, Jong-Yea; Lim, Seung-Taik

2013-04-01

257

Debranching enzyme concentration effected on physicochemical properties and ?-amylase hydrolysis rate of resistant starch type III from amylose rice starch  

Microsoft Academic Search

The effect of debranching enzyme concentration on physicochemical properties and ?-amylase hydrolysis rate of resistant starch type III from high amylose rice starch were studied. The pullulanase enzyme (8, 10, 12, 14 and 16U\\/g starch) was introduced to modify amylopectin molecules of 15% (w\\/w) gelatinized rice starches at 55°C for 16h. The debranched starches with different degrees of hydrolysis (0.14–5.27%),

Jirapa Pongjanta; Anchanee Utaipattanaceep; Onanong Naivikul; Kuakoon Piyachomkwan

2009-01-01

258

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

ERIC Educational Resources Information Center

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…

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

2006-01-01

259

Rheological behaviour of heated potato starch dispersions  

NASA Astrophysics Data System (ADS)

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.

Juszczak, L.; Witczak, M.; Ziêba, T.; Fortuna, T.

2012-10-01

260

Biotechnological relevance of starch-degrading enzymes  

SciTech Connect

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).

Stewart, G.G.

1987-01-01

261

Potential aromatic compounds as markers to differentiate between Tuber melanosporum and Tuber indicum truffles.  

PubMed

The Tuber indicum (Chinese truffle) and Tuber melanosporum (Black truffle) species are morphologically very similar but their aromas are very different. The black truffle aroma is much more intense and complex, and it is consequently appreciated more gastronomically. This work tries to determine whether the differences between the aromatic compounds of both species are sufficiently significant so as to apply them to fraud detection. An olfactometric evaluation (GC-O) of T. indicum was carried out for the first time. Eight important odorants were identified. In order of aromatic significance, these were: 1-octen-3-one and 1-octen-3-ol, followed by two ethyl esters (ethyl isobutyrate and ethyl 2-methylbutyrate), 3-methyl-1-butanol, isopropyl acetate, and finally the two sulfides dimethyldisulfide (DMDS) and dimethylsulfide (DMS). A comparison of this aromatic profile with that of T. melanosporum revealed the following differences: T. indicum stood out for the significant aromatic contribution of 1-octen-3-one and 1-octen-3-ol (with modified frequencies (MF%) of 82% and 69%, respectively), while in the case of T. melanosporum both had modified frequencies of less than 30%. Ethyl isobutyrate, ethyl 2-methylbutyrate and isopropyl acetate were also significantly higher, while DMS and DMDS had low MF (30-40%) compared to T. melanosporum (>70%). The volatile profiles of both species were also studied by means of headspace solid-phase microextraction (HS-SPME-GC-MS). This showed that the family of C8 compounds (3-octanone, octanal, 1-octen-3-one, 3-octanol and 1-octen-3-ol) is present in T. indicum at much higher levels. The presence of 1-octen-3-ol was higher by a factor of about 100, while 1-octen-3-one was detected in T. indicum only (there was no chromatographic signal in T. melanosporum). As well as showing the greatest chromatographic differences, these two compounds were also the most powerful from the aromatic viewpoint in the T. indicum olfactometry. Therefore, either of the two chromatographic methods (GC-O or HS-SPME-GC-MS), together or separately, could be used as a screening technique to distinguish between T. indicum and T. melanosporum and thus avoid possible fraud. PMID:23768334

Culleré, Laura; Ferreira, Vicente; Venturini, María E; Marco, Pedro; Blanco, Domingo

2013-11-01

262

Electrical resistance characteristics of starch foams  

Microsoft Academic Search

The insulative character of expanded polystyrene loose-fill packing material supports the immobile triboelectric charge on its surface, causing static cling. One beneficial property of starch-based loose-fill is its antistatic behavior, which prevents the buildup of electrostatic charges on the foam surface, resulting in no static cling. This investigation explores the electrical resistance characteristics of plasticized starch materials such as commercial

Paul D. Tatarka

1996-01-01

263

Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents  

PubMed Central

Background Development of an environmentally benign process for the synthesis of silver nanomaterials is an important aspect of current nanotechnology research. Among the 600 species of the genus Dioscorea, Dioscorea bulbifera has profound therapeutic applications due to its unique phytochemistry. In this paper, we report on the rapid synthesis of silver nanoparticles by reduction of aqueous Ag+ ions using D. bulbifera tuber extract. Methods and results Phytochemical analysis revealed that D. bulbifera tuber extract is rich in flavonoid, phenolics, reducing sugars, starch, diosgenin, ascorbic acid, and citric acid. The biosynthesis process was quite fast, and silver nanoparticles were formed within 5 hours. Ultraviolet-visible absorption spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction confirmed reduction of the Ag+ ions. Varied morphology of the bioreduced silver nanoparticles included spheres, triangles, and hexagons. Optimization studies revealed that the maximum rate of synthesis could be achieved with 0.7 mM AgNO3 solution at 50°C in 5 hours. The resulting silver nanoparticles were found to possess potent antibacterial activity against both Gram-negative and Gram-positive bacteria. Beta-lactam (piperacillin) and macrolide (eryth-romycin) antibiotics showed a 3.6-fold and 3-fold increase, respectively, in combination with silver nanoparticles selectively against multidrug-resistant Acinetobacter baumannii. Notable synergy was seen between silver nanoparticles and chloramphenicol or vancomycin against Pseudomonas aeruginosa, and was supported by a 4.9-fold and 4.2-fold increase in zone diameter, respectively. Similarly, we found a maximum 11.8-fold increase in zone diameter of streptomycin when combined with silver nanoparticles against E. coli, providing strong evidence for the synergistic action of a combination of antibiotics and silver nanoparticles. Conclusion This is the first report on the synthesis of silver nanoparticles using D. bulbifera tuber extract followed by an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents. PMID:22334779

Ghosh, Sougata; Patil, Sumersing; Ahire, Mehul; Kitture, Rohini; Kale, Sangeeta; Pardesi, Karishma; Cameotra, Swaranjit S; Bellare, Jayesh; Dhavale, Dilip D; Jabgunde, Amit; Chopade, Balu A

2012-01-01

264

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

PubMed Central

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 INH2? transcript encoding the full-length protein, two hybrid mRNAs (INH2?*A and INH2?*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, INH2? and the hybrid INH2? 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

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

2011-01-01

265

Color Sudoku  

NSDL National Science Digital Library

The popular sudoku puzzles use numbers, but the game could played with any set of 9 different objects! In this activity (on pages 56-75 of PDF), learners use objects of different colors (marbles, paper squares, candies) to solve sudoku puzzles. Learners use logic to determine where all the colored objects go, given the different colors already present on the puzzles. The activity includes suggestions for how to approach the game, 10 puzzles of varying size and difficulty, and links to websites with many more puzzles.

Omsi

2008-01-01

266

Color Theory  

NSDL National Science Digital Library

This Web site, developed by the Exploratories Project at Brown University, provides a series of applets to help users understand the various concepts in Color Theory. In the combined Color Mixing applet, undergraduate and high school students can discover how lights, paints, and filters interact. Users can learn about the properties of incoming light, frequency, and reflectance. The site also provides activities for metamers, Triple Cell Response, and much more. Anyone seeking help with color concepts will benefit from this educational, interactive Web site.

267

Physicochemical properties and digestibility of hydrothermally treated waxy rice starch.  

PubMed

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. PMID:25442528

Zeng, Feng; Ma, Fei; Kong, Fansheng; Gao, Qunyu; Yu, Shujuan

2015-04-01

268

Phosphoglucan phosphatase function sheds light on starch degradation.  

PubMed

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. PMID:24534096

Silver, Dylan M; Kötting, Oliver; Moorhead, Greg B G

2014-07-01

269

The Other Double Helix--The Fascinating Chemistry of Starch  

NASA Astrophysics Data System (ADS)

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.

Hancock, Robert D.; Tarbet, Bryon J.

2000-08-01

270

Colorful Electrophoresis  

NSDL National Science Digital Library

In this activity, learners follow step-by-step instructions to build a gel electrophoresis chamber using inexpensive materials from local hardware and electronic stores. Then, learners follow instructions to simulate DNA electrophoresis using food colors from the kitchen pantry.

Utah, University O.

2012-01-01

271

Stability and physicochemical properties of model salad dressings prepared with pregelatinized potato starch.  

PubMed

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 (tan?) and samples containing ? 3 wt% starch showed a weak gel-like (tan?<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. PMID:25037397

Bortnowska, Gra?yna; Balejko, Jerzy; Schube, Violetta; Tokarczyk, Grzegorz; Krzemi?ska, Natalia; Mojka, Katarzyna

2014-10-13

272

Resistant Starch and Starch Thermal Characteristics in Exotic Corn Lines Grown in Temperate and Tropical Environments  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn as a food that is heated and cooled to allow starch retrogradation has higher levels of resistant starch (RS). Increasing the amount of RS can make corn an even healthier food and may be accomplished by breeding and selection, especially by using exotic germplasm. Sixty breeding lines of introg...

273

Resistant starch formation in temperature treated potato starches varying in amylose\\/amylopectin ratio  

Microsoft Academic Search

Two genetically modified potato starches derived from the same mother line (64%, 1% and 23% amylose, respectively) were used to study the bioavailability after various heat treatments. The conditions for the treatments were of minor importance for resistant starch (RS) formation and hydrolysis results, as compared to the proportion of amylose. A high amylose content gave lower hydrolysis index (HI)

A. Margareta Leeman; Malin E. Karlsson; Ann-Charlotte Eliasson; Inger M. E. Björck

2006-01-01

274

Preparation and characterization of resistant starch III from elephant foot yam (Amorphophallus paeonifolius) starch.  

PubMed

The purpose of this study was to assess the properties of resistant starch (RS) III prepared from elephant foot yam starch using pullulanase enzyme. Native and gelatinized starches were subjected to enzymatic hydrolysis (pullulanase, 40 U/g per 10h), autoclaved (121°C/30 min), stored under refrigeration (4°C/24h) and then lyophilized. After preparation of resistant starch III, the morphological, physical, chemical and functional properties were assessed. The enzymatic and retrogradation process increased the yield of resistant starch III from starch with a concomitant increase increase in its water absorption capacity and water solubility index. A decrease in swelling power was observed due to the hydrolysis and thermal process. Te reduced pasting properties and hardness of resistant starch III were associated with the disintegration of starch granules due to the thermal process. The viscosity was found to be inversely proportional to the RS content in the sample. The thermal properties of RS increased due to retrogradation and recrystallization (P<0.05). PMID:24594151

Reddy, Chagam Koteswara; Haripriya, Sundaramoorthy; Noor Mohamed, A; Suriya, M

2014-07-15

275

STARCH-OIL INTERACTION IN DRY FILM LUBRICANTS WITH CHEMICALLY MODIFIED STARCH  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch is one of the most abundant farm-based raw materials. It is a significant component of such high volume commodity crops as corn, potato, rice, wheat, and barley. Because of the large surplus of these crops over demand, there is a great deal of interest in developing new uses for starch-base...

276

THE EFFECT OF STARCH TYPE AND OIL CONTENT ON OXIDATION OF STARCH-SOYBEAN OIL COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-oil composites (SOCs) are stable suspensions of microscopic (1-10 um) oil droplets in a starch dispersion or gel. These dispersions can be dried and reconstituted into an aqueous system without the need for emulsifiers, yet will maintain their physical stability and properties. SOCs have be...

277

Plantain and banana starches: granule structural characteristics explain the differences in their starch degradation patterns.  

PubMed

Different banana cultivars were used to investigate the influences of starch granule structure and hydrolases on degradation. The highest degrees of starch degradation were observed in dessert bananas during ripening. Scanning electron microscopy images revealed smooth granule surface in the green stage in all cultivars, except for Mysore. The small and round granules were preferentially degraded in all of the cultivars. Terra demonstrated a higher degree of crystallinity and a short amylopectin chain length distribution, resulting in high starch content in the ripe stage. Amylose content and the crystallinity index were more strongly correlated than the distribution of amylopectin branch chain lengths in banana starches. ?- and ?-amylase activities were found in both forms, soluble in the pulp and associated with the starch granule. Starch-phosphorylase was not found in Mysore. On the basis of the profile of ?-amylase in vitro digestion and the structural characteristics, it could be concluded that the starch of plantains has an arrangement of granules more resistant to enzymes than the starch of dessert bananas. PMID:21591784

Soares, Claudinéia Aparecida; Peroni-Okita, Fernanda Helena Gonçalves; Cardoso, Mateus Borba; Shitakubo, Renata; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

2011-06-22

278

Surface-associated proteins of wheat starch granules: suitability of wheat starch for celiac patients.  

PubMed

Wheat starch is used to make baked products for celiac patients in several European countries but is avoided in the United States because of uncertainty about the amounts of associated grain storage (gluten) proteins. People with celiac disease (CD) must avoid wheat, rye, and barley proteins and products that contain them. These proteins are capable of initiating damage to the absorptive lining of the small intestine in CD patients, apparently as a consequence of undesirable interactions with the innate and adaptive immune systems. In this study, starch surface-associated proteins were extracted from four commercial wheat starches, fractionated by high-performance liquid chromatography and gel electrophoresis, and identified by tandem mass spectrometry analysis. More than 150 proteins were identified, many of which (for example, histones, purothionins, and glutenins) had not been recognized previously as starch-associated. The commercial starches were analyzed by the R-5 enzyme-linked immunosorbent assay method to estimate the amount of harmful gluten protein present. One of these starches had a low gluten content of 7 ppm and actually fell within the range proposed as a new Codex Alimentarius Standard for naturally gluten-free foods (maximum 20 ppm). This low level of gluten indicates that the starch should be especially suitable for use by celiac patients, although wheat starches with levels up to 100 ppm are deemed safe in the proposed Codex standards. PMID:18837505

Kasarda, Donald D; Dupont, Frances M; Vensel, William H; Altenbach, Susan B; Lopez, Rocio; Tanaka, Charlene K; Hurkman, William J

2008-11-12

279

Cecropia peltata Accumulates Starch or Soluble Glycogen by Differentially Regulating Starch Biosynthetic Genes[W][OA  

PubMed Central

The branched glucans glycogen and starch are the most widespread storage carbohydrates in living organisms. The production of semicrystalline starch granules in plants is more complex than that of small, soluble glycogen particles in microbes and animals. However, the factors determining whether glycogen or starch is formed are not fully understood. The tropical tree Cecropia peltata is a rare example of an organism able to make either polymer type. Electron micrographs and quantitative measurements show that glycogen accumulates to very high levels in specialized myrmecophytic structures (Müllerian bodies), whereas starch accumulates in leaves. Compared with polymers comprising leaf starch, glycogen is more highly branched and has shorter branches—factors that prevent crystallization and explain its solubility. RNA sequencing and quantitative shotgun proteomics reveal that isoforms of all three classes of glucan biosynthetic enzyme (starch/glycogen synthases, branching enzymes, and debranching enzymes) are differentially expressed in Müllerian bodies and leaves, providing a system-wide view of the quantitative programming of storage carbohydrate metabolism. This work will prompt targeted analysis in model organisms and cross-species comparisons. Finally, as starch is the major carbohydrate used for food and industrial applications worldwide, these data provide a basis for manipulating starch biosynthesis in crops to synthesize tailor-made polyglucans. PMID:23632447

Bischof, Sylvain; Umhang, Martin; Eicke, Simona; Streb, Sebastian; Qi, Weihong; Zeeman, Samuel C.

2013-01-01

280

Rheological properties of starch-oil composites with high oil: starch ratios  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many applications have been developed for aqueous dispersions of jet-cooked starch-oil composites prepared by excess steam jet cooking. Previous formulations have typically contained between 20% and 50% oil by weight based on the weight of starch. In order to expand the range of potential applicat...

281

Effect of gamma irradiation on thermophysical properties of plasticized starch and starch surfactant films  

NASA Astrophysics Data System (ADS)

In this work the influence of gamma irradiation on the thermomechanical properties of the films formed in potato starch-glycerol and potato starch-glycerol-surfactant systems were examined by Dynamic Mechanical Analysis, DMA, and Differential Scanning Calorimetry, DSC, and the results were correlated to the amount of the volatile fraction in the films.

Cie?la, Krystyna; Watzeels, Nick; Rahier, Hubert

2014-06-01

282

Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch  

Technology Transfer Automated Retrieval System (TEKTRAN)

Octenylsuccinic anhydride (OSA)-modified starches with degree of substitution of 0.018 (OS-S-L) and 0.092 (OS-S-H) were prepared from granular native waxy maize starch in an aqueous slurry system. The substitution distribution of OS groups was investigated by enzyme hydrolysis followed by chromatogr...

283

Characterization of enzyme-resistant starch in maize amylose-extender mutant starches  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the human digestive system, a type of starch known as resistant starch (RS) can not be digested. RS is not absorbed in the small intestine, and is passed to the large intestine where it is fermented by bacteria to produce short-chain fatty acids, which have anti-cancer and anti-inflammatory prop...

284

Effect of waxy rice flour and cassava starch on freeze-thaw stability of rice starch gels.  

PubMed

Repeatedly frozen and thawed rice starch gel affects quality. This study investigated how incorporating waxy rice flour (WF) and cassava starch (CS) in rice starch gel affects factors used to measure quality. When rice starch gels containing 0-2% WF and CS were subjected to 5 freeze-thaw cycles, both WF and CS reduced the syneresis in first few cycles. However CS was more effective in reducing syneresis than WF. The different composite arrangement of rice starch with WF or CS caused different mechanisms associated with the rice starch gel retardation of retrogradation, reduced the spongy structure and lowered syneresis. Both swollen granules of rice starch and CS caused an increase in the hardness of the unfrozen and freeze-thawed starch gel while highly swollen WF granules caused softer gels. These results suggested that WF and CS were effective in preserving quality in frozen rice starch based products. PMID:22840036

Charoenrein, Sanguansri; Preechathammawong, Nutsuda

2012-10-01

285

Rhythmic changes in transcriptional activity during the development of potato tubers.  

PubMed

Chromatin-bound, DNA-dependent RNA polymerase (EC 2.7.7.6) activity and chromatin template availability, as measured with saturating amounts of E. coli RNA polymerase, changes rhythmically during the formation, dormancy, and sprouting of potato tubers. Active growth processes coincide with the highest RNA polymerase activity as well as the greatest template accessibility, during tuberization and sprouting. Consequently, chromatin-associated RNA and protein content is highest in young developing tubers and in old tubers at the onset of sprouting. Ribosomal RNA content, in turn, is maximal in small tubers, remains constant during dormancy, and decreases when sprouting begins, probably due to the translocation of rRNA into the sprouts. The nucleolus changes its shape and size concomitantly with the process of tuberization. PMID:24311032

Wechselberger, M; Wielgat, B; Kahl, G

1979-12-01

286

Species Recognition and Cryptic Species in the Tuber indicum Complex  

PubMed Central

Morphological delimitation of Asian black truffles, including Tuber himalayense, T. indicum, T. sinense, T. pseudohimalayense, T. formosanum and T. pseudoexcavatum, has remained problematic and even phylogenetic analyses have been controversial. In this study, we combined five years of field investigation in China with morphological study and DNA sequences analyses (ITS, LSU and ?-tubulin) of 131 Tuber specimens to show that T. pseudohimalayense and T. pseudoexcavatum are the same species. T. formosanum is a separate species based on its host plants and geographic distribution, combined with minor morphological difference from T. indicum. T. sinense should be treated as a synonym of T. indicum. Our results demonstrate that the present T. indicum, a single described morphological species, should include at least two separate phylogenetic species. These findings are of high importance for truffle taxonomy and reveal and preserve the richness of truffle diversity. PMID:21297969

Chen, Juan; Guo, Shun-Xing; Liu, Pei-Gui

2011-01-01

287

Species recognition and cryptic species in the Tuber indicum complex.  

PubMed

Morphological delimitation of Asian black truffles, including Tuber himalayense, T. indicum, T. sinense, T. pseudohimalayense, T. formosanum and T. pseudoexcavatum, has remained problematic and even phylogenetic analyses have been controversial. In this study, we combined five years of field investigation in China with morphological study and DNA sequences analyses (ITS, LSU and ?-tubulin) of 131 Tuber specimens to show that T. pseudohimalayense and T. pseudoexcavatum are the same species. T. formosanum is a separate species based on its host plants and geographic distribution, combined with minor morphological difference from T. indicum. T. sinense should be treated as a synonym of T. indicum. Our results demonstrate that the present T. indicum, a single described morphological species, should include at least two separate phylogenetic species. These findings are of high importance for truffle taxonomy and reveal and preserve the richness of truffle diversity. PMID:21297969

Chen, Juan; Guo, Shun-Xing; Liu, Pei-Gui

2011-01-01

288

Phylogenetic and populational study of the Tuber indicum complex.  

PubMed

When examined using SEM, Chinese samples of Tuber indicum and T. sinense displayed the same ascospore ornamentation as that of T. pseudohimalayense, T. indicum, collected in India by Duthie in 1899, and samples renamed T. himalayense in 1988. The different authors who named the four taxa (T. indicum, T. himalayense, T. sinense, T. pseudohimalyense) described differences in the surface of the peridium which could be considered as usual variations within a single species. We consider T. indicum, T. himalayense, T. sinense and T. pseudohimalayense as one species, T. indicum. Within this T. indicum complex, according to ITS and beta-tubulin sequences, there are two groups in China, which could be considered as geographical ecotypes. This study is the first to identify a genetic and phylogeographical structure within the Chinese Tuber species. PMID:16930973

Wang, Yongjin; Tan, Zhu Ming; Zhang, Da Cheng; Murat, Claude; Jeandroz, Sylvain; Le Tacon, François

2006-09-01

289

Effects of cooking methods and starch structures on starch hydrolysis rates of rice.  

PubMed

This study aimed to understand effects of different cooking methods, including steamed, pilaf, and traditional stir-fried, on starch hydrolysis rates of rice. Rice grains of 3 varieties, japonica, indica, and waxy, were used for the study. Rice starch was isolated from the grain and characterized. Amylose contents of starches from japonica, indica, and waxy rice were 13.5%, 18.0%, and 0.9%, respectively. The onset gelatinization temperature of indica starch (71.6 °C) was higher than that of the japonica and waxy starch (56.0 and 56.8 °C, respectively). The difference was attributed to longer amylopectin branch chains of the indica starch. Starch hydrolysis rates and resistant starch (RS) contents of the rice varieties differed after they were cooked using different methods. Stir-fried rice displayed the least starch hydrolysis rate followed by pilaf rice and steamed rice for each rice variety. RS contents of freshly steamed japonica, indica, and waxy rice were 0.7%, 6.6%, and 1.3%, respectively; those of rice pilaf were 12.1%, 13.2%, and 3.4%, respectively; and the stir-fried rice displayed the largest RS contents of 15.8%, 16.6%, and 12.1%, respectively. Mechanisms of the large RS contents of the stir-fried rice were studied. With the least starch hydrolysis rate and the largest RS content, stir-fried rice would be a desirable way of preparing rice for food to reduce postprandial blood glucose and insulin responses and to improve colon health of humans. PMID:23772830

Reed, Michael O; Ai, Yongfeng; Leutcher, Josh L; Jane, Jay-lin

2013-07-01

290

Phospholipid and phospholipase changes by jasmonic acid during stolon to tuber transition of potato  

Microsoft Academic Search

Potato tuber formation starts with the stolon swelling and is regulated by jasmonates. The cascade of events leading to tuber\\u000a formation is not completely understood. The aim of this study was to evaluate phospholipid composition and phospholipase activities\\u000a during four stages of stolon-to-tuber transition of Solanum tuberosum L., cv. Spunta, and involvement of phosphatidic acid (PA) in stolon cell expansion

Ana Cenzano; Renata Cantoro; Graciela Racagni; Cesar De Los Santos-Briones; Teresa Hernández-Sotomayor; Guillermina Abdala

2008-01-01

291

Bilateral cystoid macular edema with giant retinal achromic patch in a patient with tuberous sclerosis.  

PubMed

Retinal astrocytic hamartoma is the most common retinal finding in tuberous sclerosis and has been reported in association with cystoid macular edema. A retinal achromic patch is the second most common retinal finding in tuberous sclerosis. The authors report the first case of bilateral cystoid macular edema in which one the eyes does not have an identifiable retinal astrocytic hamartoma. They also describe a new retinal finding in tuberous sclerosis termed giant retinal achromic patch. PMID:25423644

Andrews, Laura; Lally, David R; Baumal, Caroline R

2014-01-01

292

Evaluation of the tubers and oil of Cyperus esculentus  

Microsoft Academic Search

The paper reports the proximate evaluation of dry Cyperus esculentus tubers and the characterization of the oil fraction. The proximate composition was 3.63 ± 0.28, 2.48 ± 0.33, 12.88 ± 0.91, 2.68 ± 0.08, 29.67 ± 0.47 and 52.29 ± 1.46% for moisture, ash, crude fibre, crude protein, oil and carbohydrate, respectively. The quality of the oil extracted by Soxhlet

S. C. Umerle; E. O. Okafor; A. S. Uka

1997-01-01

293

ESTuber db: an online database for Tuber borchii EST sequences  

Microsoft Academic Search

BACKGROUND: The ESTuber database (http:\\/\\/www.itb.cnr.it\\/estuber) includes 3,271 Tuber borchii expressed sequence tags (EST). The dataset consists of 2,389 sequences from an in-house prepared cDNA library from truffle vegetative hyphae, and 882 sequences downloaded from GenBank and representing four libraries from white truffle mycelia and ascocarps at different developmental stages. An automated pipeline was prepared to process EST sequences using public

Barbara Lazzari; Andrea Caprera; Cristian Cosentino; Alessandra Stella; Luciano Milanesi; Angelo Viotti

2007-01-01

294

Volatile organic compounds from a Tuber melanosporum fermentation system.  

PubMed

A total of 59 volatile organic compounds (VOCs) were identified from Tuber melanosporum fermentation: 53 from its fermented mycelia and 32 from the fermentation broth. Alcohol-derived compounds were predominant in both the fermentation mycelia and the broth, although long chain fatty acids and isoprenoids were, for the first time, also found in the mycelia. The intense wine bouquet properties of the broth arose from several specific flavor substances, including sulfur compounds, pyrazines, furans and jasmones. Comparing the VOCs identified in this work with those previously reported, our results are more similar to the composition of the Tuber fruiting-body than previous Tuber fermentations. The composition and accumulation of flavor volatiles (e.g., pyrazines, sulfur compounds, and esters) and major constituents (e.g., 3-methyl-1-butanol and 2-phenylethanol) in this fermentation were significantly influenced by the sucrose concentration in the medium. The obtained information could therefore be useful in applications to convert the flavors of truffle mycelia similar to those of the fruiting-body by optimising the fermentation process. PMID:22980851

Li, Yuan-Yuan; Wang, Guan; Li, Hong-Mei; Zhong, Jian-Jiang; Tang, Ya-Jie

2012-12-15

295

Novel in vitro inhibitory functions of potato tuber proteinaceous inhibitors.  

PubMed

Plant protease inhibitors are a structurally highly diverse and ubiquitous class of small proteins, which play various roles in plant development and defense against pests and pathogens. Particular isoforms inhibit in vitro proteases and other enzymes that are not their natural substrates, for example proteases that have roles in human diseases. Mature potato tubers are a rich source of several protease inhibitor families. Different cultivars have different inhibitor profiles. With the objective to explore the functional diversity of the natural diversity of potato protease inhibitors, we randomly selected and sequenced 9,600 cDNA clones originated from mature tubers of ten potato cultivars. Among these, 120 unique inhibitor cDNA clones were identified by homology searches. Eighty-eight inhibitors represented novel sequence variants of known plant protease inhibitor families. Most frequent were Kunitz-type inhibitors (KTI), potato protease inhibitors I and II (PIN), pectin methylesterase inhibitors, metallocarboxypeptidase inhibitors and defensins. Twenty-three inhibitors were functionally characterized after heterologous expression in the yeast Pichia pastoris. The purified recombinant proteins were tested for inhibitory activity on trypsin, eleven pharmacological relevant proteases and the non-proteolytic enzyme 5-lipoxygenase. Members of the KTI and PIN families inhibited pig pancreas elastase, ?-Secretase, Cathepsin K, HIV-1 protease and potato 5-lipoxygenase. Our results demonstrate in vitro inhibitory diversity of small potato tuber proteins commonly known as protease inhibitors, which might have biotechnological or medical applications. PMID:25260821

Fischer, Matthias; Kuckenberg, Markus; Kastilan, Robin; Muth, Jost; Gebhardt, Christiane

2015-02-01

296

Effects of food gums on viscosities of starch suspensions during pasting  

Microsoft Academic Search

Pasting curves of starches in gum (hydrocolloid) solutions at low concentrations (starch 3.6%, gum 0.4%) were produced with a Brookfield viscometer. Gums produced a variety of effects on viscosities of starches during starch pasting (increase or decrease greatly or slightly or no effect). A viscosity increase before the normal starch pasting temperature was detected for normal maize starch in the

Xiaohong Shi; James N. BeMiller

2002-01-01

297

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

PubMed Central

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

Bachem, Christian W.B.

2012-01-01

298

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

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

299

Phenolic profile, antioxidant, anti-inflammatory and cytotoxic activities of black (Tuber aestivum Vittad.) and white (Tuber magnatum Pico) truffles.  

PubMed

The aim of this study was a comprehensive investigation on phenolic profile, antioxidant, anti-inflammatory and cytotoxic activity of the still insufficiently explored black summer truffles (Tuber aestivum Vittad.) and white (Tuber magnatum Pico) truffles. Methanol and water extracts, obtained by maceration and Soxhlet extraction, were examined. Forty-five phenolics was studied using LC-MS/MS: presence of 14 compounds was confirmed, with the most dominant being p-hydroxybenzoic acid, baicalein and kaempferol (T. aestivum), epicatechin and catechin (T. magnatum). Moderate antioxidant activity of both species was determined through several assays. Only T. magnatum showed anti-inflammatory potential by inhibiting COX-1 and 12-LOX pathway products synthesis. Methanol extracts exerted cytotoxicity against some tumour cell lines (HeLa, MCF7, HT-29), besides the prominent activity of water extracts towards breast adenocarcinoma (MCF7). To conclude, these results support further investigations of phytochemicals and biological activity towards verification of nutraceutical use of both species. PMID:25038699

Beara, Ivana N; Lesjak, Marija M; Cetojevi?-Simin, Dragana D; Marjanovi?, Zaklina S; Risti?, Jelena D; Mrkonji?, Zorica O; Mimica-Duki?, Neda M

2014-12-15

300

Colorful Waves  

NSDL National Science Digital Library

You're probably really upset that all you have so far is a simple little ray model of light. When do we get to the good stuff, you say? How about now? As a bonus, you get to look at lots of pretty colors. This chapter addresses how light can be modeled as a series of waves. These waves consist of changing electric and magnetic fields that can travel through empty space, as well as through other mediums. Different frequencies of light waves correspond to different colors of light. White light is composed of all the colors of visible light. Visible light is just a small portion of the entire spectrum of electromagnetic waves.

William C. Robertson, Ph.D.

2003-01-01

301

Colorful Mathematics  

NSDL National Science Digital Library

Funded by Industry Canada's SchoolNet initiative with the cooperation of the Canadian Mathematical Society, Colorful Mathematics takes a game-oriented approach to teaching K-12 mathematics. The project has developed five coloring games that teach children about problem solving, and pattern identification, which "are all at the very heart of mathematics." The coloring approach makes difficult graph concepts "that are still the subject of active research by mathematicians, computer scientists and industry researchers" more accessible to children. The software program, which is available for free from this website, is set up to check for mistakes and challenge students to improve on their results. A Teacher's Corner section gives an overview of the games, "some sample questions for discussion with the curious student," and an overview of terminology used in the software program. The website is also available in French.

302

Shelf-life extension of fresh Tuber aestivum and Tuber melanosporum truffles by modified atmosphere packaging with microperforated films.  

PubMed

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. PMID:20546403

Rivera, Carmen Susana; Blanco, Domingo; Salvador, María Luisa; Venturini, María Eugenia

2010-05-01

303

Kool Colors  

NSDL National Science Digital Library

Learners investigate how temperature affects the rate of chemical reactions by observing how steel wool reacts with various types of Kool-Aid solutions at different temperatures. The reaction is monitored as the color fades in the Kool-Aid solutions. Background information includes how the dyes change color from an oxidation-reduction reaction. Extensions include investigating how surface area and concentration affect reaction rate. Part of the "No Hassle Messy Science with a Wow" activity guide by OMSI, where all activities use only household materials.

2013-07-30

304

The Properties and Genetics of Barley Malt Starch Degrading Enzymes  

Microsoft Academic Search

\\u000a The properties and quality of barley malt starch degrading enzymes are of primary importance to the efficiency and profitability\\u000a of brewing (beer and whiskey), and the bio-fuel (bio-ethanol) industries. The barley starch degrading enzymes hydrolyse starch\\u000a into fermentable sugars that yeast converts into alcohol. This process is key for the alcohol producing industries as the\\u000a starch substrate makes up approximately

D. E. Evans; C. Li; J. K. Eglinton

305

Physical characterisation of high amylose maize starch and acylated high amylose maize starches.  

PubMed

The particle size, water sorption properties and molecular mobility of high amylose maize starch (HAMS) and high amylose maize starch acylated with acetate (HAMSA), propionate (HAMSP) and butyrate (HAMSB) were investigated. Acylation increased the mean particle size (D(4,3)) and lowered the specific gravity (G) of the starch granules with an inverse relationship between the length of the fatty acid chain and particle size. Acylation of HAMS with fatty acids lowered the monolayer moisture content with the trend being HAMSBstarch granules by NMR spectroscopy with Carr-Purcell-Meiboom-Gill (CMPG) experiments showed that T2 long was reduced in acylated starches and that drying and storage of the starch granules further reduced T2 long. Analysis of the Free Induction Decay (FID) focussing on the short components of T2 (correlated to the solid matrix), indicated that drying and subsequent storage resulted in alterations of starch at 0.33a(w) and that these changes were reduced with acylation. In vitro enzymatic digestibility of heated starch dispersions by bacterial ?-amylase was increased by acylation (HAMSstarch. PMID:25498636

Lim, Ya-Mei; Hoobin, Pamela; Ying, DanYang; Burgar, Iko; Gooley, Paul R; Augustin, Mary Ann

2015-03-01

306

Content of starch and sugars and in vitro digestion of starch by alpha-amylase in five minor millets.  

PubMed

Five varieties of minor millets were studied for their amylose, soluble amylose, amylopectin, soluble amylopectin, reducing sugar, total sugar and starch contents. Pure starch was isolated from each variety and the enzymic degradation of starch by porcine pancreatic alpha-amylase were examined with and without gelatinisation. Gelatinised sample of Echinochloa frumentacea (var. K2) showed minimal hydrolysis and gelatinised sample of Panicum miliaceum (var. CO3) showed maximum hydrolysis of starch by porcine pancreatic alpha-amylase. Gelatinised starch was highly susceptible to enzymic digestion when compared to ungelatinised starch. The extent of starch degradation varied from 71 to 85 percent in gelatinised samples and starch degradation in ungelatinised sample varied from 10 to 18 percent. PMID:8882370

Krishnakumari, S; Thayumanavan, B

1995-12-01

307

Study and development of LDPE\\/starch partially biodegradable compounds  

Microsoft Academic Search

In this work it was investigated the incorporation of different starches, such as native, adipate, acetylated and cassava starch, in low-density polyethylene matrix (LDPE) to verify the possibility to obtain partially biodegradable product with the aim to decrease the plastics wastes in the environment. The starches were mixed to the LDPE using a high shearing mixer to guarantee the homogeneity

E. M. Nakamura; L. Cordi; G. S. G. Almeida; N. Duran; L. H. I. Mei

2005-01-01

308

RHEOLOGICAL PROPERTIES OF STARCH AND WHEY PROTEIN ISOLATE GELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Whey proteins are increasingly being combined with starches and flours to make nutritious extruded snacks. The effect of whey proteins on the rheological properties of starch was investigated. The paste viscosity of starches Amioca (~0.5% amylose), native corn (~27% amylose), Hylon VII (~70% amylose...

309

CONTROL OF DROPLET SIZE DISTRIBUTION IN STARCH-OIL COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous work has shown that a stable dispersion of oil droplets can be obtained by combining an aqueous slurry of starch and oil in an excess steam jet cooker. The resulting starch oil composites have been used in a broad range of food and industrial applications. During jet cooking, the starch i...

310

Recent processing methods for preparing starch-based bioproducts  

Technology Transfer Automated Retrieval System (TEKTRAN)

There is currently an intense interest in starch-based materials because of the low cost of starch, the replacement of dwindling petroleum-based resources with annually-renewable feedstocks, the biodegradability of starch-based products, and the creation of new markets for farm commodities. Non-trad...

311

HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Modified starch-based polymers can be engineered for specific properties by combining starch with synthetic polymers through graft copolymerization. Polyacrylamide grafted starches have received a great deal of applications in areas such as superabsorbent paper-making additives, drag reduction and ...

312

Characterization of rice starches extracted from Indian cultivars.  

PubMed

Physicochemical, morphological and pasting properties of starches isolated from four rice cultivars grown in India were studied. The amylose content ranged between 4.7 and 30.2% of starch, highest in K332 starch and lowest in SR1 starch. Swelling power, water solubility and water absorption capacity of starches increased with increase in temperature from 50 to 90?°C at 10?°C intervals. Highest swelling and water absorption was found in SR1 and lowest in K332 starches but reverse was observed in case of solubility that was highest for K332 and lowest for SR1 starch. The microstructure of starch granules from different rice cultivars showed the presence of mainly polyhedral granules having average size in the range of 4.0-5.2?µm. K332 showed the presence of smallest granules, whereas SR1 starch showed the presence of largest granules. X-ray diffraction pattern of rice starch from different cultivars showed typical A-type crystallinity. Pasting properties of starches differed significantly. Pasting temperature was highest for K332 and lowest for SR1, while peak viscosity was highest for aromatic rice and lowest for K448 starches. Higher setback was observed in K332 and lowest in SR1. PMID:23291829

Gani, Adil; Wani, S M; Masoodi, F A; Salim, Rehana

2013-04-01

313

Influence of maize genotype on rate of ruminal starch degradation  

E-print Network

Influence of maize genotype on rate of ruminal starch degradation B Michalet-Doreau1 M Champion2 influence ruminal starch degradation. The trial was performed on two maize cultivars characterised:25 for "waxy", "normal" and "extender"starchs, respectively. The 6 maize were ground to 2 mm mesh size

Paris-Sud XI, Université de

314

ISOLATION OF AMYLOSE FROM STARCH SOLUTIONS BY PHASE SEPARATION*  

Technology Transfer Automated Retrieval System (TEKTRAN)

Conventionally, fractionation of the two components of starches, amylopectin and amylose had been achieved by aqueous dispersion or aqueous leaching of granules, and selective retrogradation or alcohol precipitation of one component from starch dispersion. Recently, we found that starch solutions s...

315

HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Modified starch-based polymers can be engineered for specific properties by combining starch with synthetic polymers through graft copolymerization. Polyacrylamide grafted starch have received a great deal of applications in areas such as superabsorbent paper-making additives, drag reduction and te...

316

Original article In situ starch degradation of different feeds  

E-print Network

starch degradation of 5 feeds (barley, maize, pea, oats and wheat bran) has been measured (trial 1). The starch degradability of barley, oats and wheat bran was found to be higher than that of pea, and higher again than that of maize: 98, 97, 96, 90 and 58% respectively. For barley, oats and wheat bran, starch

Paris-Sud XI, Université de

317

Examining Colors, Color Perception, and Sight  

NSDL National Science Digital Library

Students of all ages are fascinated by color and how we perceive it. For the main activity in this chapter, your class explores colors and visual perception by mixing colors in several ways. Students learn more about colors, light, vision, and color compo

Eichinger, John

2009-05-15

318

Color Sense  

ERIC Educational Resources Information Center

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…

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

2009-01-01

319

Color transparency  

SciTech Connect

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.

Jennings, B.K. [TRIUMF, Vancouver, BC (Canada); Miller, G.A. [Washington Univ., Seattle, WA (United States). Dept. of Physics

1993-11-01

320

Polyoxometalates acid treatment for preparing starch nanoparticles.  

PubMed

In this article, a new way of preparing starch-based nanoparticles (SNPs) with high yields by a polyoxometalates acid treatment is presented. The particle morphology, mean size and size distribution of the obtained SNPs are characterized using a dynamic light scattering (DLS) and scanning electron microscope (SEM). By changing parameters such as temperature, concentration of polyoxometalates and treating time the size of SNPs can be controlled. In addition, there are no changes in the structures of the starch granules as confirmed by IR or (1)H NMR. Freeze-dried SNPs are amorphous as characterized by wide-angle X-ray diffraction (WXRD). PMID:25129776

Chen, Li; Zhang, Zhe; Zhao, Ziwei; Wang, Xiaohong; Chen, Xuesi

2014-11-01

321

Characterization of Maize Amylose-Extender (ae) Mutant Starches. Part I: Relationship Between Resistant Starch Contents and Molecular Structures  

Technology Transfer Automated Retrieval System (TEKTRAN)

Endosperm starches were isolated from kernels of seven maize amylose-extender (ae) lines. The resistant starch (RS) contents, measured using AOAC method 991.43, showed that three new ae-mutant starch lines developed by the USDA-ARS Germplasm Enhancement (GEM) and Truman State University had larger R...

322

Properties of thermoplastic starch from cassave bagasse and cassava starch and their blends with poly (lactic acid).  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cassava bagasse is an inexpensive and broadly available waste byproduct from cassava starch production. It contains roughly 50% cassava starch along with mostly fiber and could be a valuable feedstock for various bioproducts. Cassava bagasse and cassava starch were used in this study to make fiber-r...

323

Morphological and mechanical characterization of thermoplastic starch and its blends with polylactic acid using cassava starch and bagasse  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study aims the use of an agro waste coming from the industrialization of cassava starch, known as cassava bagasse (BG). This material contains residual starch and cellulose fibers which can be used to obtain thermoplastic starch (TPS) and /or blends reinforced with fibers. In this context, it w...

324

Neuro-epileptic determinants of autism spectrum disorders in tuberous sclerosis complex  

Microsoft Academic Search

Summary Tuberous sclerosis is one of the few established medical causes of autism spectrum disorder and is a unique neurogenetic model for testing theories about the brain basis of the syndrome. We conducted a retrospective case study of the neuro-epileptic risk factors predispos- ing to autism spectrum disorder in individuals with tuberous sclerosis to test current neurobiological theories of autism

Patrick F. Bolton; Rebecca J. Park; J. Nicholas; P. Higgins; Paul D. Griffiths; Andrew Pickles

2002-01-01

325

LC-MS Analysis of Phenolic Compounds in Tubers Showing Zebra Chip Symptoms  

Technology Transfer Automated Retrieval System (TEKTRAN)

A new potato disorder called zebra chip (ZC) has been identified in the United States and has been especially problematic in Texas where substantial economic losses have been incurred. Upon frying, ZC tubers develop a dark “zebra chip” pattern of discoloration. LC-MS analysis of symptomatic tubers...

326

POST HARVEST APPLICATIONS OF ZOXAMIDE AND PHOSPHITE FOR CONTROL OF POTATO TUBER ROTS CAUSED BY OOMYCETES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Potato storage tuber rots caused by the late blight and pink rot pathogens can cause severe economic losses warranting the need for effective post-harvest fungicide applications. The purpose of this study was to evaluate the efficacy of selective post-harvest fungicides in reducing tuber infections...

327

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...

328

CHANGES IN ABA BIOSYNTHETIC AND METABOLISM-RELATED GENE EXPRESSION DURING MERISTEM DORMANCY IN POTATO TUBERS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

At harvest and for an indeterminate period thereafter, potato tubers will not sprout and are physiologically dormant. Although the underlying molecular mechanisms controlling tuber dormancy are poorly understood, it has been proposed that endogenous plant hormones are intricately involved in potato ...

329

Chufa Tubers (Cyperus esculentus L.): As a New Source of Food  

Microsoft Academic Search

This work reported the proximate evaluation of dry Chufa (Cyperus esculentus L.) tubers with emphasis on the characterization of its oil extracted as compared with olive oil (Oleo europea). Moreover, fatty acids compositions of both oils were analyzed by gas liquid chromatography (GLC). Minerals content of chufa tubers were analyzed by atomic absorption spectrophotometer. Also, amino acids content of chufa

Shaker M. Arafat; Ahmed M. Gaafar; Amany M. Basuny; Shereen L. Nassef

330

The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development.  

PubMed

· 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. PMID:23496288

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

331

The Effect of Temperature and Daylength on the Germination of Potamogeton nodosus Tubers  

Microsoft Academic Search

The effects of temperature and daylength were studied in the germination of American pondweed (Potamogeton nodosus Poir.) tubers. Germination was examined at temperatures ranging from 5 to 30°C in conjunction with light treatments of short and long daylength and continuous darkness. Greatest percentage of tuber germination occurred between 15 and 20°C. Within this temperature range, daylength did not significantly affect

Nicole A. Flint; John D. Madsen

1995-01-01

332

Tubers as fallback foods and their impact on Hadza hunter-gatherers.  

PubMed

The Hadza are hunter-gatherers in Tanzania. Their diet can be conveniently categorized into five main categories: tubers, berries, meat, baobab, and honey. We showed the Hadza photos of these foods and asked them to rank them in order of preference. Honey was ranked the highest. Tubers, as expected from their low caloric value, were ranked lowest. Given that tubers are least preferred, we used kilograms of tubers arriving in camp across the year as a minimum estimate of their availability. Tubers fit the definition of fallback foods because they are the most continuously available but least preferred foods. Tubers are more often taken when berries are least available. We examined the impact of all foods by assessing variation in adult body mass index (BMI) and percent body fat (%BF) in relation to amount of foods arriving in camp. We found, controlling for region and season, women of reproductive age had a higher %BF in camps where more meat was acquired and a lower %BF where more tubers were taken. We discuss the implications of these results for the Hadza. We also discuss the importance of tubers in human evolution. PMID:19350623

Marlowe, Frank W; Berbesque, Julia C

2009-12-01

333

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...

334

Betalains in red and yellow varieties of the Andean tuber crop ulluco (Ullucus tuberosus).  

PubMed

The betalain pigments in ulluco (Ullucus tuberosus), a tuberous crop native to the Andes, have been investigated for the first time using LC-DAD-ESI-MS-MS(2) analyses. Five red, yellow, and red-spotted accessions introduced into New Zealand as a new food crop plus two red tetraploid lines were investigated. Thirty-two different betalains were identified. Both the yellow and red tubers were rich in yellow betaxanthins, and the most prominent among the 20 identified were histidine-betaxanthin, arginine-betaxanthin and glutamine-betaxanthin. Arginine-betaxanthin has been reported to occur naturally only once before and was found in yellow ulluco but not in the red tubers. Twelve betacyanins were found in red tubers, with roughly 50% of this content being betanin/isobetanin. Betacyanin levels were up to 70 microg/g fresh weight in red tubers, but were below quantifiable levels in yellow tubers. Betaxanthin levels were up to 50 microg/g fresh weight in yellow tubers. Interference by betacyanins in measuring levels of betaxanthins by visible spectrophotometry is discussed. Low concentrations of betalains were detected in leaves, whereas stems contained total levels similar to the tubers, with dopamine-betaxanthin and betanin being the major pigments. This is the first report describing both the betacyanin and betaxanthin patterns in a plant from the Basellaceae family. PMID:18662012

Svenson, Johan; Smallfield, Bruce M; Joyce, Nigel I; Sansom, Catherine E; Perry, Nigel B

2008-09-10

335

Effect of resistant starch on the cooking quality of yam (Dioscorea spp.) and cassava (Manihot esculenta) based paste products.  

PubMed

Total starch (TS) and resistant starch (RS) contents in pasty edible product of mealy and hard cooking tubers of three yam varieties and four cassava varieties were determined to evaluate their contribution in their cooking quality. TS and RS contents appeared as the main components in determining yam cooking quality. Mealy cooking yam varieties were characterized by a significant higher TS content (75.2 ± 7.7 g/100 g d.m.) and lower RS content (13.8 ± 3.4 g/100 g d.m.) than hard cooking yam varieties, which, in contrast, contained less TS (61.7 ± 12.1 g/100 g d.m.) and particularly high RS (21.8 ± 9.9 g/100 g d.m.), possibly as a consequence of the prevalence of large granules (35-40 ?m) observed by light microscope. Conversely, TS and RS contents appeared not determinant on the cooking quality of cassava. Moreover, higher amylose contents were associated with substantially elevated percentages of RS in yam and cassava, and high RS content in samples modulates their pasting properties by reducing the peak viscosity and the breakdown and requiring higher temperature and longer time to the peak. PMID:23215529

Kouadio, Olivier Kouadio; N'dri, Denis Yao; Nindjin, Charlemagne; Marti, Alessandra; Casiraghi, Maria Cristina; Faoro, Franco; Erba, Daniela; Bonfoh, Bassirou; Amani, N'guessan Georges

2013-06-01

336

Tuber Water and Pressure Potentials Decrease and Sucrose Contents Increase in Response to Moderate Drought and Heat Stress  

Technology Transfer Automated Retrieval System (TEKTRAN)

Environmental stress during the growing season can reduce the quality of stored Solanum tuberosum (potato) tubers. Sugar end defect is a serious quality concern for growers and processors of russet potatoes that is initiated by drought or heat stress. Changes in tuber water potential and tuber compo...

337

Development and characterization of starch nanoparticles by gamma radiation: potential application as starch matrix filler.  

PubMed

Gamma radiation arises as an advantageous alternative to obtain starch nanoparticles given its low cost, simple methodology and scalability. Starch nanoparticles (SNP) with sizes around 20 and 30 nm were obtained applying a dose of 20 kGy from cassava (CNP-?) and waxy maize (WNP-?) starch, respectively. They showed the same thermal degradation behavior and their maximum mass loss zone was similar to those nanoparticles obtained from acid hydrolysis (WNP-h). Additionally, CNP-? and WNP-? were used as nanofillers in a cassava matrix. Increments of 102% in storage modulus were obtained with the addition of only 2.5 wt.% of WNP-?, showing that gamma radiation is a successful methodology to obtain SNP able to be used as starch reinforcement. PMID:23769521

Lamanna, Melisa; Morales, Noé J; García, Nancy Lis; Goyanes, Silvia

2013-08-14

338

Edible canna ( Canna edulis) as a complementary starch source to cassava for the starch industry  

Microsoft Academic Search

Edible canna (Canna edulis Ker) as an alternative starch source was evaluated on the basis of genetic characteristics, agronomic traits and starch properties. Four canna varieties indigenous to Thailand were examined including Thai-green, Japanese-green, Thai-purple and Chinese-purple and compared with cassava (Manihot esculenta Crantz). Using the Random Amplified Polymorphic DNA (RAPD) technique employing ten 10-base primers, four primers implied that

Kuakoon Piyachomkwan; Sunee Chotineeranat; Chukiet Kijkhunasatian; Ratchata Tonwitowat; Siripatr Prammanee; Christopher G Oates; Klanarong Sriroth

2002-01-01

339

Refractive Errors and Strabismus in Children With Tuberous Sclerosis: A Controlled Study  

PubMed Central

Purpose To evaluate the prevalence of refractive errors and strabismus in children with tuberous sclerosis and in control subjects. Methods Twenty-three children with tuberous sclerosis and 151 control subjects were evaluated. All children underwent cycloplegic autorefraction or retinoscopy, slit-lamp biomicroscopy, and dilated fundus examination. Ocular alignment was assessed by the Hirschberg, Krimsky, or prism cover test. Results The total prevalence of hypermetropia and amblyopia was significantly higher in patients with tuberous sclerosis (p = .035) than in the control subjects (p = .002). Conclusion A high prevalence of hypermetropia seems to be an additional feature of tuberous sclerosis. Early screening for this amblyogenic factor is indicated in patients with tuberous sclerosis. PMID:19928739

Akinci, Arsen; Oner, Ozgur; Guven, Alev; Degerliyurt, Aydan; Munir, Kerim

2014-01-01

340

Transcriptome analysis reveals novel genes potentially involved in photoperiodic tuberization in potato.  

PubMed

Potato microtuber produced in vitro provides a model system to investigate photoperiod-dependent tuberization. However, the genes associated with potato tuberization remain to be elucidated. The present research involved three potato clones with distinct tuberization response to changes of photoperiod. Digital Gene Expression (DGE) Tag Profiling analysis of the short-day-sensitive clone identified 2218 genes that were regulated by day length. Both GO and KEGG pathway analysis provided insights into predominant biological processes and pathways, and enabled the selection of 56 genes associated with circadian rhythmicity, signal transduction, and development. Quantitative transcriptional analysis in the selected clones revealed 5 genes potentially associated with photoperiodic tuberization, which were predicted to encode a DOF protein, a blue light receptor, a lectin, a syntaxin-like protein, and a protein with unknown function. Our results strongly suggest that potato tuberization may be largely controlled by the homologs of genes shown to regulate flowering time in other plants. PMID:23856342

Shan, Jianwei; Song, Wei; Zhou, Jun; Wang, Xiaohuan; Xie, Conghua; Gao, Xiaoxi; Xie, Tingting; Liu, Jun

2013-10-01

341

A role for symplastic gating in the control of the potato tuber life cycle.  

PubMed

The control of the potato tuber life cycle has been the subject of significant interest over many years. A number of different approaches have been adopted and data is available regarding hormonal, metabolic and gene expression changes that occur over the tuber life cycle. Despite this intense effort, no unifying model for the control of the potato tuber life cycle has emerged. We have undertaken a detailed analysis of the tuber life cycle utilising physiological, biochemical and cell-biological techniques. It has emerged that a major factor contributing to both tuber induction and dormancy break is symplastic gating which controls the allocation of resources to meristematic or vegetative tissues. Future challenges include the determination of factors regulating symplastic gating at the molecular level and the extrapolation of these findings to other systems. PMID:19704762

Hancock, Robert D; Roberts, Alison G; Viola, Roberto

2008-01-01

342

Can loss of apical dominance in potato tuber serve as a marker of physiological age?  

PubMed

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

Eshel, Dani; Teper-Bamnolker, Paula

2012-09-01

343

Can loss of apical dominance in potato tuber serve as a marker of physiological age?  

PubMed Central

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

Eshel, Dani; Teper-Bamnolker, Paula

2012-01-01

344

Potential for treatment of severe autism in tuberous sclerosis complex  

PubMed Central

The Food and Drug Administration (FDA) has approved two mechanism-based treatments for tuberous sclerosis complex (TSC)-everolimus and vigabatrin. However, these treatments have not been systematically studied in individuals with TSC and severe autism. The aim of this review is to identify the clinical features of severe autism in TSC, applicable preclinical models, and potential barriers that may warrant strategic planning in the design phase of clinical trial development. A comprehensive search strategy was formed and searched across PubMed, Embase and SCOPUS from their inception to 2/21/12, 3/16/12, and 3/12/12 respectively. After the final search date, relevant, updated articles were selected from PubMed abstracts generated electronically and emailed daily from PubMed. The references of selected articles were searched, and relevant articles were selected. A search of clinicaltrials.gov was completed using the search term “TSC” and “tuberous sclerosis complex”. Autism has been reported in as many as 60% of individuals with TSC; however, review of the literature revealed few data to support clear classification of the severity of autism in TSC. Variability was identified in the diagnostic approach, assessment of cognition, and functional outcome among the reviewed studies and case reports. Objective outcome measures were not used in many early studies; however, diffusion tensor imaging of white matter, neurophysiologic variability in infantile spasms, and cortical tuber subcategories were examined in recent studies and may be useful for objective classification of TSC in future studies. Mechanism-based treatments for TSC are currently available. However, this literature review revealed two potential barriers to successful design and implementation of clinical trials in individuals with severe autism-an unclear definition of the population and lack of validated outcome measures. Recent studies of objective outcome measures in TSC and further study of applicable preclinical models present an opportunity to overcome these barriers. PMID:25254170

Gipson, Tanjala T; Gerner, Gwendolyn; Wilson, Mary Ann; Blue, Mary E; Johnston, Michael V

2013-01-01

345

Resistant Starch: Promise for Improving Human Health12  

PubMed Central

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. PMID:24228189

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.

2013-01-01

346

[Inheritance analysis of resistant starch content in kernels of wheat].  

PubMed

In this study, three wheat (Triticum aestivum L.) cultivars with high and low levels of resistant starch contents each were selected to obtain 15 F1 combinations from a diallel cross without reciprocals to be used to study the inheritance of resistant starch content. The results of this study are useful to select new wheat cultivar with high level of resistant starch content. Annong 90202 and D68-20 were the best among the wheat cultivars tested for general combining ability of resistant starch content, which significantly increased the resistant starch content in its progenies. The specific combining ability of Annong 90202 x 04 Dan 28 and 06-5 x D68-20 were the best among the F1 combinations, and the values of specific combining ability effects were significantly higher than other combinations. The inheritance of resistant starch content fitted the additive-dominance model, and the degree of dominance was super dominance. The alleles for increasing resistant starch content were recessive. The distribution of alleles for increasing and reducing resistant starch contents in the parental lines was not even. The number of recessive alleles for resistant starch content was greater than the dominant alleles. Annong 90202 and 04 Dan 28 had more recessive genes controlling resistant starch content, while Ningchun 18 and Xinchun 5 had more dominant genes. The narrow sense heritability of resistant starch content was 36.49%. PMID:20176562

Pang, Huan; Li, Wei-Hua; Zhang, Hong-Bin; Wang, Lin; Yin, Yong-An; Yuan, Hui-Gong; Wang, Zi-Bu

2010-02-01

347

Iodine catalyzed acetylation of starch and cellulose  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch and cellulose, earth's most abundant biopolymers, are of tremendous economic importance. Over 90% of cotton and 50% of wood are made of cellulose. Wood and cotton are the major resources for all cellulose products such as paper, textiles, construction materials, cardboard, as well as such c...

348

Swelling and Gelatinization of Oat Starches  

Microsoft Academic Search

A comparison was made between the structure and physicochemical properties of starches extracted from five normal and one naked cultivar of oat. There was little difference in the molecular size or polydispersity of the native amylose and amylopectin determined by gel permeation chromatography (GPC), or in the unit chain distribution of isoamylase- debranched amylopectin, where three peaks were resolved at

RICHARD F. TESTER; JOHN KARKALAS

349

Heat expanded starch-based compositions  

Technology Transfer Automated Retrieval System (TEKTRAN)

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 their open-cell structure precluded them from expanding further when heated. Non-porous beads, p...

350

Starch: chemistry, microstructure, processing and enzymatic degradation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch is recognized as one of the most abundant and important commodities containing value added attributes for a vast number of industrial applications. Its chemistry, structure, property and susceptibility to various chemical, physical and enzymatic modifications offer a high technological value ...

351

Branching patterns in leaf starches from Arabidopsis mutants deficient in diverse starch synthases.  

PubMed

This is the first report on the cluster structure of transitory starch from Arabidopsis leaves. In addition to wild type, the molecular structures of leaf starch from mutants deficient in starch synthases (SS) including single enzyme mutants ss1-, ss2-, or ss3-, and also double mutants ss1-ss2- and ss1-ss3- were characterized. The mutations resulted in increased amylose content. Clusters from whole starch were isolated by partial hydrolysis using ?-amylase of Bacillus amyloliquefaciens. The clusters were then further hydrolyzed with concentrated ?-amylase of B. amyloliquefaciens to produce building blocks (?-limit dextrins). Structures of the clusters and their building blocks were characterized by chromatography of samples before and after debranching treatment. While the mutations increased the size of clusters, the reasons were different as reflected by the composition of their unit chains and building blocks. In general, all mutants contained more of a-chains that preferentially increased the number of small building blocks with only two chains. The clusters of the double mutant ss1-ss3- were very large and possessed also more of large building blocks with four or more chains. The results from transitory starch are compared with those from agriculturally important crops in the context that to what extent the Arabidopsis can be a true biotechnological reflection for starch modifications through genetic means. PMID:25464087

Zhu, Fan; Bertoft, Eric; Szydlowski, Nicolas; d'Hulst, Christophe; Seetharaman, Koushik

2015-01-12

352

Characterization of normal and waxy corn starch for bioethanol production.  

PubMed

Objectives of this study were to compare ethanol production between normal and waxy corn using a cold fermentation process and to understand effects of starch structures and properties on ethanol production. Ethanol yields positively correlated (p < 0.01) with starch contents of kernels of the normal and waxy corn. The average starch-ethanol conversion efficiency of waxy corn (93.0%) was substantially greater than that of normal corn (88.2%). Waxy corn starch consisted of very little amylose and mostly amylopectin that had a shorter average branch chain length than normal corn amylopectin. Regression analyses showed that average amylopectin branch chain lengths and percentage of long branch chains (DP > 37) of waxy corn starch negatively correlated with the starch hydrolysis rate and the ethanol yield. These results indicated that starch structures and properties of the normal and waxy corn had significant effects on the ethanol yield using a cold fermentation process. PMID:23241103

Yangcheng, Hanyu; Jiang, Hongxin; Blanco, Michael; Jane, Jay-lin

2013-01-16

353

Psychosis with obsessive-compulsive symptoms in tuberous sclerosis.  

PubMed

We present a case of tuberous sclerosis complex (TSC) diagnosed in adulthood in a man initially referred for specialist neuropsychiatric assessment with psychosis and obsessive-compulsive symptoms (OCS) on a background of epilepsy and intellectual disability. To our knowledge, this is the first reported patient with TSC featuring both psychosis and OCS. This patient highlights the importance of comprehensive re-evaluation of atypical presentations of intellectual disability, epilepsy and associated neuropsychiatric symptoms, even in adulthood. This is particularly relevant in the context of significant advances in genetics, neuroscience, imaging and treatments for heritable neurogenetic disorders. PMID:24211143

Hassan, Islam K; Looi, Jeffrey C L; Velakoulis, Dennis; Gaillard, Frank; Lui, Elaine H; O'Brien, Terence J; French, Chris; Le Heron, Campbell; Adams, Sophia J

2014-05-01

354

[Chemical constituents from the tuber of Cremastra appendiculata].  

PubMed

To study the chemical constituents of "Shan-Ci-Gu" (the tuber of Cremastra appendiculata (D. Don) Makino), the compounds were isolated with silica gel and reverse phase silica gel as well as Sephadex column chromatographic method. Their structures were elucidated on the basis of modern spectra technology. Seven compounds were isolated and identified as 5-methoxybibenzyl-3, 3'-di-O-beta-D-glucopyranoside (1), militarine (2), loroglossin (3), protocatechuic acid (4), succinic acid (5), gastrodin (6), and daucosterol (7). Compound 1 is a new compound. Compounds 2 -6 were isolated from this plant for the first time. PMID:18507346

Liu, Jing; Yu, Zhi-Bin; Ye, Yun-Hua; Zhou, Ya-Wei

2008-02-01

355

Steroidal saponins from the tuber of Ophiopogon japonicus.  

PubMed

Eight novel steroidal saponins, ophiopogonins H-O (1-8), along with seven known steroidal saponins (9-15) were isolated from the tubers of Ophiopogon japonicus. The structures of these new compounds were determined by detailed spectroscopic analysis, including extensive 1D and 2D NMR data, and the analysis of hydrolytic reaction products. For the first time, rare furostanol saponins with disaccharide moiety linked at position C-26 of the aglycone were reported to be isolated from a natural source. PMID:22562001

Zhang, Tao; Kang, Li-Ping; Yu, He-Shui; Liu, Yi-Xun; Zhao, Yang; Xiong, Cheng-Qi; Zhang, Jie; Zou, Peng; Song, Xin-Bo; Liu, Chao; Ma, Bai-Ping

2012-10-01

356

Wound-Induced Membrane Lipid Breakdown in Potato Tuber 1  

PubMed Central

Freshly cut slices of potato tuber show an extensive loss of membrane lipid components which may be as great as 35% for phospholipids and 30% for glycolipids, in less than 15 minutes at 3 C. Phosphatidyl-choline, phosphatidyl-ethanolamine and mono- and di-galactosyl diglycerides comprise the bulk of the lipids that are degraded. Concomitantly, there is a pronounced loss of linoleic and linolenic acids. Whereas degradative events elicited by slicing proceed to a depth of at least 10 millimeters from the surface, phospholipid biosynthesis, as well as the development of the wound induced respiration and cyanide resistance on aging, are restricted to the superficial 1 millimeter. PMID:16661889

Theologis, Athanasios; Laties, George G.

1981-01-01

357

Localization of the Epileptogenic Foci in Tuberous Sclerosis Complex: A Pediatric Case Report  

PubMed Central

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 surrounding the tuber rather than the tuber itself. PMID:24723876

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

358

Continuous enzymatic liquefaction of starch for saccharification  

SciTech Connect

A process was explored for continuous enzymatic liquefaction of corn starch at high concentration and subsequent saccharification to glucose. The process appears to be quite efficient for conversion of starch to glucose and enzymatic liquefaction and should be readily adaptable to industrial fermentation processes. Preliminary work indicated that milled corn or other cereal grains also can be suitably converted by such a process. Essentially, the process involved incorporation of a thermostable, bacterial alpha-amylase for liquefaction and, subsequently, of a glucoamylase into the continuous mixer under conditions conductive to rapid enzymatic hydrolyses. Also studied was the effect on substrate liquefaction of variables such as starch concentration (40-70%), level of alpha-amylase (0.14-0.4%, dry starch basis), temperature (70-100 degrees C), pH (5.8-7.1), and residence time (6 and 12 minutes). The degree of liquefaction was assessed by determining 1) the Brookfield viscosity, 2) the amount of reducing groups, and 3) the rate and extent of glucose formed after glucoamylase treatment. Best liquefaction processing conditions were achieved by using 50-60% starch concentration, at 95 degrees C, with 0.4% alpha-amylase, and a 6 minute residence period in the mixer. Under these conditions, rates and extents of glucose obtained after glucoamylase treatment approached those obtained in longer laboratory batch liquefactions. The amount of glucose formed in 24 hours with the use of 0.4% glucoamylase was 86% of theory after a 6-min continuous liquefaction, compared to 90% for a 30-min laboratory batch liquefaction (95 degrees C, 0.4% alpha-amylase). (Refs. 15).

Carr, M.E.; Black, L.T.; Bagby, M.O.

1982-01-01

359

Color Burst  

NSDL National Science Digital Library

This lesson will help students gain experience in asking questions and conducting inquiry by exploring the separation of colors in water and other solvents; and to communicate and share findings of student investigations. The lesson uses a technique called paper chromatography, which is demonstrated using water, ink, and a coffee filter. Scientists use chromatography frequently to separate and identify the component parts of a mixture. This lesson will help young students gain experience in conducting simple investigations of their own while working in small groups.

360

Structure, morphology and functionality of acetylated and oxidised barley starches.  

PubMed

Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical-chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production. PMID:25172707

El Halal, Shanise Lisie Mello; Colussi, Rosana; Pinto, Vânia Zanella; Bartz, Josiane; Radunz, Marjana; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2015-02-01

361

Selected properties of acetylated adipate of retrograded starch.  

PubMed

Native potato starch (NS) and retrograded starch (R - obtained via freezing and defrosting of a starch paste) were used to prepare starch acetates: NS-A and R-A, and then acetylated distarch adipates: NS-ADA and R-ADA. The chemically-modified preparations produced from retrograded starch (R-A; R-ADA) were characterized by a higher degree of esterification compared to the modified preparations produced under the same conditions from native potato starch (NS-A; NS-ADA). Starch resistance to amylolysis was observed to increase (to 30-40 g/100 g) as a result of starch retrogradation and acetylation. Starch cross-linking had a significant impact on the increased viscosity of the paste in the entire course of pasting characteristics and on the increased values of rheological coefficients determined from the equations describing flow curves. The produced preparation of acetylated retrograded starch cross-linked with adipic acid (R-ADA) may be deemed an RS3/4 preparation to be used as a food thickening agent. PMID:24274559

Zi?ba, T; Gryszkin, A; Kapelko, M

2014-01-01

362

Starch bioengineering affects cereal grain germination and seedling establishment  

PubMed Central

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. PMID:24642850

Hebelstrup, Kim H.; Blennow, Andreas

2014-01-01

363

Starch bioengineering affects cereal grain germination and seedling establishment.  

PubMed

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment. PMID:24642850

Shaik, Shahnoor S; Carciofi, Massimiliano; Martens, Helle J; Hebelstrup, Kim H; Blennow, Andreas

2014-06-01

364

Structural properties and gelatinisation characteristics of potato and cassava starches and mutants thereof  

Microsoft Academic Search

The molecular size of amylopectin (AP) and amylose (AM), AP chain length distribution, crystallinity and granular structure (morphology and granule size distribution) of five wild type potato starches (wtps), five AM free potato starches (amfps), four high-AM potato starches (haps), one wild type cassava starch (wtcs) and one AM free cassava starch (amfcs) were investigated and related to their gelatinisation

S. V. Gomand; L. Lamberts; L. J. Derde; H. Groesaert; G. E. Vandeputte; B. Goderis; R. G. F. Visser; J. A. Delcour

2010-01-01

365

Cryo-milling of starch granules leads to differential effects on molecular size and conformation  

Microsoft Academic Search

Milling of starch granules is important for many food applications and involves a combination of mechanical and thermal energy. In order to understand the effects of mechanical force alone, four commercial starches including maize starch (MS), potato starch (PS), and two high amylose maize starches (HAMS) (Gelose 50 and Gelose 80) were cryo-milled for 20min under the same conditions. The

Sushil Dhital; Ashok K. Shrestha; Bernadine M. Flanagan; Jovin Hasjim; Michael J. Gidley

2011-01-01

366

Acid hydrolysis of native and annealed starches and branch-structure of their Naegeli dextrins  

Microsoft Academic Search

Eight commercial starches, including common corn, waxy corn, wheat, tapioca, potato, Hylon V, Hylon VII, and mung bean starch, were annealed by a multiple-step process, and their gelatinization characteristics were determined. Annealed starches had higher gelatinization temperatures, reduced gelatinization ranges, and increased gelatinization enthalpies than their native starches. The annealed starches with the highest gelatinization enthalpies were subjected to acid

Yuta Nakazawa; Ya-Jane Wang

2003-01-01

367

Properties of foam and composite materials made o starch and cellulose fiber  

Technology Transfer Automated Retrieval System (TEKTRAN)

Composite materials were made of starch and cellulose fibers. Pre-gelatinized starch was effective in dispersing pulp fiber in a starch matrix to form a viscous starch/fiber dough. The starch/fiber dough was a useful feedstock for various composite foam and plastic materials. Viscous blends of star...

368

Properties and applications of starch-converting enzymes of the ?-amylase family  

Microsoft Academic Search

Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. A large-scale starch processing industry has emerged in the last century. In the past decades, we have seen a shift from the acid hydrolysis of starch to the use of starch-converting enzymes in the production of maltodextrin, modified starches, or glucose

Marc J. E. C. van der Maarel; Bart van der Veen; Joost C. M. Uitdehaag; Hans Leemhuis; L. Dijkhuizen

2002-01-01

369

Resistance to Multiple Tuber Diseases Expressed in Somaclonal Variants of the Potato Cultivar Russet Burbank  

PubMed Central

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

Thangavel, Tamilarasan; Steven Tegg, Robert; Wilson, Calum Rae

2014-01-01

370

A critical appraisal of phloem-mobile signals involved in tuber induction  

PubMed Central

The identification of FLOWERING LOCUS T (FT) and several FT homologs as phloem-mobile proteins that regulate flowering has sparked the search for additional homologs involved in the long-distance regulation of other developmental processes. Given that flowering and tuber induction share regulatory pathways, the quest for long-distance tuberization signals has been further stimulated. Several tuberization regulators have been proposed as mobile molecules, including the FT family protein StSP6A, the plant growth regulators gibberellins and the microRNA miR172. Although some of these hypotheses are attractive and plausible, evidence that these molecules are transmissible in potato has yet to be obtained. Two mRNAs encoding transcription factors, StBEL5 and POTATO HOMEOBOX 1 (POTH1), are mobile and correlate with tuber induction. However, evidence that StBEL5 or POTH1 are required for tuberization is not available yet. Therefore, there are several good candidates for long-distance molecules in the tuberization process. Further research should test their role as systemic tuberization signals. PMID:23882274

Suárez-López, Paula

2013-01-01

371

Cultivation of Mediterranean species of Tuber (Tuberaceae) in British Columbia, Canada.  

PubMed

Based on an assessment of soil and climatic conditions in British Columbia (BC), the Truffle Association of British Columbia (TABC) determined that the cultivation of Mediterranean Tuber melanosporum and Tuber aestivum might be possible in the warmer parts of the province. With the cooperation of independent truffle growers, TABC assessed the colonization of host tree roots collected from eight truffle orchards planted 2-7 years earlier using morphological and molecular criteria. Both Tuber species persisted on the roots of inoculated trees in six of the eight truffle orchards studied. The identity of Tuber ectomycorrhizas that had been characterized morphologically as differing from those of T. melanosporum and T. aestivum were determined using DNA sequence analysis to belong to three species of truffles native to the Pacific Northwest. One of those species, Tuber anniae, had been previously reported from BC, but the other two, Tuber menseri nom. prov. and Tuber beyerlei, are reported here from BC for the first time. Recently, production of three Périgord black truffles in one truffle orchard and one Burgundy truffle in another orchard demonstrates that these truffles are able to fruit in BC. PMID:24496857

Berch, Shannon M; Bonito, Gregory

2014-08-01

372

Identification of differentially expressed genes in potato associated with tuber dormancy release.  

PubMed

Potato (Solanum tuberosum L.) tuber dormancy and sprouting is very important to potato cultivation and processing. In the present experiment, suppression subtractive hybridization was employed to identify differentially expressed genes in potato associated with tuber dormancy release. 576 random clones were selected from subtractive library and successfully sequenced. A total of 304 effective expressed sequence tags (ESTs) were obtained ultimately. The ESTs have been deposited in the EMBL\\GenBank\\DDBJ nucleotide sequence data libraries under accession numbers from JK483901 to JK484204. GO annotation showed that 45, 34 and 3 % ESTs were associated with binding, catalytic activity and signaling respectively, some of which were confirmed to be involved in plant dormancy breaking, however, 14 % of the ESTs did not show significant homology to any database proteins. A real-time quantitative PCR (RT-qPCR) analysis of the expression patterns of 14 selectable transcripts showed that 13 selected candidate genes were significantly up-regulated in the development process of tuber from dormancy to sprouting. A full length cDNA of ADP-ribosylation factor (ARF) gene was cloned and found it belonged to potato ARF1 gene. Tissue specific expression analysis showed ARF1 expression level was the highest in tuber. RT-qPCR analysis of the expression profile of ARF1 gene from potato tuber dormancy to sprouting revealed that the ARF1 gene expression was significantly increased after tuber dormancy breaking, which suggested that it probably associated with tuber dormancy and sprouting. PMID:23065212

Liu, Bailin; Zhang, Ning; Wen, Yikai; Si, Huaijun; Wang, Di

2012-12-01

373

Mycorrhization of pecan trees (Carya illinoinensis) with commercial truffle species: Tuber aestivum Vittad. and Tuber borchii Vittad.  

PubMed

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. PMID:21986799

Benucci, Gian Maria Niccolò; Bonito, Gregory; Baciarelli Falini, Leonardo; Bencivenga, Mattia

2012-07-01

374

Diversity of culturable microorganisms and occurrence of Listeria monocytogenes and Salmonella spp. in Tuber aestivum and Tuber melanosporum ascocarps.  

PubMed

The aim of this study was to investigate the total mesophilic microorganisms, Pseudomonas genus, Enterobacteriaceae family, mold and yeast counts and the presence of Listeria monocytogenes and Salmonella spp on Tuber aestivum and Tuber melanosporum ascocarps. The results confirmed that the major percentage of the microorganisms, approximately 9.0 log ufc/g, were present in the peridium, the glebas of healthy truffles being practically free of microorganisms. The predominant microbial group was the Pseudomonas averaging 8.3 and 8.4 log cfu/g on T. aestivum and T. melanosporum whole ascocarps, respectively. The Enterobacteriaceae also achieved high populations, especially in T. aestivum truffles, with 6.3 log cfu/g. Molds and yeasts never exceeded 5.0 log cfu/g. The characterization of the isolates revealed that the fluorescens pseudomonads were the most prevalent. Raoultella terrigena and Enterobacter intermedius were the dominant Enterobacteriaceae. The identification of the yeast isolates revealed five species: Debaryomyces hansenii, Issatchenkia scutulata, Rhodotorula aurantiaca, Saccharomyces dairensis and Trichosporon beigelii subspecies A and B. The mold genera detected in both species of truffles were Aspergillus, Cladosporium, Penicillium and Fusarium, Trichoderma being present only in T. aestivum. L. monocytogenes was found in 10% of the samples of T. aestivum analysed but Salmonella spp. was not detected. Knowledge of the microbial population in terms of possible food borne and pathogen microorganisms is very useful for establishing successful disinfection and storage methods to prolong the shelf-life of ascocarps of T. aestivum and T. melanosporum. PMID:20141948

Rivera, Carmen Susana; Blanco, Domingo; Oria, Rosa; Venturini, María Eugenia

2010-04-01

375

Color Theory for Design  

NSDL National Science Digital Library

This lesson will introduce students to color theory with a focus on the use of color in digital design. Students will discover the color wheel, and color harmonies. Color is a very powerful tool in design. It can, enhance a message, give an object visual weight and emphasis, and add richness and depth to a design. We can use color to signify data, to draw attention to a particular object, or to set a mood. Color ...

Jensen, Mr.

2009-10-04

376

Learning About Color  

NSDL National Science Digital Library

In this project, students will learn about primary, secondary, and complementary colors. Students will also learn about warm & cool colors, along with tints & shades. Lastly, they will create an optical illusion using complimentary colors. INTRODUCTION: Welcome students! Begin by watching this fun video about colors. LEARNING ABOUT COLOR: Now, that you've had an introduction to colors, lets play a little game! Click on the link below. Carmine s Introduction to Color Awesome! Click on the links below ...

Whitni Erickson

2009-04-18

377

Starch biosynthesis in rice endosperm requires the presence of either starch synthase I or IIIa.  

PubMed

Starch synthase (SS) I and IIIa are the first and second largest components of total soluble SS activity, respectively, in developing japonica rice (Oryza sativa L.) endosperm. To elucidate the distinct and overlapping functions of these enzymes, double mutants were created by crossing the ss1 null mutant with the ss3a null mutant. In the F(2) generation, two opaque seed types were found to have either the ss1ss1/SS3ass3a or the SS1ss1/ss3ass3a genotype. Phenotypic analyses revealed lower SS activity in the endosperm of these lines than in those of the parent mutant lines since these seeds had different copies of SSI and SSIIIa genes in a heterozygous state. The endosperm of the two types of opaque seeds contained the unique starch with modified fine structure, round-shaped starch granules, high amylose content, and specific physicochemical properties. The seed weight was ?90% of that of the wild type. The amount of granule-bound starch synthase I (GBSSI) and the activity of ADP-glucose pyrophosphorylase (AGPase) were higher than in the wild type and parent mutant lines. The double-recessive homozygous mutant prepared from both ss1 and ss3a null mutants was considered sterile, while the mutant produced by the leaky ss1 mutant×ss3a null mutant cross was fertile. This present study strongly suggests that at least SSI or SSIIIa is required for starch biosynthesis in rice endosperm. PMID:21730357

Fujita, Naoko; Satoh, Rui; Hayashi, Aki; Kodama, Momoko; Itoh, Rumiko; Aihara, Satomi; Nakamura, Yasunori

2011-10-01

378

Structure of starch synthase I from barley: insight into regulatory mechanisms of starch synthase activity.  

PubMed

Starch, a polymer of glucose, is the major source of calories in the human diet. It has numerous industrial uses, including as a raw material for the production of first-generation bioethanol. Several classes of enzymes take part in starch biosynthesis, of which starch synthases (SSs) carry out chain elongation of both amylose and amylopectin. Plants have five classes of SS, each with different roles. The products of the reaction of SS are well known, but details of the reaction mechanism remain obscure and even less is known of how different SSs select different substrates for elongation, how they compete with each other and how their activities are regulated. Here, the first crystal structure of a soluble starch synthase is presented: that of starch synthase I (SSI) from barley refined to 2.7 Å resolution. The structure captures an open conformation of the enzyme with a surface-bound maltooligosaccharide and a disulfide bridge that precludes formation of the active site. The maltooligosaccharide-binding site is involved in substrate recognition, while the disulfide bridge is reflective of redox regulation of SSI. Activity measurements on several SSI mutants supporting these roles are also presented. PMID:23695246

Cuesta-Seijo, Jose A; Nielsen, Morten M; Marri, Lucia; Tanaka, Hidenori; Beeren, Sophie R; Palcic, Monica M

2013-06-01

379

Tuberous Sclerosis and Cardiac Tumors: New Electrocardiographic Finding in an Infant  

PubMed Central

Cardiac rhabdomyoma, the primary cardiac tumor most often diagnosed in children, is frequently present in patients with tuberous sclerosis. Most pediatric patients with rhabdomyoma are asymptomatic; however, various electrocardiographic abnormalities can be detected, such as Wolff-Parkinson-White syndrome, ectopic atrial tachycardia, and atrioventricular node dysfunction. We describe the case of a 10-month-old infant girl who had tuberous sclerosis and multiple cardiac rhabdomyomas. Her electrocardiographic presentation was notable for dome-shaped T waves and no ST segment in some leads. To our knowledge, this electrocardiographic finding has not been described in patients with tuberous sclerosis and cardiac masses. PMID:25425989

Sap, Fatih; Sert, Ahmet; Odabas, Dursun

2014-01-01

380

Tuberous sclerosis and cardiac tumors: new electrocardiographic finding in an infant.  

PubMed

Cardiac rhabdomyoma, the primary cardiac tumor most often diagnosed in children, is frequently present in patients with tuberous sclerosis. Most pediatric patients with rhabdomyoma are asymptomatic; however, various electrocardiographic abnormalities can be detected, such as Wolff-Parkinson-White syndrome, ectopic atrial tachycardia, and atrioventricular node dysfunction. We describe the case of a 10-month-old infant girl who had tuberous sclerosis and multiple cardiac rhabdomyomas. Her electrocardiographic presentation was notable for dome-shaped T waves and no ST segment in some leads. To our knowledge, this electrocardiographic finding has not been described in patients with tuberous sclerosis and cardiac masses. PMID:25425989

Aslan, Eyup; Sap, Fatih; Sert, Ahmet; Odabas, Dursun

2014-09-01

381

Functional Properties of Extruded Starch Acetate Blends  

Microsoft Academic Search

Starch acetate, with degree of substitution of 2, was blended with 0, 7.5 and 15% polylactic acid (PLA), Eastar Bio Copolyester 14766 (EBC) or Mater-Bi ZF03U (MBI) and 10%, 13%, or 16% (d.b.) ethanol and twin-screw extruded at 160°C barrel temperature. Physical characteristics of the extrudates, such as radial expansion ratio, unit and bulk densities, and of the mechanical properties,

J. Guan; Q. Fang; M. A. Hanna

2004-01-01

382

Processing of porous ceramics by ‘starch consolidation’  

Microsoft Academic Search

A new consolidation method for forming porous ceramics was developed using starch as both consolidator\\/binder and pore former. Simple and complex-shaped components of porous alumina were shaped and demoulded in wet state. After drying, burn-out and sintering, materials with ultimate porosities between 23 and 70% were obtained. The overall pore structures were dominated by the large spherically shaped pores (10–80

O. Lyckfeldt; J. M. F. Ferreira

1998-01-01

383

Evaluation of porous starch as a flavour carrier.  

PubMed

A commercial porous starch was evaluated for the use as a carrier for liquid flavours. Encapsulation trials performed with diacetyl showed a high initial load and good retention over time when more polar solvents commonly used in flavour creation were used. The physical interactions between the porous starch and solvents used in flavour creation were also studied. The glass transition temperature of the starch decreased upon addition of the polar solvents, ethanol and propylene glycol. Propylene glycol also produced an exothermic peak when mixed with porous starch, possibly due to the formation of complexes between the two components. Low resolution (1)H-NMR results suggested that a stronger interaction was established between more polar solvents and the porous starch, as indicated by a more marked decrease in relaxation times and proton diffusion coefficient of the solvents on adding porous starch. PMID:22143753

Belingheri, Claudia; Curti, Elena; Ferrillo, Antonio; Vittadini, Elena

2012-03-01

384

Soybean cotyledon starch metabolism is sensitive to altered gravity conditions  

NASA Technical Reports Server (NTRS)

We have demonstrated that etiolated soybean seedlings grown under the altered gravity conditions of clinorotation (1 rpm) and centrifugation (5xg) exhibit changes in starch metabolism. Cotyledon starch concentration was lower (-28%) in clinorotated plants and higher (+24%) in centrifuged plants than in vertical control plants. The activity of ADP-glucose pyrophosphorylase in the cotyledons was affected in a similar way, i.e. lower (-37%) in the clinorotated plants and higher (+22%) in the centrifuged plants. Other starch metabolic enzyme activities, starch synthase, starch phosphorylase and total hydrolase were not affected by the altered gravity treatments. We conclude that the observed changes in starch concentrations were primarily due to gravity-mediated differences in ADP-glucose pyrophosphorylase activity.

Brown, C. S.; Piastuch, W. C.; Knott, W. M.

1994-01-01

385

Development of highly-transparent protein/starch-based bioplastics.  

PubMed

Striving to achieve cost-competitive biomass-derived materials for the plastics industry, the incorporation of starch (corn and potato) to a base formulation of albumen and glycerol was considered. To study the effects of formulation and processing, albumen/starch-based bioplastics containing 0-30 wt.% starch were prepared by thermo-plastic and thermo-mechanical processing. Transmittance measurements, DSC, DMTA and tensile tests were performed on the resulting bioplastics. Optical and tensile properties were strongly affected by starch concentration. However, DMTA at low deformation proved to be insensitive to starch addition. Thermo-mechanical processing led to transparent albumen/starch materials with values of strength at low deformation comparable to commodity plastics. Consequently, albumen biopolymers may become a biodegradable alternative to oil-derived plastics for manufacturing transparent packaging and other plastic stuffs. PMID:19900806

Gonzalez-Gutierrez, J; Partal, P; Garcia-Morales, M; Gallegos, C

2010-03-01

386

Enzymatic transformation of nonfood biomass to starch.  

PubMed

The global demand for food could double in another 40 y owing to growth in the population and food consumption per capita. To meet the world's future food and sustainability needs for biofuels and renewable materials, the production of starch-rich cereals and cellulose-rich bioenergy plants must grow substantially while minimizing agriculture's environmental footprint and conserving biodiversity. Here we demonstrate one-pot enzymatic conversion of pretreated biomass to starch through a nonnatural synthetic enzymatic pathway composed of endoglucanase, cellobiohydrolyase, cellobiose phosphorylase, and alpha-glucan phosphorylase originating from bacterial, fungal, and plant sources. A special polypeptide cap in potato alpha-glucan phosphorylase was essential to push a partially hydrolyzed intermediate of cellulose forward to the synthesis of amylose. Up to 30% of the anhydroglucose units in cellulose were converted to starch; the remaining cellulose was hydrolyzed to glucose suitable for ethanol production by yeast in the same bioreactor. Next-generation biorefineries based on simultaneous enzymatic biotransformation and microbial fermentation could address the food, biofuels, and environment trilemma. PMID:23589840

You, Chun; Chen, Hongge; Myung, Suwan; Sathitsuksanoh, Noppadon; Ma, Hui; Zhang, Xiao-Zhou; Li, Jianyong; Zhang, Y-H Percival

2013-04-30

387

Enzymatic transformation of nonfood biomass to starch  

PubMed Central

The global demand for food could double in another 40 y owing to growth in the population and food consumption per capita. To meet the world’s future food and sustainability needs for biofuels and renewable materials, the production of starch-rich cereals and cellulose-rich bioenergy plants must grow substantially while minimizing agriculture’s environmental footprint and conserving biodiversity. Here we demonstrate one-pot enzymatic conversion of pretreated biomass to starch through a nonnatural synthetic enzymatic pathway composed of endoglucanase, cellobiohydrolyase, cellobiose phosphorylase, and alpha-glucan phosphorylase originating from bacterial, fungal, and plant sources. A special polypeptide cap in potato alpha-glucan phosphorylase was essential to push a partially hydrolyzed intermediate of cellulose forward to the synthesis of amylose. Up to 30% of the anhydroglucose units in cellulose were converted to starch; the remaining cellulose was hydrolyzed to glucose suitable for ethanol production by yeast in the same bioreactor. Next-generation biorefineries based on simultaneous enzymatic biotransformation and microbial fermentation could address the food, biofuels, and environment trilemma. PMID:23589840

You, Chun; Chen, Hongge; Myung, Suwan; Sathitsuksanoh, Noppadon; Ma, Hui; Zhang, Xiao-Zhou; Li, Jianyong; Zhang, Y.-H. Percival

2013-01-01

388

Physicochemical studies of starch from foxtail millet ( Setaria italica Beauv.)  

Microsoft Academic Search

Properties of starch granules prepared from 53 varieties of foxtail millet were examined by scanning electron microscopy, amperometric iodine titrimetry and differential scanning calorimetry. The granular size of the starches ranged from 6.8 to 11.8 ?m in diameter on average. The wavelength at maximum absorption (?max) for iodine-starch complexes ranged from 579 to 600 nm and blue values (absorbance at

S Fujita; Y Sugimoto; Y Yamashita; H Fuwa

1996-01-01

389

Development of highly-transparent protein\\/starch-based bioplastics  

Microsoft Academic Search

Striving to achieve cost-competitive biomass-derived materials for the plastics industry, the incorporation of starch (corn and potato) to a base formulation of albumen and glycerol was considered. To study the effects of formulation and processing, albumen\\/starch-based bioplastics containing 0–30wt.% starch were prepared by thermo-plastic and thermo-mechanical processing. Transmittance measurements, DSC, DMTA and tensile tests were performed on the resulting bioplastics.

J. Gonzalez-Gutierrez; P. Partal; M. Garcia-Morales; C. Gallegos

2010-01-01

390

Physicochemical Characteristics as Indicators of Starch Availability from Milled Rice  

Microsoft Academic Search

The hypothesis was tested that certain physico-chemical characteristics might be used as indicators of total starch availability and rate of starch availability of milled rice. Milled unparboiled (uPB) and parboiled (PB) rice samples (n=93) were characterized using standardized methods of physical tests and chemical analyses and anin vitromethod was used for measuring the rate of starch digestion on a subsample

I. Tetens; S. K. Biswas; L. V. Glitsø; K. A. Kabir; S. H. Thilsted; N. H. Choudhury

1997-01-01

391

Enhancement of Sucrose Sweetness with Soluble Starch in Humans  

Microsoft Academic Search

The effect of soluble starch (acid-modified starch) on taste intensity was investigated in human subjects. Different concentrations of sucrose (Suc), six sweeteners, NaCl, quinine-HCl (QHCl) and citric acid (Cit) were dissolved in either distilled water (DW; standard) or starch solution (test solution). The solutions were presented to naive subjects and each subject was requested to taste and compare the sweetness

Norikazu Kanemaru; Shuitsu Harada; Yasuo Kasahara

2002-01-01

392

Inhibition of bacilli in industrial starches by nisin  

Microsoft Academic Search

  The properties of Bacillus coagulans and of other bacilli that contaminate paper and paperboard manufacturing processes were investigated under simulated industrial\\u000a conditions. Nisin (0.05 to 0.125 ?2g ml?1) blocked growth of indigenous bacilli that contaminate sizing starches. B. coagulans starch isolates, B. licheniformis, B. amyloliquefaciens, and B. stearothermophilus grew at ?250C in industrial starch and produced ?2-glucosidase and cyclodextrins. The

T S M Pirttijärvi; G Wahlström; F A Rainey; P E J Saris; M S Salkinoja-Salonen

2001-01-01

393

Effect of dry heating with ionic gums on physicochemical properties of starch.  

PubMed

Corn starch, potato starch, pea starch were impregnated with ionic gums (sodium alginate, CMC, and xanthan, 1% based on starch solids) and heat-treated in a dry state for 0, 2, or 4 h at 130°C. Effects of the dry heating on paste viscosity (RVA), microstructure and thermal properties were examined. Dry heat treatment with ionic gums reduced the pasting temperature of the three starches. Heating with xanthan increased the paste viscosity of corn and potato starch. With heat treatment, the paste viscosity of all the starch-sodium alginate mixtures decreased. Heating with CMC increased the paste viscosity of potato starch, but decreased that of corn and pea starch. After dry-heating, To, Tp and Tc of potato starch with ionic gums decreased significantly. SEM of potato starch with CMC showed that the gel structure got compacter after drying-heating. Heat treatment obviously improved the functional properties of the three starches. PMID:23194543

Sun, Qingjie; Si, Fumei; Xiong, Liu; Chu, Lijun

2013-02-15

394

40 CFR 427.30 - Applicability; description of the asbestos paper (starch binder) subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the asbestos paper (starch binder) subcategory. 427...MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Starch Binder) Subcategory § 427...Applicability; description of the asbestos paper (starch binder) subcategory....

2010-07-01

395

New data on ectomycorrhizae and soils of the Chinese truffles Tuber pseudoexcavatum and Tuber indicum, and their impact on truffle cultivation.  

PubMed

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. PMID:18813959

García-Montero, Luis G; Di Massimo, Gabriella; Manjón, José L; García-Abril, Antonio

2008-12-01

396

Novel Resistant Potato Starches on Glycemia and Satiety in Humans  

PubMed Central

This study was designed to determine the efficacy of two novel type-four resistant starches (RS4) on postprandial glycemia and ratings of fullness. Volunteers (n = 10) completed completed five interventions designed to determine the glycemic and satiety (fullness) effects of the starches (38?g,) alone and when added on top of available carbohydrate. The dose of the starches provided 30?g of resistant starch per treatment. The treatments were: commercial resistant starch added to water (PF?), noncommercial resistant starch added to water (PR?), dextrose solution (DEX, 50?g), and DEX with PenFibe starch (PF+), and DEX with the non-commercial starch added (PR+). Blood glucose was measured in the fasted state and following the randomly assigned treatments at 30, 45, 60, 90, and 120 minutes post-consumption. A visual analog scale was used to determine fullness at each time point. There were no differences in the glucose incremental areas under the curve (iAUC) for PF+ and PR+ compared with DEX. The PF? and PR? treatments had decreased (P < 0.05) iAUCs for glucose compared with DEX, PF+, and PR+. There were no treatment differences for RoF. The dose (38?g) of starches did not to alter glucose responses when added on top of 50?g of dextrose. PMID:22655177

Haub, Mark D.; Louk, Julie A.; Lopez, Tara C.

2012-01-01

397

Preparation and characterization of biodegradable copolyester-starch based foams.  

PubMed

Regular (25% amylose) and waxy corn starches blended to various ratios with Eastar Bio Copolyester 14766 (EBC) were extruded into loose-fill foams using a twin screw extruder. Included in this study were two types of corn starch, three levels of EBC content, and three levels of starch moisture content. Waxy starch produced foams with greater radial expansions and lower unit and bulk densities than regular starch. Regular starch foams had lower water solubility indices (WSIs) than waxy starch foams. Foams made of both types of starch possessed similar mechanical properties. No differences were observed in compressibilities and spring indices of either waxy or regular starch foams. Higher levels of EBC addition resulted in less radial expansion and higher unit and bulk densities. Foams made with 10% EBC had higher compressibility than foams containing 25% EBC. Spring indices of single-piece samples and compressibilities and spring indices of bulk samples were not affected by the differences in the level of EBC addition. At 19% and 22% of moisture contents, foams had greater radial expansion than at 25% moisture content. Unit and bulk densities were not affected by variations in moisture content. At 22% moisture content, a lower WSI of 18.5% was obtained. At 22% moisture content, softer foams were produced. At all three levels of moisture content, no differences were detected in the spring indices. PMID:11333028

Fang, Q; Hanna, M A

2001-06-01

398

Components interactions controlling starch-kaolinite composite films properties.  

PubMed

In order to relate the primary filler-matrix interactions to the macroscopic properties of starch-kaolinite composite material, these interactions are monitored through homo- or hetero-coagulation experiments involving both components. Turbidity measurement and Infrared spectra confirm the extreme weakness of the interactions. The addition of calcium cations shows that these weak interactions between starch and kaolinite are due to the combination of the electrostatic repulsion and hydrogen bonds formation between this two negatively charge components. Some possible relationships between the starch-kaolinite interactions and starch-kaolinite composite films properties are proposed. PMID:25498695

Mbey, J A; Thomas, F

2015-03-01

399

Fluorescent nanoparticles from starch: Facile preparation, tunable luminescence and bioimaging.  

PubMed

Fluorescent organic nanoparticles (FONs) based on carbohydrate polymers were prepared through one-pot hydrothermal treatment of starch in the presence of polyethyleneimine. These FONs (named as PEI-Starch FONs) were characterized by a series of techniques including UV-Vis absorption spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Results showed that the size of PEI-Starch FONs is 10-30nm. The PEI-Starch FONs exhibited high water dispersibility because of the existence of hydrophilic functional groups on their surface. After excited with different wavelength, PEI-Starch FONs emitted strong and excitation-dependent fluorescence. To evaluate their potential for biomedical applications, biocompatibility and cell uptake behavior of PEI-Starch FONs were further investigated. We demonstrated that PEI-Starch FONs are biocompatible with cells and can be easily internalized by cells within 3h. Taken together, novel FONs have been prepared via a simple and scalable hydrothermal method using starch and polyethyleneimine as precursors. These PEI-Starch FONs showed excellent fluorescence properties, high water dispersibility and good biocompatibility, making them highly potential for various biomedical applications. PMID:25659670

Liu, Meiying; Zhang, Xiqi; Yang, Bin; Li, Zhan; Deng, Fengjie; Yang, Yang; Zhang, Xiaoyong; Wei, Yen

2015-05-01

400

Analysis of starch structure using fluorophore-assisted carbohydrate electrophoresis.  

PubMed

The analysis of the fine structure of starches is important to the investigation of linkages between starch structure and function and to the investigation of the properties and roles of starch biosynthetic, modifying and degradation enzymes. Fluorophore-assisted carbohydrate electrophoresis has recently been introduced as a method for the analysis of the oligosaccharide populations released by the enzymatic digestion of starches, which has advantages in resolution and sensitivity over previously used methods, and provides the capacity for the facile analysis of oligosaccharide populations on either a molar or mass basis. The use of fluorophore-assisted carbohydrate electrophoresis for the analysis of oligosaccharides is reviewed with particular reference to the choice of label, efficiency of labeling and separation techniques. Examples of separations using slab gel electrophoresis, DNA sequencer analysis and capillary electrophoresis are presented and we conclude that on the basis of resolution and reproducibility, capillary electrophoresis is the method of choice for the separation of oligosaccharides of degree of polymerization from 1 to 100. Examples of isoamylase-debranched starches and glycogens analyzed by capillary electrophoresis are presented. The capillary electrophoresis analysis of starch structure through the analysis of oligosaccharides released by the debranching of limit dextrins derived from starches and glycogens is introduced as a useful diagnostic of starch structure. The potential for future development of novel diagnostics for starch structure using fluorophore-assisted carbohydrate electrophoresis is discussed. PMID:9848667

Morell, M K; Samuel, M S; O'Shea, M G

1998-11-01

401

Isolation and biochemical characterization of apios tuber lectin.  

PubMed

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 ?g/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. PMID:25584830

Kenmochi, Eri; Kabir, Syed Rashel; Ogawa, Tomohisa; Naude, Ryno; Tateno, Hiroaki; Hirabayashi, Jun; Muramoto, Koji

2015-01-01

402

Residues of metribuzin and its metabolites in potato tubers  

Microsoft Academic Search

Metribuzin [4-amino-6-t-butyl-3-(methylthio)-1,2,4-triazin-5 (4H)-one] and its major metabolites were found by gas chromatography\\u000a in harvested tubers of field-grown Russet Burbank potatoes treated with metribuzin for weed control at application rates from\\u000a 0.25 lb\\/A to 4.0 lb\\/A. Metribuzin and its diketo metabolite [6-(l,l,dimethylethyl)-3-(methyl-thio)-1,2,4-triazin-5(4H)-one]\\u000a (DK) constituted nearly all of the residues; these increased in linear proportion to metribuzin application rates between\\u000a 0.25 and

R. H. Callihan; G. F. Stallknecht; R. B. Dwelle; M. Blicharczyk

1976-01-01

403

Assessment of ectomycorrhizal biodiversity in Tuber macrosporum productive sites.  

PubMed

Tuber macrosporum Vittad. is a truffle with superb organoleptic properties, whose cultivation is still in its infancy. For the first time we have aimed to provide information on ectomycorrhizal communities in natural and cultivated T. macrosporum sites. Ectomycorrhizal morphotypes were identified using ITS nrDNA sequencing and sorted into molecular operational taxonomic unit (MOTU). We detected 16 MOTUs in the T. macrosporum cultivated plantation. Ascomycota were the most abundant (86.4%) with Helvellaceae, Pyronemataceae and Pezizaceae the most common. Twenty-two MOTUs were collected in the natural T. macrosporum site. Basidiomycota morphotypes were plentiful (70.6%) and Thelephoraceae dominated. Each site had different taxa belowground with only T. macrosporum in common, being more abundant in the natural (18.2%) than in the cultivated (14.4%) site. Species richness, Simpson and Shannon diversity indices, taxonomic diversity, distinctness and variation of taxonomic distinctness were lower in the cultivated than in the natural site. PMID:24232503

Benucci, Gian Maria Niccolò; Raggi, Lorenzo; Albertini, Emidio; Csorbai, Andrea Gógán; Donnini, Domizia

2014-05-01

404

Characterization of Tuber borchii and Arbutus unedo mycorrhizas.  

PubMed

For the first time, arbutoid mycorrhizas established between Tuber borchii and Arbutus unedo were described. Analyzed mycorrhizas were from one T. borchii natural truffle ground, dominated by Pinus pinea, as well as synthesized in greenhouse conditions. A. unedo mycorrhizas presented some typical characteristics of ectomycorrhizas of T. borchii. However, as in arbutoid mycorrhizas, ramification was cruciform and intracellular colonization in epidermal cells was present. The ability of T. borchii to form ectomycorrhizas with A. unedo opens up the possibility to also use this fruit plant for truffle cultivation. This represents an important economic opportunity in Mediterranean areas by combining both the cultivation of precious truffles and the production of edible fruits which are used fresh or in food delicacies. PMID:24535602

Lancellotti, Enrico; Iotti, Mirco; Zambonelli, Alessandra; Franceschini, Antonio

2014-08-01

405

Genetic and Phylogeographic Structures of the Symbiotic Fungus Tuber magnatum†  

PubMed Central

The quality and market price of truffles vary with the species and, traditionally, the place of origin. The premium species Tuber magnatum produces white truffles and has a patchy distribution restricted to Italy and some Balkan areas. We used polymorphic microsatellites to evaluate 316 specimens grouped into 26 populations sampled across the species' geographic range to determine if natural populations of T. magnatum are genetically differentiated. We found that the southernmost and the northwesternmost populations were significantly differentiated from the rest of the populations. The simple sequence repeat data also could be used to make inferences about the postglacial T. magnatum expansion pattern. This study is the first to identify a genetic and phylogeographic structure in T. magnatum. The presence of a genetic structure can be of practical interest in tracing truffle populations according to their geographic origin for marketing strategies. Evidence for extensive outcrossing in field populations of T. magnatum also is provided for the first time. PMID:16269685

Rubini, Andrea; Paolocci, Francesco; Riccioni, Claudia; Vendramin, Giovanni G.; Arcioni, Sergio

2005-01-01

406

Two novel furostanol saponins from the tubers of Ophiopogon japonicus.  

PubMed

Phytochemical investigation of the fresh tubers of Ophiopogon japonicus led to the isolation of two new furostanol saponins (1 and 2) together with two known steroidal saponins (3 and 4). Comprehensive spectroscopic analysis allowed the chemical structures of two new compounds to be elucidated as (25R)-26-O-[?-d-glucopyranosyl-(1 ? 2)-?-d-glucopyranosyl]-5-ene-furost-1?,3?,22?,26-tetraol-3-O-?-l-rhamnopyranosyl-(1 ? 2)-[?-d-xylopyranosyl-(1 ? 4)]-?-d-glucopyranoside (1, ophiopogonin P) and (25R)-26-O-[?-d-glucopyranosyl-(1 ? 6)-?-d-glucopyranosyl]-5-ene-furost-1?,3?,22?,26-tetraol-3-O-?-l-rhamnopyranosyl-(1 ? 2)-[?-d-xylopyranosyl-(1 ? 4)]-?-d-glucopyranoside (2, ophiopogonin Q). Furostanol saponins with the disaccharide chain linked at C-26 hydroxy group of the aglycone have been rarely reported from natural sources. PMID:23600887

Guo, Yu; Liu, Yi-Xun; Kang, Li-Ping; Zhang, Tao; Yu, He-Shui; Zhao, Yang; Xiong, Cheng-Qi; Ma, Bai-Ping

2013-01-01

407

Sambutoxin, a new mycotoxin produced by toxic Fusarium isolates obtained from rotted potato tubers.  

PubMed Central

Ninety-nine isolates of Fusarium species were obtained from rotted potato tubers from various parts of Korea. Of these isolates, 80 were identified as Fusarium oxysporum, F. solani, or F. sambucinum. The isolates of these species were grown on autoclaved wheat grains and examined for toxicity in a rat-feeding test. A total of 8 of 57 F. oxysporum isolates, 3 of 14 F. solani isolates, and 5 of 9 F. sambucinum isolates caused the death of the rats. Of the 16 toxic isolates, 1 isolate of F. oxysporum produced a substantial amount of moniliformin, which could account for its toxicity. None of the other 15 isolates produced trichothecenes, moniliformin, fusarochromanone, fumonisin B1, or wortmannin. F. sambucinum PZF-4 produced an unknown toxin in wheat culture. This new toxin, given the trivial name sambutoxin, caused toxic effects in rats, including body weight loss, feed refusal, hemorrhage in the stomach and intestines, and, finally, death when rats were fed diets supplemented with 0.05 and 0.1% sambutoxin. The toxin was also toxic to chicken embryos, and the 50% lethal concentration was 29.6 micrograms per egg. Sambutoxin formed as white crystals that turned purple when combined with reagents such as sulfuric acid and p-anisaldehyde. It exhibited a green color immediately after treatment with potassium ferricyanide-ferric chloride. Its UV spectrum had absorption maxima at 213, 233, and 254 nm, and its infrared spectrum showed an amide group at 1,650 and 1,560 cm-1 and a hydroxy group at 3,185 cm-1. Mass spectrometry showed that the molecular weight of the toxin was 453 and the molecular formula was C28H39NO4.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7811078

Kim, J C; Lee, Y W

1994-01-01

408

Properties of Granular Cold-Water-Soluble Starches Prepared by Alcoholic-Alkaline Treatments  

Microsoft Academic Search

Cereal Chem. 71(6):623-626 Granular cold-water-soluble (GCWS) starches were prepared from no detectable degradation of starch molecules during the preparation. normal maize, Hylon V (HA5), Hylon VII (HA7), and waxy maize starches The treated GCWS starches showed V-type X-ray diffraction patterns by treating the starches with mixtures of ethanol and NaOH solutions for normal maize, HA5, and HA7 starches; the GCWS

J. CHEN; J. JANE

409

In vitro starch digestibility and estimated glycemic index of sorghum products  

E-print Network

). Starch in raw grain may be degraded by enzyme action, however, when the starch is gelatinized or disrupted, it is more rapidly degraded (McNeill et al. 1975). A study showed that native and gelatinized starch from sorghum had amylase digestibility... in the crust incomplete gelatinization takes place due to water evaporation on the surface of the bread during baking. Starch hydrolysis Amylases are the enzymes that hydrolyze starch during digestion of starch-containing foods. In the gastrointestinal...

De Castro Palomino Siller, Angelina

2007-09-17

410

Biodegradable films made from low-density polyethylene (LDPE), rice starch and potato starch for food packaging applications: Part 1  

Microsoft Academic Search

Blends of LDPE and rice or potato starch were extruded in the presence of varying amounts of water, hot pressed and studied with regard to their mechanical properties and their gas\\/water permeability and biodegradability before and after storage. The presence of high starch contents ( 30%, w\\/w) had an adverse effect on the mechanical properties of LDPE\\/starch blends. Gas permeability

Ioannis Arvanitoyannis; Costas G. Biliaderis; Hiromasa Ogawa; Norioki Kawasaki

1998-01-01

411

Fetal rhabdomyoma: prenatal diagnosis, clinical outcome, and incidence of associated tuberous sclerosis complex  

Microsoft Academic Search

ObjectivesWe reviewed our institution's experience with fetal cardiac rhabdomyoma to document the clinical outcome and incidence of associated tuberous sclerosis complex (TSC) and compared our findings with those of patients diagnosed with cardiac rhabdomyoma after birth.

Rima S Bader; David Chitayat; Edmond Kelly; Greg Ryan; Jeffrey F Smallhorn; Ants Toi; Lisa K Hornberger

2003-01-01

412

Diffusion tensor imaging and related techniques in tuberous sclerosis complex: review and future directions  

PubMed Central

In this article, the authors aim to introduce the nonradiologist to diffusion tensor imaging (DTI) and its applications to both clinical and research aspects of tuberous sclerosis complex. Tuberous sclerosis complex is a genetic neurocutaneous syndrome with variable and unpredictable neurological comorbidity that includes refractory epilepsy, intellectual disability, behavioral abnormalities and autism spectrum disorder. DTI is a method for modeling water diffusion in tissue and can noninvasively characterize microstructural properties of the brain. In tuberous sclerosis complex, DTI measures reflect well-known pathological changes. Clinically, DTI can assist with detecting the epileptogenic tuber. For research, DTI has a putative role in identifying potential disease biomarkers, as DTI abnormalities of the white matter are associated with neurocognitive morbidity including autism. If indeed DTI changes parallel phenotypical changes related to the investigational treatment of epilepsy, cognition and behavior with mTOR inhibitors, it will facilitate future clinical trials. PMID:24489482

Peters, Jurriaan M; Taquet, Maxime; Prohl, Anna K; Scherrer, Benoit; van Eeghen, Agnies M; Prabhu, Sanjay P; Sahin, Mustafa; Warfield, Simon K

2013-01-01

413

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...

414

Multiple Cardiac Rhabdomyomas, Wolff-Parkinson-White Syndrome, and Tuberous Sclerosis: An Infrequent Combination  

PubMed Central

Cardiac rhabdomyomas are benign cardiac tumours and are often associated with tuberous sclerosis. They are often asymptomatic with spontaneus regresion but can cause heart failure, arrhythmias, and obstruction. There have also been a few isolated reports of Wolff-Parkinson-White syndrome occurring in association with tuberous sclerosis and the great majority has been detected in patients with concomitant rhabdomyomas. We report a 12-day-old infant girl with tuberous sclerosis who presented with intraparietal and intracavitary rhabdomyomas with a Wolff-Parkinson-White syndrome (WPW). She represents one of the few published cases of WPW syndrome and tuberous sclerosis and particularly interesting because of intramural rhabdomyomas regression with persistent intracavitary rhabdomyomas after two years of followup. PMID:25328743

Castilla Cabanes, Elena; Lacambra Blasco, Isaac

2014-01-01

415

Color Perception Optical Illusions  

NSDL National Science Digital Library

This website from eChalk contains optical illusions offering proof that our color perception is strongly influenced by surrounding colors. The site also includes educational games related to optical illusions and color.

2011-06-24

416

Color Blindness Simulations  

MedlinePLUS

Color blindness Simulations Normal Color Vision Deuteranopia Color blindness marked by confusion of purplish red and green Tritanopia A dichromatism in ... and green and reduced sensitivity to monochromatic lights. Simulations created using Image J 1.22d, National Institutes ...

417

Antibacterial, antioxidant and optical properties of edible starch-chitosan composite film containing Thymus kotschyanus essential oil  

PubMed Central

Thyme Essential oils (EO) with antimicrobial and antioxidant properties are widely used in pharmaceutical, cosmetic, and perfume industry. It is also used for flavoring and preservation of several foods. Nowadays, packaging research is receiving a considerable attention due to the development of eco-friendly materials made from natural polymers such as starch and chitosan. In this study Thymus kotschyanus EO concentrations ranging from 0 to 2.0%, incorporated in starch-chitosan composite (S-CH) film were used. Antimicrobial and antioxidant properties significantly increased with the incorporation of EO (p < 0.05). Incorporating EO, increased total color differences (DE), yellowness index (YI) and whiteness index (WI) which were significantly higher than control and its transparency was reduced. Our results pointed out that the incorporation of Thymus kotschyanus EO as a natural antibacterial agent has potential for using the developed film as an active packaging.

Mehdizadeh, Tooraj; Tajik, Hossein; Razavi Rohani, Seyed Mehdi; Oromiehie, Abdol Rassol

2012-01-01

418

Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion  

PubMed Central

Arabidopsis thaliana mutants lacking the SS4 isoform of starch synthase have strongly reduced numbers of starch granules per chloroplast, suggesting that SS4 is necessary for the normal generation of starch granules. To establish whether it plays a direct role in this process, we investigated the circumstances in which granules are formed in ss4 mutants. Starch granule numbers and distribution and the accumulation of starch synthase substrates and products were investigated during ss4 leaf development, and in ss4 mutants carrying mutations or transgenes that affect starch turnover or chloroplast volume. We found that immature ss4 leaves have no starch granules, but accumulate high concentrations of the starch synthase substrate ADPglucose. Granule numbers are partially restored by elevating the capacity for glucan synthesis (via expression of bacterial glycogen synthase) or by increasing the volumes of individual chloroplasts (via introduction of arc mutations). However, these granules are abnormal in distribution, size and shape. SS4 is an essential component of a mechanism that coordinates granule formation with chloroplast division during leaf expansion and determines the abundance and the flattened, discoid shape of leaf starch granules. PMID:23952675

Crumpton-Taylor, Matilda; Pike, Marilyn; Lu, Kuan-Jen; Hylton, Christopher M; Feil, Regina; Eicke, Simona; Lunn, John E; Zeeman, Samuel C; Smith, Alison M

2013-01-01

419

Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion.  

PubMed

Arabidopsis thaliana mutants lacking the SS4 isoform of starch synthase have strongly reduced numbers of starch granules per chloroplast, suggesting that SS4 is necessary for the normal generation of starch granules. To establish whether it plays a direct role in this process, we investigated the circumstances in which granules are formed in ss4 mutants. Starch granule numbers and distribution and the accumulation of starch synthase substrates and products were investigated during ss4 leaf development, and in ss4 mutants carrying mutations or transgenes that affect starch turnover or chloroplast volume. We found that immature ss4 leaves have no starch granules, but accumulate high concentrations of the starch synthase substrate ADPglucose. Granule numbers are partially restored by elevating the capacity for glucan synthesis (via expression of bacterial glycogen synthase) or by increasing the volumes of individual chloroplasts (via introduction of arc mutations). However, these granules are abnormal in distribution, size and shape. SS4 is an essential component of a mechanism that coordinates granule formation with chloroplast division during leaf expansion and determines the abundance and the flattened, discoid shape of leaf starch granules. PMID:23952675

Crumpton-Taylor, Matilda; Pike, Marilyn; Lu, Kuan-Jen; Hylton, Christopher M; Feil, Regina; Eicke, Simona; Lunn, John E; Zeeman, Samuel C; Smith, Alison M

2013-12-01

420

Soaking behaviour and milky extraction performance of tiger nut ( Cyperus esculentus) tubers  

Microsoft Academic Search

Three diameter sizes (D<0.5cm, 0.5cm1cm) of tiger nut (Cyperus esculentus) tubers growing in Cameroon (Central Africa) were soaked between 20°C and 100°C until water content equilibrium, and pressed for extraction of milky beverage (“horchata”). Application of Peleg model was investigated for predicting water absorption of tubers during soaking. The model showed to predict kinetics of the tiger nut

Djomdi; Richard Ejoh; Robert Ndjouenkeu

2007-01-01

421

Deoxyuridine triphosphatase expression defines the transition from dormant to sprouting potato tuber buds  

Microsoft Academic Search

Identification of molecular markers defining the end of tuber dormancy prior to visible sprouting is of agronomic interest\\u000a for potato growers and the potato processing industry. In potato tubers, breakage of dormancy is associated with the reactivation\\u000a of meristem function. In dormant meristems, cells are arrested in the G1\\/G0 phase of the cell cycle and re-entry into the G1 phase

Melanie SenningUwe Sonnewald; Uwe Sonnewald; Sophia Sonnewald

2010-01-01

422

A new sprout inhibitor of potato tuber based on carvone\\/?-cyclodextrin inclusion compound  

Microsoft Academic Search

A monoterpene, D-carvone or (4S)-(+)-carvone, present in the essential oil of caraway seeds (Carum carvi L.), acts as a sprouting inhibitor agent for potato tubers in storage. The aim of the present study was to investigate the\\u000a possibility of using carvone\\/?-cyclodextrin inclusion compound as a sprout inhibitor agent for potato tubers. A Raman study\\u000a of the interactions between ?-cyclodextrin (?-CD)

M. Costa E Silva; C. I. C. Galhano; A. M. G. Moreira Da Silva

2007-01-01

423

Construction and functional characteristics of tuber-specific and cold-inducible chimeric promoters in potato  

Microsoft Academic Search

The improvement of processing quality of potato products (fries and chips) demands less accumulation of reducing sugars (glucose\\u000a and fructose) in cold-stored potato (Solanum tuberosum) tubers. Control of gene expression to achieve this requires promoters with specificity to tubers as well as inducible activity\\u000a under low temperatures. Here we use overlapping extension PCR to construct two chimeric promoters, pCL and

Qing Zhu; Botao Song; Chi Zhang; Yongbin Ou; Conghua Xie; Jun Liu

2008-01-01

424

Fibrolipomatous hamartoma in a patient with tuberous sclerosis: report of a case.  

PubMed

Tuberous sclerosis is a rare congenital disorder with an incidence of 1 in 6000 births. The classic triad is seizure, mental deficiency, and angiofibromas. Orofacial manifestations include fibrous hyperplasia, hemangioma, bifid uvula, cleft lip and palate, macroglossia, high arched palate, and enamel defects. Benign tumors of the jaws including desmoplastic fibroma, calcifying odontogenic tumor, and odontogenic myxoma have been recently reported in tuberous sclerosis. This case report adds fibrolipomatous hamartoma of the mandible to this list. PMID:15660093

Celenk, Peruze; Alkan, Alper; Canger, E Murat; Günhan, Omer

2005-02-01

425

Colored Shadows Investigation  

NSDL National Science Digital Library

This activity (located on page 3 of the PDF) is a full inquiry investigation into mixing colors with light. Groups of learners will set up colored lights in a darkened room and record the color of shadows cast by each color. They will continue to collect data as they experiment with combinations of multiple colored lights and produce a data table to organize their findings. Relates to linked video, DragonflyTV GPS: Light and Color.

Twin Cities Public Television, Inc.

2006-01-01

426

New starch phenotypes produced by TILLING in barley.  

PubMed

Barley grain starch is formed by amylose and amylopectin in a 1:3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications. PMID:25271438

Sparla, Francesca; Falini, Giuseppe; Botticella, Ermelinda; Pirone, Claudia; Talamè, Valentina; Bovina, Riccardo; Salvi, Silvio; Tuberosa, Roberto; Sestili, Francesco; Trost, Paolo

2014-01-01

427

New Starch Phenotypes Produced by TILLING in Barley  

PubMed Central

Barley grain starch is formed by amylose and amylopectin in a 1?3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications. PMID:25271438

Sparla, Francesca; Falini, Giuseppe; Botticella, Ermelinda; Pirone, Claudia; Talamè, Valentina; Bovina, Riccardo; Salvi, Silvio; Tuberosa, Roberto; Sestili, Francesco; Trost, Paolo

2014-01-01

428

Yellow nutsedge (Cyperus esculentus L. ) control with herbicides: the role of tuberization  

SciTech Connect

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.

Pereira, W.

1985-01-01

429

Temperature cycling periods affect growth and tuberization in potatoes under continuous irradiation  

NASA Technical Reports Server (NTRS)

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.

Cao, W.; Tibbitts, T. W.

1992-01-01

430

Rapamycin reverses impaired social interaction in mouse models of tuberous sclerosis complex  

PubMed Central

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. PMID:23250422

Sato, Atsushi; Kasai, Shinya; Kobayashi, Toshiyuki; Takamatsu, Yukio; Hino, Okio; Ikeda, Kazutaka; Mizuguchi, Masashi

2012-01-01

431

Comparison of ectomycorrhizal communities in natural and cultivated Tuber melanosporum truffle grounds.  

PubMed

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. PMID:22469019

Belfiori, Beatrice; Riccioni, Claudia; Tempesta, Sabrina; Pasqualetti, Marcella; Paolocci, Francesco; Rubini, Andrea

2012-09-01

432

Mycoflora of tuber surface of white yam (Dioscorea rotundata Poir) and postharvest control of pathogens with Bacillus subtilis.  

PubMed

Bacillus subtilis (Enrenberg) Cohn was investigated for its antagonistic properties against surface mycoflora of yam (Dioscorea rotundata Poir) tubers in storage. Yam tubers inoculated with a spore suspension of B. subtilis in potato dextrose broth using a knapsack sprayer showed a drastic reduction in the range and number of mycoflora, including pathogens of the tuber surface in contrast to the control tubers, during the five-month storage period in a traditional yam barn. However, B. subtilis maintained a high frequency of occurrence during the same period. Botryodiploidia theobromae Pat, Fusarium moniliforme Wollen and Reink., Penicillium sclerotigenum Yamamoto, and Rhizoctonia sp. were displaced completely on the treated tubers. The antagonism of B. subtilis was so effective that the normal tuber surface mycoflora was greatly reduced throughout the storage period of five months by a simple initial application of the antagonist. PMID:12733628

Okigbo, Ralph N

2003-01-01

433

[The effect of thaumatin gene overexpression on the properties of H(+)-ATPase from the plasmalemma of potato tuber cells].  

PubMed

The introduction of the thaumatin gene into potato plants was accompanied by a decrease in the activity of H(+)-ATPase in the plasmalemma (PL) of tuber cells. When tubers were released from dormancy, the enzyme was activated in the tuber cells of both the original and transgenic plants. Experiments performed in vitro demonstrated that sensitivities to ambiol (AM) and jasmonic acid (JA) of H(+)-ATPase in the PL of tubers from the original plants were lower after the release from a period of deep dormancy. In preparations from the tubers of transgenic plants, the situation was reversed. The differences between the activities of H(+)-ATPase in the PL preparations produced from the original and transgenic tubers that sprouted under the action of AM and JA were detected. Thus, the overexpression of the thaumatin gene in potato plants changed the properties of H(+)-ATPase from PL. PMID:17022457

Ladyzhenskaia, E P; Korableva, N P

2006-01-01

434

Development of a Starch Iodide Method for the Determination of Phosphite in Natural Waters.  

NASA Astrophysics Data System (ADS)

Phosphorus (P) is believed to occur almost exclusively in the environment as fully oxidized phosphate (H3PO4, oxidation state +V). Recent developments in the field of microbiology and research on the origin of life have suggested a possibly significant role for reduced, inorganic forms of P such as phosphorus acid [H3PO3, P(+III)], hypophosphorus acid [H3PO2, P(+I)] and various forms of phosphides [P(-III)] in the biogeochemical cycling of P. In order to confirm the importance of reduced forms of P, we need to develop new and better methods for the detection of these compounds in the environment, often at levels below 1 mM. Traditional methods of P determination are based on the reaction of P with acidified molybdate in aqueous solution to yield phosphomolybdate heteropolyacid, which is then reduced and analyzed spectrophotometrically to quantify the total amount of P in the sample. Limitations in this technique have resulted in our development of a new method using a starch iodide complex for the detection of phosphorus acid or phosphite. Under laboratory conditions, phosphite [P (+III)] is oxidized to phosphate [P (+V)] by tri-iodide (I3). Starch reacts with excess tri-iodide present in solution to form a blue colored complex having a ? max of 580 nm. The I3, as well as other species such as I5, are responsible for the formation of the complex when they fit inside the coiled amylose structure of starch. Linear determination is possible in water samples containing 1 - 80 mM of P (+III). Measurement of the loss of blue color complex can then be correlated with phosphite concentration in the starting sample. Current efforts to optimize this method in order to reach limits of detection below 1 mM are underway. We believe that with better detection methods, the evidence for reduced P in the environment will increase. Due to chemical kinetics, microbial activity, surface catalyzed reactions and possible storage effects, it is difficult to effectively measure the low concentrations present after removing the samples from their natural environments for laboratory analysis. Therefore, to fully understand the importance of reduced P, ultimately, we hope to develop the starch iodide method into an in situ detection technique for measuring phosphite directly in natural waters where sensitive and reliable field-based methods of analysis are needed.

Barco, R. A.; Patil, D.; Salmassi, T. M.; Hanrahan, G.

2004-12-01

435

STARCH-BASED BIOPRODUCTS IN ENCAPSULATION APPLICATIONS AND FOOD PACKAGING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Microcellular starch foams have been reported with pore sizes ranging from the micron to the nanometer range. These foams can sorb volatile compounds but can also absorb more than seven times their weight in solvent. Microcellular starch foam was used as a reservoir material to study the controlled ...

436

Potential Targets for Seed Improvement through Bioengineering Starch Synthesis Pathways  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch is the principle carbohydrate in the food chain and is a renewable and biodegradable polymer widely used in the food, beverage, paper, textile, and livestock feed industries. It is the major component of the harvestable organs in many agronomic plants. The quantity and quality of starch thus ...

437

Thermal dissolution of maize starches in aqueous medium  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starches are not soluble in neutral water at room temperature. However, if they are heated in a closed container beyond the boiling point of water, they eventually dissolve. The dissolution temperature depends on the type of starch. The dissolution process was monitored in real time by measuring ...

438

PARTICLE SIZE CHARACTERIZATION OF STARCH-LIPID COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-lipid composites (SLCs) have been used as fat replacers and stabilizers in beef patties, dairy products, and baked goods and the technology has been patented under the trademark FanteskTM. The SLCs are produced by mixing aqueous starch slurry with a lipid source, and steam jet-cooking. The ...

439

A FLOWABLE PASTE FROM HIGH AMYLOSE CORN STARCH  

Technology Transfer Automated Retrieval System (TEKTRAN)

The flow and structural properties of pastes prepared from high amylose corn starch were examined. The starch was cooked in an excess-steam jet cooker in the presence of a fatty acid. The cooked product was rapidly cooled and then freeze dried or drum dried. Amylose is removed from solution by for...

440

A Review on Physicochemical and Thermorheological Properties of Sago Starch  

Microsoft Academic Search

This study was a part of a research project aiming to investigate the texture characteristics of protein - starch interaction in fish based product keropok lekor. Accordingly, the current review study focused on some physicochemical (molecular weight, viscosity, chemical composition and swelling power) and thermorheological (gelatinization, retrogradation and viscoelsticity) characteristics of sago starch alone and in mixtures with other ingredients

A. Mohamed; B. Jamilah; K. A. Abbas; R. Abdul Rahman; K. Roselina

441

Biosysthesis of Corn Starch Palmitate by Lipase Novozym 435  

PubMed Central

Esterification of starch was carried out to expand the usefulness of starch for a myriad of industrial applications. Lipase B from Candida antarctica, immobilized on macroporous acrylic resin (Novozym 435), was used for starch esterification in two reaction systems: micro-solvent system and solvent-free system. The esterification of corn starch with palmitic acid in the solvent-free system and micro-solvent system gave a degree of substitution (DS) of 1.04 and 0.0072 respectively. Esterification of corn starch with palmitic acid was confirmed by UV spectroscopy and IR spectroscopy. The results of emulsifying property analysis showed that the starch palmitate with higher DS contributes to the higher emulsifying property (67.6%) and emulsion stability (79.6%) than the native starch (5.3% and 3.9%). Modified starch obtained by esterification that possesses emulsifying properties and has long chain fatty acids, like palmitic acid, has been widely used in the food, pharmaceutical and biomedical applications industries. PMID:22837690

Xin, Jia-Ying; Wang, Yan; Liu, Tie; Lin, Kai; Chang, Le; Xia, Chun-Gu

2012-01-01

442

Some studies on starch–urea–acid reaction mechanism  

Microsoft Academic Search

Starch reacted with urea in the absence or presence of mineral acids or mineral acid salts at 150°C for various reaction durations. The acids used were phosphoric, nitric, and sulphuric and the salts used were ammonium sulphate, ammonium nitrate, ammonium chloride and magnesium sulphate. The reaction extent was followed by monitoring nitrogen content. Carrying out the reaction of starch and

M. I Khalil; S Farag; A. A Aly; A Hebeish

2002-01-01

443

Root starches other than those of white and sweet potato  

Microsoft Academic Search

Such starches are not produced in the United States but are imported. Tapioca, from cassava roots, constitutes about 86% of\\u000a them and is particularly valued in the food and adhesive industries. Sago from the pith of palm trees and cycads is used primarily\\u000a as an adhesive; arrowroot from a rhizome as a food starch.

O. B. Wurzburg

1952-01-01

444

Autophagy Contributes to Leaf Starch Degradation[C][W  

PubMed Central

Transitory starch, a major photosynthetic product in the leaves of land plants, accumulates in chloroplasts during the day and is hydrolyzed to maltose and Glc at night to support respiration and metabolism. Previous studies in Arabidopsis thaliana indicated that the degradation of transitory starch only occurs in the chloroplasts. Here, we report that autophagy, a nonplastidial process, participates in leaf starch degradation. Excessive starch accumulation was observed in Nicotiana benthamiana seedlings treated with an autophagy inhibitor and in autophagy-related (ATG) gene-silenced N. benthamiana and in Arabidopsis atg mutants. Autophagic activity in the leaves responded to the dynamic starch contents during the night. Microscopy showed that a type of small starch granule-like structure (SSGL) was localized outside the chloroplast and was sequestered by autophagic bodies. Moreover, an increased number of SSGLs was observed during starch depletion, and disruption of autophagy reduced the number of vacuole-localized SSGLs. These data suggest that autophagy contributes to transitory starch degradation by sequestering SSGLs to the vacuole for their subsequent breakdown. PMID:23564204

Wang, Yan; Yu, Bingjie; Zhao, Jinping; Guo, Jiangbo; Li, Ying; Han, Shaojie; Huang, Lei; Du, Yumei; Hong, Yiguo; Tang, Dingzhong; Liu, Yule

2013-01-01

445

In vitro starch digestion in sorghum flour from Algerian cultivars  

PubMed Central

This work aims to evaluate starch digestion in whole sorghum grains. Nine sorghum cultivars were sampled from the Sahara of Algeria. The structural characteristics of sorghum grains were measured. Total starch (TS) varied between 67.67% and 74.82%, digestible starch (DS) between 64.34% and 69.70%, and resistant starch (RS) ranged from 2.55% to 7.98%. The kinetic of starch digestion displayed first-order model. For all sorghum cultivars, starch were digested with different extents, DS at infinite time (D?) ranged from 52.58 to 102.13 g/100 g dry starch, while the hydrolysis index (HI) ranged from 41.55% to 76.93% and high average glycemic index (GIavg) ranged from 65.97 to 94.14. The results showed that there are differences in grain quality of Algerian sorghum cultivars. The starch fractions have acceptable nutritional value with good in vitro digestibility characteristics suitable for human health and nutrition. PMID:24936295

Souilah, Rachid; Djabali, Djaffar; Belhadi, Badreddine; Mokrane, Hind; Boudries, Nadia; Nadjemi, Boubekeur

2014-01-01

446

Physicochemical properties of cassava starch oxidized by sodium hypochlorite.  

PubMed

In this work, cassava starch was modified by treatment with sodium hypochlorite (NaClO) at different concentrations (0.8, 2.0 and 5.0 % of active chlorine) and selected physicochemical properties of the oxidized starches were investigated. The native and modified samples were evaluated considering moisture, carboxyl content, apparent viscosity, susceptibility to syneresis, mid-infrared spectroscopy and crystallinity index. The treatment with NaClO resulted in alterations in carboxyl content of the oxidized starches that increased with increasing concentration of the oxidant. Oxidized starches also showed higher susceptibility to syneresis, as assessed by the release of liquid during freezing and thawing. Apparent viscosity analysis showed decrease in peak viscosity of the oxidized starches. X-ray diffractograms showed that the oxidation influenced the extent of cassava starch relative crystallinity found to lie between 34.4 % (native) and 39.9 % (2.0 % active chlorine). The infrared spectra are sensitive to structural changes on starch macromolecules and presented characteristic peaks as C-O-C of the six carbon glucose ring absorbs at 1,150-1,085 cm(-1) and due to axial deformation these bands changed with the crystal structure of the starch samples. PMID:25328206

Garrido, Lúcia Helena; Schnitzler, Egon; Zortéa, Manoela Estefânea Boff; de Souza Rocha, Thaís; Demiate, Ivo Mottin

2014-10-01

447

Extrusion of pectin\\/starch blends plasticized with glycerol  

Microsoft Academic Search

The microstructural and thermal dynamic mechanical properties of extruded pectin\\/starch\\/glycerol (PSG) edible and biodegradable films were measured by scanning electron microscopy (SEM) and thermal dynamic mechanical analysis (TDMA). SEM revealed that the temperature profile (TP) in the extruder and the amount of water present during extrusion could be used to control the degree to which the starch was gelatinized. TDMA

M. L Fishman; D. R Coffin; R. P Konstance; C. I Onwulata

2000-01-01

448

IMPORTANCE AND PITFALLS OF STARCH ASSAYS: SELECTION OF METHODS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch analyses provide valuable information on diverse samples, from nutritional values of human foods and animal feeds to data for estimating yields of ethanol from grain. However, starch methods differ in their efficacy, with common methods differing in recovery by 3 to 7 percentage units. Reduce...

449

Flocculation of Kaolin by Waxy Maize Starch Phosphates  

Technology Transfer Automated Retrieval System (TEKTRAN)

Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by drying heating of starches and sodium orthophosphates at 140 deg C for 4 h. Native...

450

Flocculation of Kaolin by Waxy Maize Starch Phosphates  

Technology Transfer Automated Retrieval System (TEKTRAN)

Waxy maize starch phosphates were tested as flocculants in order to determine if they have the potential to replace petroleum-based polymer flocculants currently used commercially. Phosphorylation was carried out by dry heating of starches and sodium orthophosphates at 140 degrees C for 4 hours. N...

451

Biodegradation of a polyvinyl alcohol-starch blend plastic film  

Microsoft Academic Search

Attempts were made to elucidate the degradation mechanism of a polyvinyl alcohol (PVA)-starch blend plastic. A part of the starch fraction of this plastic was dissolved into an aqueous phase in a control test. Treatment with a PVA-degrading bacterium or enzyme gave a maximal weight loss of approximately 70% and film breakage occurred. Since this plastic contains 40% PVA, it

Tomonori Ishigaki; Yasunori Kawagoshi; Michihiko Ike; Masanori Fujita

1999-01-01

452

THERMOPLASTIC STARCH-KRAFT LIGNIN-GLYCEROL BLENDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-kraft lignin-glycerol blends were extruded in a twin-screw extruder to produce non-brittle films. One week after extrusion, films with a mid-range composition of 52% starch, 20% lignin, and 28% glycerol showed a tensile strength at break of 2.8 MPa, Young's modulus of 48 MPa, and elongation ...

453

Tissue-specific signal(s) activate the promoter of a metallocarboxypeptidase inhibitor gene family in potato tuber and berry  

Microsoft Academic Search

The molecular basis of the differential expression of the GM7-type metallocarboxypeptidase inhibitor (MCPI) genes in tuberizing (StMCPI) and non-tuberizing Solanum species (SbMCPI) was investigated. It was shown that the StMCPI is encoded by a gene family in Solanum tuberosum (potato), but SbMCPI might be a single-copy gene in the non-tuberizing species Solanum brevidens. The StMCPI promoter shows evolutionary relatedness to

Attila Molnár; Ágnes Lovas; Zsófia Bánfalvi; Lóránt Lakatos; Zsolt Polgár; Sándor Horváth

2001-01-01

454

[Insect pests dissemination by extruded starch packages].  

PubMed

We observed the viability of extruded starch products used as impact protector for fragile packing as a food source of the following stored grains pests: Cryptolestes ferrugineus (Stephens), Lasioderma serricorne (Fabr.), Oryzaephilus surinamensis (L.), Sitophilus oryzae (L.), Tribolium castaneum (Herbst) (Coleoptera) and Plodia interpunctella (Hübner) (Lepidoptera). Cryptolestes ferrugineus, L. serricorne and T. castaneum were found in these products, which are used by them as shelter and food. Under experimentation, we observed the development of O. surinamensis, S. oryzae and P. interpunctella feeding on this food source. Thus, it is recorded the viability of such material to be a potential dispersal vehicle to spread insect pests. PMID:19768278

Fraga, Felipe B; Alencar, Isabel D C C; Tavares, Marcelo T

2009-01-01

455

The effects of enhanced methionine synthesis on amino acid and anthocyanin content of potato tubers  

PubMed Central

Background Potato is a staple food in the diet of the world's population and also being used as animal feed. Compared to other crops, however, potato tubers are relatively poor in the essential amino acid, methionine. Our aim was to increase the methionine content of tubers by co-expressing a gene involved in methionine synthesis with a gene encoding a methionine-rich storage protein in potato plants. Results In higher plants, cystathionine ?-synthase (CgS) is the first enzyme specific to methionine biosynthesis. We attempted to increase the methionine content of tubers by expressing the deleted form of the Arabidopsis CgS (CgS?90), which is not regulated by methionine, in potato plants. To increase the incorporation of free methionine into a storage protein the CgS?90 was co-transformed with the methionine-rich 15-kD ?-zein. Results demonstrated a 2- to 6-fold increase in the free methionine content and in the methionine content of the zein-containing protein fraction of the transgenic tubers. In addition, in line with higher methionine content, the amounts of soluble isoleucine and serine were also increased. However, all of the lines with high level of CgS?90 expression were phenotypically abnormal showing severe growth retardation, changes in leaf architecture and 40- to 60% reduction in tuber yield. Furthermore, the colour of the transgenic tubers was altered due to the reduced amounts of anthocyanin pigments. The mRNA levels of phenylalanine ammonia-lyase (PAL), the enzyme catalysing the first step of anthocyanin synthesis, were decreased. Conclusion Ectopic expression of CgS?90 increases the methionine content of tubers, however, results in phenotypic aberrations in potato. Co-expression of the 15-kD ?-zein with CgS?90 results in elevation of protein-bound methionine content of tubers, but can not overcome the phenotypical changes caused by CgS?90 and can not significantly improve the nutritional value of tubers. The level of PAL mRNA and consequently the amount of anthocyanin pigments are reduced in the CgS?90 transgenic tubers suggesting that methionine synthesis and production of anthocyanins is linked. PMID:18549488

Dancs, Gábor; Kondrák, Mihály; Bánfalvi, Zsófia

2008-01-01

456

Structures of octenylsuccinylated starches: effects on emulsions containing ?-carotene.  

PubMed

Starches with different amylopectin contents and different molecular sizes prepared using acid hydrolysis were hydrophobically modified using octenylsuccinic anhydride (OSA). The OSA-modified starches were used as surfactants to stabilize emulsions of ?-carotene and canola oil dispersed in water. The objective of this study is to investigate the relationship between starch molecular structure and the chemical stability of the emulsified ?-carotene, as well as the colloidal stability of emulsion droplets during storage. The oil droplet size in emulsions was smaller when starch had (a) lower hydrodynamic volume (Vh) and (b) higher amylopectin content. The oxidative stability of ?-carotene was similar across samples, with higher results at increased amylopectin content but higher Vh. Steric hindrance to coalescence provided by adsorbed OSA-modified starches appears to be improved by more rigid molecules of higher degree of branching. PMID:25129720

Sweedman, Michael C; Hasjim, Jovin; Schäfer, Christian; Gilbert, Robert G

2014-11-01

457

Flavonoid profiling and transcriptome analysis reveals new gene–metabolite correlations in tubers of Solanum tuberosum L.  

PubMed Central

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns associated with the accumulation of purple tuber anthocyanins. The advanced potato selections, CO97216-3P/PW and CO97227-2P/PW, developed by conventional breeding procedures, produced tubers with incomplete expression of tuber flesh pigmentation. This feature permits sampling pigmented and non-pigmented tissues from the same tubers, in essence, isolating the factors responsible for pigmentation from confounding genetic, environmental, and developmental effects. An examination of the transcriptome, coupled with metabolite data from purple pigmented sectors and from non-pigmented sectors of the same tuber, was undertaken to identify these genes whose expression correlated with elevated or altered polyphenol composition. Combined with a similar study using eight other conventional cultivars and advanced selections with different pigmentation, it was possible to produce a refined list of only 27 genes that were consistently differentially expressed in purple tuber tissues compared with white. Within this list are several new candidate genes that are likely to impact on tuber anthocyanin accumulation, including a gene encoding a novel single domain MYB transcription factor. PMID:20110266

Stushnoff, Cecil; Ducreux, Laurence J. M.; Hancock, Robert D.; Hedley, Pete E.; Holm, David G.; McDougall, Gordon J.; McNicol, James W.; Morris, Jenny; Morris, Wayne L.; Sungurtas, Julie A.; Verrall, Susan R.; Zuber, Tatiana; Taylor, Mark A.

2010-01-01

458

Selection of a set of specific primers for the identification of Tuber rufum: a truffle species with high genetic variability.  

PubMed

Tuber rufum is a truffle widely distributed throughout Europe, which forms mycorrhizal associations with numerous species of broadleaf and coniferous trees. The possibility of T. rufum contamination in commercial truffle-infected plants makes its detection important. To facilitate the identification of T. rufum from mycorrhiza and fruitbodies, species-specific primers were designed and tested. To overcome the high intraspecific genetic variability within the internal transcribed spacer (ITS) regions of T. rufum, as demonstrated by phylogenetic analysis, two forward primers, Ru1f and Ru2f, located on the ITS1 region were designed to be used in concert with the reverse primer ITS4. Only T. rufum was amplified with this primer combination, while DNA of Tuber magnatum, Tuber brumale, Tuber maculatum, Tuber borchii, Tuber excavatum and Tuber melanosporum was not. These primers give a specific amplicon ranging between 566 and 572 bp and are able to discriminate between T. rufum, T. borchii and T. magnatum in multiplex PCR. In addition, T. rufum-specific amplicons were obtained from both spore suspensions and mycorrhiza by direct PCR. Tuber rufum mycorrhiza obtained in the greenhouse using mycelial inoculation techniques had morphological features similar to those of other species of Tuber, stressing the importance of molecular tools for their identification. PMID:18031344

Iotti, Mirco; Amicucci, Antonella; Bonito, Gregory; Bonuso, Enrico; Stocchi, Vilberto; Zambonelli, Alessandra

2007-12-01

459

Opioid mediation of starch and sugar preference in the rat  

PubMed Central

In our prior studies, administration of the opioid receptor antagonist naltrexone did not block conditioned preferences for a flavor paired with a preferred sugar solution over a flavor paired with saccharin. This may be because both training solutions were sweet, and their attractiveness was reduced by naltrexone. The present study compared the effects of naltrexone on preferences for flavors paired with sugar or starch drinks that have distinctive tastes to rats. Experiment 1 assessed naltrexone's effect on the preference for unflavored 8% cornstarch and 8% sucrose aqueous solutions/suspensions. The food-restricted rats displayed a significant sucrose preference which increased following systemic treatment with naltrexone (1 or 3 mg/kg) even though total intake of both solutions declined. In Experiment 2, rats were trained to drink flavored (cherry or grape) starch and sucrose solutions in separate one-bottle sessions. In a two-bottle choice test with both flavors presented in a sucrose-starch mixture, the rats significantly preferred the starch-paired flavor. Naltrexone treatment blocked the expression of this starch-conditioned preference. In Experiment 3, rats were treated with saline or naltrexone throughout one-bottle training with flavored sucrose and starch solutions. In a subsequent choice test, both the saline and naltrexone groups displayed significant preferences for the starch-paired flavor, indicating that opioid antagonism failed to alter the acquisition of this conditioned preference. In summary, novel outcomes of this study included the increased rather than the predicted decrease in sucrose preference produced by naltrexone. Also, starch unexpectedly conditioned the stronger flavor preference, although this can be explained by the differential post-oral reinforcing actions of starch and sucrose, and naltrexone blocked the expression, but not acquisition, of this preference. These findings suggest that the reward value of starch in liquid form is more dependent upon opioid signaling than is that of sugar. PMID:20655942

Bonacchi, Kristine B.; Ackroff, Karen; Touzani, Khalid; Bodnar, Richard J.; Sclafani, Anthony

2010-01-01

460

Shear thickening of corn starch suspensions: does concentration matter?  

PubMed

Suspensions of corn starch and water are the most common example of a shear thickening system. Investigations into the non-Newtonian flow behavior of corn starch slurries have ranged from simplistic elementary school demonstrations to in-depth rheological examinations that use corn starch to further elucidate the mechanisms that drive shear thickening. Here, we determine how much corn starch is required for the average person to ‘‘walk on water’’ (or in this case, run across a pool filled with corn starch and water). Steady shear rate rheological measurements were employed to monitor the thickening of corn starch slurries at concentrations ranging from 0 to 55 wt.% (0-44 vol.%). The steady state shear rate ramp experiments revealed a transition from continuous to discontinuous thickening behavior that exists at 52.5 wt.%. The rheological data was then compared to macro-scopic (~5 gallon) pool experiments, in which thickening behavior was tested by dropping a 2.1 kg rock onto the suspension surface. Impact-induced thickening in the ‘‘rock drop’’ study was not observed until the corn starch concentration reached at least 50 wt.%. At 52.5 wt.%, the corn starch slurry displayed true solid-like behavior and the falling rock ‘‘bounced’’ as it impacted the surface. The corn starch pool studies were fortified by steady state stress ramps which were extrapolated out to a critical stress value of 67,000 Pa (i.e., the force generated by an 80 kg adult while running). Only the suspensions containing at least 52.5 wt.% (42 vol.%) thickened to high enough viscosities (50-250 Pa s) that could reasonably be believed to support the impact of a man’s foot while running. Therefore, we conclude that at least 52.5 wt.% corn starch is required to induce strong enough thickening behavior to safely allow the average person to ‘‘walk on water’’. PMID:23484772

Crawford, Nathan C; Popp, Lauren B; Johns, Kathryn E; Caire, Lindsey M; Peterson, Brittany N; Liberatore, Matthew W

2013-04-15

461

Standard RGB Color Spaces  

Microsoft Academic Search

This paper describes the specifications and usage of standard RGB color spaces promoted today by standard bodies and\\/or the imaging industry. As in the past, most of the new standard RGB color spaces were developed for specific imaging workflow and applications. They are used as interchange spaces to communicate color and\\/or as working spaces in imaging applications. Standard color spaces

Sabine Süsstrunk; Robert Buckley; Steve Swen

1999-01-01

462

Color: An Unsuspected Influence.  

ERIC Educational Resources Information Center

Discusses the appropriate use of colors in school libraries. Highlights include how colors affect students' learning and behavior; influences on users' moods; users' ages; the use of colors to bring out the best physical attributes; and the use of color for floor coverings, window treatments, furnishings, and accessories. (LRW)

Scargall, Hollie

1999-01-01

463

Cassava starch granule structure–function properties: influence of time and conditions at harvest on four cultivars of cassava starch  

Microsoft Academic Search

Impact of environmental conditions on cassava starch variability was examined by studying four commercially important cultivars, Rayong 1, Rayong 60, Rayong 90, and Kasetsart 50 (KU 50). Age of the root and environmental conditions at harvest influenced granule structure and hydration properties. All cultivars were grown under identical field conditions, and harvested at different times. Starches extracted from cassava roots

K Sriroth; V Santisopasri; C Petchalanuwat; K Kurotjanawong; K Piyachomkwan; C. G Oates

1999-01-01

464

Effect of alkyl ketene dimer reacted starch on the properties of starch microcellular foam using a solvent exchange technique  

Microsoft Academic Search

The production of a hydrophobic starch microcellular foam (SMCF) through the addition of an alkyl ketene dimer (AKD) would be a bio-based material with valuable properties for many applications in which high specific surface area, low density and water resistance is important. Pigments for paper and coatings are a potential application. An emulsion of AKD and cooked corn starch was

Khaled El-Tahlawy; Richard Venditti; Joel Pawlak

2008-01-01

465

RGB Additive Color  

NSDL National Science Digital Library

Color is all around us. RGB is the color system that is used when mixing light. The RGB system is what we use in computers, televisions, stage lighting, displays and more. It is also called the additive color system because the colors are combined or added to each other to make the colors that we see. What wavelength goes with a color? Remember that a a nanometer is a unit of length in the metric system equal to one billionth of a meter. NASA What is a wave? NASA Color Why is the sky blue? What is RGB and how and where is it used? RGB World 21st Century Color Theory RGB colors are identified on computers by a color value that ranges for R, G, and B, ...

Engelman, Mr.

2010-12-05

466

Proteomic changes during tuber dormancy release process revealed by iTRAQ quantitative proteomics in potato.  

PubMed

Given that limited information is available with regard to tuber dormancy release related proteome, we conducted proteome analysis of tuber dormancy release process at dormant tuber (DT), dormancy release tuber (DRT) and sprouting tuber (ST) using the iTRAQ technology. A total of 1,752 proteins were identified. Among them, a subset of 316 proteins was screened as significant up- (137) and down regulated (179) between DT vs DRT. A subset of 120 proteins experienced significant up- (40) or down-regulation (80) between DRT vs ST. The differentially expressed proteins were grouped into 11 functional categories. Proteins enriched in functional categories of major carbohydrate (CHO) metabolism, glycolysis, fermentation, amino acid metabolism, protein and transport were highly up-regulated, while functional categories of photosynthesis and RNA were down-regulated between DT vs DRT. Proteins enriched in functional groups of protein, cell wall, lipid metabolism, miscellaneous, and signaling were strongly up-regulated, while functional categories of photosynthesis, hormone metabolism and protein were down-regulated between DRT vs ST. Consistent with previous documented differentially expressed genes, most of differentially expressed proteins were also identified between DT and DRT, indicating the metabolism shift from growth suspension to growth activation as tubers dormancy breaking. The changes in protein profiles showed lower concordance with corresponding alterations in transcript levels, indicating possible transcriptional and posttranscriptional regulation. Furthermore, the possible mechanism of tuber dormancy release was discussed in relation to what was known in transcripts change and other plant models from carbohydrate metabolism, protein metabolism, stress response, redox regulation, transcription regulation, DNA metabolism, amino acid metabolism, development, signaling as well as hormone metabolism. PMID:25514565

Liu, Bailin; Zhang, Ning; Zhao, Shuo; Chang, Jing; Wang, Zemin; Zhang, Guodong; Si, Huaijun; Wang, Di

2015-01-01

467

Response of Potato Tuber Cell Division and Growth to Shade and Elevated CO2  

PubMed Central

Plants adjust their sink?organ growth rates, development and distribution of dry matter in response to whole?plant photosynthate status. To advance understanding of these processes, potato (Solanum tuberosum L.) plants were subjected to CO2 and light flux treatments, and