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Regulation of starch synthesis in potato tubers  

SciTech Connect

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

Davies, H.; Oparka, K.; Viola, R.; Wright, K.; Ross, H. (Scottish Crop Res. Inst., Dundee (Scotland))



Physicochemical properties of starch obtained from Dioscorea nipponica Makino comparison with other tuber starches  

Microsoft Academic Search

In the development of food and medicine industry, more and more attentions have been paid on new starches with different properties. Dioscorea nipponica Makino, which is a widely used medicinal plant in the pharmaceutical industry, contains plenty of starches in its tubers. These starches are usually ignored and wasted during the isolation and separation of the small-molecule bioactive ingredients. In

Yi Yuan; Liming Zhang; Yujie Dai; Jiugao Yu



Regulation of sucrose to starch conversion in growing potato tubers  

Microsoft Academic Search

Growing potato tubers have been used as a model system to investigate the regulation of starch syn- thesis. Results indicate that sucrose degradation and starch synthesis are controlled via regulatory signals in response to sucrose and oxygen avail- ability. (i) Sucrose leads to a co-ordinated up-regu- lation of sucrose synthase and ADP-glucose phosphorylase at the transcriptional and post-tran- scriptional level.

Peter Geigenberger



Physical, chemical and microscopic characterization of a new starch from chayote ( Sechium edule) tuber and its comparison with potato and maize starches  

Microsoft Academic Search

In this work, the chayote tuber starch (CHS) was isolated and its chemical composition and its physical and microscopic characteristics were determined, and compared with potato (PS) and maize (MS) starches. The starch content in chayote tubers (728gkg?1 dry weight) was similar to potato tubers (700gkg?1 dry weight), with a high level of purity (>98%), while its phosphorous content was

J. Jiménez-Hernández; J. A. Salazar-Montoya; E. G. Ramos-Ramírez



Kinetics of thermal softening of cassava tubers and rheological modeling of the starch  

Microsoft Academic Search

Cassava or tapioca (Manihot esculenta Crantz) tubers having high amount of carbohydrate are utilized after boiling or processing into starch and flour. Textural\\u000a properties of raw and cooked tubers depend on variety, maturity, growing environment, physico-chemical and starch properties.\\u000a Starch is used in food preparations as gelling and thickening agent, stabilizer and texture modifier. This study aims at analyzing\\u000a and

Moothandassery Sankarakutty Sajeev; J. Sreekumar; M. Unnikrishnan; S. N. Moorthy; S. Shanavas



ldentification of the Major Starch Synthase in the Soluble Fraction of Potato Tubers  

Microsoft Academic Search

The major isoform of starch synthase from the soluble fraction of developing potato tubers has been purified and used to prepare an antibody and isolate a cDNA. The protein is 140 kD, and it is distinctly different in predicted primary amino acid sequence from other isoforms of the enzyme thus far described. lmmunoinhibition and immunoblotting experiments and analysis of tubers

Jacqueline Marshall; Christopher Sidebottom; Martine Debet; Cathie Martin; Alison M. Smith; Anne Edwards


Effect of Temperature on Starch Synthesis in Potato Tuber Tissue and in Amyloplasts  

PubMed Central

A sharp temperature optimum is observed at 21.5°C when the incorporation of [14C]sucrose into starch is measured with discs cut from developing tubers of potato (Solanum tuberosum L. cv Desirée). By contrast, increasing temperatures over the range 9 to 31°C only enhance release of 14C to respiratory CO2 and incorporation of 14C into the ethanolsoluble fraction. By comparison, starch synthesis in discs from developing corms of cocoyam (Colocasia esculenta L. Schott) is increased by raising the temperature from 15 to 35°C. The significance of a relatively low temperature optimum for starch synthesis in potato is discussed in relation to the yield limitations imposed by continuously high soil temperatures. Amyloplasts isolated from protoplasts prepared from developing potato tubers contain activities of alkaline pyrophosphatase, NAD-dependent glyceraldehyde-3-phosphate dehydrogenase, fructose-1,6-bisphosphatase, and phosphoglucomutase in addition to ADP-glucose-pyrophosphorylase, starch phosphorylase and starch synthase. Cell-free amyloplasts released by thinly slicing developing potato tubers synthesize starch from [14C]triose-phosphate generated from [14C]fructose-1,6-bisphosphate in the reaction medium. This starch synthesis is inhibited by addition of 10 millimolar inorganic phosphate and requires amyloplast integrity, suggesting the operation of a triose-phosphate/inorganic phosphate exchange carrier at the amyloplast membrane. The temperature optimum at 21.5°C observed with tissue discs is not observed with amyloplasts.

Mohabir, Gangaram; John, Philip



The influence of alterations in ADP-glucose pyrophosphorylase activities on starch structure and composition in potato tubers  

Microsoft Academic Search

.   In order to examine whether alterations in the supply of precursor molecules into the starch biosynthetic pathway affected\\u000a various characteristics of the starch, starch was isolated from potato (Solanum tuberosum L.) tubers containing reduced amounts of the enzyme ADP-glucose pyrophosphorylase (AGPase). It was found that although the\\u000a type of crystalline polymorph in the starch was not altered, the amylose

James R. Lloyd; Franziska Springer; Alain Buléon; Bernd Müller-Röber; Lothar Willmitzer; Jens Kossmann



Space Experiment on Tuber Development and Starch Accumulation for CELSS.  

National Technical Information Service (NTIS)

Potato explants (leaf, small stem section, and axillary bud), flown on STS-73, developed tubers of 1.5 cm diameter and 1.7 g mass during the 16 day period of spaceflight. The experiment was undertaken in the ASTROCULTURE(Trademark) experiment package unde...

T. W. Tibbitts J. C. Croxdale C. S. Brown



Extensive variation in fried chip color and tuber composition in cold-stored tubers of wild potato (solanum) germplasm.  


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 because of its importance to the potato-processing industry. Prior research has not characterized wild Solanum relatives of potato for tuber composition and has not determined if relationships between tuber composition and chip color after cold storage in wild species are comparable to those found for cultivated potato. Extensive inter- and intraspecific variation for chip color and tuber composition were found in the wild Solanum species examined. Tuber sugar profiles suggested that invertase activity at low temperatures differed between and within species. Tuber fructose, glucose, and sucrose concentrations partially explained chip color variation in most accessions, but asparagine concentration and percent dry matter did not. Most wild species had reducing sugar concentrations and chip color scores after 2 degrees C storage that were less than those in S. tuberosum cultivar Snowden. Sugar profiles and relationships between specific sugars and chip color in Solanum pinnatisectum were unique among the species examined. PMID:20099883

McCann, Leah C; Bethke, Paul C; Simon, Philipp W



Starch, protein, glycoalkaloids, and l -ascorbic acid content in tubers of genetically modified potato cv. Irga  

Microsoft Academic Search

Changes in contents of protein, starch, ash, l-ascorbic acid, and glycoalkaloids in tubers of 15 clones of cultivar Irga transformed with viral genome sequences in order\\u000a to improve their resistance to a necrotic strain of potato virus Y (PVYN) were investigated. The influence of modification type and year of cultivation on the contents of all chemical compounds\\u000a examined for particular

Jadwiga Sadowska; Jaros?aw Budny; Józef Fornal



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

Microsoft Academic Search

An a-amylase (EC 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



Effect of heat–moisture treatment on the structure and physicochemical properties of tuber and root starches  

Microsoft Academic Search

Starch from tubers potato (Solanum tuberosum), taro (Alocassia indica), new cocoyam (Xanthosoma sagitifolium), true yam (Dioscorea alata), and root cassava, (Manihot esculenta) crops was isolated and its morphology, composition and physicochemical properties were investigated before and after heat–moisture treatment (HMT) (100°C, for 10h at a moisture content of 30%). Native starch granules were round to oval to polygonal with smooth

A Gunaratne; R Hoover



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

PubMed Central

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 in leaves and tubers, during tuber induction and in tubers growing at different velocities. To determine velocity of potato tuber growth a new method based on X-ray Computed Tomography (X-ray CT) was established. Results Comparative transcriptome analysis between leaves and tubers revealed striking similarities with the same genes being differentially expressed in both tissues. In tubers, oscillation of granule bound starch synthase (GBSS) expression) was observed which could be linked to sucrose supply from source leaves. X-ray CT was used to determine time-dependent changes in tuber volume and the growth velocity was calculated. Although there is not a linear correlation between growth velocity and expression of starch biosynthetic genes, there are significant differences between growing and non-growing tubers. Co-expression analysis was used to identify transcription factors positively correlating with starch biosynthetic genes possibly regulating starch biosynthesis. Conclusion Most starch biosynthetic enzymes are encoded by gene families. Co-expression analysis revealed that the same members of these gene families are co-regulated in leaves and tubers. This suggests that regulation of transitory and storage starch biosynthesis in leaves and tubers, respectively, is surprisingly similar. X-ray CT can be used to monitor growth and development of belowground organs and allows to link tuber growth to changes in gene expression. Comparative transcriptome analysis provides a useful tool to identify transcription factors possibly involved in the regulation of starch biosynthesis.



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



Effect of amylose deposition on potato tuber starch granule architecture and dynamics as studied by lintnerization.  


The effect of amylose deposition on the amylopectin crystalline lamellar organization in potato starch granules was studied by mild acid, so-called lintnerization, of potato tuber starch transgenically engineered to deposit different levels of amylose. The starch granules were subjected to lintnerization at different temperatures (25, 35, and 45°C) and to two levels of solubilization, ? 45 and 80%. The rate of the lintnerization increased with temperature but was suppressed by amylose. The molecular size of the lintner dextrins increased with temperature, but this effect was suppressed by the presence of amylose. At high temperatures and low-amylose content, the degree of branches was high with the concomitant increase in size in the dextrins. A portion of the branches was resistant to debranching enzymes possibly due to specific structural formations. The effects of temperature suggested a unique granular architecture of potato starch, and a model showing the dependence of temperature on the dynamic arrangement of amylopectin and amylose in the crystalline and amorphous lamellae for the potato starch is suggested. © 2012 Wiley Periodicals, Inc. PMID:23097232

Wikman, Jeanette; Blennow, Andreas; Bertoft, Eric



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


Reserve starch is an important plant product but the actual biosynthetic process is not yet fully understood. Potato (Solanum tuberosum) tuber discs from various transgenic plants were used to analyse the conversion of external sugars or sugar derivatives to starch. By using in vitro assays, a direct glucosyl transfer from glucose 1-phosphate to native starch granules as mediated by recombinant plastidial phosphorylase was analysed. Compared with labelled glucose, glucose 6-phosphate or sucrose, tuber discs converted externally supplied [(14)C]glucose 1-phosphate into starch at a much higher rate. Likewise, tuber discs from transgenic lines with a strongly reduced expression of cytosolic phosphoglucomutase, phosphorylase or transglucosidase converted glucose 1-phosphate to starch with the same or even an increased rate compared with the wild-type. Similar results were obtained with transgenic potato lines possessing a strongly reduced activity of both the cytosolic and the plastidial phosphoglucomutase. Starch labelling was, however, significantly diminished in transgenic lines, with a reduced concentration of the plastidial phosphorylase isozymes. Two distinct paths of reserve starch biosynthesis are proposed that explain, at a biochemical level, the phenotype of several transgenic plant lines. PMID:20028468

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



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


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 product in tuber amyloplasts was between 0.007 and 0.028% of total protein in independent potato lines as determined by immunoblot analysis. Tubers from four transgenic potato lines were found to have a lowered specific gravity, a 30 to 50% reduction in the percentage of starch, and a decreased amylose/amylopectin ratio. Total soluble sugar content in these selected lines was increased by approximately 80%. Analysis of the starch from these potato lines also indicated a reduced phosphorous content. A very high degree of branching of the amylopectin fraction was detected by comparison of high and low molecular weight carbohydrate chains after debranching with isoamylase and corresponding high-performance liquid chromatography analysis of the products. Brabender viscoamylograph analysis and differential scanning calorimetry of the starches obtained from these transgenic potato lines also indicate a composition and structure much different from typical potato starch. Brabender analysis yielded very low stable paste viscosity values (about 30% of control values), whereas differential scanning calorimetry values indicated reduced enthalpy and gelatinization properties. The above parameters indicate a novel potato starch based on expression of the glgA E. coli gene product in transgenic potato. PMID:8016260

Shewmaker, C K; Boyer, C D; Wiesenborn, D P; Thompson, D B; Boersig, M R; Oakes, J V; Stalker, D M



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

PubMed Central

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 product in tuber amyloplasts was between 0.007 and 0.028% of total protein in independent potato lines as determined by immunoblot analysis. Tubers from four transgenic potato lines were found to have a lowered specific gravity, a 30 to 50% reduction in the percentage of starch, and a decreased amylose/amylopectin ratio. Total soluble sugar content in these selected lines was increased by approximately 80%. Analysis of the starch from these potato lines also indicated a reduced phosphorous content. A very high degree of branching of the amylopectin fraction was detected by comparison of high and low molecular weight carbohydrate chains after debranching with isoamylase and corresponding high-performance liquid chromatography analysis of the products. Brabender viscoamylograph analysis and differential scanning calorimetry of the starches obtained from these transgenic potato lines also indicate a composition and structure much different from typical potato starch. Brabender analysis yielded very low stable paste viscosity values (about 30% of control values), whereas differential scanning calorimetry values indicated reduced enthalpy and gelatinization properties. The above parameters indicate a novel potato starch based on expression of the glgA E. coli gene product in transgenic potato.

Shewmaker, C K; Boyer, C D; Wiesenborn, D P; Thompson, D B; Boersig, M R; Oakes, J V; Stalker, D M



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


Viscosity reduction and the effect of cell-wall degrading enzymes (CWDEs) were investigated using Canna edulis Ker. for bioethanol fermentation. The fermentation mash treated with CWDEs was much thinner (2.12 Pas) than the control mash (8.42 Pas), the fermentation efficiency was increased from 90.46% to 96.11%. HPLC analysis revealed that after treated with CWDEs, glucose and total sugar were increased by 28.07% and 7.60%, respectively. Changes in the starch granules were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM). The results suggested that the reduction in viscosity was caused by changes in saccharide composition and physical changes of the starch granules. This present study is of significance that non-starch polysaccharides and starch can be simultaneously utilized for bioethanol production using roots and tubers as feedstock. PMID:23211480

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



Regulation of sucrose and starch metabolism in potato tubers in response to short-term water deficit  

Microsoft Academic Search

.   To investigate the effect of water stress on carbon metabolism in growing potato tubers (Solanum tuberosum L.), freshly cut and washed discs were incubated in a range of mannitol concentrations corresponding to external water potential\\u000a between 0 and ?1.2 MPa. (i) Incorporation of [14C]glucose into starch was inhibited in water-stressed discs, and labeling of sucrose was increased. High glucose

Peter Geigenberger; Ralph Reimholz; Michael Geiger; Lucia Merlo; Vittoria Canale; Mark Stitt



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

PubMed Central

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

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



When growing potato tubers are detached from their mother plant there is a rapid inhibition of starch synthesis, involving inhibition of ADP-glucose pyrophosphorylase  

Microsoft Academic Search

Labelling experiments in which high-specific-activity [U-14C]sucrose or [U-14C]hexoses were injected into potato (Solanum tuberosum L. cv. Desiree) tubers showed that within 1 d of detaching growing tubers from their mother plant, there is an inhibition\\u000a of starch synthesis, a stimulation of the synthesis of other major cell components, and rapid resynthesis of sucrose. This\\u000a is accompanied by a general increase

Peter Geigenberger; Lucia Merlo; Ralph Reimholz; Mark Stitt



Effects of starches on the textural, rheological, and color properties of surimi-beef gels with microbial tranglutaminase.  


In order to evaluate effects of starches (corn starch, potato starch, and tapioca starch) on the characteristics of surimi-beef gels with microbial transglutaminase, the cooking loss, gel strength, color and rheological properties of samples were investigated. Results demonstrated that starches gave negative effects on the cooking loss of surimi-beef gels. The gel with corn starch had the highest cooking loss while that with tapioca starch showed the lowest value. The gel with potato starch obtained the highest gel strength. During the sol-gel transitions, surimi-beef complexes with 3% corn starch exhibited the highest storage modulus value, while that with 3% tapioca starch had the lowest one. The addition of starch caused the increase of L* values of surimi-beef gels. Results showed that the excessive amount of starch resulted in the decrease in gel strength of surimi-beef gels. PMID:23273461

Zhang, Fenghui; Fang, Ling; Wang, Chenjie; Shi, Liu; Chang, Tong; Yang, Hong; Cui, Min



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

Microsoft Academic Search

To change the hexose-to-sucrose ratio within phloem cells, yeast-derived cytosolic invertase was expressed in transgenic potato (Solanum tuberosum cv. Desiree) plants under control of the rolC pro- moter. Vascular tissue specific expression of the transgene was verified by histochemical detection of invertase activity in tuber cross-sections. Vegetative growth and tuber yield of transgenic plants was unal- tered as compared to

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




Technology Transfer Automated Retrieval System (TEKTRAN)

In potatoes low O2 (1.52 kPa) totally suppresses the rise in CO2 output, the rate of which remains at the same levels as that attained by tubers that have been held in air at 1oC for two days. Low O2 does not prevent the decrease in cytochrome oxidase observed in tubers held in air at 1oC. Neverth...


Fluoride-Induced Inhibition of Starch Biosynthesis in Developing Potato, Solanum tuberosum L., Tubers Is Associated with Pyrophosphate Accumulation 1  

PubMed Central

Pretreatment of discs excised from developing tubers of potato (Solanum tuberosum L.) with 10 millimolar sodium fluoride induced a transient increase in 3-phosphoglycerate content. This was followed by increases in triose-phosphate, fructose 1,6-bisphosphate and hexose-phosphate (glucose 6-phosphate + fructose 6-phosphate + glucose 1-phosphate). The effect of fluoride is attributed to an inhibition of glycolysis and a stimulation of triose-phosphate recycling (the latter confirmed by the pattern of 13C-labeling [NMR] in sucrose when tissue was supplied with [2-13C]glucose). Fluoride inhibited the incorporation of [U-14C] glucose, [U-14C]sucrose, [U-14C]glucose 1-phosphate, and [U-14C] glycerol into starch. The incorporation of [U-14C]ADPglucose was unaffected. Inhibition of starch biosynthesis was accompanied by an almost proportional increase in the incorporation of 14C into sucrose. The inhibition of starch synthesis was accompanied by a 10-fold increase in tissue pyrophosphate (PPi) content. Although the subcellular localization of PPi was not determined, a hypothesis is presented that argues that the PPi accumulates in the amyloplast due to inhibition of alkaline inorganic pyrophosphatase by fluoride ions.

Viola, Roberto; Davies, Howard V.



Physicochemical and Functional Properties of Starch from Two Species of Curcuma  

Microsoft Academic Search

The properties of starch extracted from two species of Curcuma viz. Curcuma zedoaria and Curcuma malabarica were studied. The starch from C. malabarica tubers was white in color, while that from C. zedoaria was slightly yellowish due to the presence of the yellow pigment, curcumin. The granule size and shape, amylose content and solubility did not show noticeable difference between

A. N. Jyothi; S. N. Moorthy; B. Vimala



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.

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



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.  


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



Statistical epistasis between candidate gene alleles for complex tuber traits in an association mapping population of tetraploid potato.  


Association mapping using DNA-based markers is a novel tool in plant genetics for the analysis of complex traits. Potato tuber yield, starch content, starch yield and chip color are complex traits of agronomic relevance, for which carbohydrate metabolism plays an important role. At the functional level, the genes and biochemical pathways involved in carbohydrate metabolism are among the best studied in plants. Quantitative traits such as tuber starch and sugar content are therefore models for association genetics in potato based on candidate genes. In an association mapping experiment conducted with a population of 243 tetraploid potato varieties and breeding clones, we previously identified associations between individual candidate gene alleles and tuber starch content, starch yield and chip quality. In the present paper, we tested 190 DNA markers at 36 loci scored in the same association mapping population for pairwise statistical epistatic interactions. Fifty marker pairs were associated mainly with tuber starch content and/or starch yield, at a cut-off value of q ? 0.20 for the experiment-wide false discovery rate (FDR). Thirteen marker pairs had an FDR of q ? 0.10. Alleles at loci encoding ribulose-bisphosphate carboxylase/oxygenase activase (Rca), sucrose phosphate synthase (Sps) and vacuolar invertase (Pain1) were most frequently involved in statistical epistatic interactions. The largest effect on tuber starch content and starch yield was observed for the paired alleles Pain1-8c and Rca-1a, explaining 9 and 10% of the total variance, respectively. The combination of these two alleles increased the means of tuber starch content and starch yield. Biological models to explain the observed statistical epistatic interactions are discussed. PMID:20603706

Li, Li; Paulo, Maria-João; van Eeuwijk, Fred; Gebhardt, Christiane



Statistical epistasis between candidate gene alleles for complex tuber traits in an association mapping population of tetraploid potato  

PubMed Central

Association mapping using DNA-based markers is a novel tool in plant genetics for the analysis of complex traits. Potato tuber yield, starch content, starch yield and chip color are complex traits of agronomic relevance, for which carbohydrate metabolism plays an important role. At the functional level, the genes and biochemical pathways involved in carbohydrate metabolism are among the best studied in plants. Quantitative traits such as tuber starch and sugar content are therefore models for association genetics in potato based on candidate genes. In an association mapping experiment conducted with a population of 243 tetraploid potato varieties and breeding clones, we previously identified associations between individual candidate gene alleles and tuber starch content, starch yield and chip quality. In the present paper, we tested 190 DNA markers at 36 loci scored in the same association mapping population for pairwise statistical epistatic interactions. Fifty marker pairs were associated mainly with tuber starch content and/or starch yield, at a cut-off value of q ? 0.20 for the experiment-wide false discovery rate (FDR). Thirteen marker pairs had an FDR of q ? 0.10. Alleles at loci encoding ribulose-bisphosphate carboxylase/oxygenase activase (Rca), sucrose phosphate synthase (Sps) and vacuolar invertase (Pain1) were most frequently involved in statistical epistatic interactions. The largest effect on tuber starch content and starch yield was observed for the paired alleles Pain1-8c and Rca-1a, explaining 9 and 10% of the total variance, respectively. The combination of these two alleles increased the means of tuber starch content and starch yield. Biological models to explain the observed statistical epistatic interactions are discussed. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1389-3) contains supplementary material, which is available to authorized users.

Li, Li; Paulo, Maria-Joao; van Eeuwijk, Fred



Decreased expression of plastidial adenylate kinase in potato tubers results in an enhanced rate of respiration and a stimulation of starch synthesis that is attributable to post-translational redox-activation of ADP-glucose pyrophosphorylase  

Microsoft Academic Search

Adenine nucleotides are of general importance for many aspects of cell function, but their role in the regulation of biosynthetic processes is still unclear. It was previously reported that decreased expression of plastidial adenylate kinase, catalysing the interconver- sion of ATP and AMP to ADP, leads to increased adenyl- ate pools and starch content in transgenic potato tubers. However, the

Sandra N. Oliver; Axel Tiessen; Alisdair R. Fernie; Peter Geigenberger



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



Statistical epistasis between candidate gene alleles for complex tuber traits in an association mapping population of tetraploid potato  

Microsoft Academic Search

Association mapping using DNA-based markers is a novel tool in plant genetics for the analysis of complex traits. Potato tuber\\u000a yield, starch content, starch yield and chip color are complex traits of agronomic relevance, for which carbohydrate metabolism\\u000a plays an important role. At the functional level, the genes and biochemical pathways involved in carbohydrate metabolism are\\u000a among the best studied

Li Li; Maria-João Paulo; Fred van Eeuwijk; Christiane Gebhardt



Effect of Rol Transgenes, IAA, and Kinetin on Starch Content and the Size of Starch Granules in Tubers of In Vitro Potato Plants  

Microsoft Academic Search

Stem cuttings were produced from Solanum tuberosum L., cv. Desiree, plants and their transgenic forms harboring rolB and rolC genes from Agrobacterium rhizogenes. Plants were cultured on hormone-free Murashige and Skoog nutrient medium (MS) and on MS supplemented with IAA or kinetin. In microtubers developed on these cuttings, we estimated the content of starch and the number and size of

I. A. Gukasyan; S. A. Golyanovskaya; E. V. Grishunina; T. N. Konstantinova; N. P. Aksenova; G. A. Romanov




Technology Transfer Automated Retrieval System (TEKTRAN)

Cereal or tuber starches have been extruded into low density foam. Extruded starch foam tends to embrittle and have poor mechanical properties. We have extruded starch with cellulose fiber uniformly distributed throughout the starch matrix. Fiber reinforced foam has a greater density than foam made ...


Normal starch content and composition in tubers of antisense potato plants lacking D-enzyme (4-?-glucanotransferase)  

Microsoft Academic Search

.   Transgenic potato (Solanum tuberosum L.) plants were created with sense and antisense copies of the potato D-enzyme (disproportionating enzyme; EC? cDNA\\u000a linked to patatin and cauliflower mosaic virus 35?S promoters, and screened for D-enzyme activity in tubers. Transformants\\u000a with sense constructs mostly had wild type D-enzyme activity but two plants had only about 1% wild-type activity. Transformants\\u000a with antisense

Takeshi Takaha; Joanna Critchley; Shigetaka Okada; Steven M. Smith



Starch Granule Variability in Wild Solanum Species  

Technology Transfer Automated Retrieval System (TEKTRAN)

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


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.

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



Molecular Dissection of Sensory Traits in the Potato Tuber  

Microsoft Academic Search

The aim of this research was to increase understanding of tuber sensory traits such as tuber color and flavor. For tuber color\\u000a the focus was on tuber carotenoid content. Using metabolic engineering approaches it was discovered that it was possible to\\u000a enhance considerably the amount and types of carotenoid that could accumulate in potato tubers. Transgenic lines based on\\u000a three

Wayne L. Morris; Laurence J. M. Ducreux; Glenn J. Bryan; Mark A. Taylor



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

Microsoft Academic Search

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

Alisdair R. Fernie; Ute Roessner; Peter Geigenberger



Temperature, cyanide, and oxygen effects on the respiration, chip color, sugars, and organic acids of stored tubers  

Microsoft Academic Search

The possibility that sugar accumulation of potatoes stored at low temperatures may be linked to activation of cyanide-resistant\\u000a respiration (CRR) was investigated. After a lag period of several days, continuous HCN treatment stimulated CO2 production of tubers stored in 20% O2. At 1°C in 20% O2, HCN treatment increased respiration over that effected by low temperature treatment. After several weeks

Mark Sherman; Elmer E. Ewing



Consequences of antisense RNA inhibition of starch branching enzyme activity on properties of potato starch  

Microsoft Academic Search

Antisense constructs containing cDNAs for potato starch branching enzyme (SBE) were introduced into potato (Solanum tuberosum L.). A population of transgenic plants were generated in which tuber SBE activity was reduced by between 5 and 98% of control values. No significant differences in amylose content or amylopectin branch length profiles of transgenic tuber starches were observed as a function of

Richard Safford; Steve A. Jobling; Chris M. Sidebottom; Roger J. Westcott; David Cooke; Karen J. Tober; Barbara H. Strongitharm; Alison L. Russell; Michael J. Gidley



RVA analysis of mixtures of wheat flour and potato, sweet potato, yam, and cassava starches  

Microsoft Academic Search

Rapid visco analysis (RVA) was performed to study the pasting properties of mixtures of wheat flour and tuber starches, i.e., potato starch (PS), sweet potato starch (SPS), yam starch (YS), and cassava starch (CS), at 10–50% starch in the mixtures. Lower phosphorus and higher amylose contents were observed in CS, followed by YS, SPS, and PS. The peak, breakdown, final,

I. S. M. Zaidul; N. A. Nik Norulaini; A. K. Mohd. Omar; H. Yamauchi; T. Noda




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.



The amyloplast proteome of potato tuber.  


Potato (Solanum tuberosum) is the fourth largest crop worldwide in yield, and cv. Kuras is the major starch potato of northern Europe. Storage starch is packed densely in tuber amyloplasts, which become starch granules. Amyloplasts of soil-grown mini-tubers and agar-grown micro-tubers of cv. Kuras were purified. The mini-tuber amyloplast preparation was enriched 10-20-fold and the micro-tuber amyloplast approximately fivefold over comparative total protein extracts. Proteins separated by SDS-PAGE were digested with trypsin, analysed by mass spectrometry and identified by mascot software searches against an in-house potato protein database and the NCBI non-redundant plant database. The differential growth conditions for mini- and micro-tubers gave rise to rather different protein profiles, but the major starch granule-bound proteins were identical for both and dominated by granule-bound starch synthase I, starch synthase II and alpha-glucan water dikinase. Soluble proteins were dominated by starch phosphorylase L-1, other large proteins of the classes 'starch and sucrose metabolism', 'pentose phosphate pathway', 'glycolysis', 'amino acid metabolism', and other proteins such as plastid chaperonins. The majority of the identified proteins had a predicted plastid transit peptide, supporting their presence in the amyloplast. However, several highly expressed proteins had no transit peptide, such as starch phosphorylase H, or had a predicted mitochondrial location. Intriguingly, all polyphenol oxidases, a family of enolases, one transketolase, sulfite reductase, deoxynucleoside kinase-like and dihydroxy-acid dehydrase had twin-arginine translocation motifs, and a homologue to dihydrolipoamide dehydrogenase had a Sec (secretory) motif; these motifs usually target thylakoid-like structures. PMID:18331355

Stensballe, Allan; Hald, Simon; Bauw, Guy; Blennow, Andreas; Welinder, Karen G




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. ...




Effects of Starch Properties and Thermal-processing Conditions on Surimi–Starch Gels  

Microsoft Academic Search

Effects of starch and thermal-processing conditions on texture, microstructure, and color of surimi–starch gels were investigated by measuring shear stress, shear strain and color values, as well as microstructure. The influences of starch on texture of surimi–starch gels depended on the concentration and modification of starch as well as the ratio of amylose and amylopectin. Starch increased the gel strength

Hong Yang; Jae W. Park



Tuberous Sclerosis  


... developmental delays. Behavior problems, such as hyperactivity and aggression, may occur. Some children who have tuberous sclerosis ... child had any behavior problems, such as hyperactivity, aggression, rage or self-injury? Does your child have ...


Isolation of high quality RNA from seeds and tubers of the Mexican yam bean ( Pachyrhizus erosus )  

Microsoft Academic Search

Pachyrhizus erosus is a tuberous legume native to Central America that has great potential for development as a food crop. It produces both\\u000a protein rich grain and starch filled tubers. There are two major limitations to its dietary use, the high levels of rotenone\\u000a found in the grains and the low starch content of the tubers, both of which must

Felicia Hosein



Immunocytochemical localization of ADPglucose pyrophosphorylase in developing potato tuber cells  

SciTech Connect

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

Kim, Woo Taek; Franceschi, V.R.; Okita, T.W. (Washington State Univ., Pullman (USA)); Robinson, N.L.; Morell, M.; Preiss, J. (Michigan State Univ., East Lansing (USA))



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.

Streb, Sebastian; Zeeman, Samuel C.



Testing properties of potato starch from different scales of isolations—A ringtest  

Microsoft Academic Search

Five different procedures were used to isolate potato starch from the same batch at three different scales in order to analyse what influence scaling up of the starch process had on the starch physical\\/chemical properties. Common to the five isolation processes was the steps of washing and maceration of potato tubers followed by separation of starch and cell debris by

Bente Wischmann; Tina Ahmt; Ole Bandsholm; Andreas Blennow; Niall Young; Lotte Jeppesen; Lars Thomsen



Development and growth of potato tubers in microgravity.  


A potato explant consisting of a leaf, its axillary bud, and a small segment of stem will develop a tuber in 10-14 days when grown on earth. The tubers develop from the axillary buds and accumulate starch derived from sugars produced through photosynthesis and/or mobilized from leaf tissue. Potato explants were harvested and maintained in the Astroculture (TM) unit, a plant growth chamber designed for spaceflight. The unit provides an environment with controlled temperature, humidity, CO2 level, light intensity, and a nutrient delivery system. The hardware was loaded onto the space shuttle Columbia 24 hours prior to the launch of the STS-73 mission. Explant leaf tissue appeared turgid and green for the first 11 days of flight, but then became chlorotic and eventually necrotic by the end of the mission. The same events occurred to ground control explants with approximately the same timing. At the end of the 16-day mission, tubers were present on each explant. The size and shape of the space-grown tubers were similar to the ground-control tubers. The arrangement of cells in the tuber interior and at the exterior in the periderm was similar in both environments. Starch and protein were present in the tubers grown in space and on the ground. The range in starch grain size was similar in tubers from both environments, but the distribution of grains into size classes differed somewhat, with the space-grown tubers having more small grains than the ground control tubers. Proteinaceous crystals were found in tubers formed in each condition. PMID:11541357

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



Changes in rheological properties and amylase activities of trifoliate yam, Dioscorea dumetorum, starch after harvest  

Microsoft Academic Search

Changes in rheological properties and amylase activities occurring in trifoliate yam, Dioscorea dumetorum, starch after harvest were investigated. Trifoliate yam tubers were harvested and stored under tropical ambient (28 °C) and cold room conditions (4 °C) for 12, 24 and 36 h. The D. dumetorum starches were extracted from the tubers under study and samples were evaluated for changes in their rheological

Emmanuel Ohene Afoakwa; Samuel Sefa-Dedeh



The starch phosphorylase gene is subjected to different modes of regulation in starch-containing tissues of potato  

Microsoft Academic Search

Analysis of the levels of starch phosphorylase mRNA and its product in the various organs of the potato plant indicates that the gene is differentially regulated, leading to a high accumulation of the gene product in tubers. The amount of phosphorylase transcripts synthesized in nuclei isolated from tubers and leaves indicates that the difference in the steady-state levels of phosphorylase

Benoit St-Pierre; Charles Bertrand; Anne Camirand; Mario Cappadocia; Normand Brisson



Sucrose application causes hormonal changes associated with potato tuber induction  

Microsoft Academic Search

Stems of potato plants (Solanum tuberosum L. cv. Dianella) were immersed in solutions containing water (control), sucrose, glucose, paclobutrazol, and gibberellic\\u000a acid. The effects of these treatments on the ethylene release, levels of endogenous gibberellins, glucose, sucrose, and starch\\u000a were correlated with tuberization of nodal cuttings, excised from potato stems. Paclobutrazol and sucrose improved the percent\\u000a of tuberization and\\/or increased

Ivan Šimko



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.




Nutritional value of potato tubers from field grown plants treated with deltamethrin  

Microsoft Academic Search

Summary  Tubers showed changes in their nutritional value caused by the treatment of the plants with the insecticide deltamethrin.\\u000a The level of starch was increased in comparison with control tubers; but the amylose percentage was not affected. In contrast,\\u000a the total protein content decreased in tubers from treated plants, whereas free amino acids level and ascorbic acid content\\u000a increased. The results

Fernanda Fidalgo; Isabel Santos; R. Salema



Physical and functional properties of arrowroot starch extrudates.  


Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food. PMID:19323747

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



Identification of epileptogenic tubers in patients with tuberous sclerosis complex  

Microsoft Academic Search

Identification of epileptogenic tubers in patients with tuberous sclerosis complex Tuberous sclerosis complex (TSC) is associated with epilepsy and mental retardation. The principal aim of this thesis was to identify epileptogenic tuber(s) enabling the selection of patients for epilepsy surgery. In addition we analysed possible determinants of cognitive functioning in patients with TSC. Genotype (different TSC1 and TSC2 mutations, tuber

F. E. Jansen



Effects of supercritical fluid extraction on Curcuma longa L. and Zingiber officinale R. starches  

Microsoft Academic Search

Ginger and turmeric tubers have approximately 45 and 40% of starch, respectively. These starches were analyzed before and after ginger and turmeric were subjected to supercritical fluid extraction to obtain oleoresin and essential oil. The starches were isolated and analyzed with respect to purity, amylose\\/amylopectin content, X-ray pattern, viscosity, swelling factor, granule morphology by scanning electron microscopy, gelatinization temperature by

Mara E. M. Braga; Silvânia R. M. Moreschi; M. Angela A. Meireles



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

PubMed Central

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

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



Characterisation of leucyl aminopeptidase from Solanum tuberosum tuber  

Microsoft Academic Search

Potato juice (a waste product from the starch industry) is a potential source of novel enzymes for food applications. For use in the production and improvement of food protein hydrolysates, commercially available exopeptidases, predominantly aminopeptidases, are recommended. The present study was performed to explore possible biotechnological interest of leucyl aminopeptidase (LAP) activity in the potato tuber. The LAP from potato

Zoran Vuj?i?; Nikola Lon?ar; Biljana Dojnov; Aleksandra Milovanovi?; Miroslava Vuj?i?; Nataša Boži?



Altering Trehalose-6-Phosphate Content in Transgenic Potato Tubers Affects Tuber Growth and Alters Responsiveness to Hormones during Sprouting1[C][W  

PubMed Central

Trehalose-6-phosphate (T6P) is a signaling metabolite that regulates carbon metabolism, developmental processes, and growth in plants. In Arabidopsis (Arabidopsis thaliana), T6P signaling is, at least in part, mediated through inhibition of the SNF1-related protein kinase SnRK1. To investigate the role of T6P signaling in a heterotrophic, starch-accumulating storage organ, transgenic potato (Solanum tuberosum) plants with altered T6P levels specifically in their tubers were generated. Transgenic lines with elevated T6P levels (B33-TPS, expressing Escherichia coli osmoregulatory trehalose synthesis A [OtsA], which encodes a T6P synthase) displayed reduced starch content, decreased ATP contents, and increased respiration rate diagnostic for high metabolic activity. On the other hand, lines with significantly reduced T6P (B33-TPP, expressing E. coli OtsB, which encodes a T6P phosphatase) showed accumulation of soluble carbohydrates, hexose phosphates, and ATP, no change in starch when calculated on a fresh weight basis, and a strongly reduced tuber yield. [14C]Glucose feeding to transgenic tubers indicated that carbon partitioning between starch and soluble carbohydrates was not altered. Transcriptional profiling of B33-TPP tubers revealed that target genes of SnRK1 were strongly up-regulated and that T6P inhibited potato tuber SnRK1 activity in vitro. Among the SnRK1 target genes in B33-TPP tubers, those involved in the promotion of cell proliferation and growth were down-regulated, while an inhibitor of cell cycle progression was up-regulated. T6P-accumulating tubers were strongly delayed in sprouting, while those with reduced T6P sprouted earlier than the wild type. Early sprouting of B33-TPP tubers correlated with a reduced abscisic acid content. Collectively, our data indicate that T6P plays an important role for potato tuber growth.

Debast, Stefan; Nunes-Nesi, Adriano; Hajirezaei, Mohammad R.; Hofmann, Jorg; Sonnewald, Uwe; Fernie, Alisdair R.; Bornke, Frederik



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


Starches used in food industry are extracted from roots, tubers and cereals. Seeds of jackfruit are abundant and contain high amounts of starch. They are discarded during the fruit processing or consumption and can be an alternative source of starch. The starch was extract from the jackfruit seeds and characterised to chemical, morphological and functional properties. Soft and hard jackfruit seeds showed starch content of 92.8% and 94.5%, respectively. Starch granules showed round and bell shape and some irregular cuts on their surface with type-A crystallinity pattern, similar to cereals starches. The swelling power and solubility of jackfruit starch increased with increasing temperature, showing opaque pastes. The soft seeds starch showed initial and final gelatinisation temperature of 36°C and 56°C, respectively; while hard seeds starch presented initial gelatinisation at 40°C and final at 61°C. These results suggest that the Brazilian jackfruit seeds starches could be used in food products. PMID:24054264

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



Starch synovitis.  

PubMed Central

Three patients with unexplained synovial inflammation were found to have an ulcerative, granulomatous synovitis on biopsy. Maize starch was identified in giant cells within the granulomata. Starch synovitis has clinical and histological similarities to starch peritonitis, which is thought to be an example of a cell mediated immune response. Images

Freemont, A J; Porter, M L; Tomlinson, I; Clague, R B; Jayson, M I



The molecular deposition of transgenically modified starch in the starch granule as imaged by functional microscopy.  


The molecular deposition of starch extracted from normal plants and transgenically modified potato lines was investigated using a combination of light microscopy, environmental scanning electron microscopy (ESEM) and confocal laser scanning microscopy (CLSM). ESEM permitted the detailed (10 nm) topographical analysis of starch granules in their hydrated state. CLSM could reveal internal molar deposition patterns of starch molecules. This was achieved by equimolar labelling of each starch molecule using the aminofluorophore 8-amino-1,3,6-pyrenetrisulfonic acid (APTS). Starch extracted from tubers with low amylose contents (suppressed granule bound starch synthase, GBSS) showed very little APTS fluorescence and starch granules with low molecular weight amylopectin and/or high amylose contents showed high fluorescence. Growth ring structures were sharper in granules with normal or high amylose contents. High amylose granules showed a relatively even distribution in fluorescence while normal and low amylose granules had an intense fluorescence in the hilum indicating a high concentration of amylose in the centre of the granule. Antisense of the starch phosphorylating enzyme (GWD) resulted in low molecular weight amylopectin and small fissures in the granules. Starch granules with suppressed starch branching enzyme (SBE) had severe cracks and rough surfaces. Relationships between starch molecular structure, nano-scale crystalline arrangements and topographical-morphological features were estimated and discussed. PMID:14572478

Blennow, Andreas; Hansen, Michael; Schulz, Alexander; Jørgensen, Kirsten; Donald, Athene M; Sanderson, James



Effects of mucilage on the thermal and pasting properties of yam, taro, and sweet potato starches  

Microsoft Academic Search

This study investigates the effects of water-soluble mucilages (0, 2.5, and 5 g\\/100 g; w\\/w, dry basis) on the thermal and pasting properties of isolated starches from three root and tuber crops. The results show that yam tuber presents the greatest level of mucilage and also possess the largest amylose content of the three isolated starches. The addition of mucilage caused a

Chien-Chun Huang; Phoency Lai; I.-Hua Chen; Yi-Fan Liu; Chiun-C. R. Wang



Enhancing the expression of starch synthase class IV results in increased levels of both transitory and long-term storage starch.  


Starch is an important renewable raw material with an increasing number of applications. Several attempts have been made to obtain plants that produce modified versions of starch or higher starch yield. Most of the approaches designed to increase the levels of starch have focused on the increment of the amount of ADP-glucose or ATP available for starch biosynthesis. In this work, we show that the overexpression of starch synthase class IV (SSIV) increases the levels of starch accumulated in the leaves of Arabidopsis by 30%-40%. In addition, SSIV-overexpressing lines display a higher rate of growth. The increase in starch content as a consequence of enhanced SSIV expression is also observed in long-term storage starch organs such as potato tubers. Overexpression of SSIV in potato leads to increased tuber starch content on a dry weight basis and to increased yield of starch production in terms of tons of starch/hectare. These results identify SSIV as one of the regulatory steps involved in the control of the amount of starch accumulated in plastids. PMID:21645200

Gámez-Arjona, Francisco M; Li, Jun; Raynaud, Sandy; Baroja-Fernández, Edurne; Muñoz, Francisco J; Ovecka, Miroslav; Ragel, Paula; Bahaji, Abdellatif; Pozueta-Romero, Javier; Mérida, Ángel



Almidón retrogradado para uso en compresión directa. I. Caracterización y pregelatinización del almidón de chayote Retrograded starch for direct compaction. I. Process and characterization of chayotes starch  

Microsoft Academic Search

The direct compaction excipients have showed to be highly efficient, and that is why some of them have been developed from different starch sources. The starch extracted from tuberous chayote roots (Sechium edule), can be attractive in pharmaceutical field because it gives highly viscose water solutions and have high amylose proportion. With the objet to impart it appropriate compaction properties,

María de Lourdes



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


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



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.

Songstad, Susan



Mutan produced in potato amyloplasts adheres to starch granules  

Microsoft Academic Search

Production of water-insoluble mutan polymers in Kardal potato tubers was investigated after expression of a full-length (GtfI) and a truncated mutansucrase gene referred to as GtfICAT (GtfI without glucan-binding domain) from Streptococcus downei. Subsequent effects on starch biosynthesis at the molecular and biochemical levels were studied. Expression of the GtfICAT gene resulted in the adhesion of mutan material on starch

Geraldine A. Kok-Jacon; Jean-Paul Vincken; Luc C. J. M. Suurs; Richard G. F. Visser



Production of the raw-starch digesting amylase of Aspergillus sp. K-27  

Microsoft Academic Search

Aspergillus sp. K-27, isolated from soil, produced extracellular glucoamylase and a-amylase using wheat starch as a carbon source, and its productivity was doubled by the addition of a-methyl-d-glucoside to the medium. The crude enzyme preparation, which was found to be a mixture of 70% glucoamylase and 30% a-amylase, well degraded not only cereal starches but also tuber and root starches,

Jun-ichi Abe; Frederico W. Bergmann; Kazuaki Obata; Susumu Hizukuri



Physicochemical Properties of Common and Tartary Buckwheat Starch  

Microsoft Academic Search

Cereal Chem. 74(1):79-82 Physicochemical properties of starch of three common ( Fagopyrum esculentum) and three tartary ( F. tataricum) buckwheat varieties from Shanxi Province, China, were compared. Starch color, especially b*, differed greatly between tartary (7.99-9.57) and common (1.97-2.42) buckwheat, indicating that removal of yellow pigments from tartary buckwheat flour may be problematic during starch isolation. Starch swelling volume in

Wende Li; Rufa Lin; Harold Corke



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


Calcium alginate-starch entrapped bitter gourd peroxidase has been employed for the treatment of a textile industrial effluent in batch as well as in continuous reactor. The textile effluent was recalcitrant to decolorization by bitter gourd peroxidase; thus, its decolorization was examined in the presence of a redox mediator, 1.0 mM 1-hydroxybenzotriazole. Immobilized enzyme exhibited same pH and temperature optima for effluent decolorization as attained by soluble enzyme. Immobilized enzyme could effectively remove more than 70% of effluent color in a stirred batch process after 3 h of incubation. Entrapped bitter gourd peroxidase retained 59% effluent decolorization reusability even after its tenth repeated use. The two-reactor system containing calcium alginate-starch entrapped enzyme retained more than 50% textile effluent decolorization efficiency even after 2 months of its operation. The absorption spectra of the treated effluent exhibited a marked difference in the absorption at various wavelengths as compared to untreated effluent. The use of a two-reactor system containing immobilized enzyme and an adsorbent will be significantly successful for treating industrial effluents at large scale, and it will help in getting water free from aromatic pollutants. PMID:19015823

Matto, Mahreen; Satar, Rukhsana; Husain, Qayyum



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.



Evidence against sink limitation by the sucrose-to-starch route in potato plants expressing fructosyltransferases.  


To investigate whether the route from sucrose to starch limits sink strength of potato tubers, we established an additional storage carbohydrate pool and analyzed allocation of imported assimilates to the different pools. Tuber specific expression of the fructan biosynthetic enzymes of globe artichoke resulted in accumulation of fructans to about 5% of the starch level, but did not increase tuber dry weight per plant. While partial repression of starch synthesis caused yield reduction in wild-type plants, it stimulated fructan accumulation, and yield losses were ameliorated in tubers expressing fructosyltransferases. However, a nearly complete block of the starch pathway by inhibition of sucrose synthase could not be compensated by the fructan pathway. Although fructan concentrations rose, yield reduction was even enhanced, probably because of a futile cycle of fructan synthesis and degradation by invertase, which is induced when sucrose synthase is knocked out. The data do not support a limitation of sink strength by enzyme activities of the starch pathway but point to an energy limitation of storage carbohydrate formation in potato tubers. PMID:21679192

Zuther, Ellen; Hoermiller, Imke I; Heyer, Arnd G



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


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



Structural and thermodynamic properties of starches extracted from GBSS and GWD suppressed potato lines.  


A combined DSC-SAXS approach was employed to study the effects of amylose and phosphate esters on the assembly structures of amylopectin in B-type polymorphic potato tuber starches. Amylose and phosphate levels in the starches were specifically engineered by antisense suppression of the granule bound starch synthase (GBSS) and the glucan water dikinase (GWD), respectively. Joint analysis of the SAXS and DSC data for the engineered starches revealed that the sizes of amylopectin clusters, thickness of crystalline lamellae and the polymorphous structure type remained unchanged. However, differences were found in the structural organization of amylopectin clusters reflected in localization of amylose within these supramolecular structures. Additionally, data for annealed starches shows that investigated potato starches possess different types of amylopectin defects. The relationship between structure of investigated potato starches and their thermodynamic properties was recognized. PMID:17188347

Kozlov, Sergey S; Blennow, Andreas; Krivandin, Alexei V; Yuryev, Vladimir P



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


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



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

PubMed Central

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

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



Novel candidate genes influencing natural variation in potato tuber cold sweetening identified by comparative proteomics and association mapping  

PubMed Central

Background Higher plants evolved various strategies to adapt to chilling conditions. Among other transcriptional and metabolic responses to cold temperatures plants accumulate a range of solutes including sugars. The accumulation of the reducing sugars glucose and fructose in mature potato tubers during exposure to cold temperatures is referred to as cold induced sweetening (CIS). The molecular basis of CIS in potato tubers is of interest not only in basic research on plant adaptation to environmental stress but also in applied research, since high amounts of reducing sugars affect negatively the quality of processed food products such as potato chips. CIS-tolerance varies considerably among potato cultivars. Our objective was to identify by an unbiased approach genes and cellular processes influencing natural variation of tuber sugar content before and during cold storage in potato cultivars used in breeding programs. We compared by two-dimensional polyacrylamide gel electrophoresis the tuber proteomes of cultivars highly diverse for CIS. DNA polymorphisms in genomic sequences encoding differentially expressed proteins were tested for association with tuber starch content, starch yield and processing quality. Results Pronounced natural variation of CIS was detected in tubers of a population of 40 tetraploid potato cultivars. Significant differences in protein expression were detected between CIS-tolerant and CIS-sensitive cultivars before the onset as well as during cold storage. Identifiable differential proteins corresponded to protease inhibitors, patatins, heat shock proteins, lipoxygenase, phospholipase A1 and leucine aminopeptidase (Lap). Association mapping based on single nucleotide polymorphisms supported a role of Lap in the natural variation of the quantitative traits tuber starch and sugar content. Conclusions The combination of comparative proteomics and association genetics led to the discovery of novel candidate genes for influencing the natural variation of quantitative traits in potato tubers. One such gene was a leucine aminopeptidase not considered so far to play a role in starch sugar interconversion. Novel SNP’s diagnostic for increased tuber starch content, starch yield and chip quality were identified, which are useful for selecting improved potato processing cultivars.



Autism and Tuberous Sclerosis  

Microsoft Academic Search

Autism and pervasive developmental disorders (PDD) are common in tuberous sclerosis (TSC). The frequency of autism is about 25%, with 40–45% of TSC cases meeting criteria for autism or PDD. Among autistic populations, the frequency of TSC is 1–4% and perhaps as high as 8–14% among the subgroup of autistic individuals with a seizure disorder. Mental retardation (MR) and seizures,

Susan L. Smalley



Tuber storage proteins.  


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



Thermal behaviour of starch and oxidized starch  

Microsoft Academic Search

Thermal gravimetric analysis, and differential thermal behaviour of unoxidized and oxidized starch were studied. Degradation was found to be first order in sample weight reaction. The activation energy values and the rate constants were calculated from the kinetic of weight loss. Unoxidized starch was found to be less stable than oxidized starch and the stability of the samples was arranged

Aisha A. A. Soliman; Nabila A. El-Shinnawy; Fardous Mobarak



Immunological Comparison oftheStarch Branching EnzymesfromPotato TubersandMaizeKernels1  

Microsoft Academic Search

Starch branching enzymewaspurified frompotato (Solanum tuberosum L.)tubers asasingle species of79kilodaltons and specific antibodies wereprepared against boththenative enzyme andagainst thegel-purified, denatured enzyme. Theactivity of potato branching enzymecould onlybeneutralized byantinative potato branching enzyme, whereas bothtypesofantibodies re- acted withdenatured potato branching enzyme. Starch branching enzymeswerealsoisolated frommaize(ZeamaysL.)kernels. Allofthedenatured formsofthemaizeenzymereacted with antidenatured potato branching enzyme, whereas recognition by antinative potato branching enzymewaslimited tomaizebranch- ingenzymesIandllb. Antibodies

Greetje H. Vos-Scheperkeuter; Will J. Feenstra


A study of the rate of recycling of triose phosphates in heterotrophic Chenopodium rubrum cells, potato tubers, and maize endosperm  

Microsoft Academic Search

We have investigated whether starch accumulation in heterotrophic cell-suspension cultures of Chenopodium rubrum L., developing potato (Solarium tuberosum L.) tubers or maize (Zea mays L.) endosperm involves import of triose phosphates or of hexose units into the plastid, and whether there is a rapid recycling of triose phosphates back to hexose phosphates in the cytosol of these tissues, (i) Cell

Wolf-Dieter Hatzfeld; Mark Stitt



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


Starch, an essential component of an equilibrated diet, is present in cereals such as common and durum wheat, maize, rice, and rye, in roots and tubers such as potato and cassava, and in legumes such as peas. During food processing, starch mainly undergoes nonchemical transformations. Here, we focus on the occurrence of starch in food raw materials, its composition and properties, and its transformations from raw material to final products. We therefore describe a number of predominant food processes and identify research needs. Nonchemical transformations that are dealt with include physical damage to starch, gelatinization, amylose-lipid complex formation, amylose crystallization, and amylopectin retrogradation. A main focus is on wheat-based processes. (Bio)chemical modifications of starch by amylolytic enzymes are dealt with only in the context of understanding the starch component in bread making. PMID:22129331

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



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


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



Surface area estimation of potato tubers  

Microsoft Academic Search

Surface areas of tubers of the potato cultivars Cara, Désirée, King Edward and Maris Piper were estimated empirically by measuring the area of adhesive tape required to cover each tuber surface. Measuring the area of thin peelings of all four cultivars underestimated tuber surface area, the degree of underestimation increasing with decreasing tuber size. ‘Shape factors’ (D), calculated as:D =

N. H. Banks



Ultrastructural Changes in Potato Tuber Pith Cells during Brown Center Development.  


Electron microscopy revealed that subjecting ;Russet Burbank' potato (Solanum tuberosum L.) plants to 2 days of cool temperature growing conditions (18 degrees C days/10 degrees C nights) did not produce visible damage or changes in tuber pith tissue when compared to warm-grown tubers (23 degrees C days/18 degrees C nights). However, damage to some tuber pith cells was observed after 5 days of cool treatment. Eight days of cool treatment produced extensive alterations in cell structure. The cytoplasm of the cool-treated tuber pith cells had become highly vesiculated and there was evidence of complete destruction of amyloplast membranes and tonoplasts. In many cases the starch grains appeared to be undergoing hydrolysis suggesting total disruption of normal cell function. Sixteen days of cool treatment were sufficient to produce visible brown center development in all cool-grown tubers examined. Electron microscopy of these tissues revealed that, although some organelles were still present, the cytoplasm had become extremely vesiculated and lacked any resemblance to that of tissue from warm-grown tubers. Gross, irregular thickening of cell walls was also detected. PMID:16664768

Van Denburgh, R W; Hiller, L K; Koller, D C



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.

Kumar, GNM.; Knowles, N. R.



Subunit interactions specify the allosteric regulatory properties of the potato tuber ADP-glucose pyrophosphorylase  

Microsoft Academic Search

ADP-glucose pyrophosphorylase (AGPase) catalyzes the first committed step of starch synthesis in plants. The potato tuber enzyme contains a pair of catalytic small subunits (SSs) and a pair of non-catalytic large subunits (LSs). We have previously identified a LS mutant containing a P52L replacement, which rendered the enzyme with down-regulatory properties. To investigate the structure–function relationships between the two subunits

Dongwook Kim; Seon-Kap Hwang; Thomas W. Okita



Reduced penetrance in tuberous sclerosis  

Microsoft Academic Search

Two first cousins are reported with clinical evidence of tuberous sclerosis. The intervening brother and sister show no evidence of the disease on clinical and Wood's lamp examination, nor on CT scan.

M Baraitser; M A Patton



The tuberous sclerosis complex  

PubMed Central

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

Orlova, Ksenia A.; Crino, Peter B.



The legwd mutant uncovers the role of starch phosphorylation in pollen development and germination in tomato.  


Starches extracted from most plant species are phosphorylated. alpha-Glucan water dikinase (GWD) is a key enzyme that controls the phosphate content of starch. In the absence of its activity starch degradation is impaired, leading to a starch excess phenotype in Arabidopsis and in potato leaves, and to reduced cold sweetening in potato tubers. Here, we characterized a transposon insertion (legwd::Ds) in the tomato GWD (LeGWD) gene that caused male gametophytic lethality. The mutant pollen had a starch excess phenotype that was associated with a reduction in pollen germination. SEM and TEM analyses indicated mild shrinking of the pollen grains and the accumulation of large starch granules inside the plastids. The level of soluble sugars was reduced by 1.8-fold in mutant pollen grains. Overall, the transmission of the mutant allele was only 0.4% in the male, whereas it was normal in the female. Additional mutant alleles, obtained through transposon excision, showed the same phenotypes as legwd::Ds. Moreover, pollen germination could be restored, and the starch excess phenotype could be abolished in lines expressing the potato GWD homolog (StGWD) under a pollen-specific promoter. In these lines, where fertility was restored, homozygous plants for legwd::Ds were isolated, and showed the starch excess phenotype in the leaves. Overall, our results demonstrate the importance of starch phosphorylation and breakdown for pollen germination, and open up the prospect for analyzing the role of starch metabolism in leaves and fruits. PMID:18764922

Nashilevitz, Shai; Melamed-Bessudo, Cathy; Aharoni, Asaph; Kossmann, Jens; Wolf, Shmuel; Levy, Avraham A



Effect of temperature on carbohydrate content, ADP glucose pyrophosphorylase, and ATP and PPi-dependent phosphofructokinase activity of potato tuber callus tissue  

Microsoft Academic Search

Callus derived from Lemhi Russet and Russet Burbank tuber tissue was incubated at 20°C and 30°C on a high sucrose medium for starch-formation and subjected to simulated storage and reconditioning treatments at 5°C and 25°C after transfer of the callus to a medium without a carbon source. Percent dry weight of callus from both cultivars averaged about 21% after starch

Steven R. Hagen; Paul Muneta



Seed Starch Synthesis  

Microsoft Academic Search

Maize plants accumulate starch as a carbohydrate energy reserve in the seed endosperm. Starch is composed of two homopolymers of ? -D-glucose, amylose (Am) and amylopectin (Ap), which are organized to form water insoluble semicrystalline granules. Am comprises ~25% of starch, and is essentially a linear molecule in which glucosyl monomers are joined via ? -(1?4) linkages to form long

Martha James; Alan Myers


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



Suitability of Edible Bean and Potato Starches for Starch Noodles  

Microsoft Academic Search

Cereal Chem. 73(3):302-308 Starch noodles were prepared from two types of bean (navy and cial starch noodles with respect to cooking loss and cooked weight. Tex- pinto) starch and three sources of potato starch (ND651-9, Mainechip, ture profile analysis (TPA) results showed starch noodles made from and commercial potato starch). Physicochemical properties of those bean starches had higher hardness values,




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


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. PMID:12867548

Cook, Martha E; Croxdale, Judith G



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.  


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



Cerebellar pathology in tuberous sclerosis.  


Cerebellar involvement in tuberous sclerosis is rare and generally nonsymptomatic. The authors describe a cerebellar tuber in a 5-year-old boy with tuberous sclerosis. A CT scan at age 2 years showed the characteristic cortical, white matter, and subependymal lesions of tuberous sclerosis. At 5 years, when the patient was symptomatic with ataxia, the CT and MRI scans revealed additionally the presence of a right cerebellar enhancing lesion with edema. A total surgical resection was undertaken. The cerebellar lesion was very firm and demonstrated marked disorganization of neuronal architecture in the cerebellar folia, with bizzare ectopic neurons in the molecular and granule cell layers and white matter, along with calcification, gliosis, and Rosenthal fiber deposition. Balloon cells with glassy, pale, eosinophilic cytoplasm were also present. There was a marked loss of myelin in the white matter, with significant vacuolation and gliosis. Electron microscopy documented abundant lysosomal inclusions, prominent rough endoplasmic reticulum and Golgi complexes, microtubules, intermediate filaments, and synaptic contacts. While there is much speculation as to the precise nature of cerebellar pathology in tuberous sclerosis, this case demonstrates conclusively that the cerebellar lesions reflect anomolous neuronal development and migration akin to supratentorial lesions and can rarely be symptomatic. PMID:9805358

Jay, V; Edwards, V; Musharbash, A; Rutka, J T


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. ...

Sturgell, Mr.




Technology Transfer Automated Retrieval System (TEKTRAN)

At harvest, potato (Solanum tuberosum L.) tubers are dormant and will not sprout. As the period of postharvest storage is extended, tuber dormancy is broken and sprout growth commences. The loss of tuber dormancy and onset of sprout growth is accompanied by numerous biochemical changes, many of wh...


Metabolic and Developmental Adaptations of Growing Potato Tubers in Response to Specific Manipulations of the Adenylate Energy Status1[W][OA  

PubMed Central

Heterotrophic carbon metabolism has been demonstrated to be limited by oxygen availability in a variety of plant tissues, which in turn inevitably affects the adenylate status. To study the effect of altering adenylate energy metabolism, without changing the oxygen supply, we expressed a plastidially targeted ATP/ADP hydrolyzing phosphatase (apyrase) in tubers of growing potato (Solanum tuberosum) plants under the control of either inducible or constitutive promoters. Inducible apyrase expression in potato tubers, for a period of 24 h, resulted in a decrease in the ATP-content and the ATP-ADP ratio in the tubers. As revealed by metabolic profiling, this was accompanied by a decrease in the intermediates of sucrose to starch conversion and several plastidially synthesized amino acids, indicating a general depression of tuber metabolism. Constitutive tuber-specific apyrase expression did not lead to a reduction of ATP, but rather a decrease in ADP and an increase in AMP levels. Starch accumulation was strongly inhibited and shifted to the production of amylopectin instead of amylose in these tubers. Furthermore, the levels of almost all amino acids were decreased, although soluble sugars and hexose-Ps were highly abundant. Respiration was elevated in the constitutively expressing lines indicating a compensation for the dramatic increase in ATP hydrolysis. The increase in respiration did not affect the internal oxygen tensions in the tubers. However, the tubers developed a ginger-like phenotype having an elevated surface-volume ratio and a reduced mass per tuber. Decreased posttranslational redox activation of ADP-glucose pyrophosphorylase and a shift in the ratio of soluble starch synthase activity to granule-bound starch synthase activity were found to be partially responsible for the alterations in starch structure and abundance. The activity of alcohol dehydrogenase was decreased and pyruvate decarboxylase was induced, but this was neither reflected by an increase in fermentation products nor in the cellular redox state, indicating that fermentation was not yet induced in the transgenic lines. When taken together the combined results of these studies allow the identification of both short- and long-term adaptation of plant metabolism and development to direct changes in the adenylate status.

Riewe, David; Grosman, Lukasz; Zauber, Henrik; Wucke, Cornelia; Fernie, Alisdair R.; Geigenberger, Peter



DETERMINAÇÃO DA COR, IMAGEM SUPERFICIAL TOPOGRÁFICA E ÂNGULO DE CONTATO DE BIOFILMES DE DIFERENTES FONTES DE AMIDO 1 Determination of color, topographic superficial image and contact angle of the biofilms of different starch sources  

Microsoft Academic Search

Nowadays, the pollution has considerably increased by the large amount of the non-degradable synthetic plastics that is discarded everyday in the environment. One of the alternatives that could contribute to minimize this problem would be the use of the starch as main composite in biodegradable films also called biofilms; in other words, this material is easily degradable when disposed in

Washington Azevêdo da Silva; Joelma Pereira; Carlos Wanderlei; Piler de Carvalho; Fabiana Queiroz Ferrua


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...


Fusion proteins comprising the catalytic domain of mutansucrase and a starch-binding domain can alter the morphology of amylose-free potato starch granules during biosynthesis.  


It has been shown previously that mutan can be co-synthesized with starch when a truncated mutansucrase (GtfICAT) is directed to potato tuber amyloplasts. The mutan seemed to adhere to the isolated starch granules, but it was not incorporated in the starch granules. In this study, GtfICAT was fused to the N- or C-terminus of a starch-binding domain (SBD). These constructs were introduced into two genetically different potato backgrounds (cv. Kardal and amf), in order to bring GtfICAT in more intimate contact with growing starch granules, and to facilitate the incorporation of mutan polymers in starch. Fusion proteins of the appropriate size were evidenced in starch granules, particularly in the amf background. The starches from the various GtfICAT/SBD transformants seemed to contain less mutan than those from transformants with GtfICAT alone, suggesting that the appended SBD might inhibit the activity of GtfICAT in the engineered fusion proteins. Scanning electron microscopy showed that expression of SBD-GtfICAT resulted in alterations of granule morphology in both genetic backgrounds. Surprisingly, the amf starches containing SBD-GtfICAT had a spongeous appearance, i.e., the granule surface contained many small holes and grooves, suggesting that this fusion protein can interfere with the lateral interactions of amylopectin sidechains. No differences in physico-chemical properties of the transgenic starches were observed. Our results show that expression of granule-bound and "soluble" GtfICAT can affect starch biosynthesis differently. PMID:17160452

Nazarian Firouzabadi, Farhad; Kok-Jacon, Géraldine A; Vincken, Jean-Paul; Ji, Qin; Suurs, Luc C J M; Visser, Richard G F



The starch granuloma syndrome.  


Starch glove powder is not entirely innocuous when introduced into the peritoneal cavity. Foreign body granulomas formed as relation to starch deposited in the peritoneal cavity may closely resemble malignant seedlings and thus mislead the surgeon in his proposed treatment of bowel cancer. In addition, the occurrence of starch granuloma peritonitis may provoke an unnecessary operation in a patient presenting with fever and peritoneal irritation a few weeks after a seemingly uncomplicated laparotomy. PMID:1092975

Vellar, I D



Epilepsy in Tuberous Sclerosis Complex  

Microsoft Academic Search

Tuberous Sclerosis Complex (TSC) is a multisystem genetic disor- der characterized by hamartomatous lesions involving skin, brain, kidneys, eyes and heart. Because of the wide variability of clinical expression and severity of TSC and the absence of a reliable mo- lecular marker of the disease, diagnosis can be difficult in patients with only subtle manifestations. Genetic linkage studies indicate that

Paolo Curatolo; Danila De Luca; Magda Verdecchia



Is starch flavor unitary? Evidence from studies of cooked starch.  


Although starch is the world's most abundant nutritive carbohydrate, its sensory properties are not as well understood as those of sugars. Previous researchers have assumed that all starches have the same flavor. The present experiments examined flavor differences among starches. Untrained rats were offered a choice of suspensions containing raw versus cooked starch. For some starches (potato and rice), rats strongly preferred cooked over uncooked starch. For other starches (regular corn, corn amylopectin, and wheat), rats showed little or no preference for cooked over uncooked starch. In order to determine whether the greater preference for cooked starch reflects a difference in flavor intensity, rats were conditioned to avoid potato or corn amylopectin starches by pairing ingestion of these substances with lithium chloride injections. Rats trained to avoid raw starch also avoided cooked starch, indicating that cooked and raw starch have similar flavors. However, when these trained rats were offered a choice between cooked and raw starch, they avoided the raw starch; this result is inconsistent with the assumption that cooking enhances the intensity of starch flavor. Similar results were obtained with corn amylopectin and potato starch, even though these starches differ greatly with regard to the effects of cooking on preference in untrained rats. However, rats trained to avoid potato starch avoided this starch to a greater degree than did rats trained to avoid corn amylopectin; conversely, rats trained to avoid corn amylopectin avoided this starch to a greater degree than did rats trained to avoid potato starch. Therefore, the flavor of starch is complex; there are specific flavor notes related to species and cooking.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1409917

Ramirez, I



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.

Odeku, Oluwatoyin A.; Akinwande, Babatunde L.



Determination of the starch-phosphorylating enzyme activity in plant extracts.  


For quantification of alpha-glucan, water dikinase (GWD) activity in crude extracts of plant tissues a radio-labeling assay was established that uses soluble starch and (33)P-labeled ATP as phosphate acceptor and donor, respectively. A constant rate of starch labeling was observed only if the ATP applied was labeled at the beta position. In wild-type extracts from leaves of Arabidopsis thaliana (L.) Heynh. the maximum rate of starch phosphorylation was approximately 27 pmol min(-1) (mg protein)(-1). Leaf extracts from the GWD-deficient sex1 mutants of Arabidopsis showed no significant incorporation of phosphate whereas extracts from potato (Solanum tuberosum L.) tuber expressing a GWD antisense construct exhibited less activity than the wild-type control. To our knowledge this is the first time that a quantification of the starch-phosphorylating activity has been achieved in plant crude extracts. PMID:12624767

Ritte, Gerhard; Steup, Martin; Kossmann, Jens; Lloyd, James R



Observations on the structure and osmotic potentials of parenchyma associated with the internal phloem of potato tubers  

Microsoft Academic Search

The structure and osmotic potentials of parenchyma cells associated with internal phloem of growing, dormant, and sprouting\\u000a potato tubers (Solanum tuberosum L. cv. Irish Cobbler) were studied. Companion cells, specialized parenchyma cells, and storage parenchyma cells were recognizable\\u000a by differences in structural characteristics. Companion cells were usually densely cytoplasmic with numerous large mitochondria\\u000a and plastids with little or no starch.

Carol A. Peterson; R. L. Peterson; W. G. Barker



The effect of exogenous sugars on the control of flux by adenosine 5'-diphosphoglucose pyrophosphorylase in potato tuber discs  

Microsoft Academic Search

The aim of this work was to investigate the effect of exogenous sugars on the extent to which starch synthesis in potato (Solanum tuberosum L.) is controlled by adenosine 5'-diphosphoglucose pyrophosphorylase (EC; AGPase). Tuber discs were incubated in the presence of a range of concentrations of glucose and sucrose, and metabolic fluxes measured following the supply of [U-14C]glucose and

Lee J. Sweetlove; Kim L. Tomlinson; Steven A. Hill



Application of Calcium Alginate–Starch Entrapped Bitter Gourd ( Momordica charantia ) Peroxidase for the Removal of Colored Compounds from a Textile Effluent in Batch as well as in Continuous Reactor  

Microsoft Academic Search

Calcium alginate–starch entrapped bitter gourd peroxidase has been employed for the treatment of a textile industrial effluent\\u000a in batch as well as in continuous reactor. The textile effluent was recalcitrant to decolorization by bitter gourd peroxidase;\\u000a thus, its decolorization was examined in the presence of a redox mediator, 1.0 mM 1-hydroxybenzotriazole. Immobilized enzyme\\u000a exhibited same pH and temperature optima for effluent

Mahreen Matto; Rukhsana Satar; Qayyum Husain



Regulation of Starch Biosynthesis  

Microsoft Academic Search

Transient or long-term storage of photosynthate in starch granules can be considered as the last step of eukaryotic photosynthesis. Storage of glucose into structures larger than the size of an individual bacterial cell is slowly uncovering as an exceedingly complex mechanism, which distinguishes the chloroplast from its ancestor prochloron or cyanobacterial-like cell. There is no question that starch biosynthesis has

Steven G. Ball


Starch mobilization in leaves  

Microsoft Academic Search

Starch mobilization is well understood in cereal endosperms, but both the pathway and the regulation of the process are poorly characterized in other types of plant organs. Arabidopsis leaves offer the opportunity for rapid progress in this area, because of the genomic resources available in this species and the ease with which starch synthesis and degradation can be monitored and

Alison M. Smith; Samuel C. Zeeman; David Thorneycroft; Steven M. Smith



A [beta]-Amylase in Potato Tubers Is Induced by Storage at Low Temperature.  

PubMed Central

A new starch-degrading enzyme activity is induced by storage of potato (Solanum tuberosum L.) tubers at low temperatures (L. Hill, R. Reimholz, R. Schroder, T.H. Nielsen, M. Stitt [1996] Plant Cell Environ 14: 1223-1237). The cold-induced activity was separated from other amylolytic activities in zymograms based on iodine staining of polyacrylamide gels containing amylopectin. A similar band of activity was detected at normal growth temperatures in leaves, stems, and growing tubers but was present only at low activity in warm-stored tubers. The cold-induced enzyme was separated by ion-exchange chromatography from other amylolytic activities. It has a broad neutral pH optimum. Characterization of its hydrolytic activity with different substrates showed that the cold-induced activity is a [beta]-amylase present at low activity in tubers stored at 20[deg]C and induced progressively when temperatures are decreased to 5 and 3[deg]C. The first clear induction of [beta]-amylase activity was observed within 3 d of storage at 3[deg]C, and the activity increased 4- to 5-fold within 10 d. The possible involvement of the cold-induced [beta]-amylase in sugar accumulation during cold storage is discussed.

Nielsen, T. H.; Deiting, U.; Stitt, M.



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



Isolation and characterization of a cDNA encoding granule-bound starch synthase in cassava (Manihot esculenta Crantz) and its antisense expression in potato  

Microsoft Academic Search

A tuber-specific cDNA library of cassava (Manihot esculenta Crantz) was constructed and a full-length cDNA for granule-bound starch synthase (GBSS, also known as waxy protein), the enzyme responsible for the synthesis of amylose in reserve starch, was cloned. Sequencing of the cloned cDNA showed that it has 74% identity with potato GBSS and 60–72% identity with GBSS from other plant

S. N. I. M. Salehuzzaman; E. Jacobsen; R. G. F. Visser



Characterization of Arenga starch in comparison with sago starch.  


The aim of this research was to characterize the composition and physical properties of palm starch obtained from Arenga pinnata in comparison with another palm starch from Metroxylon sago. The amylose contents of both starches were not significantly different. Peak gelatinization temperature was also similar at approximately 67 °C, but arenga starch showed a narrower range of gelatinization temperature than sago. The crystallinity and swelling power capacity of arenga starch were lower than those of sago. Arenga and sago starch paste at low concentrations showed shear thinning behavior, and sago formed a more viscous sol/paste than arenga. The sol-gel transition concentration of sago starch paste was found at a lower concentration than arenga starch. At high concentrations, gel from arenga starch was more rigid than that of sago. The breaking properties and texture profile of both starch gels were also clearly different, suggesting that they are suited for different applications. PMID:23399292

Adawiyah, Dede R; Sasaki, Tomoko; Kohyama, Kaoru



Influence of oxidized starch on the properties of thermoplastic starch.  


Thermoplastic starch was prepared by adding oxidized starches and glycerol together into starch. The addition of oxidized starch improved the rheological properties and also increased the toughness of thermoplastic starch. Compared with TPS30, the elongation at break increased from 126.8% to 152.5% when 5wt% OS 117% was added. Good compatibility of thermoplastic starch between the matrix and oxidized starch was confirmed by SEM. The addition of oxidized starch lowered the storage modulus and glass transition temperature (Tg) of thermoplastic starch, decreasing Tg from 34.1 to 30°C when 10 wt% OS117% was added. The thermal stability of blending was improved by adding oxidized starches, i.e. when 5 wt% OS70% was added, T5% increased from 134 to 156°C. PMID:23688492

Zhang, Yu-Rong; Wang, Xiu-Li; Zhao, Guo-Ming; Wang, Yu-Zhong



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.



Lymphangioleiomyomatosis and Tuberous Sclerosis Complex  

Microsoft Academic Search

Lymphangioleiomyomatosis (LAM) is a rare multisystemic disease of women of child-bearing age and affects mainly the lungs,\\u000a promoting cystic destruction of lung parenchyma or leading to abdominal tumor formation (e.g., angiomyolipomas, lymphangioleiomyomas).\\u000a LAM can arise sporadically or in association with tuberous sclerosis complex (TSC), an autosomal inherited syndrome characterized\\u000a by hamartoma-like tumor growth and pathologic features that are distinct from

Dimitrios Chorianopoulos; Grigoris Stratakos



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

Microsoft Academic Search

Potato was designated for food production in the controlled ecological life-support system CELSS because its tubers as it is known contain starch and significant protein content and are edible food after the long-term storage We used the cultivation of potato miniplants under influence of long-term horizontal clinorotation 2 rev min which imitated microgravity as a model for the technology of

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



Nutritional Value of Chemically Modified Corn Starches  

Microsoft Academic Search

Male and female weanling rats were fed daily 5 g of a balanced diet supplemented with 1 or 2 g of corn starch, oxidized corn starch, corn starch phosphate, or hydroxyethyl corn starch. Commercially modified corn starches produced the same weight gain as normal corn starch during 21 days of feeding. In contrast to commercial starches, a very highly oxidized

Roy L. Whistler; Alan M. Belfort



The mode of sucrose degradation in potato tubers determines the fate of assimilate utilization.  


Cytosolic (U-IN-2) or apoplasmic (U-IN-1) targeting of yeast invertase in potato tubers leads to a reduction in sucrose and an increase in glucose content, but specific phenotypical changes are dependent on the subcellular targeting of the enzyme. Cytosolic expression leads to a more severe phenotype with the most striking aspects being reduced starch content and increased respiration. Despite extensive research, the regulatory mechanisms leading to these changes remain obscure. Recent technological advancements regarding potato transcriptional and genomic research presented us with the opportunity to revisit these lines and perform detailed gene expression analysis, in combination with extensive metabolic profiling, to identify regulatory networks underlying the observed changes. Our results indicate that in both genotypes reduced UDP-glucose production is associated with a reduced expression of cell wall biosynthetic genes. In addition, U-IN-1 tubers are characterized by elevated expression of senescence-associated genes, coupled to reduced expression of genes related to photosynthesis and the cytoskeleton. We provide evidence that increased respiration, observed specifically in U-IN-2 tubers, might be due to sugar signaling via released trehalose-6-phosphate inhibition of the SnRK1 complex. In both genotypes, expression of the plastidic glucose-6-phosphate transporter (GPT) is significantly down-regulated. This leads to a shift in the cytosolic to plastidic glucose-6-phosphate ratio and hence might limit starch synthesis but also the oxidative pentose phosphate pathway. This might explain the observed changes in several additional plastid localized pathways, most notably reduced expression of fatty acid biosynthetic genes and an accumulation of shikimate. Interestingly, a strict negative correlation between invertase and GPT expression could be observed in a wide range of potato tubers. This reciprocal regulation may be part of a more general switch controlling energy versus storage metabolism, suggesting that the fate of assimilate utilization is coordinated at the level of sucrose degradation. PMID:22639642

Ferreira, Stephanus J; Sonnewald, Uwe



The Mode of Sucrose Degradation in Potato Tubers Determines the Fate of Assimilate Utilization  

PubMed Central

Cytosolic (U-IN-2) or apoplasmic (U-IN-1) targeting of yeast invertase in potato tubers leads to a reduction in sucrose and an increase in glucose content, but specific phenotypical changes are dependent on the subcellular targeting of the enzyme. Cytosolic expression leads to a more severe phenotype with the most striking aspects being reduced starch content and increased respiration. Despite extensive research, the regulatory mechanisms leading to these changes remain obscure. Recent technological advancements regarding potato transcriptional and genomic research presented us with the opportunity to revisit these lines and perform detailed gene expression analysis, in combination with extensive metabolic profiling, to identify regulatory networks underlying the observed changes. Our results indicate that in both genotypes reduced UDP-glucose production is associated with a reduced expression of cell wall biosynthetic genes. In addition, U-IN-1 tubers are characterized by elevated expression of senescence-associated genes, coupled to reduced expression of genes related to photosynthesis and the cytoskeleton. We provide evidence that increased respiration, observed specifically in U-IN-2 tubers, might be due to sugar signaling via released trehalose-6-phosphate inhibition of the SnRK1 complex. In both genotypes, expression of the plastidic glucose-6-phosphate transporter (GPT) is significantly down-regulated. This leads to a shift in the cytosolic to plastidic glucose-6-phosphate ratio and hence might limit starch synthesis but also the oxidative pentose phosphate pathway. This might explain the observed changes in several additional plastid localized pathways, most notably reduced expression of fatty acid biosynthetic genes and an accumulation of shikimate. Interestingly, a strict negative correlation between invertase and GPT expression could be observed in a wide range of potato tubers. This reciprocal regulation may be part of a more general switch controlling energy versus storage metabolism, suggesting that the fate of assimilate utilization is coordinated at the level of sucrose degradation.

Ferreira, Stephanus J.; Sonnewald, Uwe



Colorants and colorant modifiers  

US Patent & Trademark Office Database

The present invention relates to a substrate having therein or thereon a composition containing, at least one molecular includant. In one embodiment, the molecular includant comprises a cyclodextrin. The present invention also relates to the substrate further comprising at least one ultraviolet radiation transorber and also to the substrate further comprising a colorant. Additionally, the present invention relates to a method of making the substrate in which a composition comprising a molecular includant is incorporated into or onto the substrate. In one embodiment of this invention, the substrate has thereon or therein a colored composition comprising a colorant and a molecular includant. In another embodiment, the colorant is a mutable colorant which, upon irradiation in the present of an ultraviolet radiation transorber, can be mutated.

MacDonald; John Gavin (Decatur, GA); Nohr; Ronald Sinclair (Alpharetta, GA)



Transgenic potato (Solanum tuberosum) tubers synthesize the full spectrum of inulin molecules naturally occurring in globe artichoke (Cynara scolymus) roots.  


The ability to synthesize high molecular weight inulin was transferred to potato plants via constitutive expression of the 1-SST (sucrose:sucrose 1-fructosyltransferase) and the 1-FFT (fructan: fructan 1-fructosyltransferase) genes of globe artichoke (Cynara scolymus). The fructan pattern of tubers from transgenic potato plants represents the full spectrum of inulin molecules present in artichoke roots as shown by high-performance anion exchange chromatography, as well as size exclusion chromatography. These results demonstrate in planta that the enzymes sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1-fructosyltransferase are sufficient to synthesize inulin molecules of all chain lengths naturally occurring in a given plant species. Inulin made up 5% of the dry weight of transgenic tubers, and a low level of fructan production also was observed in fully expanded leaves. Although inulin accumulation did not influence the sucrose concentration in leaves or tubers, a reduction in starch content occurred in transgenic tubers, indicating that inulin synthesis did not increase the storage capacity of the tubers. PMID:10890908

Hellwege, E M; Czapla, S; Jahnke, A; Willmitzer, L; Heyer, A G



Transgenic potato (Solanum tuberosum) tubers synthesize the full spectrum of inulin molecules naturally occurring in globe artichoke (Cynara scolymus) roots  

PubMed Central

The ability to synthesize high molecular weight inulin was transferred to potato plants via constitutive expression of the 1-SST (sucrose:sucrose 1-fructosyltransferase) and the 1-FFT (fructan: fructan 1-fructosyltransferase) genes of globe artichoke (Cynara scolymus). The fructan pattern of tubers from transgenic potato plants represents the full spectrum of inulin molecules present in artichoke roots as shown by high-performance anion exchange chromatography, as well as size exclusion chromatography. These results demonstrate in planta that the enzymes sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1-fructosyltransferase are sufficient to synthesize inulin molecules of all chain lengths naturally occurring in a given plant species. Inulin made up 5% of the dry weight of transgenic tubers, and a low level of fructan production also was observed in fully expanded leaves. Although inulin accumulation did not influence the sucrose concentration in leaves or tubers, a reduction in starch content occurred in transgenic tubers, indicating that inulin synthesis did not increase the storage capacity of the tubers.

Hellwege, Elke M.; Czapla, Sylvia; Jahnke, Anuschka; Willmitzer, Lothar; Heyer, Arnd G.



Color vision  

Microsoft Academic Search

Among basic vision research, which aim to reveal higher levels of the human visual function, I review recent advances in color vision, focusing on color memory and categorical color perception research. It is known that color varies continuously in color space. At the same time, however, we recognize colors as categories: such as, red, green, yellow, and blue although there

Keiji Uchikawa



Viscoelasticity of Cowpea Starch Gels  

Microsoft Academic Search

Cereal Chem. 77(3):309-314 The mechanical behavior of cowpea starch gels (10%, w\\/v) at small and large deformations were investigated in comparison with acorn, corn, and potato starches in storage at 4°C for seven days. The rapid visco- grams of starch paste (7%, w\\/v) revealed that cowpea starch had a larger setback (1,135 cP) than other starches (465-830 cP), although peak

So-Yoon Won; WonSeok Choi; Hyesook S. Lim; Ki-Yul Cho; Seung-Taik Lim



MRI findings reveal three different types of tubers in patients with tuberous sclerosis complex  

PubMed Central

Cortical tubers are very common in tuberous sclerosis complex (TSC) and widely vary in size, appearance and location. The relationship between tuber features and clinical phenotype is unclear. The aim of the study is to propose a classification of tuber types along a spectrum of severity, using magnetic resonance imaging (MRI) characteristics in 35 patients with TSC and history of epilepsy, and to investigate the relationship between tuber types and genetics, as well as clinical manifestations. Three types of tubers were identified based on the MRI signal intensity of their subcortical white matter component. (1) Tubers Type A are isointense on volumetric T1 images and subtly hyperintense on T2 weighted and fluid-attenuated inversion recovery (FLAIR); (2) Type B are hypointense on volumetric T1 images and homogeneously hyperintense on T2 weighted and FLAIR; (3) Type C are hypointense on volumetric T1 images, hyperintense on T2 weighted, and heterogeneous on FLAIR characterized by a hypointense central region surrounded by a hyperintense rim. Based on the dominant tuber type present, three distinct patient groups were also identified: Patients with Type A tuber dominance have a milder phenotype. Patients with Type C tuber dominance have more MRI abnormalities such as subependymal giant cell tumors, and were more likely to have an autism spectrum disorder, a history of infantile spasms, and a higher frequency of epileptic seizures, compared to patients who have a dominance in Type B tubers, and especially to those with a Type A dominance.

Gallagher, Anne; Grant, Ellen P.; Madan, Neel; Jarrett, Delma Y.; Lyczkowski, David A.



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 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.


Enzymatic acylation of starch.  


Starch a cheap, abundant and renewable natural material has been chemically modified for many years. The popular modification acylation has been used to adjust rheological properties as well as deliver polymers with internal plasticizers and other potential uses. However the harsh reaction conditions required to produce these esters may limit their use, especially in sensitive applications (foods, pharmaceuticals, etc.). The use of enzymes to catalyse acylation may provide a suitable alternative due to high selectivities and mild reaction conditions. Traditional hydrolase-catalysed synthesis in non-aqueous apolar media is hard due to lack of polysaccharide solubility. However, acylated starch derivatives have recently been successfully produced in other non-conventional systems: (a) surfactant-solubilised subtilisin and suspended amylose in organic media; (b) starch nanoparticles dispersed in organic medium with immobilised lipase; (c) aqueous starch gels with lipase and dispersed fatty acids. We attempt a systematic review that draws parallels between the seemingly unrelated approaches described. PMID:22138593

Alissandratos, Apostolos; Halling, Peter J



Hormone Metabolism During Potato Tuber Dormancy  

Technology Transfer Automated Retrieval System (TEKTRAN)

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


Potato Tubers and Soil Aeration1  

Microsoft Academic Search

Potato plants are more sensitive to soil oxygen stress than many other common crops. Some recent literature suggests this may be due to a relatively high oxygen requirement for tuber growth, rather than a greater requirement for the roots per se. Consequently, the oxygen consumption of growing potato tubers (Solanum tuberosum cv. Russet Burbank) was measured in the field on

J. W. Cary



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


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. PMID:11803968

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



Multiplex PCR for the identification of white Tuber species  

Microsoft Academic Search

Species-specific primers selected from the internal transcribed spacer region sequence were used to set up a multiplex polymerase chain reaction (PCR) able to simultaneously identify the white truffle species Tuber magnatum, Tuber borchii, Tuber maculatum and Tuber puberulum. Furthermore, a primer specific for the competitive fungus Sphaerosporella brunnea was designed and added to the multiplex PCR set, allowing the detection

Antonella Amicucci; Chiara Guidi; Alessandra Zambonelli; Lucia Potenza; Vilberto Stocchi



Cardiac involvement in tuberous sclerosis.  

PubMed Central

OBJECTIVE--To assess the incidence, importance, and history of cardiac involvement in infants and children with tuberous sclerosis. DESIGN--Prospective study; clinical examination, sector and Doppler echocardiography, standard and ambulatory electrocardiography. SETTING--A tertiary referral centre. PATIENTS--21 patients with tuberous sclerosis aged 1 day to 16 years (mean 6.3 years); follow up investigations were available in 14 cases (10 retrospective, 4 prospective; mean follow up 4.3 years). RESULTS--Multiple cardiac rhabdomyomas in the right ventricle (11) and left ventricle (14) as well as in the right atrium (1) were present in 14/21 patients. Two of them had obstruction of the left ventricular inflow and outflow tract related to a tumour. In the remaining 7 patients, echocardiography was normal in 4 and equivocal in 3 cases. The standard electrocardiogram (n = 20) showed ventricular hypertrophy (2), ventricular pre-excitation (1), arrhythmias (2), and repolarisation disturbances (4) in 7/13 patients with rhabdomyomas but was normal in all patients with a normal or equivocal echocardiogram. The ambulatory electrocardiogram (n = 19) showed frequent premature atrial (2) and polymorphous ventricular (2) contractions. The polymorphous ventricular contractions coexisted with rhabdomyomas. No arrhythmias that needed medical treatment were found. Follow up investigations showed return to a normal standard electrocardiogram in 3 patients. Definite regression or complete disappearance of the tumour occurred in 6 infants. CONCLUSIONS--Cardiac rhabdomyomas, although often present in these patients with tuberous sclerosis, caused neither major arrhythmias nor haemodynamic obstruction except in the neonatal period. The indication for operation is limited to cases with life threatening obstruction or arrhythmias refractory to medical treatment. Images

Muhler, E G; Turniski-Harder, V; Engelhardt, W; von Bernuth, G



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


The occurrence of hypoxic conditions in plants not only represents a stress condition but is also associated with the normal development and growth of many organs, leading to adaptive changes in metabolism and growth to prevent internal anoxia. Internal oxygen concentrations decrease inside growing potato tubers, due to their active metabolism and increased resistance to gas diffusion as tubers grow. In the present work, we identified three hypoxia-responsive ERF (StHRE) genes whose expression is regulated by the gradual decrease in oxygen tensions that occur when potato tubers grow larger. Increasing the external oxygen concentration counteracted the modification of StHRE expression during tuber growth, supporting the idea that the actual oxygen levels inside the organs, rather than development itself, are responsible for the regulation of StHRE genes. We identified several sugar metabolism-related genes co-regulated with StHRE genes during tuber development and possibly involved in starch accumulation. All together, our data suggest a possible role for low oxygen in the regulation of sugar metabolism in the potato tuber, similar to what happens in storage tissues during seed development. PMID:21954444

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



[A primary epileptogenic tuber revealed after corpus callosotomy in a patient with tuberous sclerosis complex and multiple tubers].  


Identification of primary epileptogenic tuber is often challenging in patients with bilateral multiple tubers in tuberous sclerosis complex. We report a 3 year old girl with tuberous sclerosis complex presenting with intractable epilepsy and multiple tubers, who was successfully treated by corpus callosotomy and subsequent resective surgery. She initially presented with West syndrome which was intractable to ACTH therapy and multiple antiepileptic medications. Her EEG was characterized by generalized and multifocal spikes, and by non-focal changes at seizure onset. Ictal single photon emission computed tomography(SPECT)showed no focal hyperperfusion. Total corpus callosotomy was performed to alleviate her drop attacks. Post-operatively, interictal spikes were completely lateralized to the right hemisphere. Since her seizures were still kept uncontrolled with medications, second pre-surgical evaluation was planned and ictal SPECT disclosed focal hyperperfusion at a tuber in the right frontal lobe. After complete resection of the right frontal tuber, she was completely seizure free on antiepileptic medications for 1 year with no additional neurological deficits. Generalized or multifocal electroencephalographic(EEG)spikes are occasionally lateralized to one hemisphere after corpus callosotomy, which may help identifying the primary epileptogenic focus. Repeat pre-surgical evaluation is important after corpus callosotomy in patients with generalized or multifocal epileptiforms in EEG. PMID:23648659

Sato, Keisuke; Iwasaki, Masaki; Uematsu, Mitsugu; Nakasato, Nobukazu; Tominaga, Teiji



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

Konicek-Moran, Richard



Multiplex PCR for the identification of white Tuber species.  


Species-specific primers selected from the internal transcribed spacer region sequence were used to set up a multiplex polymerase chain reaction (PCR) able to simultaneously identify the white truffle species Tuber magnatum, Tuber borchii, Tuber maculatum and Tuber puberulum. Furthermore, a primer specific for the competitive fungus Sphaerosporella brunnea was designed and added to the multiplex PCR set, allowing the detection of the Tuber species and the contaminant fungus in a one-step reaction. PMID:10930749

Amicucci, A; Guidi, C; Zambonelli, A; Potenza, L; Stocchi, V



In Vitro Digestibility of Banana Starch Cookies  

Microsoft Academic Search

Banana starch was isolated and used for preparation of two types of cookies. Chemical composition and digestibility tests were carried out on banana starch and the food products, and these results were compared with corn starch. Ash, protein, and fat levels in banana starch were higher than in corn starch. The high ash amount in banana starch could be due




Color realism and color science  

Microsoft Academic Search

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at

Alex Byrne; David R. Hilbert



Echocardiography and genetic counselling in tuberous sclerosis.  

PubMed Central

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

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



Film blowing of thermoplastic starch  

Microsoft Academic Search

Thermoplastic starch materials are often based on a combination of starch, glycerol and water. In the present study, two potato starch grades were employed; a native (natural) grade and an oxidised and hydroxypropylated grade of the native material, in order to produce the thermoplastic material. The primary aim of the study was to identify possible routes for film blowing thermoplastic

Mats Thunwall; Vanda Kuthanová; Antal Boldizar; Mikael Rigdahl



Food Starches and Dental Caries  

Microsoft Academic Search

Sucrose and starches are the predominant dietary carbohydrates in modern societies. While the causal relationship between sucrose and dental caries development is indisputable, the relationship between food starch and dental caries continues to be debated and is the topic of this review. The current view of dental caries etiology suggests that in-depth evaluation of the starch-caries relationship requires the consideration

P. Lingstrom; J. van Houte; S. Kashket



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


The glucosyl residues comprising starch can be phosphorylated at either the C3 or the C6 position of the molecule because of the activities of two distinct dikinase enzymes. After hydrolysis of the starch, the C6 phosphorylation is easy to measure using a routine enzyme assay for glucose 6-phosphate, but the C3 phosphorylation is more difficult to assay. A mass spectrometric (MS) method has been developed that, in a single run, can distinguish and quantify the glucose 3-phosphate and glucose 6-phosphate produced by hydrolysis of starch and can also measure the glucose content to give an accurate estimate of the starting material. The MS method involves quantification by LC/MS with external standards, using normal-phase hydrophilic interaction liquid chromatography and selective reaction monitoring. The MS method has been used to determine degrees of starch phosphorylation in a diverse group of potato lines, revealing threefold differences in phosphorylation between high- and low-phosphate lines. The method was also used to show that cold storage of potato tubers for up to 24weeks had little substantive effect on the levels of starch phosphorylation. MS provided an effective and efficient means of determining both the C6 and the C3 phosphorylation of starch. PMID:22982506

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



High-Resolution Metabolic Phenotyping of Genetically and Environmentally Diverse Potato Tuber Systems. Identification of Phenocopies  

PubMed Central

We conducted a comprehensive metabolic phenotyping of potato (Solanum tuberosum L. cv Desiree) tuber tissue that had been modified either by transgenesis or exposure to different environmental conditions using a recently developed gas chromatography-mass spectrometry profiling protocol. Applying this technique, we were able to identify and quantify the major constituent metabolites of the potato tuber within a single chromatographic run. The plant systems that we selected to profile were tuber discs incubated in varying concentrations of fructose, sucrose, and mannitol and transgenic plants impaired in their starch biosynthesis. The resultant profiles were then compared, first at the level of individual metabolites and then using the statistical tools hierarchical cluster analysis and principal component analysis. These tools allowed us to assign clusters to the individual plant systems and to determine relative distances between these clusters; furthermore, analyzing the loadings of these analyses enabled identification of the most important metabolites in the definition of these clusters. The metabolic profiles of the sugar-fed discs were dramatically different from the wild-type steady-state values. When these profiles were compared with one another and also with those we assessed in previous studies, however, we were able to evaluate potential phenocopies. These comparisons highlight the importance of such an approach in the functional and qualitative assessment of diverse systems to gain insights into important mediators of metabolism.

Roessner, Ute; Willmitzer, Lothar; Fernie, Alisdair R.



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



Heat stress and the tuberization stimulus  

Microsoft Academic Search

Heat stress may lower potato tuber yields through reduction in the net amount of photosynthate available for total plant growth\\u000a and through reduced partitioning to the tubers. The latter effect is generally more serious and is the main subject of this\\u000a paper. High temperatures have much the same effect on partitioning as do long days, and there are significant genetic

E. E. Ewing



New Tuber species found in Poland  

Microsoft Academic Search

New information from a survey of truffles carried out in southern part of Poland in September 2007 is presented. The fruit\\u000a bodies of Tuber aestivum, T. excavatum, T. rufum and one unidentified Tuber sp. were found. The soil chemistry of the five T. aestivum sites was analysed. Our inventory showed that T. aestivum prefers the mixed forest with host-trees such

Dorota Hilszcza?ska; Zbigniew Sierota; Mario Palenzona



Corn Starch Plastic  

NSDL National Science Digital Library

In this activity, learn how you can make plastic out of corn (corn starch). Use this activity to explore polymers and PLA, polylactic acid, a plastic that is easier to compost. This activity guide includes a step-by-step instructional video. Safety note: Younger learners will require adult supervision.

Center, Saint L.



Transcriptomic analysis of potato tuber development and tuber quality traits using microarray technology  

Microsoft Academic Search

The potato crop is one of the most important food crops in the world and in order to understand how in potato plants the formation of potato tubers and the determination of different tuber quality traits are regulated, we need to identify and characterize the genes that are involved in regulating these processes. The aim of the research described in

B. A. Kloosterman



Alkaline extraction of starch from Australian lentil cultivars Matilda and Digger optimised for starch yield and starch and protein quality  

Microsoft Academic Search

The Australian lentils, Lens culinaris: Matilda (Green Lentil) and Digger (Red Lentil) contain 44–45% starch (HPLC method) and 30–33% protein (LECO Analyser). This paper describes, first, the identification of optimum starch extraction conditions where yield is high and starch and protein damage is acceptable and, second, the properties of the starch and protein recovered. Starch was extracted from the flour

H. C. Lee; A. K. Htoon; J. L. Paterson



Quantification of total iodine in intact granular starches of different botanical origin exposed to iodine vapor at various water activities.  


Iodine has been used as an effective tool for studying both the structure and composition of dispersed starch and starch granules. In addition to being employed to assess relative amylose contents for starch samples, it has been used to look at the molecular mobility of the glucose polymers within intact starch granules based on exposure to iodine vapor equilibrated at different water activities. Starches of different botanical origin including corn, high amylose corn, waxy corn, potato, waxy potato, tapioca, wheat, rice, waxy rice, chick pea and mung bean were equilibrated to 0.33, 0.75, 0.97 water activities, exposed to iodine vapor and then absorbance spectra and LAB color were determined. In addition, a new iodine quantification method sensitive to <0.1% iodine (w/w) was employed to measure bound iodine within intact granular starch. Amylose content, particle size distribution of granules, and the density of the starch were also determined to explore whether high levels of long linear glucose chains and the surface area-to-volume ratio were important factors relating to the granular iodine binding. Results showed, in all cases, starches complexed more iodine as water content increased and waxy starches bound less iodine than their normal starch counterparts. However, much more bound iodine could be measured chemically with waxy starches than was expected based on colorimetric determination. Surface area appeared to be a factor as smaller rice and waxy rice starch granules complexed more iodine, while the larger potato and waxy potato granules complexed less than would be expected based on measured amylose contents. Corn, high amylose corn, and wheat, known to have starch granules with extensive surface pores, bound higher levels of iodine suggesting pores and channels may be an important factor giving iodine vapor greater access to bind within the granules. Exposing iodine vapor to moisture-equilibrated native starches is an effective tool to explore starch granule architecture. PMID:21962455

Manion, Bruce; Ye, Mei; Holbein, Bruce E; Seetharaman, Koushik



Expression of the interleukin 17 in cortical tubers of the tuberous sclerosis complex.  


The role of interleukin 17 (IL-17) to epilepsy-associated cortical tubers of tuberous sclerosis complex (TSC) is unknown. We investigated the expression patterns of the IL-17 and IL-17 receptor (IL-17R) in cortical tubers of TSC compared with normal control cortex (CTX). We found that IL-17 and IL-17R were clearly upregulated in cortical tubers at the protein levels. Immunostaining indicated that IL-17 was specifically distributed in the innate immunity cells (DNs, GCs, astrocytes, and microglia) and adaptive immunity cells (T-lymphocytes) as well as the endothelial cells of blood vessels. The overexpression and distribution patterns of IL-17 may be involved in the epileptogenicity of cortical tubers in TSC. PMID:23906968

He, Jiao-Jiang; Wu, Ke-Fu; Li, Song; Shu, Hai-Feng; Zhang, Chun-Qing; Liu, Shi-Yong; Yang, Mei-Hua; Yin, Qing; Yang, Hui



Preparation of high-fructose syrup from the tubers of the Jerusalem artichoke (Helianthus tuberosus L.  


Fructose has recently received much attention due to renewed interest in natural sweeteners. In addition, fructose has some advantages to sucrose in sweetness, solubility, viscosity, and dental health characteristics. Fructose is deposited as storage fructans of the inulin (beta-1,2) type in tubers and rhizomes of the Compositae family. The utilization of the Jerusalem artichoke (Helianthus tuberosus) tuber as a source of fructose syrup is discussed. This plant has the potential to produce more sugar per acre than corn or sugar beets. In addition, the artichoke has higher frost resistance and lower heat unit requirements than corn and is somewhat more tolerant to low moisture conditions than sugar beets. A high quality fructose syrup can be produced from artichoke tubers. The extraction step was found to be particularly important since development of adverse colors and flavors must be prevented. The fructans may be acid or enzyme hydrolyzed but the latter method gave a higher quality syrup. Ion-exchange resins and activated charcoal were effective in removing coloring and flavoring materials, and also reduced other noncarbohydrate constituents. Since the enzymatic hydrolysis of the fructans is an attractive alternative to acid hydrolysis, a process was developed for producing and purifying a special beta-fructofuranosidase (inulase) from Saccharomyces fragilis. Inulase has a much higher specificity for fructans than commerically available beta-fructofuranosidase (invertase). PMID:41685

Fleming, S E; GrootWassink, J W



Strategies for the manufacture of resistant starch  

Microsoft Academic Search

Starch not hydrolyzed in the small intestine is considered to be enzyme-resistant starch (RS). Because individuals differ in their ability to digest starch, there is no absolute distinction between RS and digestible starch. A method for in vitro determination of RS should be validated using a human population average value. In any starch material, the constituent molecules will have a

Donald B Thompson



Yields of yeast growth on starch  

Microsoft Academic Search

Summary A survey was made of 81 starch-assimilating yeasts, representing 59 species and varieties, with respect to their capacity for the direct conversion of starch into SCP. The extent of starch conversion by the native amylases of the strains during exponential growth, expressed as yield on starch (final amount of dry biomass formed per unit mass of starch originally supplied),

I. Spencer-Martins; N. van Uden



Improving starch for food and industrial applications  

Microsoft Academic Search

Progress in understanding starch biosynthesis, and the isolation of many of the genes involved in this process, has enabled the genetic modification of crops in a rational manner to produce novel starches with improved functionality. For example, potato starches have been created that contain unprecedented levels of amylose and phosphate. Amylose-free short-chain amylopectin starches have also been developed; these starches

Steve Jobling



Synthesis of starch acetate: Statistical designed experiments to optimize the reaction conditions  

Microsoft Academic Search

The synthesis conditions for Durabond A corn starch acetate (SA) were varied by using statistical designed experiments with the aim to optimize the yield and solubility, and to minimize the color. The thirty experiments in the design vary the: (1) Percentage water in the starch (0, 3, 6); (2) catalyst concentration (0.25, 0.60, 0.95 wt%); (3) total amount of acetic

Stefanos Lepeniotis; Bernice I. Feuer



Color realism and color science.  


The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically, types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in the mind." The article has two other purposes: First, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. The first part explains the problem of color realism and makes some useful distinctions. These distinctions are then used to expose various confusions that often prevent people from seeing that the issues are genuine and difficult, and that the problem of color realism ought to be of interest to anyone working in the field of color science. The second part explains the various leading answers to the problem of color realism, and (briefly) argues that all views other than our own have serious difficulties or are unmotivated. The third part explains and motivates our own view, that colors are types of reflectances and defends it against objections made in the recent literature that are often taken as fatal. PMID:14598439

Byrne, Alex; Hilbert, David R



Engineering starch accumulation by manipulation of phosphate metabolism of starch.  


A new understanding of leaf starch degradation has emerged in the last 10 years. It has been shown that starch phosphorylation and dephosphorylation are critical components of this process. Glucan, water dikinase (GWD) (and phosphoglucan, water dikinase) adds phosphate to starch, and phosphoglucan phosphatase (SEX4) removes these phosphates. To explore the use of this metabolism to manipulate starch accumulation, Arabidopsis (Arabidopsis thaliana) plants were engineered by introducing RNAi constructs designed to reduce expression of AtGWD and AtSEX4. The timing of starch build-up was altered with ethanol-inducible and senescence-induced gene promoters. Ethanol induction of RNAi lines reduced transcript for AtGWD and AtSEX4 by 50%. The transgenic lines had seven times more starch than wild type at the end of the dark period but similar growth rates and total biomass. Elevated leaf starch content in maize leaves was engineered by making an RNAi construct against a gene in maize that appeared to be homologous to AtGWD. The RNAi construct was expressed using the constitutive ubiquitin promoter. Leaf starch content at the end of a night period in engineered maize plants was 20-fold higher than in untransformed plants with no impact on total plant biomass. We conclude that plants can be engineered to accumulate starch in the leaves with little impact on vegetative biomass. PMID:22321580

Weise, Sean E; Aung, Kimberly; Jarou, Zach J; Mehrshahi, Payam; Li, Ziru; Hardy, Anna C; Carr, David J; Sharkey, Thomas D



Production and performance of potato mini-tubers  

Microsoft Academic Search

Production of mini-tubers as a source for seed potato was investigated by growing in soil micropropagated plants and micro-tubers produced from micropropagated plants. Cultures of several cultivars were initiated from indexed tubers and multiplied on modified MS medium. Cultures were micropropagated by using a modular system which allowed batch handling. Micropropagated plants produced mini-tubers in glasshouse after 70–115 days of

B. S. Ahloowalia



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



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



Perfect Colorings.  

National Technical Information Service (NTIS)

A problem that arises when the segmentation of a file in a network is considered without redundancy is studied. This problem translates to a graph coloring problem: k colorability. Several basic results for perfectly k colorable graphs are proved. It is s...

E. M. Bakker J. Vanleeuwen R. B. Tan



Effective Coloration  

Microsoft Academic Search

We are concerned here with recursive function theory analogs of certain problems in chromatic graph theory. The motivating question for our work is: Does there exist a recursive (countably infinite) planar graph with no recursive 4-coloring? We obtain the following results: There is a 3-colorable, recursive planar graph which, for all $k$, has no recursive $k$-coloring; every decidable graph of

Dwight R. Bean



Physicochemical characterisation of sago starch  

Microsoft Academic Search

The physico-chemical characteristics of various sago starch samples from South East Asia were determined and compared to starches from other sources. X-ray diffraction studies showed that all the sago starches exhibited a C-type diffraction pattern. Scanning electron microscopy showed that they consist of oval granules with an average diameter around 30?m. Proximate composition studies showed that the moisture content in

Fasihuddin B Ahmad; Peter A Williams; Jean-Louis Doublier; Sylvie Durand; Alain Buleon



Chronic renal failure and its treatment in tuberous sclerosis  

Microsoft Academic Search

Background. Chronic renal failure is rare in tuberous sclerosis, but its precise frequency is not known and treatment modalities have not been evaluated. Methods. A questionnaire was addressed to the 260 French dialysis centres and the characteristics of 65 patients with tuberous sclerosis and chronic renal failure were analysed. Results. In France the approximate prevalence of tuber- ous sclerosis with

F. Schillinger; R. Montagnac



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...


Caecal fermentation in rats fed diets containing transgenic potato tubers  

Microsoft Academic Search

Caecal fermentation in rats fed diets with 40% autoclaved potato tubers was examined. The potato tubers of the conventional cultivar, Irga, somaclone Irga, and four transgenic lines with genetically improved resistance to a necrotic strain of potato virus Y (PVY N ) were compared. As regards the analysed indices, tubers of transgenic clone R1F (truncated gene coding PVY N

J. Ju?kiewicz; Z. Zdu?czyk; S. Frejnagel; J. Fornal



Technology Transfer Automated Retrieval System (TEKTRAN)

Among the known hormones, the most convincing case for a critical role in the control of tuberization, has been made for plant hormone gibberellin. High GA level is known to inhibit tuberization, and tuberization is promoted by reducing GA level. Calcium is known to be a second messenger regulating ...


Autism and the Cerebellum: Evidence from Tuberous Sclerosis.  

ERIC Educational Resources Information Center

A study examined the relationship between neuroimaging findings and the behavioral characteristics of 29 patients with tuberous sclerosis. Findings indicate a positive linear relationship between a patient's total number of tubers and degree of intellectual impairment. The number of tubers in the cerebellum was associated with more autistic…

Weber, Anna M.; Egelhoff, John C.; McKellop, J. Mark; Franz, David Neal



Suppressed expression of autophagosomal protein LC3 in cortical tubers of tuberous sclerosis complex.  


Tuberous sclerosis complex (TSC) is characterized by benign tumors and hamartomas, including cortical tubers. Hamartin and tuberin, encoded by the TSC 1 and 2 genes, respectively, constitute a functional complex that negatively regulates the mammalian target of rapamycin (mTOR) signaling pathway, eventually promoting the induction of autophagy. In the present study, we assessed the induction of autophagy in cortical tubers surgically removed from seven patients with TSC in comparison with five controls of cortical tissue taken from non-TSC patients with epilepsy. Immunoblotting demonstrated a marked reduction of LC3B-I and LC3B-II in tubers relative to the controls. In tubers, strong, diffuse and dot-like immunoreactivity (IR) for LC3B was observed in dysmorphic neurons and balloon cells, but LC3B-IR in other neurons with normal morphology was significantly weaker than that in neurons in the controls. Immunoelectron microscopy revealed diffuse distribution of LC3B-IR within the cytoplasm of balloon cells. The dot-like pattern may correspond to abnormal aggregation bodies involving LC3. In an autopsy patient with TSC, we observed that LC3B-IR in neurons located outside of the tubers was preserved. Thus, autophagy is suppressed in tubers presumably through the mTOR pathway, and possibly a pathological autophagy reaction occurs in the dysmorphic neurons and balloon cells. PMID:22974335

Miyahara, Hiroaki; Natsumeda, Manabu; Shiga, Atsushi; Aoki, Hiroshi; Toyoshima, Yasuko; Zheng, Yingjun; Takeuchi, Ryoko; Murakami, Hiroatsu; Masuda, Hiroshi; Kameyama, Shigeki; Izumi, Tatsuro; Fujii, Yukihiko; Takahashi, Hitoshi; Kakita, Akiyoshi



Color Quiz  

NSDL National Science Digital Library

Please take this Quiz. It is not that hard. Remember If you understand color, you will be able to use color in your artwork more effectively. For your Quiz please answer the 18 questions below. Here are some sites you have already seen that will help you answer the questions. Color Theory Color Vocabulary Wikipedia color theory You may write your answers down on a piece of paper or you can type the answers up. Make sure name, period, and date are on assignment ...

Freeman, Ms.



Color Quiz  

NSDL National Science Digital Library

Please take this Quiz. It is not that hard. Remember If you understand color, you will be able to use color in your artwork more effectively. For your Quiz please answer the 18 questions below. Here are some sites you have already seen that will help you answer the questions. Color Theory Color Vocabulary Wikipedia color theory You may write your answers down on a piece of paper or you can type the answers up. Make sure name, period, and date are on assignment ...




Effects of growing environments, planting date, and stem treatments on sandersonia tuber weight and secondary tuber development  

Microsoft Academic Search

Sandersonia (Sandersonia aurantiaca Hook) tuber growth and secondary tuber development were assessed in two growing environments (a greenhouse and outdoors), at three planting dates (1 October, 1 December, and 1 February) and with six stem pruning treatments. Tubers of c. 1 g were used. The pruning treatments consisted of cutting the stem just above the second flower when 50% of

G. E. Clark; G. K. Burge



Structural and morphological factors influencing the quantification of resistant starch II in starches of different botanical origin  

Microsoft Academic Search

Seven cereal starches and 11 pea starches were analysed for total starch, amylose content, resistant starch type II (RS), total dietary fibre (TDF) and starch damage. The data from the cereal starches could be interpreted on basis of the already published polymorph type. In the pea starch series RS and TDF correlated with the amylose content for most starches. But

H. Themeier; J. Hollmann; U. Neese; M. G. Lindhauer



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



Color terms and color concepts  

Microsoft Academic Search

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

Jules Davidoff



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



The effect of storage temperature on reducing sugars, pH, and phosphorylase enzyme activity in potato tubers  

Microsoft Academic Search

Summary  The influence of storage at 40 and 70 F on reducing sugars, pH, phosphorylase enzyme activity in potato tubers, and the effect\\u000a on chipping quality, was investigated. In addition to the expected increase in reducing sugars and decline in chip color during\\u000a storage at 40 F, the pH decreased markedly and phosphorylase enzyme activity increased. Conditioning at 70 F, after

R. B. Hyde; J. W. Morrison



Alpine Russet: A Potato Cultivar Having Long Tuber Dormancy Making it Suitable for Processing from Long-term Storage  

Microsoft Academic Search

Alpine Russet is a later maturing, oblong-long, lightly russeted potato cultivar, notable for having tuber dormancy comparable\\u000a to Russet Burbank. Processing quality of Alpine Russet from long-term storage is superior to Russet Burbank, with low percent\\u000a reducing sugars and uniform fry color due to a low percentage difference of sugars between the bud and stem ends. Alpine Russet\\u000a yields were

Jonathan L. Whitworth; Richard G. Novy; Jeffrey C. Stark; Joseph J. Pavek; Dennis L. Corsini; Steven L. Love; Nora Olsen; Sanjay K. Gupta; Tina Brandt; M. Isabel Vales; Alvin R. Mosley; Solomon Yilma; Steve R. James; Dan C. Hane; Brian A. Charlton; Clinton C. Shock; N. Richard Knowles; Mark J. Pavek; Jeffrey S. Miller; Charles R. Brown



Processing of Color Words Activates Color Representations  

ERIC Educational Resources Information Center

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

Richter, Tobias; Zwaan, Rolf A.



Processing of Color Words Activates Color Representations  

ERIC Educational Resources Information Center

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

Richter, Tobias; Zwaan, Rolf A.



Microbial starch-binding domains as a tool for modifying starch biosynthesis  

Microsoft Academic Search

Modification of the starch biosynthesis pathway holds an enormous potential for tailoring novel starches in planta . In this thesis, we have explored the possibility of anchoring effector proteins in potato starch granules during starch biosynthesis by using starch-binding domains (SBDs) of starch degrading enzymes. In this way, starches with new or improved functionalities may be generated. <\\/span>For this, a

Q. Ji



Color categories and color appearance  

PubMed Central

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 were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses.

Webster, Michael A.; Kay, Paul



Xanthated Starch Amine Paper Additives.  

National Technical Information Service (NTIS)

Novel amphoteric starch derivatives, xanthated starch amines, have been employed as wet-end paper additives for improving both wet and dry strength. They are easily repulpable, readily biodegradable, effective in a broad range of furnish pH's, and are com...

M. E. Carr



Starch and Iron Absorption. (32431).  

National Technical Information Service (NTIS)

Decreased iron absorption was observed in rats fed protein deficient starch and sucrose diets. This was not caused by a direct intraluminal effect of starch or sucrose upon iron absorption. The abnormality was attributed to both a retarded rate of growth ...

F. D. Garretson M. E. Conrad



Starch-filled polymer composites  

Technology Transfer Automated Retrieval System (TEKTRAN)

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


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



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



Developing Biodegradable Plastics from starch  

Microsoft Academic Search

The diversity and ubiquity of plastic products substantially testify to the versatility of the special class of engineering materials known as polymers. However, the non-biodegradability of these petrochemical-based materials has been a source of environmental concerns and hence, the driving force in the search for 'green' alternatives for which starch remains the frontliner. Starch is a natural biopolymer consisting predominantly

Olayide O. Fabunmi; Lope G. Tabil Jr; Satyanarayan Panigrahi; Peter R. Chang


Modeling human color categorization: color discrimination and color memory  

Microsoft Academic Search

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The experiments conducted prove the difference between color categorization by the cognitive processes color discrimination and

E. L. van den Broek; E. M. van Rikxoort; M. J. H. Puts; L. G. Vuurpijl; T. Heskes; P. Lucas; W. Wiegerinck



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

Microsoft Academic Search

The ERM (ezrin, radixin, and moesin) proteins belong to the band-4.1 superfamily of membrane-cytoskeleton-linking proteins which bind to the actin cytoskeleton via their C-terminal sequences and bind ERM binding membrane proteins (ERMBMPs). We investigated the immunohistochemical expression of two of the ERM proteins (ezrin and moesin) in developing human cerebral cortex and in cortical tubers from patients with tuberous sclerosis

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



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


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



Tuber-specific expression of a yeast invertase and a bacterial glucokinase in potato leads to an activation of sucrose phosphate synthase and the creation of a sucrose futile cycle.  


Fluxes were investigated in growing tubers from wild-type potato (Solanum tuberosum L. cv.Desiree) and from transformants expressing a yeast invertase in the cytosol under the control of the tuber-specific patatin promoter either alone (EC;U-IN2-30) or in combination with a Zymomonas mobilis glucokinase (EC; GK3-38) by supplying radiolabelled [14C]sucrose, [14C]glucose or [14C]fructose to tuber discs for a 90-min pulse and subsequent chase incubations of 4 and 12 h, and by supplying [14C]fructose for 2 h and 4 h to intact tubers attached to the mother plant. Contrary to the expectation that this novel route for sucrose degradation would promote starch synthesis,the starch content decreased in the transgenic lines.Labelling kinetics did not reveal whether this was due to changes in the fluxes into or out of starch. However,they demonstrated that glycolysis is enhanced in the transgenic lines in comparison to the wild type. There was also a significant stimulation of sucrose synthesis,leading to a rapid cycle of sucrose degradation and resynthesis. The labelling pattern indicated that sucrose phosphate synthase (SPS; EC was responsible for the enhanced recycling of label into sucrose. In agreement, there was a 4-fold and 6-fold increase in the activation status of SPS in U-IN2-30 and GK3-38,respectively, and experiments with protein phosphatase inhibitors indicated that this activation involves enhanced dephosphorylation of SPS. It is proposed that this activation of SPS is promoted by the elevated glucose 6-phosphate levels in the transgenic tubers.These results indicate the pitfalls of metabolic engineering without a full appreciation of the metabolic system and regulatory circuits present in the tissue under investigation. PMID:19402252

Trethewey, R N; Riesmeier, J W; Willmitzer, L; Stitt, M; Geigenberger, P



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



Aspects of the Physical Chemistry of Starch  

Microsoft Academic Search

Starch makes an important contribution to food structure and hence quality. Often there is a need to modify the behaviour of starch in food materials. One approach is to use knowledge of the physical chemistry of starch to modify component interactions and hence change behaviour. In this review we examine recent research on the phase behaviour and dynamics of starch

R. Parker; S. G. Ring



Sago starch and its utilisation.  


The importance and development of industrial biotechnology processing has led to the utilisation of microbial enzymes in various applications. One of the important enzymes is amylase, which hydrolyses starch to glucose. In Malaysia, the use of sago starch has been increasing, and it is presently being used for the production of glucose. Sago starch represents an alternative cheap carbon source for fermentation processes that is attractive out of both economic and geographical considerations. Production of fermentable sugars from the hydrolysis of starches is normally carried out by an enzymatic processes that involves two reaction steps, liquefaction and saccharification, each of which has different temperature and pH optima with respect to the maximum reaction rate. This method of starch hydrolysis requires the use of an expensive temperature control system and a complex mixing device. Our laboratory has investigated the possibility of using amylolytic enzyme-producing microorganisms in the continuous single-step biological hydrolysis of sago flour for the production of a generic fermentation medium. The ability of a novel DNA-recombinated yeast, Saccharomyces cerevisiae strain YKU 107 (expressing alpha-amylase production) to hydrolyse gelatinised sago starch production has been studied with the aim of further utilizing sago starch to obtain value-added products. PMID:16233345

Abd-Aziz, Suraini



Cloning and expression analysis of a potato cDNA that encodes branching enzyme evidence for co-expression of starch biosynthetic genes  

Microsoft Academic Search

One of the key enzymes involved in the formation of amylopectin, which is the major component of starch, is branching enzyme. A cDNA for potato branching enzyme was cloned by screening a tuber-specific cDNA expression library using an antiserum directed against a denatured preparation of the protein. Complementation of an Escherichia coli strain deficient in branching enzyme was achieved using

Jens Koßmann; Richard G. F. Visser; Bernd Müller-Röber; Lothar Willmitzer; Uwe Sonnewald



Technical advance: simultaneous analysis of metabolites in potato tuber by gas chromatography-mass spectrometry.  


A new method is presented in which gas chromatography coupled to mass spectrometry (GC-MS) allows the quantitative and qualitative detection of more than 150 compounds within a potato tuber, in a highly sensitive and specific manner. In contrast to other methods developed for metabolite analysis in plant systems, this method represents an unbiased and open approach that allows the detection of unexpected changes in metabolite levels. Although the method represents a compromise for a wide range of metabolites in terms of extraction, chemical modification and GC-MS analysis, for 25 metabolites analysed in detail the recoveries were found to be within the generally accepted range of 70-140%. Further, the reproducibility of the method was high: the error occurring in the analysis procedures was found to be less than 6% for 30 out of 33 compounds tested. Biological variability exceeded the systematic error of the analysis by a factor of up to 10. The method is also suited for upscaling, potentially allowing the simultaneous analysis of a large number of samples. As a first example this method has been applied to soil- and in vitro-grown tubers. Due to the simultaneous analysis of a wide range of metabolites it was immediately apparent that these systems differ significantly in their metabolism. Furthermore, the parallel insight into many pathways allows some conclusions to be drawn about the underlying physiological differences between both tuber systems. As a second example, transgenic lines modified in sucrose catabolism or starch synthesis were analysed. This example illustrates the power of an unbiased approach to detecting unexpected changes in transgenic lines. PMID:10929108

Roessner, U; Wagner, C; Kopka, J; Trethewey, R N; Willmitzer, L



Color Lines.  

ERIC Educational Resources Information Center

Teaching about color and value scales emphasizes a systematic approach to the effects of color and may reinforce assumptions rooted in racism. Describes how an 8th grade art class challenged the symbolism of black as evil and white as good. By showing that this is a culturally constructed meaning, art teachers model that such meaning can also be…

Gude, Olivia



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


The impedance at frequencies of 1-1000 kHz and dynamic bending storage modulus measured by the vibrating reed method were compared for potato tuber tissue, which had been processed by various methods. Raw potato tuber tissue strips were either heated for 30 min up to 100 degrees C or frozen-thawed. Some samples were osmotically dehydrated in a mannitol solution up to a concentration of 0.7 mol/l. The electrical reactance correlated well with the storage modulus of heated or frozen-thawed potato tissues, but not with the storage modulus of the mannitol-treated tissue. The storage modulus appeared to be strongly dependent on the turgor pressure of the cells which was drastically decreased by the heating, freezing-thawing, and osmotic treatments. The electrical properties reflect the cell integrity, and a large difference was observed between the change in impedance after heating or freezing-thawing, and that after the osmotic treatment. A significant change in the electric properties was also observed for a starch suspension at the gelatinization temperature. However, the contribution due to gelatinization did not appear to play an important role in the change of electrical properties of potato tissue by heating. PMID:12162541

Dejmek, Petr; Miyawaki, Osato



Powder and compaction characteristics of pregelatinized starches.  


Pregelatinized starch is widely used as a pharmaceutical aid, especially as a filler-binder. It is known that the tableting performance of excipients could be affected by their source. The aim of this study was to evaluate the powder and tableting properties of pregelatinized starches obtained from yucca, corn and rice and compare those properties with those of Starch 1500. This material had the lowest particle size, and porosity and largest density and best flow. However, yucca starch and corn starch showed an irregular granule morphology, better compactibility and compressibility than Starch 1500. Their onset of plastic deformation and their strain rate sensitivity was comparable to that of Starch 1500. These two materials showed compact disintegration slower that Starch 1500. Conversely, rice starch showed a high elasticity, and friability, low compactibility, which are undesirable for direct compression. This study demonstrated the potential use of pregelatinized starches, especially those obtained from yucca and corn as direct compression filler-binders. PMID:22822539

Rojas, J; Uribe, Y; Zuluaga, A



Color management.  


In summary, color psychology is one of the most important, but most often neglected, forces in enhancing the image and profitability of the hospital gift shop. While many hospital gift shops may be updated and beautified with the purchase of costly equipment and the hiring of expensive design consultants, the effective use of color may be all that is necessary to change the shop atmosphere. In addition, color is extremely inexpensive and flexible; it can be changed easily, in lieu of moving heavy displays and fixtures, rewiring, or remodeling. Finally, color is powerful. In an age of intense competition and rapidly expanding technology, color is one design tool that can make a difference. PMID:10284566

Caudill, D W



Translucent Tissue Defects in Solanum tuberosum L: I. Alterations in Amyloplast Membrane Integrity, Enzyme Activities, Sugars, and Starch Content.  


Kennebec (cv) potatoes randomly developed translucent areas in their centrally located pith-parenchymal cells during storage. These defective areas were characterized as having reduced starch concentration and increased levels of free sugars (i. e. sucrose and glucose) and inorganic phosphate. Electron micrographs of potato tubers stored at 10 degrees +/- 1 degrees C for 8 months indicated that the amyloplast membrane was still intact and continuous around starch granules in both normal and prematurely sweetened tissue. The total activities of phosphorylase and sucrose-6-P synthase were elevated 5.4- and 3.8-fold, respectively, in the defective tissue compared to healthy nonsweetened tubers while there were no significant differences in the levels of sucrose synthase, UDPglucose pyrophosphorylase, invertase, or alpha-amylase. Total and specific activities of acid phosphatase were only slightly elevated in translucent tissue but their increase was significant (P < 0.05, t test) over that seen in healthy tubers. The premature sweetening in storage may have been indirectly triggered by moisture and heat stress experienced during development. Translucency eventually led to physical deterioration of the tissue. PMID:16664271

Sowokinos, J R; Lulai, E C; Knoper, J A




Microsoft Academic Search

Effect of seed tuber size and planting space on tuber yield and tuber size of potato (S.tuberosum) was studied in red-yellow latosols of dry zone under irrigation. It was found that the number of stems and tubers produced per plant significantly increased with increasing seed tuber size and planting space. The numbers of stems and tubers per plant were significantly



Characteristics of crosslinked potato starch and starch-filled linear low-density polyethylene films  

Microsoft Academic Search

Potato starch was crosslinked with 0.1, 0.5, 1.0 and 2.0g epichlorohydrin per 100g of starch and some physicochemical characteristics of the starch were determined. Starch-filled linear low-density polyethylene cast films were prepared to contain 5 or 10% crosslinked starch. Mechanical properties of these films were measured and compared to those of the films containing native potato starch. Molar degree of

Meera Kim; Sun-Ja Lee



Comparison of Cationic and Unmodified Starches in Reactive Extrusion of Starch–Polyacrylamide Graft Copolymers  

Microsoft Academic Search

Graft copolymers of starch and polyacrylamide (PAAm) were prepared using reactive extrusion in a corotating twin screw extruder.\\u000a The effect of cationic starch modification was examined using unmodified and cationic dent starch (?23% amylose) and waxy\\u000a maize starch (?2% amylose). For a fixed acrylamide\\/starch feed ratio, conversion, graft content, and grafting efficiency were\\u000a essentially unaffected by starch type or modification.

J. L. Willett; V. L. Finkenstadt



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.




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.


Cytokinins and Tuber Initiation in the Potato Solanum tuberosum L  

Microsoft Academic Search

SEVERAL experiments have implicated the presence of a specific stimulus responsible for the initiation of tuber formation1, but there are few reports of the effect of cytokinins on the process2,3. Courduroux2 suggested that the specific tuber forming substance may be related to cytokinins but he did not demonstrate a requirement for cytokinins in tuber induction. The interplay of gibberellins and

C. E. Palmer; O. E. Smith



Clinically Relevant Imaging in Tuberous Sclerosis  

PubMed Central

Tuberous sclerosis (TS), also known as Bourneville disease or Bourneville–Pringle disease, is an autosomal dominant genetic disorder classically characterized by the presence of hamartomatous growths in multiple organs. TS and tuberous sclerosis complex (TSC) are different terms for the same genetic condition. Both terms describe clinical changes due to mutations involving either of the two genes named TSC1 and TSC2, which regulate cell growth. The diagnosis of TSC is established using diagnostic criteria based on clinical and imaging findings. Routine screening and surveillance of patients with TSC is needed to determine the presence and extent of organ involvement, especially the brain, kidneys, and lungs, and identify the development of associated complications. As the treatment is organ specific, imaging plays a crucial role in the management of patients with TSC.

Radhakrishnan, Rupa; Verma, Sadhna



Identification of Armillaria nabsnona in gastrodia tubers.  


The symbiosis between Armillaria species and an achlorophylous orchid Gastrodia elata BLUME has been reported. The main species described as a symbiont is Armillaria mellea (VAHL: FR.) KUMMER, known widely as a primary root rot pathogen. Samples collected from the rhizomorphs attached to the tuber of G. elata were separated and analyzed. Molecular analysis based on sequencing of the intergenic spacer 1 (IGS-1) and internal transcribed spacer (ITS) regions of the ribosomal DNA (rDNA) was performed, coupled with restriction fragment length polymorphism (RFLP) of the IGS-1 region. Cultural morphology and features of basidiomata were also used to characterize the isolates. Phylogenetic analysis and morphological data strongly suggested that the fungus present in the tubers of G. elata is Armillaria nabsnona. This is the first report of occurrence of this Armillaria species in association with G. elata. PMID:18591784

Sekizaki, Haruo; Kuninaga, Shiro; Yamamoto, Mizuho; Asazu, Sandra Naomi; Sawa, Satoko; Kojoma, Mareshige; Yokosawa, Ryozo; Yoshida, Naotoshi



SPL Color  

Center for Drug Evaluation (CDER)

... Color Keyword Names in the Scalable Vector Graphics (SVG) 1.1 Specification recommended by the World Wide Web Consortium (W3C) on ... More results from


Regulation of Potato Tuber Protein Accumulation by Gibberellic Acid 1  

PubMed Central

Many studies have shown that gibberellic acid (GA3) inhibits tuberization in potato (Solanum tuberosum L.). In this study, we have utilized the 40 kilodalton glycoprotein, patatin, as a marker for biochemical events associated with the process of tuberization. To determine the effects of exogenous applications of GA3 on the induction of the accumulation of this major tuber protein, we measured patatin levels in tubers from treated whole plants, petioles from a single-node cutting system with GA3 applied in a lanolin paste, and stolon tips cultured in vitro on an inductive medium supplemented with GA3. In all three systems, GA3 inhibited the accumulation of patatin and the major 15 and 22 kilodalton tuber proteins. This effect appeared to be selective since most of the other proteins were not affected and, in tubers, at least one protein was stimulated by GA3. These results suggest that GA3 can reverse biochemical events of tuberization in tubers as well as prevent the accumulation of the major tuber proteins in other inducible tissues. Images Fig. 1 Fig. 4

Hannapel, David J.; Miller, J. Creighton; Park, William D.



Tuberous Sclerosis Complex and DNA Repair  

Microsoft Academic Search

\\u000a \\u000a Tuberous sclerosis complex (TSC) is an autosomal dominant disorder in humans characterized by the development of hamartomas\\u000a in several organs, including renal angiomyolipomas, cardiac rhabdomyomas and subependymal giant cell astrocytomas. TSC causes\\u000a disabling neurologic disorders, including epilepsy, mental retardation and autism. Brain lesions, including subependymal and\\u000a subcortical hamartomas, have also been reported in TSC patients. TSC is associated with hamartomas

Samy L. Habib


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.

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



Morphology of starch digestion in the horse.  


Structure of starch in feed and chyme of horses (7 with a cannula at the caudal end of the jejunum and 2 with a cecal fistula) after feeding high starch diets (maize: whole, broken, ground, expanded and as silage, oats: whole, rolled or ground, rolled barley, raw potatoes, and tapioca) was investigated by light and electron microscopy. Structure of feed starch and morphology or starch degradation in the chyme corresponded to data on preileal starch digestibility which was investigated in a parallel study. Barriers for starch digestion in the gastrointestinal tract of the horse were structure of the plant storage organ, as for example, a tight connection between starch granules in maize gains as well as the structure of the starch granules itself. The highly digestible oat starch was degraded by exocorrosion around the grains, whereas in other, less digestible, starch types degradation occurred by endocorrosion via pin holes. The number and size of the pin holes increased with increasing preileal starch digestibility. The effect of various ways of decomposition on preileal digestibility increased with advanced destruction of the original starch structure. Expanding was most effective. The granules were destroyed completely and the starch became soluble. Simple examination by light microscopy is a fast method to evaluate the degree of starch decomposition in the feed. PMID:9270343

Kienzle, E; Pohlenz, J; Radicke, S



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


Acid invertase is believed to play a regulatory role during plant developmental processes and to respond to environmental stimuli. The expression profiles of the entire acid invertase family are not yet available for potato. By searching existing databases, it was determined that there are at least six acid invertase genes in potato, including four cell-wall invertase genes and two vacuolar invertase genes. They were subjected to comparative expression profiling in various organs of potato plants and in stored tubers to exploit their potential functions. The results revealed that each gene exhibited a unique expression pattern, which differed in transcript abundance or showed organ-specific features, pointing to the possible involvement of individual genes in plant development. The vacuolar invertase gene StvacINV1 had the highest expression level among three genes detected in the potato tubers. Further storage experiments showed that StvacINV1 was strongly induced by low temperatures, which is consistent with glucose accumulation in cold-stored tubers. Suppression of StvacINV1 by the antisense transformation in potato confirmed that lower StvacINV1 transcript abundance in transgenic tubers is related to lower reducing sugar content and lighter chip color in comparison with the wild type. The evidence strongly suggests that StvacINV1 is a gene involved in regulation of cold-induced sweetening of potato tubers. This provides an avenue for studying the mechanism involved in the regulation of the cold-induced sweetening trait and for agronomic enhancement. PMID:21691778

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



Colored Coalescent Theory  

Microsoft Academic Search

We introduce a colored coalescent process which recovers random colored genealogical trees. Here a colored genealogical tree has its vertices colored black or white. Moving backward along the colored genealogical tree, the color of vertices may change only when two vertice coalesce. The rule that governs the change of color involves a parameter $x$. When $x=1\\/2$, the colored coalescent process

Jianjun Tian; Xiao-Song Lin



Expression and cellular distribution of vascular endothelial growth factor-C system in cortical tubers of the tuberous sclerosis complex.  


Cortical tubers are malformations of cortical development in patients with tuberous sclerosis complex (TSC), and highly associated with pediatric intractable epilepsy. Recent evidence has shown that signaling mediated through vascular endothelial growth factor-C (VEGF-C) and its receptors, VEGFR-2 and VEGFR-3, has direct effects on both neurons and glial cells. To understand the potential role of VEGF-C system in the pathogenesis of cortical tubers, we investigated the expression patterns of VEGF-C signaling in cortical tubers compared with age-matched normal control cortex (CTX). We found that VEGF-C, VEGFR-2 and VEGFR-3 were clearly upregulated in tubers at both the mRNA and protein levels, compared with CTX. The in situ hybridization and immunostaining results demonstrated that VEGF-C, VEGFR-2 and VEGFR-3 were highly expressed in dysplastic neurons (DNs), giant cells (GCs) and reactive astrocytes within tubers. Most DNs/GCs expressing VEGF-C and its receptors co-labeled with neuronal rather than astrocytic markers, suggesting a neuronal lineage. In addition, protein levels of Akt-1, p-Bad and ERK1/2, the important downstream factors of the VEGF-C pathway, were significantly increased in cortical tubers, indicating involvement of VEGF-C-dependent prosurvival signaling in cortical tubers. Taken together, our results suggest a putative role for the VEGF-C signaling pathway in the pathogenesis of cortical tubers. PMID:21767323

Zhang, Chun-Qing; Shu, Hai-Feng; Yin, Qing; An, Ning; Xu, Sen-Lin; Yin, Jin-Bo; Song, Ye-Chun; Liu, Shi-Yong; Yang, Hui



Slowly Digestible Starch: Concept, Mechanism, and Proposed Extended Glycemic Index  

Microsoft Academic Search

Starch is the major glycemic carbohydrate in foods, and its nutritional property is related to its rate and extent of digestion and absorption in the small intestine. A classification of starch into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) based on the in vitro Englyst test is used to specify the nutritional quality of starch.

Genyi Zhang; Bruce R. Hamaker



Technological induction of mucoadhesive properties on waxy starches by grinding  

Microsoft Academic Search

In the present work the mucoadhesive properties of two native starches (maize starch and waxy maize starch) and one pregelatinized waxy maize starch have been investigated. Subsequently the possibility of inducing or improving the mucoadhesive properties of these starches by simple technological processes such as milling and spray-drying has been assessed.Native starches were first checked for physical properties [intrinsic viscosity,

F Ferrari; S Rossi; A Martini; L Muggetti; R De Ponti; C Caramella



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.


Starch degradation and starch pattern indices; interpretation and relationship to maturity  

Microsoft Academic Search

Indication of starch hydrolysis by iodine staining is widely used in determining when to harvest apples, yet few quantitative changes in apple starch have been reported and no reports relate these to changes in iodine staining. Starch accumulation and degradation during fruit development was examined in ‘Fuji’ and ‘Royal Gala’ apples. Both cultivars displayed similar patterns in starch accumulation and

Paul Brookfield; Peter Murphy; Roger Harker; Elspeth MacRae



Starch digestion by feedlot cattle: Predictions from analysis of feed and fecal starch and nitrogen  

Microsoft Academic Search

To evaluate the utility of N as a diges- tion marker to predict total tract starch digestion, data from 32 metabolism trials involving 147 steers and 637 individual starch digestibility measurements were com- piled. All trials were conducted at the University of California Desert Research and Extension Center. To- tal tract starch digestibility was determined from con- centrations of starch

R. A. Zinn; A. Barreras; L. Corona; F. N. Owens; R. A. Ware



Observed limit of Solanum jamesii tuber dormancy at 14 years  

Technology Transfer Automated Retrieval System (TEKTRAN)

Control of tuber dormancy is of interest for commercial potato production and for germplasm preservation in the genebank. We previously reported (AJPR 87:226-228) that tubers of greenhouse-grown Solanum jamesii from 1999 sprouted after 8+ years of storage in a continuous 40F (5C) cooler. One populat...


Antimicrobial activity of Curcuma zedoaria and Curcuma malabarica tubers  

Microsoft Academic Search

The antimicrobial activity of extracts of Curcuma zedoaria and Curcuma malabarica tubers was tested against six bacterial and two fungal strains using the agar well diffusion and broth dilution methods. Petroleum ether, hexane, chloroform, acetone and ethanol extracts exhibited antibacterial as well as antifungal activity. Acetone and hexane extracts of both tubers showed comparable antimicrobial activity as indicated by minimum

B. Wilson; G. Abraham; V. S. Manju; M. Mathew; B. Vimala; S. Sundaresan; B. Nambisan



Multiple Signaling Pathways Control Tuber Induction in Potato  

Microsoft Academic Search

Potatoes (tubers of Solanum tuberosum) are grown and eaten in more countries than any other crop, and in the global economy they are the fourth most important crop after the three cereals maize, rice, and wheat. Therefore, research into potato tuber initiation and development, which enables our understanding and possible manipula- tion of these processes, is of great relevance. In

Stephen D. Jackson



Developmental expression of the tuberous sclerosis proteins tuberin and hamartin  

Microsoft Academic Search

Tuberous sclerosis complex is an autosomal dominant multisystem disorder, characterized by the development of hamartomas in multiple organs, primarily the skin, heart, kidney, and brain. The tuberous sclerosis genes, TSC1 and TSC2, encode hamartin and tuberin, respectively. Employing specific antibodies for hamartin and tuberin, we analyzed the expression of these two proteins by Western blot analyses in normal developing human

Vanishree Murthy; Anat O. Stemmer-Rachamimov; Luciana A. Haddad; Jennifer E. Roy; Andrea N. Cutone; Roberta L. Beauchamp; Nicole Smith; David N. Louis; Vijaya Ramesh



Expression of lipoxygenase in wounded tubers of Solanum tuberosum L.  

PubMed Central

A lipoxygenase cDNA clone from Solanum tuberosum L. was analyzed to study the role of lipoxygenases in potato development and wound response. Sequence analysis and comparison of the deduced amino acid sequence revealed high homology to other plant lipoxygenases. Expression of the cDNA sequences in Escherichia coli and subsequent analysis of bacterial protein extracts showed lipoxygenase activity using linoleic, linolenic, or arachidonic acid as substrates. Transcripts encoding the potato lipoxygenase were most abundant in tuber tissue, lower in roots, and hardly detectable in leaves, petioles, and stems. The induction of lipoxygenase expression in tubers by wounding was dependent on various parameters. Whereas lipoxygenase transcript levels increased in discs from stored tubers incubated under aerobic conditions, tubers taken from a growing plant did not accumulate lipoxygenase transcripts in response to wounding. Incubation of tuber discs in buffer did not lead to an increase in lipoxygenase RNA levels; however, methyl jasmonate stimulated lipoxygenase expression after 24 h in stored tubers. Proteinase inhibitor II mRNAs decreased in stored tubers as well as in discs from growing tubers.

Geerts, A; Feltkamp, D; Rosahl, S



Characterization of Autism in Young Children With Tuberous Sclerosis Complex  

Microsoft Academic Search

Both cognitive impairment and autism are common in the tuberous sclerosis complex, but the relationship between the 2 diagnoses has not been formally explored. The authors evaluated 20 clinic-referred children with tuberous sclerosis complex at ages 18, 24, 36, and 60 months and classified them as autism, autism spectrum disorder, or normal on the basis of the Autism Diagnostic Observation

Shafali S. Jeste; Mustafa Sahin; Patrick Bolton; George B. Ploubidis; Ayla Humphrey



Attention-Deficit Hyperactivity Disorder (ADHD) and Tuberous Sclerosis Complex  

Microsoft Academic Search

The neurobiological basis of attention-deficit hyperactivity disorder (ADHD) in tuberous sclerosis complex is still largely unknown. Cortical tubers may disrupt several brain networks that control different types of attention. Frontal lobe dysfunction due to seizures or epileptiform electroencephalographic discharges may perturb the development of brain systems that underpin attentional and hyperactive functions during a critical early stage of brain maturation.

Elisa DAgati; Romina Moavero; Caterina Cerminara; Paolo Curatolo



Measurement of intercellular adhesion in the cooked potato tuber  

Microsoft Academic Search

Methods are described for the direct measurement of intercellular adhesion and for the measurement of tuber firmness with a ‘simple puncture tester’ and with the Wolodkewitsch tenderometer. The data obtained with these techniques indicated that, in the cooked potato, tuber firmness depends on intercellular adhesion. The results obtained with the Wolodkewitsch tenderometer were found to be directly related to those

D. J. Linehan; J. C. Hughes



Reevaluation of the Life Cycle of Tuber magnatum  

Microsoft Academic Search

Tuber spp. are Ascomycetes fungi that establish an ecto- mycorrhizal symbiosis with trees and shrubs. As a result of this mutualistic symbiosis, ascocarps known as truffles are pro- duced. Some Tuber spp. produce edible truffles that, given their distinctive taste and aroma, are highly valued by gourmets. Research on these fungi has focused on promoting the culti- vation of these

Francesco Paolocci; Andrea Rubini; Claudia Riccioni; Sergio Arcioni



Highly Absorbent Starch-Containing Polymeric Compositions.  

National Technical Information Service (NTIS)

The patent application concerns aqueous fluid-absorbing compositions comprising water-insoluble alkali salts of saponified gelatinized-starch-polyacrylonitrile graft polymers containing gelatinized starch (GS) and saponified polyacrylonitrile (HPAN). The ...

M. G. Weaver E. B. Bagley G. F. Fants W. M. Doane



Analysis of natural variation of the potato tuber proteome reveals novel candidate genes for tuber bruising.  


Potato (Solanum tuberosum) presents a challenging organism for the genetic and molecular dissection of complex traits due to its tetraploidy and high heterozygosity. One such complex trait of high agronomic interest is the tuber susceptibility to bruising upon mechanical impact, which involves an enzymatic browning reaction. We have compared the tuber proteome of two groups of 10 potato cultivars differing in bruising susceptibility to (i) identify de novo proteins that contribute to bruising, based on differential protein expression, and (ii) validate these proteins by combining proteomics with association genetics. The comparison of 20 potato varieties yields insight into the high natural variation of tuber protein patterns due to genetic background. Seven genes or gene families were found that were both differentially expressed on the protein level between groups and for which DNA polymorphisms were associated with the investigated traits. A putative class III lipase was identified as a novel factor contributing to the natural variation of bruising. Additionally, tuber proteome changes triggered by mechanical impact, within and between groups, were monitored over time. Differentially expressed proteins were found, notably lipases, patatins, and annexins, showing remarkable time-dependent protein variation. PMID:22047174

Urbany, Claude; Colby, Thomas; Stich, Benjamin; Schmidt, Lysann; Schmidt, Jürgen; Gebhardt, Christiane



Nutrient Metabolism Dietary Native Resistant Starch but Not Retrograded Resistant Starch Raises Magnesium and Calcium Absorption in Rats1  

Microsoft Academic Search

The effects on calcium and magnesium absorption of dietary native and retrograded cornstarch were studied in rats. Uncooked high amylose starch granules (35% of total glucose equivalents as enzyme- resistant starch) and cooked and cooled (-20 C) high amylose starch (24% of total glucose equivalents as retrograded resistant starch) were used as test starches, and cooked normal starch (3% of



Effect of non-starch polysaccharides on the in vitro digestibility and rheological properties of rice starch gel  

Microsoft Academic Search

The starch digestibility and rheological properties of gels were evaluated in the presence of three non-starch polysaccharides (agar, xanthan gum and konjac glucomannan) with rice starch. Each polysaccharide was added to 30% (w\\/w) rice starch suspension at defined concentrations and starch gels were prepared. The extent of starch gel digestibility was determined by an in vitro method and rheological properties

Tomoko Sasaki; Kaoru Kohyama



Proteome and phosphoproteome analysis of starch granule-associated proteins from normal maize and mutants affected in starch biosynthesis  

Microsoft Academic Search

In addition to the exclusively granule-bound starch synthase GBSSI, starch granules also bind significant proportions of other starch biosynthetic enzymes, particularly starch synthases (SS) SSI and SSIIa, and starch branching enzyme (BE) BEIIb. Whether this association is a functional aspect of starch biosyn- thesis, or results from non-specific entrapment dur- ing amylopectin crystallization, is not known. This study utilized genetic,

Florent Grimaud; H. Rogniaux; M. G. James; A. M. Myers; V. Planchot



Grafting of 2-butenyl acrylate onto starch  

Microsoft Academic Search

The monomer 2-butenyl acrylate was reacted with starch by exposure to either ⁶°Co irradiation or ceric ion initiation. Monomer conversion in the presence of starch is greater than in the absence of starch, indicating that a starch initiating mechanism takes place for ⁶°Co irradiated samples. Acetone extraction indicates little or no soluble homopolymer in the grafts. Portions of the samples

T. P. Abbott; C. James



Starch Formation in the Cereal Endosperm  

Microsoft Academic Search

Starch comprises ?70% of the dry weight of a cereal seed. Because the vast majority of\\u000a this starch is in the cereal endosperm and cereals are the major agricultural plants grown world-wide, endosperm\\u000a starch is the largest single contributor to the world's calorie supply. Starch biosynthesis in the endosperm\\u000a is described herein. Emphasis is placed on classical “biochemical genetics”, with the

L. Curtis Hannah


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


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



Starch Granulomatosis of the Peritoneum  

PubMed Central

Starch glove powder is used extensively by surgeons in Britain and is generally considered innocuous so that precautions to prevent granuloma formation, previously taken when talc glove powder was in use, are now neglected. Reported here are five cases of starch granulomatosis of the peritoneum occurring over a period of a few months. This condition requires reoperation within a limited time for its diagnosis and may be confused macroscopically with disseminated malignant disease or tuberculosis or may simply cause adhesions. Recognition is dependent on a high degree of suspicion by both surgeon and histopathologist, as special histological techniques may be necessary. Consequently, it is only in a minority of the florid cases that a diagnosis is made, and the condition would appear to be much more common than is generally realized. A plea is made for scrupulous care to avoid starch powder contamination of the operative field. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6

Neely, Julian; Davies, J. Douglas



Peritonitis from Starch Glove Powder  

PubMed Central

Contamination of surgical wounds by starch glove powders has produced peritoneal inflammation and adhesions in many patients. Some have required surgical operation because of possible infection, others because of obstruction of the intestine. Resolving granulomas and fibrosis have been observed as incidental asymptomatic lesions in some patients during reoperation for other conditions. Starch granules are probably capable of producing inflammation in any patient, and the degree is believed to be related to the amount of starch present. Care in removing glove powder from gloves before they are worn in an operation will diminish or eliminate the problem. Removal can be accomplished by rubbing the gloves with a moist sterile towel or laparotomy tape. ImagesFigure 1.Figure 2.

Dutra, Frank R.; Jensen, C. David



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


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



Digestibility of Different Sources of Starch  

Microsoft Academic Search

The increasing environmental restrictions can make it necessary to reduce the dietary protein content. Hence, the focus on carbohydrates increases. In an experiment we focused on the glycemic index and starch digestibility in 7 different starch sources. We were not successful in determining the glycemic index, and the method used for analysis of starch content was insufficiently accurate. Among the

Carsten Hejlesen; Peter Sandbøl



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...



Microsoft Academic Search

Starch is the main product of photosynthesis and its the most dominant reserve polysaccaride that stored in photosynthetic and non-photosynthetic tissues. Starch is a staple food in human and animal diets, but also a raw material widely used for industrial purposes, such as food, paper and textile. Starch granule structure, amylose and amylopectin moleculer structure, amylose and amylopectin ratio, and

Hülya ÖLÇER; Betül AKIN



Processing and Properties of Expanded Starch Materials  

Microsoft Academic Search

Expanded starch materials are prepared from normal potato starch (NPS) and amylopectin potato starch (PAP) using two-step extrusion with an intermediate conditioning in order to control the moisture content. The moisture content is the driving force for the expansion during the second extrusion. The effect of two different plasticizers, urea and glycerol, are compared with regard to the foaming ability

Mia Sjöqvist; Antal Boldizar; Mikael Rigdahl



Microstructural characterization of yam starch films  

Microsoft Academic Search

Yam starch films were produced by thermal gelatinization of starch suspensions using different starch and glycerol concentrations and were compared to control samples without glycerol. Films were characterized by polarized light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermomechanical analysis (TMA), X-ray diffraction, water vapor permeability (WVP) and water sorption isotherms. The polarized light microscopy and DSC data

Suzana Mali; Maria Victória E Grossmann; Maria A Garcia; Miriam N Martino; Noemi E Zaritzky



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/...


Modification of granular starch with protein  

Microsoft Academic Search

This research was undertaken to modify starch with natural products, namely proteins. Motivation for this project was a 1943 patent by A. D. Fuller, which described a modified starch product, made with various substances in the presence of small amounts of hypochlorite (NaClO), that behaved like a crosslinked starch (characterized by an increase in peak viscosity and a decrease in

Bridget Ryan Manis



Properties of Starch Blends with Biodegradable Polymers  

Microsoft Academic Search

Starch, one of the most inexpensive and most readily available of all natural polymers, can be processed into thermoplastic materials only in the presence of plasticizers and under the action of heat and shear. Poor water resistance and low strength are limiting factors for the use of materials manufactured only from starch, and hence the modification of starch is often

Xiu-Li Wang; Ke-Ke Yang; Yu-Zhong Wang



Cloning and characterization of PKC-homologous genes in the truffle species Tuber borchii and Tuber magnatum  

Microsoft Academic Search

The protein kinases C (PKCs) define a growing family of ubiquitous signal transducting serine\\/threonine kinases that control ion conductance channels, release of hormones and cell growth and proliferation. Degenerated oligonucleotides were used as primers for polymerase chain reactions to amplify PKC-related sequences from the white truffle species Tuber magnatum and Tuber borchii. The deduced amino acid sequences of cloned sequences

Roberto Ambra; Giuseppe Macino



Starch and By-Products from a Laboratory-Scale Barley Starch Isolation Procedure  

Microsoft Academic Search

Cereal Chem. 78(5):507-513 Starch was isolated from three different barleys with normal, high- amylose, or high-amylopectin (waxy) starch. The laboratory-scale starch isolation procedure included crushing of grains, steeping, wet milling, and sequential filtration and washing with water and alkali, respectively. Yield and content of starch, protein, and dietary fiber, including ?-glucan, were analyzed in isolated starch and in the by-products

A. A. M. Andersson; R. Andersson; P. Åman



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.



Feather Coloration  

NSDL National Science Digital Library

In this activity, learners make observations, formulate a hypothesis and draw conclusions based on a simple experiment about feather coloration. For this test, learners will compare a peacock feather and a pheasant feather. Background information contains explanation of pigment feathers and structural feathers. This lesson plan includes questions to ask learners and online resources.

Houston, Children'S M.



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.



Colorful television  

NASA Astrophysics Data System (ADS)

What are the challenges and rewards for American men and women of color who chose to become scientists? The Public Broadcasting Service intends to show us through an upcoming 6-hour documentary series entitled “Breakthrough: The Changing Face of Science in America.”

Carlowicz, Michael


Colorful Accounting  

ERIC Educational Resources Information Center

|As instructors of accounting, we should take an abstract topic (at least to most students) and connect it to content known by students to help increase the effectiveness of our instruction. In a recent semester, ordinary items such as colors, a basketball, and baseball were used to relate the subject of accounting. The accounting topics of…

Warrick, C. Shane



Evaluation of the Eff ect of Density on Potato Yield and Tuber Size Distribution  

Microsoft Academic Search

Potato (Solanum tuberosum) yield has been opti- mized for in-row spacings ranging from 15 to 40 cm depending on region, targeted market, vari- ety, and other factors. Production goals require optimizing tuber size to maximize crop value. Our goal was to evaluate the effect of plant, stem, and tuber density on stem and tuber set, potato yield, tuber size distribution,

Alvin J. Bussan; Paul D. Mitchell; Michael E. Copas; Michael J. Drilias



Lipid metabolism during aging of high-?-linolenate-phenotype potato tubers  

Microsoft Academic Search

Previous studies demonstrated that high levels of ?-linolenate in cell membranes of potato tubers (achieved by overexpressing fatty acid desaturases) enhances lipid peroxidation, oxidative stress, and tuber metabolic rate, effectively accelerating the physiological age of tubers. This study details the changes in lipid molecular species of microsomal and mitochondrial membranes from wild-type (WT) and high-?-linolenate tubers during aging. The microsomal

Vladimir Zabrouskov; N. Richard Knowles



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

SciTech Connect

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

Kumar, G.N.M.; Knowles, N.R. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Agricultural, Food and Nutritional Science; Houtz, R.L. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Horticulture and Landscape Architecture



Age-Induced Protein Modifications and Increased Proteolysis in Potato Seed-Tubers1  

PubMed Central

Long-term aging of potato (Solanum tuberosum) seed-tubers resulted in a loss of patatin (40 kD) and a cysteine-proteinase inhibitor, potato multicystatin (PMC), as well as an increase in the activities of 84-, 95-, and 125-kD proteinases. Highly active, additional proteinases (75, 90, and 100 kD) appeared in the oldest tubers. Over 90% of the total proteolytic activity in aged tubers was sensitive to trans-epoxysuccinyl-l-leucylamido (4-guanidino) butane or leupeptin, whereas pepstatin was the most effective inhibitor of proteinases in young tubers. Proteinases in aged tubers were also inhibited by crude extracts or purified PMC from young tubers, suggesting that the loss of PMC was responsible for the age-induced increase in proteinase activity. Nonenzymatic oxidation, glycation, and deamidation of proteins were enhanced by aging. Aged tubers developed “daughter” tubers that contained 3-fold more protein than “mother” tubers, with a polypeptide profile consistent with that of young tubers. Although PMC and patatin were absent from the older mother tubers, both proteins were expressed in the daughter tubers, indicating that aging did not compromise the efficacy of genes encoding PMC and patatin. Unlike the mother tubers, proteinase activity in daughter tubers was undetectable. Our results indicate that tuber aging nonenzymatically modifies proteins, which enhances their susceptibility to breakdown; we also identify a role for PMC in regulating protein turnover in potato tubers.

Kumar, G.N. Mohan; Houtz, Robert L.; Knowles, N. Richard



Analysis of genes differentially expressed during potato tuber life cycle and isolation of their promoter regions  

Microsoft Academic Search

The potato tuber life cycle involves several developmental stages including tuberisation, tuber growth, dormancy and sprouting. Gene expression during the potato tuber life cycle has been monitored using a RNA fingerprinting technique termed cDNA-AFLP. The expression profile of the nearly 2000 transcript derived fragments (TDFs) was analysed and general conclusions concerning the different stages of tuber life cycle and tissue

Luisa M. Trindade; Beatrix M. Horvath; Ralph van Berloo; Richard G. F. Visser



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



Temporally regulated expression of a yeast invertase in potato tubers allows dissection of the complex metabolic phenotype obtained following its constitutive expression.  


The constitutive cytosolic expression of a yeast ( Saccharomyces cerevisiae ) invertase within potato ( Solanum tuberosum ) tubers has previously been documented to produce a dramatic metabolic phenotype in which glycolysis, respiration and amino acid synthesis are markedly enhanced at the cost of starch synthesis. These transgenic lines were further characterised by a massive cycle of sucrose degradation and resynthesis via sucrose-phosphate synthase. We have recently developed a B33 patatin driven alc gene construct allowing tight chemical control of gene expression following supply of acetaldehyde with minimal pleiotropic effects of the inducing agent on metabolism. This construct was used for chemical induction of the yeast invertase gene after 10-weeks growth to dissect the complex metabolic phenotype obtained after constitute expression. Inducible expression led to increased invertase activity within 24 h in well-defined areas within growing tubers. Although the sucrose levels were reduced, there was no effect on the levels of starch whilst levels of many amino acids decreased. Labelling experiments revealed that these lines exhibited increased rates of sucrose cycling, whereas rates of glycolysis and of starch synthesis were not substantially changed. From these results we conclude that sucrose cycling is stimulated in response to a short-term increase in the rate of sucrose mobilisation, providing evidence for a role of sucrose cycling as a buffering capacity that regulates the net rate of sucrose usage. In contrast, the dramatic increase in hexose-phosphate levels and the switch from starch synthesis to respiration seen on the constitutive expression of the invertase was not observed in the inducible lines, suggesting that this is the result of cumulative pleiotropic effects that occurred when the transgene was expressed throughout development. PMID:15604730

Junker, Björn H; Wuttke, René; Tiessen, Axel; Geigenberger, Peter; Sonnewald, Uwe; Willmitzer, Lothar; Fernie, Alisdair R



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


Native American populations are known to have cultivated a large number of plants and domesticated them for their starch-rich underground organs. Suggestions that the likely source of many of these crops, the tropical forest, was an early and influential centre of plant husbandry have long been controversial because the organic remains of roots and tubers are poorly preserved in archaeological sediments from the humid tropics. Here we report the occurrence of starch grains identifiable as manioc (Manihot esculenta Crantz), yams (Dioscorea sp.) and arrowroot (Maranta arundinacea L.) on assemblages of plant milling stones from preceramic horizons at the Aguadulce Shelter, Panama, dated between 7,000 and 5,000 years before present (BP). The artefacts also contain maize starch (Zea mays L.), indicating that early horticultural systems in this region were mixtures of root and seed crops. The data provide the earliest direct evidence for root crop cultivation in the Americas, and support an ancient and independent emergence of plant domestication in the lowland Neotropical forest. PMID:11057665

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



Molecular cloning and analysis of four potato tuber mRNAs  

Microsoft Academic Search

Tuberization in potato is a complex developmental process involving the expression of a specific set of genes leading to the synthesis of tuber proteins. We here report the cloning and analysis of mRNAs encoding tuber proteins. From a potato tuber cDNA library four different recombinants were isolated which hybridized predominantly with tuber mRNAs. Northern blot hybridization experiments showed that three

Willem J. Stiekema; Freek Heidekamp; Wim G. Dirkse; Joke van Beckum; Peter de Haan; Carolien ten Bosch; Jeanine D. Louwerse



Relationships of hollow heart in Irish potatoes to carbohydrate reabsorption and growth rate of tubers  

Microsoft Academic Search

Tubers of Irish Cobbler that were hollow grew faster than non-hollow tubers on the same plant. However, tubers of varieties\\u000a without hollow heart grew just as rapidly as tubers of the variety with hollow heart. Therefore tuber growth rate was related\\u000a to hollow heart occurring within a variety but could not account for differences between varieties. When plant foliage was

I. J. Crumbly; D. C. Nelson; M. E. Duysen



Possible prevention of tuberous sclerosis complex lesions.  


Tuberous sclerosis complex (TSC) is a genetic disorder characterized by mammalian target of rapamycin (mTOR) activation and growth of benign tumors. Some TSC lesions, such as cardiac rhabdomyomas and cortical tubers in the brain, occur in fetuses, and some, such as renal angiomyolipomas (AMLs) and skin angiofibromas, develop over years. Recently, the mTOR inhibitor everolimus was shown to be effective in the treatment of subependymal giant cell astrocytomas (a brain tumor) and renal AMLs (kidney tumors) in TSC patients. We present monozygotic twin sisters affected with TSC. Since age 4 years, 1 of the sisters has been treated with everolimus; the other sister received no mTOR inhibitor treatment. After 24-month follow-up, everolimus treatment resulted in a significant brain tumor volume decrease in the treated twin. This child presents no facial angiofibroma, and no renal AMLs. The brain tumor in the nontreated sister is stable in size, but in the meantime, she has developed significant facial angiofibroma and renal AMLs. This observation indicates that early mTOR inhibition in TSC patients may prevent the development of TSC lesions and alter the natural history of the disease. PMID:23733802

Kotulska, Katarzyna; Borkowska, Julita; Jozwiak, Sergiusz



Changes in potato phenylpropanoid metabolism during tuber development.  


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 were highest in immature tubers, as were some transcript levels and enzyme activities including phenylalanine ammonia lyase (PAL). Phenylpropanoid concentration differences between mature and immature tubers varied by genotype, but in some cases were approximately three-fold. The most abundant phenylpropanoid was chlorogenic acid (5CGA), which decreased during tuber maturation. Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) transcripts were highly expressed relative to other phenylpropanoid genes, but were not well correlated with 5CGA concentrations (r = -0.16), whereas HQT enzyme activity was. In contrast to 5CGA, less abundant chlorogenic isomers increased during development. Concentrations of hydroxycinnamic acid amides were higher in immature tubers, as was expression of arginine- and ornithine decarboxylases. Expression of several genes involved in carbohydrate or shikimate metabolism, including sucrose synthase and DAHP, showed similar developmental patterns to phenylpropanoid pools, as did shikimate dehydrogenase enzyme activity. Sucrose, glucose and fructose concentrations were highest in immature tubers. Exogenous treatment of potatoes with sugars stimulated phenylpropanoid biosynthesis, suggesting sugars contribute to the higher phenylpropanoid concentrations in immature tubers. These changes in phenylpropanoid expression suggest the nutritional value of potatoes varies during development. PMID:23434926

Navarre, Duroy A; Payyavula, Raja S; Shakya, Roshani; Knowles, N Richard; Pillai, Syamkumar S



Cationic starch nanoparticles based on polyelectrolyte complexes.  


Cationic starch nanoparticles were obtained by aqueous polyelectrolyte complex formation between cationic quaternary ammonium substituted starches and anionic sodium tripolyphosphate. The formation of nanosized starch particles of spherical shape was verified by dynamic light scattering and scanning electron microscopy measurements. The cationic starch nanoparticles of different constitution and containing various contents of free quaternary ammonium groups were produced and their zeta potential was modulated between +4 mV and +34 mV by varying polycation/polyanion ratio. Furthermore, the polyelectrolyte complex formation was confirmed by differential scanning calorimetry and FTIR analyses. The thermal stability of cationic starch nanoparticles increased with the introduction of polysalt into polyelectrolyte complex. The solubilization capacity of nanoparticles was varying with the concentration and composition as revealed by fluorescence probe experiments. The capability to accommodate hydrophobic pyrene quest molecule was decreasing with the increasing number of cationic groups in cationic starches and little depended on polyanion/polycation ratio in starch nanoparticles. PMID:22326820

Rutkaite, Ramune; Bendoraitiene, Joana; Klimaviciute, Rima; Zemaitaitis, Algirdas



Color Television and Colorimetry  

Microsoft Academic Search

The high lights of the history of color measurement and of color photography are reviewed. Following this introduction, the principles of modern 3-color colorimetry are developed from a hypothetical experiment in color matching. The conventional theory of \\

W. T. Wintringham



Tuberous sclerosis complex presenting as bilateral large renal angiomyolipomas.  


Tuberous sclerosis is an inherited disorder that can present with seizures, mental retardation, cutaneous lesions and visceral hamartomas, but can be entirely asymptomatic. The disease occurs in 1:100 000 persons in all races with nearly equal distribution between the sexes. Tuberous sclerosis is often associated with renal angiomyolipomas (AMLs), which occur in up to 80% of these patients. Here we report a case of a patient who presented with bilateral large renal AMLs and was detected to have tuberous sclerosis complex. PMID:22878994

Redkar, Neelam; Patil, Meenakshi Amit; Dhakate, Tushar; Kolhe, Prasad



Tuberous sclerosis: case report and investigation of family members  

PubMed Central

Familial tuberous sclerosis probably occurs more often than is indicated by the literature: many family members show signs of being carriers of the gene for the disease when carefully examined. This article reports on a family with documented tuberous sclerosis in three generations and discusses the examination and investigation of at-risk family members, including the newborn, for signs of the disease. The potential teratogenic effects of anticonvulsants, used to control seizures in tuberous sclerosis, are also discussed. ImagesFig. 1Fig. 3AFig. 3B

Wilson, R. Douglas; Hall, Judith G.; McGillivray, Barbara C.



Color space conversion for linear color grading  

NASA Astrophysics Data System (ADS)

Color grading is an important process for various industries such as food processing, fruit and vegetable grading, etc. Quality and price are often determined by the color of product. For example, darker red color for apples means higher price. In color machine vision applications, image is acquired with a color CCD camera that outputs color information in three channels, red, gree, and blue. When grading color, these three primary colors must be processed to determine the color level for separation. A very popular color space conversion technique for color image processing is RGB-to-HSI, where HSI represents hue, saturation, and intensity, respectively. However, the conversion result is still 3D information that makes determining color grades very difficult. A new color space conversion technique that can be implemented for high-speed real-time processing for color grading is introduced in this paper. Depending on the application, different color space conversion equations must be used. The result of this technique is a simple one-dimensional array that represents different color levels. This linear array makes linear color grading adjustment possible.

Lee, Dah Jye



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.

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



Nonthermal starch hydrolysis using ultra high pressure: I. Effects of acids and starch concentrations  

Microsoft Academic Search

Corn starches with 2mol\\/l hydrochloric acid (HCl), 2mol\\/l sulfuric acid (H2SO4) and 2mol\\/l oxalic acid (C2H2O4) were pressurized at 600MPa for 30min. Corn starch with C2H2O4 formed a gel after ultra-high-pressure (UHP) treatment. Corn starch with HCl showed partial disintegration but starch with H2SO4 maintained its shape. Corn starch with HCl showed higher (0.42–0.47) degree of hydrolysis compared to starch

Jae-Hwang Lee; Hyun-Wook Choi; Byung-Yong Kim; Myong-Soo Chung; Dong-Seob Kim; Sung Won Choi; Dong-Un Lee; Seok-Jun Park; Nam-Yoon Hur; Moo-Yeol Baik



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


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


Effect of granular characteristics on pasting properties of starch blends.  


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



Physicochemical and functional properties of ozone-oxidized starch.  


The effects of oxidation by ozone gas on some physicochemical and functional properties of starch (corn, sago, and tapioca) were investigated. Starch in dry powder form was exposed to ozone for 10 min at different ozone generation times (OGTs). Carboxyl and carbonyl contents increased markedly in all starches with increasing OGTs. Oxidation significantly decreased the swelling power of oxidized sago and tapioca starches but increased that of oxidized corn starch. The solubility of tapioca starch decreased and sago starch increased after oxidation. However, there was an insignificant changed in the solubility of oxidized corn starch. Intrinsic viscosity [eta] of all oxidized starches decreased significantly, except for tapioca starch oxidized at 5 min OGT. Pasting properties of the oxidized starches followed different trends as OGTs increased. These results show that under similar conditions of ozone treatment, the extent of starch oxidation varies among different types of starch. PMID:19489606

Chan, Hui T; Bhat, Rajeev; Karim, Alias A



A sweetpotato SRD1 promoter confers strong root-, taproot-, and tuber-specific expression in Arabidopsis, carrot, and potato.  


Harvestable, starch-storing organs of plants, such as fleshy taproots and tubers, are important agronomic products that are also suitable target organs for use in the molecular farming of recombinant proteins due to their strong sink strength. To exploit a promoter directing strong expression restricted to these storage organs, we isolated the promoter region (3.0 kb) of SRD1 from sweetpotato (Ipomoea batatas cv. 'White Star') and characterized its activity in transgenic Arabidopsis, carrot, and potato using the ?-glucuronidase (GUS) gene (uidA) as a reporter gene. The SRD1 promoter conferred root-specific expression in transgenic Arabidopsis, with SRD1 promoter activity increasing in response to exogenous IAA. A time-course study of the effect of IAA (50 ?M) revealed a maximum increase in SRD1 promoter activity at 24 h post-treatment initiation. A serial 5' deletion analysis of the SRD1 promoter identified regions related to IAA-inducible expression as well as regions containing positive and negative elements, respectively, controlling the expression level. In transgenic carrot, the SRD1 promoter mediated strong taproot-specific expression, as evidenced by GUS staining being strong in almost the entire taproot, including secondary phloem, secondary xylem and vascular cambium. The activity of the SRD1 promoter gradually increased with increasing diameter of the taproot in the transgenic carrot and was 10.71-fold higher than that of the CaMV35S promoter. The SRD1 promoter also directed strong tuber-specific expression in transgenic potato. Taken together, these results demonstrate that the SRD1 promoter directs strong expression restricted to the underground storage organs, such as fleshy taproots and tubers, as well as fibrous root tissues. PMID:21660481

Noh, Seol Ah; Lee, Haeng-Soon; Huh, Gyung Hye; Oh, Mi-Joung; Paek, Kyung-Hee; Shin, Jeong Sheop; Bae, Jung Myung



Starch-Based Plastic Foams From Various Starch Sources1  

Microsoft Academic Search

Cereal Chem. 73(5):601-604 Corn, tapioca, wheat, rice, and potato starches were extruded with grafted as was confirmed by X-ray diffraction patterns of extrudates and 30% polystyrene and 5% magnesium silicate or 1% polycarbonate or water solubility indexes. The expansion, unit density and water solubility 0.5% azodicarbonamide in a single screw C. W. Brabender laboratory index of the extrudates depended on



Starch hydrolysis by the ruminal microflora.  


The effects of grain type and processing on ruminal starch digestion are well documented but poorly understood at the biochemical and molecular levels. Waxy grains have starches high in amylopectin and are more readily digested than nonwaxy grains. However, the composition of the endosperm cell matrix and the extent to which the starch granules are embedded within it also affect starch digestion rates. Continued work is needed to determine the influence of specific cell matrix proteins, protein-starch interactions and cell wall carbohydrates on starch availability. The microbial populations that metabolize starch are diverse, differing in their capacities to hydrolyze starch granules and soluble forms of starch. Surveys show that the amylases are under regulatory control in most of these organisms, but few studies have addressed the types of amylolytic enzymes produced, their regulation and the impact of other plant polymers on their synthesis. Research in these areas, coupled with the development and use of isogeneic or near-isogeneic grain cultivars with biochemically defined endosperm characteristics, will enhance our ability to identify mechanisms to manipulate ruminal starch digestion. PMID:1370325

Kotarski, S F; Waniska, R D; Thurn, K K



Thermal and rheological properties of breadfruit starch.  


The thermal and rheological properties of breadfruit starch were studied using DSC and 2 different rheometers. It was found that the gelatinization temperature of starch with excess moisture content (>70%) was at approximately 75 °C. A new endotherm was detected at about 173 °C when the moisture content was lower than required for full gelatinization of the starch. A detailed examination revealed that this endotherm represented the melting of amylose-lipid complexes. Breadfruit starch paste exhibited shear-thinning fluid characteristics, and good thermal and pH stability. The setback viscosity of the breadfruit starch was lower than that of potato and corn starches. The rheological properties of the breadfruit starch paste was well described by the Herschel-Bulkley model at a shear rate of 0 to 100 s(-1), where R(2) is greater than 0.95, and it behaved like a yield-pseudoplastic fluid. Both the storage modulus and loss modulus of the paste initially increased sharply, then dropped after reaching the gelatinization peak. Breadfruit starch gel showed both flexibility and viscosity. Suspension with 6% starch content exhibited very weak gel rigidity; however, this increased significantly at starch contents above 20%. PMID:21535676

Wang, Xueyu; Chen, Ling; Li, Xiaoxi; Xie, Fengwei; Liu, Hongshen; Yu, Long



Molecular disassembly of starch granules during gelatinization and its effect on starch digestibility: a review.  


Starch is the most important glycemic carbohydrate in foods. The relationship between the rate and extent of starch digestion to produce glucose for absorption into the bloodstream and risk factors for diet-related diseases is of considerable nutritional interest. Native starch is attacked slowly by enzymes, but after hydrothermal processing its susceptibility to enzymatic breakdown is greatly increased. Most starch consumed by humans has undergone some form of processing or cooking, which causes native starch granules to gelatinize, followed by retrogradation on cooling. The extent of gelatinization and retrogradation are major determinants of the susceptibility of starch to enzymatic digestion and its functional properties for food processing. The type and extent of changes that occur in starch as a result of gelatinization, pasting and retrogradation are determined by the type of the starch, processing and storage conditions. A mechanistic understanding of the molecular disassembly of starch granules during gelatinization is critical to explaining the effects of processing or cooking on starch digestibility. This review focuses on the molecular disassembly of starch granules during starch gelatinization over a wide range of water levels, and its consequential effect on in vitro starch digestibility and in vivo glycemic index. PMID:24096569

Wang, Shujun; Copeland, Les



The Simultaneous Abolition of Three Starch Hydrolases Blocks Transient Starch Breakdown in Arabidopsis*  

PubMed Central

In this study, we investigated which enzymes are involved in debranching amylopectin during transient starch degradation. Previous studies identified two debranching enzymes, isoamylase 3 (ISA3) and limit dextrinase (LDA), involved in this process. However, plants lacking both enzymes still degrade substantial amounts of starch. Thus, other enzymes/mechanisms must contribute to starch breakdown. We show that the chloroplastic ?-amylase 3 (AMY3) also participates in starch degradation and provide evidence that all three enzymes can act directly at the starch granule surface. The isa3 mutant has a starch excess phenotype, reflecting impaired starch breakdown. In contrast, removal of AMY3, LDA, or both enzymes together has no impact on starch degradation. However, removal of AMY3 or LDA in addition to ISA3 enhances the starch excess phenotype. In plants lacking all three enzymes, starch breakdown is effectively blocked, and starch accumulates to the highest levels observed so far. This provides indirect evidence that the heteromultimeric debranching enzyme ISA1-ISA2 is not involved in starch breakdown. However, we illustrate that ISA1-ISA2 can hydrolyze small soluble branched glucans that accumulate when ISA3 and LDA are missing, albeit at a slow rate. Starch accumulation in the mutants correlates inversely with plant growth.

Streb, Sebastian; Eicke, Simona; Zeeman, Samuel C.



A study on the in vivo digestibility of retrograded starch  

Microsoft Academic Search

The digestibility of different forms of starch was examined in an ileostomy model. Six otherwise healthy ileostomists were fed a controlled polysaccharide-free diet for four days, on three of which a test starch was added at breakfast. 50 g starch was fed as either whole or homogenized chick peas or as a retrograded starch gel. A readily digestible wheat starch

R. L. Botham; V. J. Morris; T. R. Noel; S. G. Ring



Factors affecting the digestibility of raw and gelatinized potato starches  

Microsoft Academic Search

The enzymatic digestibilities of raw and gelatinized starches in various potato starches, as well as sweet potato, cassava, and yam starches, were estimated, along with other starch properties, such as the phosphorus content, median granule size, and rapid visco analyzer (RVA) pasting properties. Furthermore, correlation coefficients were calculated between the hydrolysis rates (HR) by amylase and other starch quality parameters.

T. Noda; S. Takigawa; C. Matsuura-Endo; T. Suzuki; N. Hashimoto; N. S. Kottearachchi; H. Yamauchi; I. S. M. Zaidul



Physicochemical characterization of starch ferulates of different degrees of substitution  

Microsoft Academic Search

Starch ferulates were prepared by reacting potato starch with ferulic acid chloride, using pyridine as a catalyst in dimethyl sulfoxide. Starch ferulates of different degrees of substitution (DS) were prepared and their formation was confirmed by the presence of the carbonyl signal around 1726cm?1 in the FT-IR spectra. The thermal characteristics of the native starch and starch ferulates of different

Sindhu Mathew; T. Emilia Abraham



Dialdehyde starch and zein plastic: Mechanical properties and biodegradability  

Microsoft Academic Search

Dialdehyde starch (DAS) and zein, a hydrophobic corn protein, were investigated to produce biodegradable plastics with improved water resistance and mechanical properties. In the study, dialdehyde starch and zein ratio, plasticizers, and degree of starch oxidation were examined. Increased molding temperature and level of starch oxidation decreased water absorption of the plastic. Tensile strength and Young's modulus increased with starch

Kris E. Spence; Jay-lin Jane; Anthony L. Pometto



Resistant starch in cereals: Exploiting genetic engineering and genetic variation  

Microsoft Academic Search

Some of the starch consumed by humans is not digested in the small intestine. Such starch, known as resistant starch, is fermented in the large intestine and leads to the production of short chain fatty acids. Increased consumption of resistant starch is associated with improved cardio-vascular health. A high proportion of amylose in the starch consumed is correlated with increased

Sadequr Rahman; Anthony Bird; Ahmed Regina; Zhongyi Li; Jean Philippe Ral; Steve McMaugh; David Topping; Matthew Morell



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.


Glucosyloxybenzyl 2-Isobutylmalates from the tubers of Gymnadenia conopsea.  


Seven new glucosyloxybenzyl 2-isobutylmalates, gymnosides I-VII (1-7), were isolated from the tubers of Gymnadenia conopsea. The structures of 1-7 were determined on the basis of chemical and physicochemical evidence. PMID:16792404

Morikawa, Toshio; Xie, Haihui; Matsuda, Hisashi; Yoshikawa, Masayuki



Isolation and characterization of some mycelia inhabiting Tuber ascomata.  


Tuber spp. are ectomycorrhizal ascomycetes that produce subterranean ascomata known as truffles. Truffles can be regarded as complex microhabitats hosting bacteria and yeasts. In this paper we show that guest filamentous fungi are also associated to truffle ascomata, regardless of the Tuber spp., and report the morpho-molecular characterization of seven truffle-hosted mycelia isolated from healthy and intact Tuber ascomata. Some of these isolates were shown to be related to the fungal endophytes of plants. Interestingly, the truffle-hosted mycelia grew stuck to the hyphal wall of their partner when co-cultivated with the Tuber borchii mycelium, but not when co-cultivated with the test species Agaricus macrosporus. The present data suggest that guest filamentous fungi can be added to the list of truffle-interacting microorganisms. PMID:18023164

Pacioni, Giovanni; Leonardi, Marco; Aimola, Pierpaolo; Ragnelli, Anna Maria; Rubini, Andrea; Paolocci, Francesco



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


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



Protein trypsin inhibitor from potato tubers.  


A protein of 22 kDa designated as PKTI-22 was isolated from potato tubers (Solanum tuberosum L., cv. Istrinskii) and purified to homogeneity using CM-Sepharose CL-6B ion-exchange chromatography. The protein efficiently suppressed the activity of trypsin, affected chymotrypsin less, and did not affect subtilisin Carlsberg. The N-terminal sequence of PKTI-22 (20 amino acid residues) was found to be highly homologous with the amino acid sequences of the potato Kunitz-type proteinase inhibitors of group B (PKPI-B) that were aligned from the corresponding gene sequences and was identical to the sequence (from the 2nd to the 20th residue) of the recombinant protein PKPI-B10. These data together with the observed similarity of the properties of two proteins indicate that the PKTI-22 protein is encoded by the PKPI-B10 gene. PMID:20331422

Revina, T A; Kladnitskaya, G V; Gerasimova, N G; Gvozdeva, E L; Valueva, T A



Change in content of sugars and free amino acids in potato tubers under short-term storage at low temperature and the effect on acrylamide level after frying.  


Changes in the sugar and amino acid contents of potato tubers during short-term storage and the effect on the acrylamide level in chips after frying were investigated. The acrylamide content in chips began to increase after 3 days of storage at 2 degrees C in response to the increase of glucose and fructose contents in the tubers. There was strong correlation between the reducing sugar content and acrylamide level, R(2)=0.873 for fructose and R(2)=0.836 for glucose. The sucrose content had less correlation with the acrylamide content because of its decrease after 4 weeks of storage at 2 degrees C, while the reducing sugar in potato tubers and the acrylamide in chips continued to increase. The contents of the four amino acids, i.e., asparatic acid, asparagine, glutamic acid and glutamine, showed no significant correlation with the acrylamide level. These results suggest that the content of reducing sugars in potato tubers determined the degree of acrylamide formation in chips. The chip color, as evaluated by L* (lightness), was correlated well with the acrylamide content. PMID:16041124

Ohara-Takada, Akiko; Matsuura-Endo, Chie; Chuda, Yoshihiro; Ono, Hiroshi; Yada, Hiroshi; Yoshida, Mitsuru; Kobayashi, Akira; Tsuda, Shogo; Takigawa, Shigenobu; Noda, Takahiro; Yamauchi, Hiroaki; Mori, Motoyuki



Cooking kinetics of potato tubers determined by vibration techniques  

Microsoft Academic Search

A laser Doppler vibrometer (LDV) was used for remote sensing of potato cooking behavior. Non-destructive determinations of characteristic tuber resonant frequencies (modes M1 and M2) displayed in the amplitude–frequency plots (AFP) prior, during, and after steam cooking of the whole tubers were used to establish cooking kinetic coefficients for four different potato varieties. All measurements for a single potato were

Jiri Blahovec; Shinichiro Kuroki; Naoki Sakurai



Effect of cadmium on glutathione reductase in potato tubers  

Microsoft Academic Search

Short-term treatment of potato tuber (Solanum tuberosum L.) discs with CdCl2 changed glutathione reductase (GR) activity depending on cadmium ions concentrations, kind of tuber and time of incubation.\\u000a The increase of GR activity at 10 and 100 µmol·dcm?3 of CdCl2 solutions was marked in less resistant tissues of cv. Bintje after 24 hrs, and was slight in more resistant tissues

Andrzej Stroi?ski; Jan Kubi?; Ma?gorzata Zielezi?ska



Inheritance of glucose content in tubers of diploid potato families  

Microsoft Academic Search

During two consecutive years 17 unselected families of diploid potatoes in comparison to their parents and standard cultivars\\u000a were assessed for glucose content in tubers. Glucose content was evaluated using Potato Test Strips in tubers stored at 10\\u000a C, 4 C, and 4 C followed by reconditioning at 18 C. Distribution of glucose content in families indicated that the trait

Henryka Jakuczun; Ewa Zimnoch-Guzowska



Genetic aspects of tuberous sclerosis in the west of Scotland  

Microsoft Academic Search

Complete ascertainment of tuberous sclerosis was attempted in the west of Scotland (population 2,763,000). A total of 101 patients was identified, giving an overall minimum prevalence of 1 in 27,000, but for children under 10 years of age the minimum prevalence was 1 in 12,000. Both parents of 84 of the ascertained cases were assessed for signs of tuberous sclerosis.

J R Sampson; S J Scahill; J B Stephenson; L Mann; J M Connor



Biallelic TSC gene inactivation in tuberous sclerosis complex  

PubMed Central

Background: A pivotal developmental question is whether tubers in tuberous sclerosis complex (TSC) form by germline and somatic TSC1 or TSC2 gene mutations. Loss of TSC1 or TSC2 in vitro and in vivo leads to mTORC1 cascade activation and ribosomal protein S6 phosphorylation (P-S6). Giant cells (GCs) in tubers exhibit S6 phosphorylation, suggesting cell-specific loss of TSC gene function. Methods: TSC1 and TSC2 gene mutations were investigated in DNA extracted from tuber sections (n = 6) and microdissected P-S6–labeled GCs by sequencing and loss of heterozygosity (LOH) analysis to define germline and somatic mutations. Results: A germline TSC1 mutation was defined in 1 case and TSC2 mutations were defined in 5 cases. LOH was not detected in whole tuber sections or microdissected P-S6–labeled GCs. TSC1 and TSC2 were sequenced in microdissected P-S6–immunolabeled GCs. In 5 specimens, a somatic mutation was identified in single GCs that was not detected in whole tuber sections or leukocyte DNA. Four somatic mutations were novel variants (1 nonsense and 3 missense mutations) and 1 additional nonsense somatic mutation was previously reported as a germline mutation. In 1 case, no somatic mutation was identified. There was reduced expression of TSC1 or TSC2 transcripts in the TSC1 or TSC2 associated specimens. In the cases containing a nonsense mutation, no transcript mRNA was detected, suggesting nonsense-mediated degradation. Conclusions: We provide evidence to support the hypothesis that tubers form by biallelic TSC1 or TSC2 gene inactivation reflecting a “2-hit” mechanism of germline and somatic mutational events. GLOSSARY AML = angiomyolipoma; DN = dysplastic neuron; FFPE = formalin fixed, paraffin embedded; GC = giant cell; H-E = hematoxylin and eosin; LOH = loss of heterozygosity; TSC = tuberous sclerosis complex.

Crino, Peter B.; Aronica, Eleonora; Baltuch, Gordon; Nathanson, Katherine L.



Diffusion of oxygen through lenticels in potato tuber  

Microsoft Academic Search

Summary  Diffusion into the potato tuber of oxygen for respiration takes place only through lenticels, and not through the rest of\\u000a the periderm. The number of lenticels which were capable of injection with methylene blue solution was observed to be about\\u000a 100 per tuber. Rates of oxygen diffusion per lenticel varied from 0.024 to 0.296 cm3 h?1 atm?1 with a mean

M. J. Wigginton



Age of potato seed tubers affects growth and yield  

Microsoft Academic Search

Summary  In summer crop regions the storage period of home grown seed tubers is not necessarily short. The yield reduction that is\\u000a due to planting seed tubers after passing the suitable age and the senile degeneration occur consistently. In each variety,\\u000a the effect that is due to the advanced age is not so outstanding in the field. However, the decrease in

Kojiro Kawakami




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...


Raw starch degradation by the non-raw starch-adsorbing bacterial alpha amylase of Bacillus sp. IMD 434  

Microsoft Academic Search

The raw starch-digesting alpha amylase of Bacillus sp. IMD 434 was purified to homogeneity and displayed substantial hydrolysis of raw starch but did not adsorb onto the insoluble substrates, corn, rice, wheat or potato starch, at any of the pH values examined. The degree of hydrolysis ranged from 10% hydrolysis of potato starch to 32% hydrolysis of corn starch after

Lynn M. Hamilton; Catherine T. Kelly; William M. Fogarty



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.



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


Compartmentation of metabolism in developing seeds is poorly understood due to the lack of data on metabolite distributions at the subcellular level. In this report, a non-aqueous fractionation method is described that allows subcellular concentrations of metabolites in developing barley endosperm to be calculated. (i) Analysis of subcellular volumes in developing endosperm using micrographs shows that plastids and cytosol occupy 50.5% and 49.9% of the total cell volume, respectively, while vacuoles and mitochondria can be neglected. (ii) By using non-aqueous fractionation, subcellular distribution between the cytosol and plastid of the levels of metabolites involved in sucrose degradation, starch synthesis, and respiration were determined. With the exception of ADP and AMP which were mainly located in the plastid, most other metabolites of carbon and energy metabolism were mainly located outside the plastid in the cytosolic compartment. (iii) In developing barley endosperm, the ultimate precursor of starch, ADPglucose (ADPGlc), was mainly located in the cytosol (80-90%), which was opposite to the situation in growing potato tubers where ADPGlc was almost exclusively located in the plastid (98%). This reflects the different subcellular distribution of ADPGlc pyrophosphorylase (AGPase) in these tissues. (iv) Cytosolic concentrations of ADPGlc were found to be close to the published K(m) values of AGPase and the ADPGlc/ADP transporter at the plastid envelope. Also the concentrations of the reaction partners glucose-1-phosphate, ATP, and inorganic pyrophosphate were close to the respective K(m) values of AGPase. (v) Knock-out of cytosolic AGPase in Riso16 mutants led to a strong decrease in ADPGlc level, in both the cytosol and plastid, whereas knock-down of the ADPGlc/ADP transporter led to a large shift in the intracellular distribution of ADPGlc. (v) The thermodynamic structure of the pathway of sucrose to starch was determined by calculating the mass-action ratios of all the steps in the pathway. The data show that AGPase is close to equilibrium, in both the cytosol and plastid, whereas the ADPGlc/ADP transporter is strongly displaced from equilibrium in vivo. This is in contrast to most other tissues, including leaves and potato tubers. (vi) Results indicate transport rather than synthesis of ADPGlc to be the major regulatory site of starch synthesis in barley endosperm. The reversibility of AGPase in the plastid has important implications for the regulation of carbon partitioning between different biosynthetic pathways. PMID:22200665

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



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



Effect of Batter Solids and Starch Type on the Structure of Baked Starch Foams  

Microsoft Academic Search

Cereal Chem. 76(5):682-687 The effects of starch type on the properties of baked starch foams were investigated. Starch types used for baking were normal corn, normal potato, waxy corn, high-amylopectin potato, wheat, and tapioca. Solids content of the starch batters used to bake foam trays ranged from 25 to 45%. Pro- cessing parameters and physical properties of the foams were

J. W. Lawton; R. L. Shogren; K. F. Tiefenbacher



Consequence of Starch Damage on Rheological Properties of Maize Starch Pastes 1  

Microsoft Academic Search

Cereal Chem. 79(6):897-901 Waxy and normal maize starches were damaged to different extents by ball milling, with waxy starch notably more susceptible to damage. Starch damage caused substantial decreases in shear stress or apparent viscosity in both waxy and normal maize starch pastes at a wide range of shear rates (5.6 to 400 1\\/sec). Shear stress or apparent viscosity decreases

Xian-Zhong Han; Osvaldo H. Campanella; Nadege C. Mix; Bruce R. Hamaker



Flocculation of microalgae using cationic starch  

Microsoft Academic Search

Due to their small size and low concentration in the culture medium, cost-efficient harvesting of microalgae is a major challenge.\\u000a We evaluated the potential of cationic starch as a flocculant for harvesting microalgae using jar test experiments. Cationic\\u000a starch was an efficient flocculant for freshwater (Parachlorella, Scenedesmus) but not for marine microalgae (Phaeodactylum, Nannochloropsis). At high cationic starch doses, dispersion

Dries Vandamme; Imogen Foubert; Boudewijn Meesschaert; Koenraad Muylaert



Physicochemical characterization of mung bean starch  

Microsoft Academic Search

Starch from mung bean (Vigna radiata) was isolated and some of the important characteristics determined. The yield of starch was 31.1% on a whole-seed basis. The shape of the starch granule was oval to round to bean shaped, with granules 7–26 ?m in diameter. Scanning electron micrographs revealed the presence of smooth surfaces. The gelatinization temperature range was 58–67–82°C and

R. Hoover; Y. X. Li; G. Hynes; N. Senanayake



Effects of Maturity on Corn Starch Properties  

Microsoft Academic Search

Cereal Chem. 79(5):703-706 The effect of maturity on the quality of starch for two corn hybrids harvested at three different stages of development was measured by differential scanning calorimetry, rapid viscosity analysis, scanning electron microscopy, and image analysis. The onset of gelatinization and peak temperatures were 2-5°C higher for starch from immature grain than starch from mature grain. The gelatinization

S. D. Jennings; D. J. Myers; L. A. Johnson; L. M. Pollak



Structural and molecular properties of dialdehyde starch  

Microsoft Academic Search

Dialdehyde starch (DAS) of degree of oxidation (DO) of 1.5% (DAS1-5), 5% (DAS5), 15% (DAS15) and 25% (DAS25) was prepared from potato starch in the periodate oxidation reaction with electrochemical recovery of the oxidant. Molecular weights (Mw) and radii of gyration (Rg) of polysaccharide chains of native and oxidized starches were measured by means of a high-performance size exclusion chromatography

Maciej Fiedorowicz; Andrzej Para



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



Physical characterization of cassava starch biofilms with special reference to dynamic mechanical properties at low temperatures  

Microsoft Academic Search

Biofilms based on cassava starch and containing glycerol as a plasticizer were characterized with respect to the effect of potassium sorbate concentration and pH on color, crystallinity and mechanical performance al low temperature.It could be observed that a lower pH resulted in lower values of yellow index and tan? and higher crystallinities.Crystallinity decreased with sorbate addition, which also resulted, in

Lucía Famá; Silvia K. Flores; Lía Gerschenson; Silvia Goyanes



Functionality of batters containing different starch types for deep-fat frying of chicken nuggets  

Microsoft Academic Search

The effect of various starch types (amylomaize, corn, waxymaize, pregelatinized tapioca) on quality attributes (texture, moisture content, oil content, color, coating pick up, cooking yield, volume and porosity) of deep-fat fried chicken nuggets were studied. Chicken samples, 0.04 m in diameter and 0.015 m in thickness, taken from the breast portion, were coated with batters composed of a 3:5 solid

Bilge Altunakar; Serpil Sahin; Gulum Sumnu



Enzyme digestibility of starch and methods to produce enzyme-resistant starch to improve human health  

Microsoft Academic Search

The objectives of this study were to understand how intrinsic and extrinsic factors of o2 and QPM starches affected the enzyme digestibility of their starches, to develop novel and economical technologies to produce RS for health benefits. Enzyme digestibilities of starch present in opaque-2 maize (o2) and quality protein maize (QPM) were analyzed to evaluate the uses of the two

Jovin Hasjim



Studies on the morphological and rheological properties of granular cold water soluble corn and potato starches  

Microsoft Academic Search

Granulated cold water soluble (GCWS) starches were prepared from corn starch and starches separated from four potato cultivars using alcoholic-alkaline method. The morphological, thermal and rheological properties of GCWS corn and potato starches were studied. The amylose content of the GCWS starches from corn and potato starches were significantly lower as compared to their counterparts native starches. GCWS potato starches

Jaspreet Singh; Narpinder Singh



Microalgae--novel highly efficient starch producers.  


The freshwater alga Chlorella, a highly productive source of starch, might substitute for starch-rich terrestrial plants in bioethanol production. The cultivation conditions necessary for maximizing starch content in Chlorella biomass, generated in outdoor scale-up solar photobioreactors, are described. The most important factor that can affect the rate of starch synthesis, and its accumulation, is mean illumination resulting from a combination of biomass concentration and incident light intensity. While 8.5% DW of starch was attained at a mean light intensity of 215?µmol/(m2 s1), 40% of DW was synthesized at a mean light intensity 330?µmol/(m2 s1). Another important factor is the phase of the cell cycle. The content of starch was highest (45% of DW) prior to cell division, but during the course of division, its cellular level rapidly decreased to about 13% of DW in cells grown in light, or to about 4% in those kept in the dark during the division phase. To produce biomass with high starch content, it is necessary to suppress cell division events, but not to disturb synthesis of starch in the chloroplast. The addition of cycloheximide (1?mg/L), a specific inhibitor of cytoplasmic protein synthesis, and the effect of element limitation (nitrogen, sulfur, phosphorus) were tested. The majority of the experiments were carried out in laboratory-scale photobioreactors, where culture treatments increased starch content to up to about 60% of DW in the case of cycloheximide inhibition or sulfur limitation. When the cells were limited by phosphorus or nitrogen supply, the cellular starch content increased to 55% or 38% of DW, respectively, however, after about 20?h, growth of the cultures stopped producing starch, and the content of starch again decreased. Sulfur limited and cycloheximide-treated cells maintained a high content of starch (60% of DW) for up to 2 days. Sulfur limitation, the most appropriate treatment for scaled-up culture of starch-enriched biomass, was carried out in an outdoor pilot-scale experiment. After 120?h of growth in complete mineral medium, during which time the starch content reached around 18% of DW, sulfur limitation increased the starch content to 50% of DW. PMID:21404251

Brányiková, Irena; Maršálková, Barbora; Doucha, Ji?í; Brányik, Tomáš; Bišová, Kate?ina; Zachleder, Vilém; Vítová, Milada



Hextend, High Molecular Weight Hydroxyethyl Starch 6% ...  

Center for Biologics Evaluation and Research (CBER)

... Hextend, High Molecular Weight Hydroxyethyl Starch 6% (Hetastarch) in Buffered Electrolyte Dextrose Solution. Product ... More results from


Color Color Relations and NGC 6791  

NASA Astrophysics Data System (ADS)

Johnson-Cousins UBVRIJHK color sequences in old, metal rich open cluster NGC 6791 are assembled and analyzed. Multiple color-color sequences favor a reddening that is on the mild end of recent estimates, around E(B-V) = 0.12 mag when compared to metal-sensitive color-color calibration sequences. Distance and age estimates show much larger scatter and depend strongly on isochrone author. This cluster is a Space Interferometry Mission target, and this work is a spinoff of SIM preparatory science. The color-color calibration work is interesting in itself and shows several as yet unexploited methods for estimating the reddening, especially of sequences of KM dwarfs. Attachment of color-temperature relations yields an almost completely empirical color calibration suitable for attachment to isochrone sets at all metallicities.

Worthey, Guy



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


Simultaneous silencing of asparagine synthetase (Ast)-1 and -2 limits asparagine (ASN) formation and, consequently, reduces the acrylamide-forming potential of tubers. The phenotype of silenced lines appears normal in the greenhouse, but field-grown tubers are small and cracked. Assessing the effects of silencing StAst1 and StAst2 individually, we found that yield drag was mainly linked to down-regulation of StAst2. Interestingly, tubers from untransformed scions grafted onto intragenic StAst1/2-silenced rootstock contained almost the same low ASN levels as those in the original silenced lines, indicating that ASN is mainly formed in tubers rather than being transported from leaves. This conclusion was further supported by the finding that overexpression of StAst2 caused ASN to accumulate in leaves but not tubers. Thus, ASN does not appear to be the main form of organic nitrogen transported from leaves to tubers. Because reduced ASN levels coincided with increased levels of glutamine, it appears likely that this alternative amide amino acid is mobilized to tubers, where it is converted into ASN by StAst1. Indeed, tuber-specific silencing of StAst1, but not of StAst2, was sufficient to substantially lower ASN formation in tubers. Extensive field studies demonstrated that the reduced acrylamide-forming potential achieved by tuber-specific StAst1 silencing did not affect the yield or quality of field-harvested tubers. PMID:22726556

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



The role of water during plasticization of native starches  

Microsoft Academic Search

Flexible, starch-based plastics of native corn, potato, waxy corn and wheat starch were produced by compression moulding mixtures of native starch and glycerol in the weight ratio 0.30 (Wglycerol\\/Wdry starch). In these premixes, the weight ratio water\\/dry starch was varied between 0.112 and 0.422. The mechanical properties of these compression moulded starches, with a glass—rubber transition temperature below room temperature,

Stephan H. D. Hulleman; Frank H. P. Janssen; Herman Feil



Resistant glutarate starch from adlay: Preparation and properties  

Microsoft Academic Search

Reaction conditions were optimized to increase the content of resistant starch in adlay starch using esterification with glutaric acid, and the physicochemical properties of the prepared glutarate starches were investigated. Different amounts of glutaric acid (0.1–0.5g\\/g starch, dry weight basis) were reacted with adlay starch at various temperatures (70–130°C) and reaction times (3–9h). The resistant starch levels increased with increased

Mi Jung Kim; Seung Jun Choi; Sang Ick Shin; Ma Ri Sohn; Chang Joo Lee; Yang Kim; Wan Il Cho; Tae Wha Moon



Public Workshop: Risks and Benefits of Hydroxyethyl Starch ...  

Center for Biologics Evaluation and Research (CBER)

... Starch Solutions. -. Public Workshop: Risks and Benefits of Hydroxyethyl Starch Solutions - Presentations. -. Regulatory Overview ... More results from


Measurement of the water potential of stored potato tubers.  


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

Bland, W L; Tanner, C B



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.



Soil moisture and the infection of young potato tubers by Streptomyces scabies (common scab)  

Microsoft Academic Search

Majestic potatoes planted in soil naturally infested withStreptomyces scabies were trickle irrigated to prevent infection of the tubers except during consecutive 7-day periods in the first eight weeks when tubers were developing (28 May to 23 July).

D. H. Lapwood; T. F. Hering



Chemical Variations Observed in Irradiated, Treated with IPC and Control Potato Tubers.  

National Technical Information Service (NTIS)

The content in soluble sugars, ascorbic acid and phenolic acids of potato tubers preserved by irradiation and IPC, during a storage period of five months are studied. In the irradiated tubers, soluble sugars increased immediately after the irradiation, in...

M. P. Mazon Matanzo J. Fernandez Gonzalez



Color matching from memory  

Microsoft Academic Search

Short-term color memory of two groups of university students, 20 with prior color coursework, and 20 with no color-related training, was evaluated in four hue categories: yellow, yellow-red, green, and purple. Munsell dimensions of hue, value, and chroma were used to select four target colors and nine distractor colors for each of the targets. Four of the distractor colors differed

Helen H. EPPS; Naz KAYA


Environmentally degradable starch filled low density polyethylene  

Microsoft Academic Search

Legislative threats restricting the use of disposable nondegradable plastic because of its environmental problems have generated interest in the use of degradable plastics. An extensive search for potential biodegradable fillers for thermoplastics led to the conclusion that, even today, starch is a cost effective additive with the best commercial promise. Demand for biodegradable plastics is increasing, so starch filled thermoplastics

Piyush B. Shah; S. Bandopadhyay; Jayesh R. Bellare



Starch characterization and ethanol production of sorghum.  


This study aimed to characterize and compare the chemical structures, physical properties, and enzymatic hydrolysis rates of five sorghum starches (6B73, 6C21, 6C69, 7R34, and X789) with that of corn starch (B73). Sorghum kernels consisted of 68.7-70.6% starch, more than the B73 corn (67.4%). Sorghum starches displayed higher gelatinization temperatures (66.6-67.4 °C), greater gelatinization enthalpy changes (13.0-14.0 J/g), and greater percentages of retrogradation (60.7-69.1%), but slower enzymatic hydrolysis rates (83.8-87.8% at 48 h) than the B73 corn starch (61.7 °C, 10.1 J/g, 51.5%, and 88.5%, respectively). These differences could result from the sorghum amylopectins consisting of fewer short branch chains (DP 6-12) (12.8-14.0%) than the corn amylopectin (15.0%). The sorghum starches showed greater peak and breakdown viscosities but lower setback viscosities than the B73 corn starch, resulting from the lower amylose content of the sorghum starches. After 96 h of fermentation, most ground sorghums exhibited lower ethanol yields (30.5-31.8%) than the ground B73 corn (31.8%). PMID:21604720

Ai, Yongfeng; Medic, Jelena; Jiang, Hongxin; Wang, Donghai; Jane, Jay-Lin



Paint removal using wheat starch blast media  

Microsoft Academic Search

A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of

Terry Foster; John Oestreich



Plasticization of corn starch by polyol mixtures  

Microsoft Academic Search

Polyol mixtures including mixture of conventional plasticizer glycerol and higher molecular weight polyol (HP) such as xylitol, sorbitol and maltitol were used to plasticize corn starch by melt-blending method, and effect of the polyol mixture on the pocessibility, microstructures, thermal stability and mechanical properties of these starch composites (SC) were investigated. The introduction of HP providing greater processing torque can

Xiuying Qiao; Zhongzhu Tang; Kang Sun



Starch Wastewater Treatment with Effective Microorganisms Bacteria  

Microsoft Academic Search

Starch wastewater has high turbidity and COD, heavy odor after anaerobic processing. Discharging this kind of sewage could cause serious environmental pollution, and therefore it need to be treated and reached the national standard before discharge. This experiment based on the specific characteristics of starch wastewater. The process was designed as follows: after anaerobic hydrolysis prior to degradation of refractory

Zhou Guizhong; Li Jia; Fan Huiju; Sun Jing; Zhao Xiaoqing



Polymorphism of resistant starch type III  

Microsoft Academic Search

Starch fraction, which is resistant to enzymatic digestion, is produced during retrogradation. This fraction, termed resistant starch type III (RSIII), has health benefits such as pre-biotic effects, improving lipid and cholesterol metabolism, and reducing the risk of colon cancer. Since RSIII preserves its nutritional functionality during cooking processes, it may be used as a food ingredient. This research is part

Keren Shamai; Havazelet Bianco-Peled; Eyal Shimoni



Production of PLA-Starch Fibers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Composites of polylactic acid (PLA) with starch have been prepared previously in an effort to reduce cost as well as to modify other properties such as biodegradation rate. However, strength and elongation both decrease on addition of starch due to poor adhesion and stress concentration at the inte...



Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-graft-poly(acrylamide) was hydrolyzed with an enzyme cocktail composed of a-amylose and a-amylogluosidase in excess. Although the starch-graft-poly(acrylamide) was not water-soluble, it was water-swellable and vulnerable to enzyme attack. After digestion, the hydrolysate was evaluated using...


Pasting characteristics of starch-lipid composites  

Technology Transfer Automated Retrieval System (TEKTRAN)

Starch-lipid composites (SLC) have been used as fat replacers and stabilizers in beef patties, dairy products, and baked goods. The SLC are produced by mixing aqueous starch slurry with a lipid source, and steam jet-cooking. The SLC may be dried using a drum drier and then milled in a Retch mill. ...


?-Amylase inactivation during corn starch hydrolysis process  

Microsoft Academic Search

The effects of operating conditions on the enzymatic hydrolysis of corn starch were investigated. A commercial ?-amylase produced by Bacillus sp. was used for the hydrolysis experiments. The degree of starch hydrolysis (%) and residual ?-amylase activity (%) was investigated versus process variables, including pH, temperature, viscosity, impeller speed, processing time and some materials added such as hydrolysate, maltose, glucose,

Dilek K?l?ç Apar; Belma Özbek



?-Amylase inactivation during rice starch hydrolysis  

Microsoft Academic Search

The effects of operating conditions on the enzymatic hydrolysis of rice starch were investigated using a commercial ?-amylase produced by Bacillus spp. in a stirred batch reactor. The degree of starch hydrolysis (%) and residual ?-amylase activity (%) were investigated versus process variables including pH, temperature, viscosity, impeller speed, processing time and some materials added such as hydrolysate, maltose, glucose,

Dilek K?l?ç Apar; Belma Özbek



Contamination of progeny tubers of potato plants by seed- and leaf-borne Erwinia carotovora  

Microsoft Academic Search

Marker strains ofE. carotovora var.carotovora and var.atroseptica spread from inoculated rotting tubers, buried at seed tuber level under potato plants in the field, to rhizosphere soil and progeny tubers late in the 1983 and 1984 growing seasons when weather conditions were wet. In 1982, tuber rotting was arrested in the dry soil conditions which prevailed after their burial and little

M. C. M. Pérombelon



Evaluation of procedures for detection of pectolytic Erwinia spp. on potato tubers  

Microsoft Academic Search

The effectiveness of a tuber incubation method for detection ofErwinia carotovora var.atroseptica andE. carotovora var.carotovora in potato tubers was compared with a lenticel sampling procedure. In the first method, tubers were injured by puncturing\\u000a lenticels with sterile toothpicks, then wrapped in moist paper towels and polyvinylidene film, and placed in closed chambers\\u000a flushed with N2. In later experiments, wrapping tubers

S. H. De Boer; A. Kelman



Molecular therapies for tuberous sclerosis and neurofibromatosis.  


Neurofibromatosis type 1 (NF1) and tuberous sclerosis complex (TSC) are autosomal-dominant genetic disorders that result from dysregulation of the PI3K/AKT/mammalian target of rapamycin (mTOR) pathway. NF1 is caused by mutations in the NF1 gene on chromosome 17q11.2. Its protein product, neurofibromin, functions as a tumor suppressor and ultimately produces constitutive upregulation of mTOR. TSC is caused by mutations in either the TSC1 (chromosome 9q34) or TSC2 (chromosome 16p.13.3) genes. Their protein products, hamartin and tuberin, respectively, form a dimer that acts via the GAP protein Rheb (Ras homolog enhanced in brain) to directly inhibit mTOR, again resulting in upregulation. Specific inhibitors of mTOR are in clinical use, including sirolimus, everolimus, temsirolimus, and deforolimus. Everolimus has been shown to reduce the volume and appearance of subependymal giant cell astrocytomas (SEGA), facial angiofibromas, and renal angiomyolipomas associated with TSC, with a recent FDA approval for SEGA not suitable for surgical resection. This article reviews the use of mTOR inhibitors in these diseases, which have the potential to be a disease-modifying therapy in these and other conditions. PMID:22544507

Franz, David Neal; Weiss, Brian D



Diffusion features of white matter in tuberous sclerosis with tractography.  


Normal-appearing white matter has been shown via diffusion tensor imaging to be affected in tuberous sclerosis complex. Under the hypothesis that some systems might be differentially affected, including the visual pathways and systems of social cognition, diffusion properties of various regions of white matter were compared. For 10 patients and 6 age-matched control subjects, 3 T magnetic resonance imaging was assessed using diffusion tensor imaging obtained in 35 directions. Three-dimensional volumes corresponding to the geniculocalcarine tracts were extracted via tractography, and two-dimensional regions of interest were used to sample other regions. Regression analysis indicated lower fractional anisotropy in the splenium of corpus callosum and geniculocalcarine tracts in tuberous sclerosis complex group, as well as lower axial diffusivity in the internal capsule, superior temporal gyrus, and geniculocalcarine tracts. Mean and radial diffusivity of the splenium of corpus callosum were higher in the tuberous sclerosis complex group. The differences in diffusion properties of white matter between tuberous sclerosis complex patients and control subjects suggest disorganized and structurally compromised axons with poor myelination. The visual and social cognition systems appear to be differentially involved, which might in part explain the behavioral and cognitive characteristics of the tuberous sclerosis complex population. PMID:20117745

Krishnan, Michelle L; Commowick, Olivier; Jeste, Shafali S; Weisenfeld, Neil; Hans, Arne; Gregas, Matthew C; Sahin, Mustafa; Warfield, Simon K



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


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



Rapid estimation of potato tuber total protein content with coomassie brilliant blue G-250  

Microsoft Academic Search

A new method for measuring protein with Coo-massie Brilliant Blue G-250 has been adapted for use as a screening method in a potato tuber protein improvement breeding program. The method is simple, fast and inexpensive, and has successfully estimated the total protein content of a broad range of tuber genotypes having dissimilar amino acid profiles and tuber maturities. Correlation between

J. C. Snyder; S. L. Desborough



Proton Spectroscopic Findings in Children With Epilepsy Owing to Tuberous Sclerosis Complex  

Microsoft Academic Search

Tuberous sclerosis complex is an autosomal dominant disorder that often causes refractory seizures. The presence of multiple lesions makes it difficult to identify a single lesion responsible for the epilepsy. Our purpose is to assess the single-voxel proton spectroscopic findings of the tubers in 11 children with tuberous sclerosis complex. Prior to age 4 years, all of the patients had

Zuhal Yapici; Alp Dincer; Mefkure Eraksoy



Biochemical and textural changes in trifoliate yam Dioscorea dumetorum tubers after harvest  

Microsoft Academic Search

Biochemical and textural changes were investigated in trifoliate yam Dioscorea dumetorum tubers, after harvest, in an attempt to study the chemical and physical changes associated with the raw and cooked tubers and how these relate to the hardening phenomenon of the tubers after harvest. A 2×2×3×4 factorial experiment, with cultivar, storage condition, treatment and storage time as their respective variables,

Samuel Sefa-Dedeh; Emmanuel Ohene Afoakwa




Technology Transfer Automated Retrieval System (TEKTRAN)

The development of a potato cultivar with increased calcium accumulation ability in the tuber is very important. Potato tuber tissue is known to be naturally deficient in calcium. Lack of adequate calcium is associated with tuber defects such as internal brown spot, hollow heart, and storage rot. We...


The Color Tag Design and Color Model Study in Mirosot  

Microsoft Academic Search

The paper gives a new color pattern based on contrasting the advantages and disadvantages of several kinds of color tag schemes. It adopts HSI color space and improves the transition from RGB color model to HSI color model by analyzing the particular characteristic of RGB color model, YUV color model and HSI color model. The test results and the site

Ma Gang; Liu Tian-shi; Han Jia-xin; Wang Xiao-xiao



Ocatin. A novel tuber storage protein from the andean tuber crop oca with antibacterial and antifungal activities.  


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



Intractable epilepsy in hemimegalencephaly and tuberous sclerosis complex.  


Hemimegalencephaly is a rare brain malformation consisting of the enlargement of 1 hemisphere, often associated with abnormal cortical gyration, thick cortex, large neurons, and increased astrocytes. Cranial asymmetry is the first clinical sign usually present at birth; in the most severe cases, hemimegalencephaly may be evident during pregnancy. Hemiparesis, intractable epilepsy, and developmental delay are the typical clinical manifestations. Tuberous Sclerosis Complex is an autosomal dominant disorder affecting about 1 in 6000 live births; the number of spontaneous mutations is remarkable. It is characterized by the development of hamartias, or nongrowing lesions, and hamartomas, which grow as benign tumors and rarely progress to malignancy. These lesions most frequently involve the brain, skin, kidneys, eyes, and heart. The rare association of hemimegalencephaly and tuberous sclerosis complex has been reported in a few cases. The authors report the case of a 4-year-old boy with left hemimegalencephaly, tuberous sclerosis complex genetically confirmed, and intractable epilepsy originating from the nonhemimegalencephalic hemisphere. PMID:17608312

Guerra, Maria P; Cavalleri, Francesca; Migone, Nicola; Lugli, Licia; Delalande, Olivier; Cavazzuti, Giovanni B; Ferrari, Fabrizio



Structural and functional properties of starches from field peas  

Microsoft Academic Search

Starch was isolated from seven varieties of field peas (Pisumsativum L.) and characterised using a combination of physical, chemical and functional tests. The total starch content of the peas ranged between 34% and 42.7% of dry matter, and the amylose content of the starch was between 35% and 38%. Average particle diameter of the seven starches varied between 21.4 and

Shujun Wang; Peter Sharp; Les Copeland



Digestibility of starch fractions in wholegrain rolled oats  

Microsoft Academic Search

A practical in vitro method was tested for measuring differences in rapidly digested starch (RDS measured at 20min), slowly digested starch (SDS between 20 and 120min) and inaccessible digestible starch (IDS as carbohydrate digested after homogenising at 120min to release inaccessible starch and digesting for a further 40min) in wholegrain cereal samples retaining some grain structure, using in vitro pancreatic

Suman Mishra; John A. Monro



Chemical Method for the Determination of Starch in Polyethylene  

Microsoft Academic Search

A chemical\\/spectrophotometric procedure has been developed that allows the determination of starch and some modified starches (as glucosyl residues) in polyethylene films and pellets. The method uses samples containing up to 60 mg polyethylene and determines the anhydrous starch content of samples possessing starch loads in the range typically encountered with degradable plastics (5–40%). The method consists of dissolution of

Alfred R. Fratzke; Wei Sung; Roque L. Evangelista; Žkivko L. Nikolov



Starch–cassia gum interactions: A microstructure – Rheology study  

Microsoft Academic Search

We present for the first time the interactions of starch and cassia gum – a novel galactomannan recently approved for use in food processing. Viscoelastic, pasting and microstructural characterization of various starches (waxy; high amylose; normal; cross-linked waxy corn starch; potato starch) containing different levels of the cassia gum was carried out. Significant changes were observed in the morphology of

Lovedeep Kaur; Jaspreet Singh; Harjinder Singh; Owen J. McCarthy



The Moisture Migration Behavior of Plasticized Starch Biopolymer  

Microsoft Academic Search

Using plasticized starch pellets as a precursor for making thermoformed products is a commercially viable and profitable idea. However, drying of plasticized starch is quite complex in nature, partly due to the synergistic interactions between starch and plasticizers in the presence of water. The migration of water from starch pellets plasticized by two components, glycerol and xylitol, at three different

Huihua Liu; Deeptangshu Chaudhary



Chemoreception for an insoluble nonvolatile substance: starch taste?  


Substances that are insoluble in both water and lipids, such as starch, are commonly assumed to be tasteless. Starch was suspended in water with a viscous gum. Rats given a choice of fluid containing starch and the same fluid without starch consistently preferred fluids containing starch. Rats were able to detect as little as 0.5% starch from several species of plants (corn, rice, wheat, and potato). In contrast, rats ignored comparable concentrations of cellulose suspended in water. Rats were also capable of choosing the fluid containing higher levels of starch when given a choice of 1 vs. 2% starch or 0.5 vs. 1% starch. This ability to detect starch did not appear to be mediated by salivary alpha-amylase because 1) raw starch is highly resistant to hydrolysis by salivary amylase, 2) starch preference was not correlated with the susceptibility of the starch to hydrolysis by salivary amylase, and 3) starch preference was not blocked by partial or extensive desalivation. Attempts to extract impurities with either organic solvents or water did not provide any evidence that such impurities contribute to starch preference. These experiments point to a seemingly novel form of chemoreception that could be useful to animals that need to identify starch-rich foods. PMID:1704196

Ramirez, I



Thermal analysis of mixtures of wheat flour and potato starches  

Microsoft Academic Search

Potato starches with various contents of amylose from the Eniwa, Benimaru, and Norin No. 1 cultivars were blended with wheat flour at 10 to 50% potato starch (on a weight basis), and differential scanning calorimetry (DSC) studies were then conducted to determine if there were any traces of starch at 30% wt suspension. The amylose content of Eniwa potato starch

I. S. M. Zaidul; H. Yamauchi; C. Matsuura-Endo; S. Takigawa; T. Noda



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



Color: A Functionalist Proposal  

Microsoft Academic Search

In this paper I propose and defend an account of color that I call color functionalism. I argue that functionalism is a non-traditional species of primary quality theory, and that it accommodates our intuitions about color and the facts of color science better than more widely discussed alternatives.

Jonathan Cohen



Organizing color in dentistry.  


Although esthetic dentistry techniques have grown more sophisticated, the fabrication and control of color in dentistry can be improved. An organized and precise system is necessary to combine artistic and scientific approaches. For this, a color order system, based on Munsell's notations and spectrophotometric research on the color space of natural teeth, would provide restorations of excellent color. PMID:2447140

Miller, L



Image bleed in color ink-jet printing of plain paper  

NASA Astrophysics Data System (ADS)

The bleed of one color into another is detrimental to perceived print quality of color-printed images, and is one of the problems encountered in ink-jet color printing. Rapid absorption of ink dye and vehicle into the paper acts to prevent coalescence of color droplets, but too strong an absorption of the vehicle along the paper fibers causes spreading and feathering of the image boundary. The process is therefore very delicate and sensitive to the physical and chemical characteristics of the paper surface. In this work, color bleed of characters printed on experimental sheets by an HP 500C DeskJet printer was measured quantitatively by image analysis. The effects of variation of internal sizing on color bleed and color optical density were measured, as well as effects resulting from surface treatments with different levels of starch and polymeric surface size. Results were compared with analogous measurements for printing without an adjacent color, and also for black ink printing on the same paper. The level of starch in the surface treatment was most important in controlling color bleed, whereas surface size was most helpful in preventing image spread in black ink printing, and in increasing the optical density of both black and composite black images.

Barker, Lesley J.; dePierne, Otto S.; Proverb, Robert J.; Wasser, Richard B.



Adhesion of Vibrio cholerae to granular starches.  


Cholera is a severe diarrheal disease caused by specific serogroups of Vibrio cholerae that are pathogenic to humans. Cholera can become epidemic and deadly without adequate medical care. Appropriate rehydration therapy can reduce the mortality rate from as much as 50% of the affected individuals to <1%. Thus, oral rehydration therapy (ORT) is an important measure in the treatment of this disease. To further reduce the symptoms associated with cholera, improvements in oral rehydration solution (ORS) by starch incorporation were suggested. Here, we report that V. cholerae adheres to starch granules incorporated in ORS. Adhesion of 98% of the cells was observed within 2 min when cornstarch granules were used. Other starches showed varied adhesion rates, indicating that starch source and composition play an important role in the interaction of V. cholerae and starch granules. Sugars metabolized by V. cholerae showed a repressive effect on the adhesion process. The possible mechanisms involved are discussed. Comparing V. cholerae adhesion with the adhesion of other pathogens suggests the involvement of starch degradation capabilities. This adhesion to granular starch can be used to improve ORT. PMID:16085883

Gancz, Hanan; Niderman-Meyer, Orly; Broza, Meir; Kashi, Yechezkel; Shimoni, Eyal



Permeation of volatile compounds through starch films.  


The aim of this study was to gain insight into the factors that affect the permeation of volatiles through starch films. These films were obtained by casting gelatinized starch/water/glycerol mixtures. The films were dried and conditioned under different conditions (temperature and relative humidity) resulting in films that vary in the degree of starch crystallinity and glycerol and water content. The permeation of two model volatiles (carvone and diacetyl) at 20 degrees C and at 30, 60, or 90% relative humidity (RH) was analyzed gravimetrically. Further, the solubility of the two model compounds (under conditions where the permeation experiments were carried out) was determined. From the obtained permeation and solubility data, the diffusion coefficients of these compounds in the different starch films were calculated. The crystallinity in the starch films increased with increasing water content of the films during preparation. The water content of the resulting films in turn increased with increasing glycerol and when the films were exposed to a higher RH during drying or conditioning. For films with the same composition, the flux for diacetyl was greater than for carvone. The solubilities of diacetyl and carvone were slightly dependent on the properties of the films. It was found that with increasing starch crystallinity the diffusion coefficient for both compounds decreases, which is probably due to the impermeability of starch crystallites. Interestingly, in films with about the same extent of crystallinity, the diffusion can be described with the free volume model, with water and glycerol determining the amount of free volume. PMID:15003033

Yilmaz, Gülden; Jongboom, Remy O J; Feil, Herman; van Dijk, Cees; Hennink, Wim E


Survivin expression in tuberous sclerosis complex cells.  


Tuberous Sclerosis Complex (TSC) is a tumor suppressor gene disorder with mutations of TSC1/TSC2 genes. This leads to the development of hamartomas that most frequently affect central nervous system, kidney, and skin. Angiomyolipomas are abdominal masses made up of muscle vessels and adipose tissues that grow mostly in proximity to kidneys and liver. Bleeding and kidney failure are the major justification for surgery. This study shows that angiomyolipoma-derived human smooth muscle TSC2-/- cells express the apoptosis inhibitor protein survivin when exposed to IGF-1. Survivin expression is also triggered whenever culture conditions perturb normal TSC2-/- cell function, such as the omission of EGF from the growth medium, the supplementation of anti-EGFR, blockade of PI3K and ERK, or inhibition of mTOR. Interestingly, single or simultaneous inhibition of PI3K by LY294002 and ERK by PD98059 does not prevent IGF-1-mediated survivin expression. Apoptogenic Smac/DIABLO, which is constitutively expressed by TSC2-/- A+ cells, is down-regulated by IGF-1 even in the presence of LY294002 and PD98059. These cells release IGF-1 by means of a negative feedback-regulated mechanism that is overrun when they are exposed to antibodies to IGF-1R, which increases the released amount by more than 400%. The autocrine release of IGF-1 may therefore be a powerful mechanism of survival of the tightly packed cells in the thick-walled vessels of TSC angiomyolipoma and in lymphangioleiomyomatosis (LAM) nodules. Future experimental therapies for TSC and LAM may result from the targeted inhibition of survivin, which may enhance sensitivity to TSC2 therapy. PMID:17592551

Carelli, Stephana; Lesma, Elena; Paratore, Simona; Grande, Vera; Zadra, Giorgia; Bosari, Silvano; Di Giulio, Anna Maria; Gorio, Alfredo


Degree of starch access: An enzymatic method to determine starch degradation potential of corn grain and corn silage  

Microsoft Academic Search

Starch supplied from corn grain or corn silage is an important source of dietary energy for lactating dairy cows and other ruminants, but few laboratory methods are available to determine starch digestion potential. A laboratory method, degree of starch gelatinization (DSG), commonly used by the food industry to assess relative differences in starch characteristics of human foods was modified for

H. M. Blasel; P. C. Hoffman; R. D. Shaver



Foliar Symptoms Caused by Potato mop-top virus on Potato Plants During Vegetative Propagation in Scotland and Their Association With Tuber Yield, Spraing and Tuber Infection  

Microsoft Academic Search

The effect of foliar symptomatic infection by Potato mop-top virus (PMTV) on yield of tubers, spraing and infection in daughter tubers, and foliar symptom development and tuber infection in\\u000a the following generations of propagation was investigated in commercial seed potato crops in Scotland. Six crops covering\\u000a cvs Atlantic, Hermes, Nicola and Cara were studied between 2000 and 2006 by labelling

S. F. Carnegie; A. M. Cameron; M. McCreath



Microwave-accelerated methylation of starch.  


A novel microwave-accelerated method for methylating soluble starch is described. Soluble starch could be fully methylated in 72% yield within 4.66 min using iodomethane and 30% potassium hydroxide under microwave irradiation. The completely methylated starch thus obtained was hydrolyzed with 60% HCO(2)H for 1.5 min under 80% MW power, followed by 0.05 M H(2)SO(4) for 2.0 min under 100% MW power. The partially methylated monosaccharides were separated by preparative paper chromatography and identified by their melting points and optical rotations. PMID:17961526

Singh, Vandana; Tiwari, Ashutosh



Phase separation and rheology of aqueous starch\\/galactomannan systems  

Microsoft Academic Search

Phase behaviour (at 258C and 608C), phase separation kinetics and rheological properties of aqueous starch\\/galactomannan systems were studied. Pure, soluble amylopectin and waxy maize starch dispersions with varying degrees of granule disintegration were employed to investigate the effect of starch granules and aggregation of starch polysaccharides. Polysaccharide blends were made by either mixing starch and galactomannan stock solutions (solution-based preparations)

C. B. Clossa; B. Conde-Petit; I. D. Roberts; F. Escher


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



Fatty Acids, Membrane Permeability, and Sugars of Stored Potato Tubers 1  

PubMed Central

The relationships of potato (Solanum tuberosum L.) tuber membrane permeability and membrane lipid composition to sugar accumulation were examined. Tubers from four potato cultivars were stored for 40 weeks at 3°C and 9°C. Rates of tuber membrane electrolyte leakage, total fatty acid composition, free fatty acid composition, and sugar content were measured throughout the storage period. Storage of tubers at 3°C caused dramatic increases in total fatty acid unsaturation, membrane permeability, and sugar content compared to tubers stored at 9°C. Cultivars with higher levels of fatty acid unsaturation had lower rates of membrane electrolyte leakage and lower sugar contents. We propose that high initial levels or high induced levels of membrane lipid unsaturation mitigate increases in tuber membrane permeability during storage, thus positively influencing the processing quality of stored potato tubers.

Spychalla, James P.; Desborough, Sharon L.



Color Repeatability of Spot Color Printing  

Microsoft Academic Search

A methodology that quantifies variation as well as deviation of spot color printing is developed. Two types of color variations, i.e., spatial (side-to-side) and temporal (begin-to-end), are described. The use of the cumulative relative frequency (CRF) of ?E, from colorimetric data collected across the width of the signature, was used to describe spatial variation or uniformity of spot color printing.

Robert Chung


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


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



Memory for color reactivates color processing region  

Microsoft Academic Search

and gray abstract shapes. During retrieval, old and new shapes,were,presented,in gray and participants responded ‘old-colored’, ‘old-gray’, or ‘new’. Within color perception regions, color memory related activity was observed in the left fusiform gyrus, adjacent to the collateral sulcus. A retinotopic mapping,analysis,indicated,this activity occurred,within color processing,region,V8. The present,feature specific evidence,provides,compelling support,for a constructive,view of memory.,NeuroReport 00:000–000 ,,2009 Wolters Kluwer Health |

Scott D. Slotnick


Genetic elimination of a starch granule protein, SGP1, of wheat generates an altered starch with apparent high amylose  

Microsoft Academic Search

A starch granule protein, SGP-1, is a starch synthase bound to starch granules in wheat endosperm. A wheat lacking SGP-1 was\\u000a produced by crossing three variants each deficient in one of three SGP-1 classes, namely SGP-A1, -B1 or -D1. This deficient\\u000a wheat (SGP–1 null wheat) showed some alterations in endosperm starch, meaning that SGP-1 is involved in starch synthesis.\\u000a Electrophoretic

M. Yamamori; S. Fujita; K. Hayakawa; J. Matsuki; T. Yasui



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



A color compensation vision system for color-blind people  

Microsoft Academic Search

In this paper, we propose a color compensation vision system for color-blind people. About 8% of males and less than 1% of females have faulty color perception from birth. The degree to which a person may possess abnormal color vision ranges from slight difficulty in recognizing shades of color to total loss of color vision. Most types of defective color

T. Ohkubo; K. Kobayashi



Aesthetics of color combinations  

NASA Astrophysics Data System (ADS)

The previous literature on the aesthetics of color combinations has produced confusing and conflicting claims. For example, some researchers suggest that color harmony increases with increasing hue similarity whereas others say it increases with hue contrast. We argue that this confusion is best resolved by considering three distinct judgments about color pairs: (a) preference for the pair as a whole, (b) perceived harmony of the two colors, and (c) preference for the figural color when viewed against the background color. Empirical support for this distinction shows that pair preference and harmony ratings both increase as hue similarity increases, but preference correlates more strongly with component color preferences and lightness contrast than does harmony. Although ratings of both pair preference and harmony decrease as hue contrast increases, ratings of figural color preference increase as hue contrast with the background increases. Our results refine and clarify well-known and often contradictory claims of artistic color theory.

Schloss, Karen B.; Palmer, Stephen E.



Hextend High Molecular Weight Hydroxyethyl Starch 6%  

Center for Biologics Evaluation and Research (CBER)

Text Version... Drug, and Cosmetic Act for Hextend, High Molecular Weight Hydroxyethyl Starch 6 ... to demonstrate that the drug product is safe and effective for use ... More results from


Resolution for color photography  

NASA Astrophysics Data System (ADS)

Although it is well known that luminance resolution is most important, the ability to accurately render colored details, color textures, and colored fabrics cannot be overlooked. This includes the ability to accurately render single-pixel color details as well as avoiding color aliasing. All consumer digital cameras on the market today record in color and the scenes people are photographing are usually color. Yet almost all resolution measurements made on color cameras are done using a black and white target. In this paper we present several methods for measuring and quantifying color resolution. The first method, detailed in a previous publication, uses a slanted-edge target of two colored surfaces in place of the standard black and white edge pattern. The second method employs the standard black and white targets recommended in the ISO standard, but records these onto the camera through colored filters thus giving modulation between black and one particular color component; red, green, and blue color separation filters are used in this study. The third method, conducted at Stiftung Warentest, an independent consumer organization of Germany, uses a whitelight interferometer to generate fringe pattern targets of varying color and spatial frequency.

Hubel, Paul M.; Bautsch, Markus



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

National Technical Information Service (NTIS)

Tuberous sclerosis complex (TSC) is an autosomal disorder resulting from mutations in the TSC1 or TSC2 genes that is associated with epilepsy, cognitive disability, and autism. TSC1/TSC2 gene mutations lead to developmental alterations in brain structure ...

P. B. Crino



Unsprouted potato tubers treated with gibberellic acid (GA 3 )  

Microsoft Academic Search

Tubers (still unsprouted after an eight months' storage period) of the late varietyLibertas with slow growth in youth and few stems were treated with gibberellic acid (GA3) in 1958 and 1959. Two sprayings gave similar results as dipping for 15 minutes. 25 ppm probably had more effect than 12,5 ppm.

F. J. H. Van Hiele




Technology Transfer Automated Retrieval System (TEKTRAN)

The ion chromatographic method for the quantification of phytate (InsP6) in foods was adapted for the analysis of roots and tubers. To maximize sensitivity, UV detection following post-column derivatization was compared with evaporative light scattering detection (ELSD). Detection limits for phyta...


Tuberous sclerosis complex and epilepsy: recent developments and future challenges.  


Tuberous sclerosis complex (TSC) is a congenital syndrome characterized by the widespread development of benign tumors in multiple organs, caused by mutations in one of the tumor suppressor genes, TSC1 or TSC2. About 80% of affected patients have a new mutation, and the remaining 20% have inherited a TSC gene mutation from a parent. The disorder affects approximately 1 in 6000 individuals. Cortical tubers are the neuropathological hallmark of TSC. The most common neurological manifestations of TSC are epilepsy, mental retardation, and autistic behavior. Epilepsy occurs in up to 80-90% of patients and is often intractable, with a poor response to anticonvulsant medications. While the molecular basis of TSC is well established, far less is known about the mechanisms of epilepsy in this disorder. In this article, we first summarize known clinical aspects of TSC with emphasis on its neurological features. Then, based on the molecular, pathological, immunohistochemical, neurochemical, and physiological properties of tubers in patients with TSC and in animal models, we discuss possible mechanisms of seizures and epileptogenesis in TSC. Finally, we provide an updated literature review and a consensus statement from the Tuberous Sclerosis Complex Working Group for future research into the mechanisms of epilepsy in TSC. PMID:17386056

Holmes, Gregory L; Stafstrom, Carl E



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.



The ectomycorrhizal community in natural Tuber borchii grounds.  


Although Tuber borchii is a commercially valuable truffle, its habitat has been virtually ignored. Here, we examine the ectomycorrhizal fungal communities in natural T. borchii grounds. Ectomycorrhizas under T. borchii ascomata and up to 1 m away were collected and morphologically assigned to pine or oak host plants. They were then morphotyped and molecular typed using internal transcribed spacer regions. Seventy ectomycorrhizal taxa were identified, many of which were rare. Tuber borchii dominated, forming 20% of ectomycorrhizas, with Thelephoraceae, Inocybaceae and Sebacinaceae being the other main species. Species composition was markedly affected by the host plant, although community structure and composition was also influenced by the location from which the soil cores were collected. Tuber dryophilum, an edible truffle, but without commercial value, shared the habitat with T. borchii. Its mycorrhizas were never found together with those of T. borchii. Tuber borchii was present on both oaks and pines, but was more abundant in soil cores where the roots of both hosts were present. It is suggested that the presence of young oaks contributed to the maintenance of T. borchii colonization on pines. PMID:20199569

Iotti, Mirco; Lancellotti, Enrico; Hall, Ian; Zambonelli, Alessandra



Hemorrhagic angiomyolipoma and tuberous sclerosis complex: a case report.  


Tuberous sclerosis was first described in 1862 by von Recklinghausen. Since then there have been many advances in our understanding of the diagnosis, pathogenesis, and treatment of this disease complex, especially after it was characterized genetically. While many patients who have tuberous sclerosis present with the classic triad of mental retardation, seizures, and facial "adenoma sebaceum," most do not because of its variable penetrance. The diagnostic criteria have been revised to include patients with tuberous sclerosis who do not match the classic pattern. Here we describe a 44-year-old female without a prior diagnosis who did not have the classic triad but who presented with flank pain. Hemorrhagic angiomyolipoma was diagnosed by computerized tomography scan and she was treated by an embolization procedure. We review tuberous sclerosis and underscore the need to consider this diagnosis for the following reasons: 1. it is not uncommon (slightly more than one in 6,000 live births); 2. its presentation is protean; 3. once the diagnosis is made, search can be made for associated findings that may lead to additional morbidity if not carefully managed, e.g., if an angio-myolipoma is diagnosed, it can be followed and possibly treated; and 4. owing to its autosomal dominant pattern of inheritance, members of the family can be screened appropriately. PMID:12407954

Mirchandani, Gautam R; Kempton, James E; Dainiak, Christopher; Kraus, Mark L



Hydroxyethyl starch in severe sepsis: end of starch era?  


EXPANDED ABSTRACT: CITATION: Perner A, Haase N, Guttormsen AB, Tenhunen J, Klemenzson G, Åneman A, Madsen KR, Møller MH, Elkjær JM, Poulsen LM, Bendtsen A, Winding R, Steensen M, Berezowicz P, Søe-Jensen P, Bestle M, Strand K, Wiis J, White JO, Thornberg KJ, Quist L, Nielsen J, Andersen LH, Holst LB, Thormar K, Kjældgaard AL, Fabritius ML, Mondrup F, Pott FC, Møller TP, Winkel P, Wetterslev J; 6S Trial Group; Scandinavian Critical Care Trials Group: Hydroxyethyl starch 130/0.42 versus Ringer's acetate in severe sepsis. N Engl J Med 2012, 367:124-34. BACKGROUND: Hydroxyethyl starch (HES) is widely used for fluid resuscitation in ICUs, but its safety and efficacy have not been established in patients with severe sepsis. METHODS: OBJECTIVE: To assess the effects of HES 130/0.4 compared with a balanced crystalloid solution on mortality and end-stage kidney failure in patients with severe sepsis. DESIGN: Multicenter, parallel-group, blinded, randomized clinical trial, in patients with severe sepsis. INTERVENTIONS: Patients with severe sepsis admitted to the ICU received fluid resuscitation with either 6% HES 130/0.42 (Tetraspan) or Ringer's acetate at a dose of up to 33 ml per kilogram of ideal body weight per day. RESULTS: Of the 804 patients who underwent randomization, 798 were included in the modified intention-to-treat population. The two intervention groups had similar baseline characteristics. At 90 days after randomization, 201 of 398 patients (51%) assigned to HES 130/0.42 had died, as compared with 172 of 400 patients (43%) assigned to Ringer's acetate (relative risk, 1.17; 95% confidence interval (CI), 1.01 to 1.36; P = 0.03); 1 patient in each group had end-stage kidney failure. In the 90-day period, 87 patients (22%) assigned to HES 130/0.42 were treated with renal replacement therapy versus 65 patients (16%) assigned to Ringer's acetate (relative risk, 1.35; 95% CI, 1.01 to 1.80; P = 0.04), and 38 patients (10%) and 25 patients (6%), respectively, had severe bleeding (relative risk, 1.52; 95% CI, 0.94 to 2.48; P = 0.09). The results were supported by multivariate analyses, with adjustment for known risk factors for death or acute kidney injury at baseline. CONCLUSIONS: Patients with severe sepsis assigned to fluid resuscitation with HES 130/0.42 had an increased risk of death at day 90 and were more likely to require renal replacement therapy compared with those receiving Ringer's acetate. PMID:23509901

Estrada, Carlos A; Murugan, Raghavan



Modeling cassava starch saccharification with amyloglucosidase  

Microsoft Academic Search

A solution of ?-amylase liquefied cassava starch, 30% (w\\/v), was saccharified with amyloglucosidase at 45°C, pH 4.5, in a\\u000a batch reactor in the presence and absence of added glucose. Reactor conversion results were modeled with a multisubstrate\\u000a model that considers intermediate dextrins of starch hydrolysis, reversibility of some reactions, substrate and product inhibition,\\u000a and competition among dextrins and isomaltose formation.

Gisella Maria Zanin; Flávio Faria De Moraes



Structure and Functionality of Barley Starches  

Microsoft Academic Search

Cereal Chem. 75(5):747-754 Amylose contents of prime starches from nonwaxy and high-amylose barley, determined by colorimetric method, were 24.6 and 48.7%, respec- tively, whereas waxy starch contained only a trace (0.04%) of amylose. There was little difference in isoamylase-debranched amylopectin between nonwaxy and high-amylose barley, whereas amylopectin from waxy bar- ley had a significantly higher percentage of fraction with degree

Z. Czuchajowska; A. Klamczynski; B. Paszczynska; B.-K. Baik



Starch digestion and utilization in ruminants.  


For most grain, except corn and sorghum, 90% or more of starch is normally fermented in the rumen. With corn, up to 30% or more could escape ruminal fermentation; most of the starch escaping fermentation would be digested in the small intestine or fermented in the large intestine. The capacity for digestion of raw starch in the small intestine is limited to 100 to 200 g/d in sheep. Gelled starch could be digested in quantities up to 200 to 300 g/d. The capacity would ultimately be limited by lack of enzymes involved in hydrolysis of short chain di- and oligosaccharides and also by capacity for absorption of glucose. Starch fermented in the cecum leads to an increase of N loss in the feces. In some instances, the high propionic acid proportion arising from fermentation of starch exceeds the capacity of the liver for metabolism. In growing lambs and goats, this creates problems of synthesis of branched-chain fatty acids in adipose tissue and, in dairy cows, problems of low milk yield and milk fat production. The low ruminal pH that often occurs when starchy grain is included in diets for ruminants can cause depression in fiber digestion. Some of these problems can be overcome by reducing extent of cereal processing and other methods that prevent low ruminal pH. It is concluded that due to limited capacity for starch digestion postruminally and high animal variability, deliberate attempts to increase postruminal digestion of starch are unlikely to be beneficial and are likely to create potential digestive problems. PMID:3793653

Orskov, E R



Radiation coloration resistant glass  


A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

Tomozawa, M.; Watson, E.B.; Acocella, J.



Heat expanded starch-based compositions.  


A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period. PMID:17432870

Glenn, Gregory M; Klamczynski, Artur K; Holtman, Kevin M; Shey, Justin; Chiou, Bor-Sen; Berrios, Jose; Wood, Delilah; Orts, William J; Imam, Syed H



Towards the rational design of cereal starches.  


A major challenge in cereal biotechnology is to achieve the rational design of renewable polymers to meet specific requirements for improving human health, nutrition, and food quality, to increase the energy supply, and to provide safer and more profitable industrial inputs. The field of starch synthesis research has advanced at a rapid pace over the past decade, and many core observations about the pathway are well established over a range of species. Owing to the complexity of the starch-synthesis process, in which suites of enzymes act at the interface between soluble and insoluble phases, the rational design of starch granules with specific functionality is still in its infancy. Our fundamental biochemical knowledge of starch biosynthesis has recently advanced, and this new information could be exploited to create novel variability in carbohydrate polymers in cereal grains. We propose two strategies for moving more rapidly towards truly rational design of starch. First, the focusing of fundamental research on processes that are involved in the regulation of starch synthesis and granule assembly. Second, the development of iterative strategies, exploiting new molecular genetics tools, to screen for desired properties in high-throughput systems. PMID:15753002

Morell, Matthew K; Myers, Alan M



Novel starch-related enzymes and carbohydrates.  


In chloroplasts, both biosynthesis and degradation of starch are strictly regulated but the mechanisms involved are still incompletely understood. Recent studies revealed two novel and regulatory relevant aspects in the biochemistry of starch: the phosphorylation of starch and the starch-related metabolism of cytosolic heteroglycans. Starch phosphorylation occurs by a sequential action of two plastidial enzymes, the glucan, water dikinase (GWD; EC and the phosphoglucan, water dikinase (PWD; EC Both enzymes utilize ATP as dual phosphate donor and transfer the terminal phosphate group to water whereas the beta-phosphate is used for esterification of glucosyl moieties. The metabolism of starch-derived degradation products is closely linked to recently discovered cytosolic heteroglycans that possess, as prominent constituents, arabinose, galactose, glucose and fucose. The pattern of glycosidic linkages is highly complex comprising more than 25 different bonds. During the dark period the size distribution or the amount of the cytosolic heteroglycans increases depending on the plant species. As revealed by in vitro 14C labeling assays, the heteroglycans act as both glucosyl acceptors and donors for two cytosolic glucosyl transferases, the phosphorylase (EC and the transglucosidase (EC and, at least in part, both enzymes utilize the same glucosyl acceptor and donor sites. In mutants of Arabidopsis thaliana L. that are deficient in the cytosolic transglucosidase both the structure and (bio)chemical properties of the heteroglycans are altered. PMID:17666166

Fettke, J; Eckermann, N; Kötting, O; Ritte, G; Steup, M



Direct potentiometric determination of starch using a platinum redox sensor.  


Here, we describe the development of a platinum redox sensor for the direct potentiometric quantification of starch in solution. The sensor measures the decrease in free triiodide ion after it complexes with starch to form a starch-triiodide complex. This decrease was, therefore, correlated with starch concentration, and the composition and stability of the potassium triiodide solution were optimised. The starch-triiodide complex was characterized potentiometrically at variable starch and triiodide concentrations. We also propose a response mechanism for the platinum redox sensor towards starch and an appropriate theoretical model. The optimised method exhibited satisfactory accuracy and precision and was in good agreement with a standard spectrophotometric method. The sensor was tested over a range of 0.4-9 mg starch, with recoveries ranging from 97.8% to 103.4% and a detection limit of 0.01 mg starch. PMID:23265448

Saka?, Nikola; Sak-Bosnar, Milan; Horvat, Marija



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.



The Effect of Vine Kill and Harvest Date on Tuber Skin Set, Respiration Rates and Tuber Sugars  

Technology Transfer Automated Retrieval System (TEKTRAN)

Russet Burbank potatoes were grown using standard procedures for planting, fertilization, irrigation, and pest management. Vine kill and harvest occurred on three staggered dates that spanned approximately six weeks. Vines were either killed chemically or left untreated and tubers were harvested fro...


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

SciTech Connect

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

McLaughlin, M.J.; Tiller, K.G.; Beech, T.A. [CSIRO Div. of Soils, Glen Osmond (Australia)] [and others



In vitro starch digestion correlates well with rate and extent of starch digestion in broiler chickens  

Microsoft Academic Search

Current feed evaluation systems for poultry are based on digested components (fat, protein and nitrogen-free extracts). Digestible starch is the most important energy source in broiler chicken feeds and is part of the nitrogen-free extract fraction. Digestible starch may be predicted using an in vitro method that mimics digestive processes in the gastrointestinal tract of broiler chickens. An experiment was

Roelof E. Weurding; R. Veldman; Willem A. G. Veen; Aar van der P. J; Martin W. A. Verstegen



Baked starch foams: starch modifications and additives improve process parameters, structure and properties  

Microsoft Academic Search

Single-use packaging articles made of expanded polystyrene (EPS) are currently used to serve and pack a variety of food and non-food products. Recently, there have been efforts to develop and commercialize materials from renewable resources such as starch to replace EPS. Starch based foams are, however, brittle and sensitive to water, and thus require expensive coating steps when exposure to

R. L Shogren; J. W Lawton; K. F Tiefenbacher



Cecropia peltata accumulates starch or soluble glycogen by differentially regulating starch biosynthetic genes.  


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




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...


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


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



Starch degradation by the mould Trichoderma viride. I. The mechanism of starch degradation.  


The mechanism of starch degradation by the fungus Trichoderma viride was studied in strain CBS 354.44, which utilizes glucose, starch and dextrins but is unable to assimilate maltose. It was shown that the amylolytic enzyme system is completely extracellular, equally well induced by starch, amylose or amylopectin and that it consists mainly of enzymes of the glucoamylase type which yield glucose as the main product of starch hydrolysis. Small amounts of alpha-amylase are produced also. The enzymes produced in starch cultures degrade starch, amylose and amylopectin equally well. Enzyme synthesis in starch media takes place to a considerable extent after exhaustion of the carbon source when maximum growth has been attained. Low-molecular dextrins are degraded by extracellular enzymes of the glucoamylase type. These enzymes are produced in media containing starch or dextrins. Maltotriose is consumed for only one third leaving maltose in the culture filtrate. Maltose is hardly attacked and hardly induces any amylolytic enzyme activity. No stable alpha-glucosidase appears to be produced. PMID:10832

Schellart, J A; Visser, F M; Zandstra, T; Middelhoven, W J



Temperature and dietary starch level affected protein but not starch digestibility in gilthead sea bream juveniles.  


A study was carried out with gilthead sea bream juveniles to assess the effect of water temperature (18 and 25°C) and dietary pregelatinized starch level (10, 20 and 30%) on digestibility of protein and starch and on the activity of proteolytic and amylolytic enzymes. ADC of pregelatinized starch was very high (>99%) irrespectively of dietary inclusion level, and it was not affected by water temperature. ADC of protein was also high (>90%) but improved at the higher water temperature. Dietary starch interacted with protein digestibility, which decreased as dietary starch level increased. Temperature affected both acid and basic protease activities, with acid protease activity being higher at 25°C and basic protease activity being higher at 18°C. However, total proteolytic activity and amylase activities were not affected by water temperature. Dietary carbohydrate exerted no effect on proteolytic or amylolitic activities. It is concluded that gilthead sea bream juveniles digest pregelatinized starch very efficiently irrespective of water temperature, due to adjustments of amylase activity to cope with temperature differences. Pregelatinized starch interacts negatively with protein digestibility, with the ADC of protein decreasing as dietary starch levels increase. PMID:21728054

Couto, A; Enes, P; Peres, H; Oliva-Teles, A



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.

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



Starch hydroxyalkylation: Physicochemical properties and enzymatic digestibility of native and hydroxypropylated finger millet ( Eleusine coracana) starch  

Microsoft Academic Search

Starch was isolated from finger millet (Eleusine coracana) and it was etherified with propylene oxide to produce hydroxypropylated derivative. The specific specie used in this study is African finger millet known as jeero. The yield of starch obtained from finger millet on dry weight basis was 52.4%. Progressive increases in molar substitution (MS) were observed as the volume of propylene

Olayide S. Lawal



Focus on Color Photography  

ERIC Educational Resources Information Center

Photographs and text describe techniques by which color negative film can be developed and printed. An equipment list, by which black and white printing facilities can be converted to make color prints, is provided. (CP)

Galindez, Peter



Color vision: retinal blues.  


Two complementary studies have resolved the circuitry underlying green-blue color discrimination in the retina. A blue-sensitive interneuron provides the inhibitory signal required for computing green-blue color opponency. PMID:22917511

Johnston, Jamie; Esposti, Federico; Lagnado, Leon



Colored Stochastic Petri Nets.  

National Technical Information Service (NTIS)

Colored stochastic Petri nets are presented as an extension of the stochastic Petri nets model in which the tokens, the transitions, and the corresponding probability measurement are colored. The development leads to a simplification of the basic model an...

A. Zenie



Light, Color, and Mirrors.  

ERIC Educational Resources Information Center

Describes an exercise in which students can use flashlights, mirrors, and colored paper to discover scientific principles regarding optics. Addresses the concepts of angles of incidence and reflection, colored vs. white light, and mirror images. (WRM)

Tiburzi, Brian; Tamborino, Laurie; Parker, Gordon A.



Skin color enhancement based on favorite skin color in HSV color space  

Microsoft Academic Search

Skin color enhancement based on favorite skin color is proposed to make skin color displayed on large screen flat panel TVs agree with human favorite skin color. A robust skin detection method in different intensity is obtained after analyzing the distribution of skin color in HSV color space. The favorite skin color region is found via a psychological experiment too.

Xiao-Ning Zhang; Jue Jiang; Zhi-Hu Liang; Chun-Liang Liu



Shifting human color memory  

Microsoft Academic Search

Persons who witnessed an automobile accident involving a green car were exposed to information that the car was blue. On a\\u000a subsequent color recognition test, most subjects shifted their color selection in the direction of the misleading information\\u000a and away from the actual perceived color. Shifting was greater for subjects who did not initially commit themselves to a color\\u000a selection.

Elizabeth F. Loftus



Texture affects color emotion  

Microsoft Academic Search

Several studies have recorded color emotions in subjects viewing uniform color (UC) samples. We conduct an experiment to measure and model how these color emotions change when texture is added to the color samples. Using a computer monitor, our subjects arrange samples along four scales: warm–cool, masculine–feminine, hard–soft, and heavy–light. Three sample types of increasing visual complexity are used: UC,

M. P. Lucassen; T. Gevers; A. Gijsenij



Trichromatic opponent color classification  

Microsoft Academic Search

Stimuli varying in intensity and chromaticity, presented on numerous backgrounds, were classified into red\\/green, blue\\/yellow and white\\/black opponent color categories. These measurements revealed the shapes of the boundaries that separate opponent colors in three-dimensional color space. Opponent color classification boundaries were generally not planar, but their shapes could be summarized by a piecewise linear model in which increment and decrement

E. J. Chichilnisky; Brian A. Wandell



Significance of inoculation density and carbon source on the mycelial growth and Tuber polysaccharides production by submerged fermentation of Chinese truffle Tuber sinense  

Microsoft Academic Search

Truffles are among the most valuable gourmet mushrooms on the market. By taking Chinese truffle Tuber sinense as a typical example, a submerged fermentation process for the production of mycelia and Tuber polysaccharides was developed for the first time. Significances of inoculation density, carbon source and its initial concentration were studied in details. For inoculation density within the range of

Ya-Jie Tang; Ling-Li Zhu; Dong-Sheng Li; Zhi-Yuan Mi; Hong-Mei Li



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


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



Reimagining the Color Wheel  

ERIC Educational Resources Information Center

|Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

Snyder, Jennifer



Color and Psychological  

Microsoft Academic Search

Color is a ubiquitous perceptual experience, yet little scientific information about the influence of color on affect, cognition, and behavior is available. Accord- ingly, we have developed a general model of color and psychologicalfunctioning,whichwepresentinthisarticle. We also describe a hypothesis derived from this model re- garding the influence of red in achievement contexts. In addition, we report a series of experiments

Andrew J. Elliot; Markus A. Maier


Color and Psychological Functioning  

Microsoft Academic Search

Color is a ubiquitous perceptual experience, yet little scientific information about the influence of color on affect, cognition, and behavior is available. Accordingly, we have developed a general model of color and psychological functioning, which we present in this article. We also describe a hypothesis derived from this model regarding the influence of red in achievement contexts. In addition, we

Andrew J. Elliot; Markus A. Maier



Color: Implications in dentistry  

PubMed Central

The success of restorative dentistry is determined on the basis of functional and esthetic results. To achieve esthetics, four basic determinants are required in sequence; viz., position, contour, texture and color. The knowledge of the concept of color is essential for achieving good esthetics. This review compiles the various aspects of color, its measurements and shade matching in dentistry.

Sikri, Vimal K



A Semester of Color  

ERIC Educational Resources Information Center

Every Thursday evening, ten high school students meet at the Riverdale Art Project, a New York City-based art program that the author co-founded ten years ago. Students are participating in a semester-long color workshop where they learn about color theory in a structured and engaging way. Focusing on five essential characteristics of color…

Rabinovitch, Andrea



Four Color Theorem  

NSDL National Science Digital Library

Suppose we have a map in which no single territory is made up of disconnected regions. How many colors are needed to color the territories of this map, if all the territories that share a border segment must be of different colors?


The nature of colors  

Microsoft Academic Search

Color is a visible aspect of objects and lights, and as such is an objective characteristic of our phenomenal world. Correspondingly also objects and lights are objective, although their subjectivity cannot be disregarded since they belong to our phenomenal world. The distinction between perception and sensation deals with colors seen either in complex displays or in isolation. Reality of colors

Osvaldo da Pos



Digital color imaging  

Microsoft Academic Search

This paper surveys current technology and research in the area of digital color imaging. In order to establish the background and lay down terminology, fundamental concepts of color perception and measurement are first presented us- ing vector-space notation and terminology. Present-day color recording and reproduction systems are reviewed along with the common mathematical models used for representing these devices. Algorithms

Gaurav Sharma; H. Joel Trussell



Color in Minerals  

NSDL National Science Digital Library

Why do minerals have color? When is that color diagnostic, and when is it likely to fool you? Why is color important, and what can it tell us about the chemistry of minerals? This exercise will try to answer some of these questions, and to introduce students to the fascinating world of mineral spectroscopy, where chemistry meets mineralogy.

Dyar, Darby


Starches of varied digestibilities differentially modify intestinal function in rats.  


Starches of different digestibilities may enter the colon to different extents and alter colonic function. Male Fischer 344 rats were fed diets containing 25% cooked potato starch, arrowroot starch, high amylose cornstarch or raw potato starch for 6 wk. Fecal weight, transit time, colonic thymidine kinase activity (a marker for cell proliferation), and weight, starch content and pH of the cecum and proximal and distal colon were measured. Raw potato starch was much less completely digested than high amylose cornstarch, resulting in a 32-fold greater amount of undigested starch entering the cecum in the raw potato starch group. Both the high amylose cornstarch and raw potato starch diets significantly enhanced fecal weight and produced large intestinal hypertrophy, effects that were greatest in the raw potato starch group. Raw potato starch feeding was associated with the highest level of thymidine kinase activity, although the differences in thymidine kinase activity among the four groups were not significant. This diet also produced a 50% longer transit time. Entry of a large amount of raw potato starch into the colon resulted in greater luminal acidity, greater luminal bulk and slower transit. A much smaller amount of starch entered the colon in the high amylose cornstarch group and resulted in fecal bulking but no alteration in transit. PMID:8263598

Lajvardi, A; Mazarin, G I; Gillespie, M B; Satchithanandam, S; Calvert, R J



Measurement of Color Constancy by Color Memory Matching  

Microsoft Academic Search

Degree of color constancy was measured when color memory was involved in color comparison judgment. We used the Optical Society of America (OSA) Uniform Color Scales as stimulus color samples, and chose 20 color samples as test stimuli. Four illuminants of 1700, 3000, 6500, and 30, 000 K were tested. The observer, completely adapted to a test illuminant, saw a

Keiji Uchikawa; Ichiro Kuriki; Yuzuru Tone



Theorems on list-coloring  

NASA Astrophysics Data System (ADS)

Graph coloring is a well-known and wellstudied area of graph theory with many applications. In this paper, we will consider two generalizations of graph coloring. In particular, list-coloring and sum-list-coloring.

Vedavathi, N.; Gurram, Dharmaiah



Hypoxic stress inhibits multiple aspects of the potato tuber wound response. [Solanum tuberosum L  

SciTech Connect

Potato (Solanum tuberosum L.) tubers subjected to wounding under hypoxic stress do not synthesize RNA species that are induced in response to wounding in aerobic conditions. Further, wound-response proteins fail to be synthesized when wounded tubers are transferred to hypoxic conditions although messenger RNAs which encode them persist for many hours after transfer. Hypoxic stress also prevents the incorporation of ({sup 3}H)thymidine by wounded tubers that occurs in aerobic conditions. In contrast, hypoxic tubers accumulate and translate transcripts of genes whose products are involved in anaerobic metabolism whether or not they are wounded. Both the hypoxic response and the aerobic wound response preclude the synthesis of proteins encoded by messenger RNAs which accumulated during the tuberization process and which can be translated in vitro. Finally, wounding elicits the degradation of a subset of these tuberization-associated transcripts. These data indicate a complex and precise regulation of gene expression at several levels of macromolecular synthesis.

Butler, W.; Cook, L.; Vayda, M.E. (Univ. of Maine, Orono (USA))



Role of Starch Granules in Controlling Expansion of Dough During Baking  

Microsoft Academic Search

Cereal Chem. 76(6):920-924 The role of starch granules in the expansion of doughs during baking was investigated using artificial flours made from dry vital wheat gluten and wheat starch, potato starch, or tapioca starch. The three starches were selected because of their diverse gelatinization properties. Baking tests on flour from tapioca starch gave the largest loaf volume and the most

Chiharu Kusunose; Toshiko Fujii; Hiroshi Matsumoto



Influence of acetic anhydride on physicochemical, morphological and thermal properties of corn and potato starch  

Microsoft Academic Search

The physicochemical, morphological, thermal and rheological properties of acetylated corn and potato starches, prepared using acetic anhydride at different levels (4–12 g), were compared. Corn starch showed lower acetyl (%) and degree of substitution (DS) than potato starches under similar experimental conditions. The acetylated corn and potato starches showed slightly higher amylose contents than their counterpart native starches. Acetylated starches

Narpinder Singh; Deepika Chawla; Jaspreet Singh



Locations of hypochlorite oxidation in corn starches varying in amylose content  

Microsoft Academic Search

The general oxidation mechanism by hypochlorite on starch has been well studied, but the information on the distribution of the oxidation sites within starch granules is limited. This study investigated the locations where the oxidation occurred within corn starch granules varying in amylose content, including waxy corn starch (WC), common corn starch (CC), and 50% and 70% high-amylose corn starch

Daris Kuakpetoon; Ya-Jane Wang



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



Etendue conserved color mixing  

NASA Astrophysics Data System (ADS)

Colored variable lighting is being used in more and more locations to enhance the "beauty" and "atmosphere" of interiors and exteriors. Lamps based on different colored LED are an obvious choice for such systems. The light from the differently colored LEDS needs to be mixed together very well because otherwise objects in the beam could create colored shadows. The difficulty is that we often want a lighting system where the light is collimated, where we can set the color of the beam, and where the lamp is as small as possible with an as small as possible exit diameter. This means that ideally we would like to mix colors etendue preserving. In this paper we discuss a new method of color mixing with dichroic color filters, which aims to achieve this. It is based on a special arrangement of the color filters, whereby the filters act as collimators. We have build prototypes and have done raytracing simulations. These show that we can indeed mix light of different wavelengths and make relatively small, color-variable, collimated, high brightness, light-sources. The advantages are an increase in brightness, a reduction/elimination of the colored shadows, and a small volume. This new method can, e.g., be used in spotlights, mini-beamers and logo projectors.

van Gorkom, R. P.; van As, M. A.; Verbeek, G. M.; Hoelen, C. G. A.; Alferink, R. G.; Mutsaers, C. A.; Cooijmans, H.



Color display for dichromats  

NASA Astrophysics Data System (ADS)

We have proposed colormaps to replace a widely used 216 colors palette in order to allow a designer with normal color vision to simulate the colors seen by dichromats. As dichromats lack one class of cone photo pigment, they confuse colors that differ only in the excitation of the missing class of photo pigment. The method is based on the LMS colorimetric system, which specifies colors in terms of the relative excitations of the cones. We have constructed a rule to reduce any set of confused colors to a single three- component specification. We have introduced a modification, assuming that the video display primaries and nominal white are representative of recent standards for Cathode Ray Tube monitors and that its video-transfer function is a power function with an exponent of 2.2. For everyday practice, replacing a normal palette by a reduced palette provides an immediate warning of possible losses of readability of a display by color-deficients.

Vienot, Francoise; Brettel, Hans



Color Use in Design  

NSDL National Science Digital Library

In this activity, you will learn a little bit about color theory and how it can effect the colors that you choose for a design. This activity covers the Arizona State CTE Standard for demonstrating drawing and visualization skills required for graphic communications (Standard #13). Read each section below carefully and follow the links provided to find more information on the topics discussed. When you are finished with the lesson, complete the assignment at the bottom of the screen. Introduction There are certain colors that look good together in designs and there is a reason for it. Colors that look good together are based on their relationship to each other on a color wheel. In the following lesson, you are going explore the color wheel and the color relationships ...




Relation of potato tuber growth and skin maturity to infection by common scab, Streptomyces scabies  

Microsoft Academic Search

Summary  Cut surfaces of tuber tissue of either resistant or susceptible varieties permitted abundant, macroscopically visible growth\\u000a ofS. scabies after being autoclaved or fumigated with propylene oxide. Sparse aerial mycelium developed on freshly cut, washed tuber surfaces.\\u000a In contrast, macroscopically visible growth ofS. scabies was prevented by intact skin surfaces of mature tubers which had been washed only, or autoclaved, or

W. J. Hooker; O. T. Page



In vitro mass tuberization and virus-free seed-potato production in Taiwan  

Microsoft Academic Search

This is the first report ofin vitro tuberization becoming feasible for agriculture in seed-potato production. The optimum condition forin vitro mass tuberization of virus-free potatoes were: 10 mg\\/1 BA, 8% sucrose. 20°C incubating temperature, and eight hours of 100\\u000a lux incubation photoperiod. An estimated 36,000 dormant, miniature tubers were harvested from the aseptic containers incubated\\u000a on a 10m2 bench area

Po-jen Wang; Ching-yeh Hu



Effects of soil fumigation on verticillium wilt, nematodes and other diseases of potato roots and tubers  

Microsoft Academic Search

Summary  Fumigation of soil was shown to affect subsequent potato crops by several different mechanisms.Rhizoctonia on roots and as black scurf on tubers,Verticillium wilt, pink eye of tubers, vascular browning in tubers, weeds and nematodes are involved. During the relatively dry years\\u000a herein reported, fumigation gave a maximum yield increase of about 20%. Of the fumigants tested, Vorlex was the most

P. M. Miller; L. V. Edgington; Arthur Hawkins



Involvement of sucrose synthase in sucrose synthesis during mobilization of fructans in dormant Jerusalem artichoke tubers.  


The relative contribution of sucrose synthase and sucrose-phosphate synthase to sucrose synthesis in dormant tubers of Jerusalem artichokes was determined. Feeding dormant tubers alternatively with mixtures of [14C]glucose and unlabeled fructose, and [14C]glucose and [14C]fructose has shown that sucrose synthase contributes ca. 95-97% to sucrose synthesis. This is the first report of sucrose synthesis in Jerusalem artichokes dormant tubers. PMID:11074271

Noël; Pontis



BNA 070012, - 6% Hydroxyethyl Starch in 0.9% Sodium ...  

Center for Biologics Evaluation and Research (CBER)

Text Version... and C6 of glucose units of the starch polymer (amylopectin). ... Because starch polymers are comparatively large molecules, even so-called medium ... More results from


Initiator Effects in Reactive Extrusion of Starch Graft Copolymers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Graft copolymers of starch with water-soluble polymers such as polyacrylamide have potential applications including hydrogels, superabsorbents, and thickening agents. Reactive extrusion is a rapid, continuous method for production of starch graft copolymers with high reaction and grafting efficienc...


Single color and single flavor color superconductivity  

Microsoft Academic Search

We survey the nonlocked color-flavor-spin channels for quark-quark (color superconducting) condensates in QCD, using a Nambu Jona-Lasinio model. We also study isotropic quark-antiquark (mesonic) condensates. We make mean-field estimates of the strength and sign of the self-interaction of each condensate, using four-fermion interaction vertices based on known QCD interactions. For the attractive quark pairing channels, we solve the mean-field gap

Mark G. Alford; Jeffrey A. Bowers; Jack M. Cheyne; Greig A. Cowan



Human preference for individual colors  

Microsoft Academic Search

Color preference is an important aspect of human behavior, but little is known about why people like some colors more than others. Recent results from the Berkeley Color Project (BCP) provide detailed measurements of preferences among 32 chromatic colors as well as other relevant aspects of color perception. We describe the fit of several color preference models, including ones based

Stephen E. Palmer; Karen B. Schloss



Color Television-Part I  

Microsoft Academic Search

A brief history of color television and the reasons leading up to the Columbia Broadcasting System color television system have been presented. A general theory for color television, including color, flicker, and electrical characteristics, is also given. Equipment for color-television transmission and reception has been designed and constructed based on these principles. I. INTRODUCTION Much of the significance of color

P. C. Goldmark; J. N. Dyer; E. R. Piore; J. M. Hollywood



Conformational Contribution to the Heat Capacity of Starch and Starch-Water  

NASA Astrophysics Data System (ADS)

The heat capacities of starch and starch-water have been measured using adiabatic calorimetry, and standard differential scanning calorimetry (DSC) and are reported from 5 K to 510 K. The amorphous starch containing 10 wt water shows a glass transition around 350 K. The heat capacities of the solid of amorphous, dry starch is linked to an approximate group vibrational spectrum, and the Tarasov equation is used to estimate the heat capacity contribution due to skeletal vibrations ( theta1 = 830 K and theta2 = 85 K theta3 = 85 K, Nskeletal = 17). The calculated and experimental heat capacities agree to better than ±3between 5 and 250 K. The experimental heat capacities of starch-water and dry starch are compared over the whole range of temperatures. Above the glass transition the differences are interpreted as contributions of different conformational heat capacities from interacting chain of carbohydrate with water. The conformational part is evaluated from a fit of the experimental Cp of starch-water, decreased by the vibrational and the external Cp to a one-dimensional Ising model with two discrete states and stiffness, cooperativity, and degeneracy parameters. NSF, Polymers Program, DMR-9703692, and the Div. of Mat. Sci., BES, DOE at ORNL, managed by Lockheed Martin Energy Research Corp., DE-AC05-96OR22464.

Pyda, Marek; Wunderlich, Bernhard