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Sample records for starch residues document

  1. Agro-industrial residue from starch extraction of Pachyrhizus ahipa as filler of thermoplastic corn starch films.

    PubMed

    López, O V; Versino, F; Villar, M A; García, M A

    2015-12-10

    Biocomposites films based on thermoplastic corn starch (TPS) containing 0.5% w/w fibrous residue from Pachyrhizus ahipa starch extraction (PASR) were obtained by melt-mixing and compression molding. PASR is mainly constituted by remaining cell walls and natural fibers, revealed by Scanning Electron Microscopy (SEM). Chemical composition of the residue indicated that fiber and starch were the principal components. Biocomposites thermo-stability was determined by Thermo-Gravimetric Analysis. A continuous PASR-TPS interface was observed by SEM, as a result of a good adhesion of the fibrous residue to starch matrix. Likewise, films containing PASR presented fewer superficial cracks than TPS ones, whereas their fracture surfaces were more irregular. Besides, the presence of PASR increased starch films roughness, due to fibers agglomerates. Films reinforced with PASR showed significantly lower water vapor permeability (WVP). In addition, PARS filler increased maximum tensile strength and Young's modulus of TPS films, thus leading to more resistant starch matrixes.

  2. Sweet potato starch residue as starting material to prepare polyacrylonitrile adsorbent via SI-SET-LRP.

    PubMed

    Hao, Zhihai; Wang, Dongju; Chen, Hou; Sun, Jinming; Xu, Yuanyuan

    2014-02-26

    Sweet potato starch residue (SPSR) was used as starting material to prepare an eco-friendly adsorbent. SPSR was modified by bromoacetyl bromide to obtain a macroinitiator for surface-initiated single electron transfer-living radical polymerization (SI-SET-LRP) of acrylonitrile (AN) catalyzed by La(0)/hexamethylenetetramine (HMTA) in N,N-dimethylformamide (DMF) in the presence of ascorbic acid (VC). The amidoxime (AO) adsorbent was prepared by the reaction of the graft copolymer bromoactylated sweet potato starch (BSPS)/polyacrylonitrile (BSPS-g-PAN) with hydroxylamine. The maximum adsorption capacity for Hg(II) was 4.03 mmol·g(-1). This simple method provided a novel approach to recycle and reuse agricultural residues for controlling heavy metal pollution.

  3. Quarry residuals RI/FS scoping document. [Weldon Spring quarry

    SciTech Connect

    Not Available

    1991-10-01

    The purpose of this document is to serve as a planning tool for the implementation of the Quarry Residual Remedial Investigation/Feasibility Study (RI/FS) process and to provide direct input to revising and updating the 1988 Work Plan for the Weldon Spring Site Remedial Action Project (WSSRAP) Remedial Investigation/Feasibility Study-Environmental Impact Statement for the Weldon Spring Site (RI/FS-EIS) (Peterson et al. 1988) for this effort. The scoping process is intended to outline the tasks necessary to develop and implement activities in compliance with the Comprehensive Environmental Response, Compensation and Liability Act-National Environmental Policy Act (CERCLA-NEPA) process from detailed planning through the appropriate decision document. In addition to scoping the entire process, this document will serve as the primary tool for planning and accomplishing all activities to be developed in the Quarry Residual RI/FS Work Plan. Subsequent tasks are difficult to plan at this time. 10 refs., 5 figs., 5 tabs.

  4. Direct fermentation of potato starch and potato residues to lactic acid by Geobacillus stearothermophilus under non-sterile conditions

    PubMed Central

    Smerilli, Marina; Neureiter, Markus; Wurz, Stefan; Haas, Cornelia; Frühauf, Sabine; Fuchs, Werner

    2015-01-01

    BACKGROUND Lactic acid is an important biorefinery platform chemical. The use of thermophilic amylolytic microorganisms to produce lactic acid by fermentation constitutes an efficient strategy to reduce operating costs, including raw materials and sterilization costs. RESULTS A process for the thermophilic production of lactic acid by Geobacillus stearothermophilus directly from potato starch was characterized and optimized. Geobacillus stearothermophilus DSM 494 was selected out of 12 strains screened for amylolytic activity and the ability to form lactic acid as the major product of the anaerobic metabolism. In total more than 30 batches at 3–l scale were run at 60 °C under non-sterile conditions. The process developed produced 37 g L−1 optically pure (98%) L-lactic acid in 20 h from 50 g L−1 raw potato starch. As co-metabolites smaller amounts (<7% w/v) of acetate, formate and ethanol were formed. Yields of lactic acid increased from 66% to 81% when potato residues from food processing were used as a starchy substrate in place of raw potato starch. CONCLUSIONS Potato starch and residues were successfully converted to lactic acid by G. stearothermophilus. The process described in this study provides major benefits in industrial applications and for the valorization of starch-rich waste streams. © 2015 The Authors.Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:25937690

  5. Risk Assessment Document for Coke Oven MACT Residual Risk

    EPA Pesticide Factsheets

    The residual risk analysis described in this report addresses four coke plants subject to the 1993coke oven MACT standards (40 CFR Part 63 Subpart L) and estimates potential risks due to HAPsemissions from facilities involved in coking operations.

  6. The roles of histidine residues at the starch-binding site in streptococcal-binding activities of human salivary amylase.

    PubMed

    Tseng, C C; Miyamoto, M; Ramalingam, K; Hemavathy, K C; Levine, M J; Ramasubbu, N

    1999-02-01

    Human salivary alpha-amylase participates in the initial digestion of starch and may be involved in the colonization of viridans streptococci in the mouth. To elucidate the role of histidine residues located near the starch-binding site on the streptococcal-binding activity, the wild type and three histidine mutants, H52A, H299A and H305A were constructed and expressed in a baculovirus system. While His52 is located near the non-reducing end of the starch-binding pocket (subsite S3/S4), the residues His299 and His305 are located near the subsites S1/S1'. For the wild type, the cDNA encoding the leader and secreted sequences of human salivary amylase was amplified by polymerase chain reaction from a human submandibular salivary-gland cDNA library, and subcloned into the baculovirus shuttle vector pVL1392 downstream of the polyhedrin promoter. Oligonucleotide-based, site-directed mutagenesis was used to generate the mutants expressed in the baculovirus system. Replacing His52 or His299 or His305 to Ala residue did not alter the bacterial-binding activity significantly, but these mutants did show differences in their catalytic activities. The mutant H52A showed negligible reduction in enzymatic activity compared to that of wild type for the hydrolysis of starch and oligosaccharides. In contrast, the H299A and H305A mutants showed a 12 to 13-fold reduction (90-92%) in starch-hydrolysing activity. In addition, the k(cat) for the hydrolysis of oligosaccharides by H299A decreased by as much as 11-fold for maltoheptaoside. This reduction was even higher (40-fold) for the hydrolysis of p-nitrophenyl maltoside, with a significant change in K(M). The mutant H305A, however, exhibited a reduction in k(cat) only, with no changes in the K(M) for the hydrolysis of oligosaccharides. The reduction in the k(cat) for the H305A mutant was almost 93% for maltoheptaoside hydrolysis. The pH activity profile for the H305A mutant was also significantly different from that of the wild type

  7. Recovery of Glucose from Residual Starch of Sago Hampas for Bioethanol Production

    PubMed Central

    Awg-Adeni, D. S.; Bujang, K. B.; Hassan, M. A.; Abd-Aziz, S.

    2013-01-01

    Lower concentration of glucose was often obtained from enzymatic hydrolysis process of agricultural residue due to complexity of the biomass structure and properties. High substrate load feed into the hydrolysis system might solve this problem but has several other drawbacks such as low rate of reaction. In the present study, we have attempted to enhance glucose recovery from agricultural waste, namely, “sago hampas,” through three cycles of enzymatic hydrolysis process. The substrate load at 7% (w/v) was seen to be suitable for the hydrolysis process with respect to the gelatinization reaction as well as sufficient mixture of the suspension for saccharification process. However, this study was focused on hydrolyzing starch of sago hampas, and thus to enhance concentration of glucose from 7% substrate load would be impossible. Thus, an alternative method termed as cycles I, II, and III which involved reusing the hydrolysate for subsequent enzymatic hydrolysis process was introduced. Greater improvement of glucose concentration (138.45 g/L) and better conversion yield (52.72%) were achieved with the completion of three cycles of hydrolysis. In comparison, cycle I and cycle II had glucose concentration of 27.79 g/L and 73.00 g/L, respectively. The glucose obtained was subsequently tested as substrate for bioethanol production using commercial baker's yeast. The fermentation process produced 40.30 g/L of ethanol after 16 h, which was equivalent to 93.29% of theoretical yield based on total glucose existing in fermentation media. PMID:23509813

  8. Studies on the Pasting and Rheology of Rice Starch with Different Protein Residual

    NASA Astrophysics Data System (ADS)

    Lin, Qinlu; Liu, Zhonghua; Xiao, Huaxi; Li, Lihui; Yu, Fengxiang; Tian, Wei

    Indica rice starch and japonica rice starch were used in the study. The protein contents of the two rice variety were respectively 0.43%, 0.62%, 0.84%, 1.08%, 1.25%. The pasting and rheological properties of samples were determined with Rapid Visco Analyzer and dynamic rheometer. The results indicated that, with the increase of protein content, the peak viscosity, breakdown viscosity and final viscosity of rice starch paste decreased, the setback viscosity increased and the pasting temperature did not change significantly. With the increase of protein content, the consistency coefficient of starch decreased, the corresponding yield stress also decreased, however, the flow behavior index increased with the decrease of consistency coefficient. At same temperature, the storage modulus G' was greater when the protein content was higher.

  9. A single residue mutation abolishes attachment of the CBM26 starch-binding domain from Lactobacillus amylovorus alpha-amylase.

    PubMed

    Rodríguez-Sanoja, Romina; Oviedo, N; Escalante, L; Ruiz, B; Sánchez, S

    2009-03-01

    Starch is degraded by amylases that frequently have a modular structure composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. The C-terminal domain from the Lactobacillus amylovorus alpha-amylase has an unusual architecture composed of five tandem starch-binding domains (SBDs). These domains belong to family 26 in the carbohydrate-binding modules (CBM) classification. It has been reported that members of this family have only one site for starch binding, where aromatic amino acids perform the binding function. In SBDs, fold similarities are better conserved than sequences; nevertheless, it is possible to identify in CBM26 members at least two aromatic residues highly conserved. We attempt to explain polysaccharide recognition for the L. amylovorus alpha-amylase SBD through site-directed mutagenesis of aromatic amino acids. Three amino acids were identified as essential for binding, two tyrosines and one tryptophan. Y18L and Y20L mutations were found to decrease the SBD binding capacity, but unexpectedly, the mutation at W32L led to a total loss of affinity, either with linear or ramified substrates. The critical role of Trp 32 in substrate binding confirms the presence of just one binding site in each alpha-amylase SBD.

  10. Characterization of Maize Amylose-extender (ae) Mutant Starches. Part II: Structures and Properties of Starch Residues Remaining After Enzymatic Hydrolyis at Boiling-water Temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEMS-0067 maize ae-line starch developed by Truman State University and the Germplasm Enhancement of Maize (GEM) Project consisted of 39.4%-43.2% resistant-starch (RS), which was larger than the existing ae-line starches of H99ae, OH43ae, B89ae, and B84ae (11.5%-19.1%) as reported in part I of the s...

  11. The Role of Cysteine Residues in Redox Regulation and Protein Stability of Arabidopsis thaliana Starch Synthase 1

    PubMed Central

    Skryhan, Katsiaryna; Cuesta-Seijo, Jose A.; Nielsen, Morten M.; Marri, Lucia; Mellor, Silas B.; Glaring, Mikkel A.; Jensen, Poul E.; Palcic, Monica M.; Blennow, Andreas

    2015-01-01

    Starch biosynthesis in Arabidopsis thaliana is strictly regulated. In leaf extracts, starch synthase 1 (AtSS1) responds to the redox potential within a physiologically relevant range. This study presents data testing two main hypotheses: 1) that specific thiol-disulfide exchange in AtSS1 influences its catalytic function 2) that each conserved Cys residue has an impact on AtSS1 catalysis. Recombinant AtSS1 versions carrying combinations of cysteine-to-serine substitutions were generated and characterized in vitro. The results demonstrate that AtSS1 is activated and deactivated by the physiological redox transmitters thioredoxin f1 (Trxf1), thioredoxin m4 (Trxm4) and the bifunctional NADPH-dependent thioredoxin reductase C (NTRC). AtSS1 displayed an activity change within the physiologically relevant redox range, with a midpoint potential equal to -306 mV, suggesting that AtSS1 is in the reduced and active form during the day with active photosynthesis. Cys164 and Cys545 were the key cysteine residues involved in regulatory disulfide formation upon oxidation. A C164S_C545S double mutant had considerably decreased redox sensitivity as compared to wild type AtSS1 (30% vs 77%). Michaelis-Menten kinetics and molecular modeling suggest that both cysteines play important roles in enzyme catalysis, namely, Cys545 is involved in ADP-glucose binding and Cys164 is involved in acceptor binding. All the other single mutants had essentially complete redox sensitivity (98–99%). In addition of being part of a redox directed activity “light switch”, reactivation tests and low heterologous expression levels indicate that specific cysteine residues might play additional roles. Specifically, Cys265 in combination with Cys164 can be involved in proper protein folding or/and stabilization of translated protein prior to its transport into the plastid. Cys442 can play an important role in enzyme stability upon oxidation. The physiological and phylogenetic relevance of these findings

  12. Growth performance and carcass characteristics of feedlot Thai native × Lowline Angus crossbred steer fed with fermented cassava starch residue.

    PubMed

    Pilajun, Ruangyote; Wanapat, Metha

    2016-04-01

    Ten Thai native × Lowline Angus crossbred (50:50) steers were used in a completely randomized design to receive two treatments including concentrate containing cassava chips (Control) and fermented cassava starch residue (FCSR) as major carbohydrate sources. FCSR was prepared as yeast (Saccharomyces cerevisiae) inoculates with exogenous enzyme addition. All steers received ad libitum rice straw and concentrate in equal proportions (1:1). Replacement of cassava chip with FCSR increased neutral detergent fiber and acid detergent fiber intakes but decreased non-protein nitrogen intake of steers. Digestibility of dry matter, organic matter, and crude protein were decreased with replacement of cassava chip by FCSR; however, digested nutrients were similar between groups. Replacement of cassava chip in the concentrate with FCSR resulted in comparable growth performance and feed efficiency of the feedlot steers. Moreover, carcass characteristics in terms of yield and meat quality of the steers were not affected by cassava chips replaced by FCSR as a major carbohydrate source in the concentrate. In conclusion, replacement of cassava chip in the concentrate with FCSR decreased feed digestibility; however, it did not impact negatively on growth performance and carcass traits of feedlot Thai native × Lowline Angus crossbred steers.

  13. Agro-industrial residues and starch for growth and co-production of polyhydroxyalkanoate copolymer and α-amylase by Bacillus sp. CFR-67.

    PubMed

    Shamala, T R; Vijayendra, S V N; Joshi, G J

    2012-07-01

    Polyhydroxyalkanoates (PHA) and α-amylase (α-1,4 glucan-4-glucanohydrolase, E.C. 3.2.1.1) were co-produced by Bacillus sp. CFR-67 using unhydrolysed corn starch as a substrate. Bacterial growth and polymer production were enhanced with the supplementation of hydrolysates of wheat bran (WBH) or rice bran (RBH) individually or in combination (5-20 g L(-1), based on weight of soluble substrates-SS). In batch cultivation, a mixture of WBH and RBH (1:1, 10 g L(-1) of SS) along with ammonium acetate (1.75 g L(-1)) and corn starch (30 g L(-1)) produced maximum quantity of biomass (10 g L(-1)) and PHA (5.9 g L(-1)). The polymer thus produced was a copolymer of polyhydroxybutyrate-co-hydroxyvalerate of 95:5 to 90:10 mol%. Presence of WBH and corn starch (10-50 g L(-1)) in the medium enhanced fermentative yield of α-amylase (2-40 U mL(-1) min(-1)). The enzyme was active in a wide range of pH (4-9) and temperature (40-60°C). This is the first report on simultaneous production of copolymer of bacterial PHA and α-amylase from unhydrolysed corn starch and agro-industrial residues as substrates.

  14. Starch poisoning

    MedlinePlus

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

  15. Slow digestion property of native cereal starches.

    PubMed

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

    2006-11-01

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

  16. Mechanism of removal of undesirable residual amylase, insoluble starch, and select colorants from refinery streams by powdered activated carbons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need in the world-wide sugar industry to find a practical and economical solution to remove or inactivate residual alpha-amylase that are high temperature stable from factory or refinery streams. A survey of refineries that used amylase and had activated carbon systems for decolorization,...

  17. Starch gelatinization.

    PubMed

    Ratnayake, Wajira S; Jackson, David S

    2009-01-01

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

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

    PubMed

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

    2008-06-11

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

  19. Deficiency of maize starch-branching enzyme i results in altered starch fine structure, decreased digestibility and reduced coleoptile growth during germination

    PubMed Central

    2011-01-01

    Background Two distinct starch branching enzyme (SBE) isoforms predate the divergence of monocots and dicots and have been conserved in plants since then. This strongly suggests that both SBEI and SBEII provide unique selective advantages to plants. However, no phenotype for the SBEI mutation, sbe1a, had been previously observed. To explore this incongruity the objective of the present work was to characterize functional and molecular phenotypes of both sbe1a and wild-type (Wt) in the W64A maize inbred line. Results Endosperm starch granules from the sbe1a mutant were more resistant to digestion by pancreatic α-amylase, and the sbe1a mutant starch had an altered branching pattern for amylopectin and amylose. When kernels were germinated, the sbe1a mutant was associated with shorter coleoptile length and higher residual starch content, suggesting that less efficient starch utilization may have impaired growth during germination. Conclusions The present report documents for the first time a molecular phenotype due to the absence of SBEI, and suggests strongly that it is associated with altered physiological function of the starch in vivo. We believe that these results provide a plausible rationale for the conservation of SBEI in plants in both monocots and dicots, as greater seedling vigor would provide an important survival advantage when resources are limited. PMID:21599988

  20. Making starch.

    PubMed

    Smith, A M

    1999-06-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Starch phosphorylation: insights and perspectives.

    PubMed

    Mahlow, Sebastian; Orzechowski, Sławomir; Fettke, Joerg

    2016-07-01

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

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

    PubMed

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

    2015-01-01

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

  4. Maltase-glucoamylase: Mucosal regulator of prandial starch glucogenesis and complimentary hepatic gluconeogenesis of mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In previous studies we have shown that maltase-glucoamylase (Mgam) is required for efficient starch digestion and insulin response to starch feeding. It was hypothesized that the slower rate of starch digestion by residual sucrase-isomaltase (Si) maltase failed to regulate gluconeogenesis. Here, rat...

  5. Plant-crafted starches for bioplastics production.

    PubMed

    Sagnelli, Domenico; Hebelstrup, Kim H; Leroy, Eric; Rolland-Sabaté, Agnès; Guilois, Sophie; Kirkensgaard, Jacob J K; Mortensen, Kell; Lourdin, Denis; Blennow, Andreas

    2016-11-05

    Transgenically-produced amylose-only (AO) starch was used to manufacture bioplastic prototypes. Extruded starch samples were tested for crystal residues, elasticity, glass transition temperature, mechanical properties, molecular mass and microstructure. The AO starch granule crystallinity was both of the B- and Vh-type, while the isogenic control starch was mainly A-type. The first of three endothermic transitions was attributed to gelatinization at about 60°C. The second and third peaks were identified as melting of the starch and amylose-lipid complexes, respectively. After extrusion, the AO samples displayed Vh- and B-type crystalline structures, the B-type polymorph being the dominant one. The AO prototypes demonstrated a 6-fold higher mechanical stress at break and 2.5-fold higher strain at break compared to control starch. Dynamic mechanical analysis showed a significant increase in the storage modulus (E') for AO samples compared to the control. The data support the use of pure starch-based bioplastics devoid of non-polysaccharide fillers.

  6. Effect of resistant starch on hydrolysis and fermentation of corn starch for ethanol.

    PubMed

    Sharma, Vivek; Rausch, Kent D; Graeber, James V; Schmidt, Shelly J; Buriak, Philip; Tumbleson, M E; Singh, Vijay

    2010-03-01

    Starch samples with 0% or 30% amylose were subjected to four different liquefaction enzyme treatments (at various temperature and pH conditions) followed by simultaneous saccharification and fermentation (SSF). Resistant starch (RS) measurements were conducted for the initial starch sample, after liquefaction and after SSF. Initial RS was higher for 30% amylose starch samples (16.53 g/100 g sample) compared with 0% amylose (0.76 g/100 g sample). Higher initial RS resulted in lower conversion of starch into sugars and lower final ethanol yields. The four enzymes hydrolyzed RS, but in varying amounts. Higher temperature liquefaction hydrolyzed a larger portion of RS, resulting in higher ethanol concentrations and lower final residual solids (non-fermentables), whereas lower temperature liquefaction hydrolyzed a smaller portion of RS and resulted in lower ethanol concentrations and higher final residual solids. Decreases in resistant starch after high temperature liquefaction were 55% to 74%, whereas low temperature liquefaction decreases were 11% to 43%. For all enzyme treatments, RS content of starch samples decreased further after SSF.

  7. Gourd and squash artifacts yield starch grains of feasting foods from preceramic Peru.

    PubMed

    Duncan, Neil A; Pearsall, Deborah M; Benfer, Robert A

    2009-08-11

    In a study of residues from gourd and squash artifacts, we recovered starch grains from manioc (Manihot esculenta), potato (Solanum sp.), chili pepper (Capsicum spp.), arrowroot (Maranta arundinacea), and algarrobo (Prosopis sp.) from feasting contexts at the Buena Vista site, a central Peruvian preceramic site dating to approximately 2200 calendar years B.C. This study has implications for the study of plant food use wherever gourds or squashes are preserved, documents the earliest evidence for the consumption of algarrobo and arrowroot in Peru, and provides insights into foods consumed at feasts.

  8. Starch metabolism in leaves.

    PubMed

    Orzechowski, Sławomir

    2008-01-01

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

  9. Mammalian mucosal α-glucosidases coordinate with α-amylase in the initial starch hydrolysis stage to have a role in starch digestion beyond glucogenesis.

    PubMed

    Dhital, Sushil; Lin, Amy Hui-Mei; Hamaker, Bruce R; Gidley, Michael J; Muniandy, Anbuhkani

    2013-01-01

    Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function.

  10. Retrogradation enthalpy does not always reflect the retrogradation behavior of gelatinized starch.

    PubMed

    Wang, Shujun; Li, Caili; Zhang, Xiu; Copeland, Les; Wang, Shuo

    2016-02-10

    Starch retrogradation is a term used to define the process in which gelatinized starch undergoes a disorder-to-order transition. A thorough understanding of starch retrogradation behavior plays an important role in maintaining the quality of starchy foods during storage. By means of DSC, we have demonstrated for the first time that at low water contents, the enthalpy change of retrograded starch is higher than that of native starch. In terms of FTIR and Raman spectroscopic results, we showed that the molecular order of reheated retrograded starch samples is lower than that of DSC gelatinized starch. These findings have led us to conclude that enthalpy change of retrograded starch at low water contents involves the melting of recrystallized starch during storage and residual starch crystallites after DSC gelatinization, and that the endothermic transition of retrograded starch gels at low water contents does not fully represent the retrogradation behavior of starch. Very low or high water contents do not favor the occurrence of starch retrogradation.

  11. Retrogradation enthalpy does not always reflect the retrogradation behavior of gelatinized starch

    PubMed Central

    Wang, Shujun; Li, Caili; Zhang, Xiu; Copeland, Les; Wang, Shuo

    2016-01-01

    Starch retrogradation is a term used to define the process in which gelatinized starch undergoes a disorder-to-order transition. A thorough understanding of starch retrogradation behavior plays an important role in maintaining the quality of starchy foods during storage. By means of DSC, we have demonstrated for the first time that at low water contents, the enthalpy change of retrograded starch is higher than that of native starch. In terms of FTIR and Raman spectroscopic results, we showed that the molecular order of reheated retrograded starch samples is lower than that of DSC gelatinized starch. These findings have led us to conclude that enthalpy change of retrograded starch at low water contents involves the melting of recrystallized starch during storage and residual starch crystallites after DSC gelatinization, and that the endothermic transition of retrograded starch gels at low water contents does not fully represent the retrogradation behavior of starch. Very low or high water contents do not favor the occurrence of starch retrogradation. PMID:26860788

  12. Starch nanoparticles: a review.

    PubMed

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

    2010-05-10

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

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

    NASA Astrophysics Data System (ADS)

    Robyt, John F.

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

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

    PubMed

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

    2009-03-01

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

  15. Starch bioengineering affects cereal grain germination and seedling establishment

    PubMed Central

    Hebelstrup, Kim H.; Blennow, Andreas

    2014-01-01

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

  16. Starch Metabolism in Arabidopsis

    PubMed Central

    Streb, Sebastian; Zeeman, Samuel C.

    2012-01-01

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

  17. Characterization of starch nanoparticles

    NASA Astrophysics Data System (ADS)

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

    2009-01-01

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

  18. Physical and Chemical Modification of Starches - A Review.

    PubMed

    Din, Zia-Ud-; Xiong, Hanguo; Fei, Peng

    2015-11-03

    The development of green material in the last decade has been increased which tends to reduce the impact of human on the environment. Starch as an agro-sourced polymer has become much popular recently due to its characteristics such as wide availability, low cost and total compostability without toxic residues. Starch is the most abundant organic compound found in nature after cellulose. Starches are inherently unsuitable for most applications and, therefore, must be modified physically and/or chemically to enhance their positive attributes and/or to minimize their defects. Modification of starches is generally carried out by using physical methods that are simple and inexpensive due to the absence of chemical agents. On the other hand, chemical modification involves the exploitation of hydroxyl group present in the starches that brings about the desired results for the utilization of starches for specific applications. All these techniques have the tendency to produce starches with altered physicochemical properties and modified structural attributes for various food and non-food applications. This paper reviews the recent knowledge and developments using physical modification methods, some chemical modification methods and a combination of both to produce a novel molecule with substantial applications, in food industry along with future perspectives.

  19. Production of Poly(3-hydroxybutyrate) from waste potato starch.

    PubMed

    Haas, Richard; Jin, Bo; Zepf, Florian Tobias

    2008-01-01

    There has been a considerable interest in using low cost carbon substrates for the production of Poly(3-hydroxybutyrate) (PHB). We have shown that saccharified waste potato starch can be used as a viable alternative carbon source in high cell density PHB production. Using Ralstonia eutropha NCIMB 11599 with phosphate limitation, 179 g/l biomass, 94 g/l PHB, Y(biomass/starch) = 0.46 g/g, Y(PHB/starch) = 0.22 g/g, and PHB productivity = 1.47 g/(l*h) were achieved. Residual maltose accumulated in the fed-batch reactor but caused no noticeable inhibition. Performance with saccharified starch was virtually identical to that with glucose.

  20. Gelatinization temperature of rice explained by polymorphisms in starch synthase.

    PubMed

    Waters, Daniel L E; Henry, Robert J; Reinke, Russell F; Fitzgerald, Melissa A

    2006-01-01

    The cooking quality of rice is associated with the starch gelatinization temperature (GT). Rice genotypes with low GT have probably been selected for their cooking quality by humans during domestication. We now report polymorphisms in starch synthase IIa (SSIIa) that explain the variation in rice starch GT. Sequence analysis of the eight exons of SSIIa identified significant polymorphism in only exon 8. These single nucleotide polymorphisms (SNPs) were determined in 70 diverse genotypes of rice. Two SNPs could classify all 70 genotypes into either high GT or low GT types which differed in GT by 8 degrees C. 'A' rather than 'G' at base 2412 determined whether a methionine or valine was present at the corresponding amino acid residue in SSIIa, whilst two adjacent SNPs at bases 2543 and 2544 coded for either leucine (GC) or phenylalanine (TT). Rice varieties with high GT starch had a combination of valine and leucine at these residues. In contrast, rice varieties with low GT starch had a combination of either methionine and leucine or valine and phenylalanine at these same residues. At least two distinct polymorphisms have apparently been selected for their desirable cooking qualities in the domestication of rice.

  1. Food microstructure and starch digestion.

    PubMed

    Singh, Jaspreet; Kaur, Lovedeep; Singh, Harjinder

    2013-01-01

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

  2. Evaluation of the Significance of Starch Surface Binding Sites on Human Pancreatic α-Amylase.

    PubMed

    Zhang, Xiaohua; Caner, Sami; Kwan, Emily; Li, Chunmin; Brayer, Gary D; Withers, Stephen G

    2016-11-01

    Starch provides the major source of caloric intake in many diets. Cleavage of starch into malto-oligosaccharides in the gut is catalyzed by pancreatic α-amylase. These oligosaccharides are then further cleaved by gut wall α-glucosidases to release glucose, which is absorbed into the bloodstream. Potential surface binding sites for starch on the pancreatic amylase, distinct from the active site of the amylase, have been identified through X-ray crystallographic analyses. The role of these sites in the degradation of both starch granules and soluble starch was probed by the generation of a series of surface variants modified at each site to disrupt binding. Kinetic analysis of the binding and/or cleavage of substrates ranging from simple maltotriosides to soluble starch and insoluble starch granules has allowed evaluation of the potential role of each such surface site. In this way, two key surface binding sites, on the same face as the active site, are identified. One site, containing a pair of aromatic residues, is responsible for attachment to starch granules, while a second site featuring a tryptophan residue around which a malto-oligosaccharide wraps is shown to heavily influence soluble starch binding and hydrolysis. These studies provide insights into the mechanisms by which enzymes tackle the degradation of largely insoluble polymers and also present some new approaches to the interrogation of the binding sites involved.

  3. Fractionation and reconstitution experiments provide insight into the role of wheat starch in frozen dough.

    PubMed

    Tao, Han; Wang, Pei; Ali, Barkat; Wu, Fengfeng; Jin, Zhengyu; Xu, Xueming

    2016-01-01

    The wheat dough was subjected to freezing/thawing treatment for 0, 3, 7, and 10 cycles and fractionated into non-gluten proteins and starch. High-performance liquid chromatography revealed changes in molecular mass distribution occurred for the extracted non-gluten proteins. As for the residual starch, it reflected a loss of chemical components such as amylose, proteins and lipids induced by freezing treatment. X-ray diffraction revealed increased crystallinity in separated starch as the freezing cycle was repeated. Rapid visco-analyser exhibited different pasting behaviors on starch pellets, especially on the breakdown and setback viscosities. In the reconstituted dough, an increase was observed in storage and loss modulus, corresponding to the presence of freezing/thawing-treated starches, which was changed as a result of higher water absorption. These results extended the knowledge of starch granules in dough deterioration upon freezing process and might contribute to the better understanding of frozen dough quality loss.

  4. Physicochemical properties of kiwifruit starch.

    PubMed

    Li, Dongxing; Zhu, Fan

    2017-04-01

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

  5. Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization

    PubMed Central

    Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

    2016-01-01

    A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites. PMID:27319782

  6. Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization.

    PubMed

    Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

    2016-06-20

    A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites.

  7. Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization

    NASA Astrophysics Data System (ADS)

    Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

    2016-06-01

    A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites.

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

    PubMed

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

    2009-01-05

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

  9. Thermoplastic starch-waxy maize starch nanocrystals nanocomposites.

    PubMed

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

    2006-02-01

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

  10. Omega documentation

    SciTech Connect

    Howerton, R.J.; Dye, R.E.; Giles, P.C.; Kimlinger, J.R.; Perkins, S.T.; Plechaty, E.F.

    1983-08-01

    OMEGA is a CRAY I computer program that controls nine codes used by LLNL Physical Data Group for: 1) updating the libraries of evaluated data maintained by the group (UPDATE); 2) calculating average values of energy deposited in secondary particles and residual nuclei (ENDEP); 3) checking the libraries for internal consistency, especially for energy conservation (GAMCHK); 4) producing listings, indexes and plots of the library data (UTILITY); 5) producing calculational constants such as group averaged cross sections and transfer matrices for diffusion and Sn transport codes (CLYDE); 6) producing and updating standard files of the calculational constants used by LLNL Sn and diffusion transport codes (NDFL); 7) producing calculational constants for Monte Carlo transport codes that use group-averaged cross sections and continuous energy for particles (CTART); 8) producing and updating standard files used by the LLNL Monte Carlo transport codes (TRTL); and 9) producing standard files used by the LANL pointwise Monte Carlo transport code MCNP (MCPOINT). The first four of these functions and codes deal with the libraries of evaluated data and the last five with various aspects of producing calculational constants for use by transport codes. In 1970 a series, called PD memos, of internal and informal memoranda was begun. These were intended to be circulated among the group for comment and then to provide documentation for later reference whenever questions arose about the subject matter of the memos. They have served this purpose and now will be drawn upon as source material for this more comprehensive report that deals with most of the matters covered in those memos.

  11. Effect of the production method on the properties of RS3/RS4 type resistant starch. Part 2. Effect of a degree of substitution on the selected properties of acetylated retrograded starch.

    PubMed

    Kapelko, M; Zięba, T; Michalski, A

    2012-12-01

    Resistant starch displays health-promoting properties. Starch preparations produced through acetylation of retrograded starch may be applied as a food additive. Apart from prebiotic properties, they may as well model the texture of a food product. The objective of this study was to determine the effect of retrogradation and acetylation conditions on properties of the produced RS3/4 type resistant starch. Native potato starch was used to produce starch pastes (1, 4, 10, 18 or 30g/100g), that were frozen, defrosted and dried. The resultant preparations of retrograded starch were acetylated with various doses of an acetic acid anhydride (3.25, 6.5, 13.0, 26.0 or 52.0ml/100g). The acetylated preparations of retrograded starch were characterised by increasing solubility in water and swelling power as well as a lower amylose content along with an increasing degree of their substitution with residues of acetic acid. Dependencies of: pasting temperatures, viscosity of the prepared pastes, and resistance of acetylated starch to the action of amyloglucosidase on the degree of substitution with acetic acid residues were described with a second degree polynomial function. The extent and range of changes were found to depend on the concentration of paste used to produce a retrograded starch preparation. The maximum resistance of RS3/4 preparations to the action of amyloglucosidase ranged from 28.7 to 45.9g/100g.

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

    PubMed

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

    2000-03-01

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

  13. Effects of dry method esterification of starch on the degradation characteristics of starch/polylactic acid composites.

    PubMed

    Zuo, Ying Feng; Gu, Jiyou; Qiao, Zhibang; Tan, Haiyan; Cao, Jun; Zhang, Yanhua

    2015-01-01

    Maleic anhydride esterified corn starch was prepared by dry method. Esterified starch/polylactic acid (PLA) biodegradable composite was produced via melt extrusion method with blending maleic anhydride esterified corn starch and PLA. The influence of the dry method esterification of starch on the degradation characteristics of starch/PLA composites was investigated by the natural aging degradation which was soil burial method. Test results of mass loss rate showed that the first 30 days of degradation was mainly starch degradation, and the degradation rate of esterified starch/PLA (ES/PLA) was slower than that of native starch/PLA (NS/PLA). Therefore, the damage degree of ES/PLA on the surface and inside was smaller than that of NS/PLA, and the infrared absorption peak intensities of C-O, C=O and C-H were stronger than that of NS/PLA. With the increasing time of soil burial degradation, the damage degree of NS/PLA and ES/PLA on the exterior and interior were gradually increased, whereas the infrared absorption peak intensities of C-O, C=O and C-H were gradually decreased. The XRD diffraction peak intensity of PLA in composites showed an increased trend at first which was then followed by a decreased one along with the increasing time of soil burial degradation, indicating that the degradation of amorphous regions of PLA was earlier than its crystalline regions. When the soil burial time was the same, the diffraction peak intensity of PLA in ES/PLA was stronger than that of NS/PLA. If the degradation time was the same, T0, Ti and residual rate of thermal decomposition of NS/PLA were larger than those of ES/PLA. The tensile strength and bending strength of composites were decreased gradually with soil burial time increasing. Both the tensile strength and bending strength of ES/PLA were stronger than those of NS/PLA.

  14. Specific oxidation pattern of soluble starch with TEMPO-NaBr-NaClO system.

    PubMed

    Hao, Jie; Lu, Jiaojiao; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2016-08-01

    Oxidized starch, one of the most important starch derivatives, has many different properties and applications. Currently, there are two ways to produce oxidized starch, through specific and nonspecific oxidation. Specific oxidation using the stable nitroxyl radical, 2,2,6,6-tetramethyl preparidinloxy (TEMPO), with NaBr and NaClO can produce oxidized starches with different properties under good quality control. In the current study, we examine the products of specifically oxidized starch. As the amount of oxidant and the temperature, two critical factors impacting the oxidation of starch were thoroughly investigated. Analysis of the molecular weight (MW), degree of oxidization (DO) and the detailed structures of corresponding products was accomplished using gel permeation chromatography with multi-angle laser light scattering (GPC-MALLS), infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and quadrapole time-of-flight mass spectrometry (Q/TOF-MS). According to the analytical results, the oxidation patterns of starch treated with specific oxidant TEMPO-NaBr-NaClO were established. When high amounts of oxidant was applied, more glucose residues within starch were oxidized to glucuronic acids (higher DO) and substantial degradation to starch oligosaccharides was observed. By selecting a reaction temperature of 25°C a high DO could be obtained for a given amount of oxidant. The reducing end sugar residue within oxidized starch was itself oxidized and ring opened in all TEMPO-NaBr-NaClO reactions. Furthermore, extra oxidant generated additional novel structures in the reducing end residues of some products, particularly in low temperature reactions.

  15. Understanding and influencing starch biochemistry.

    PubMed

    Kossmann, J; Lloyd, J

    2000-01-01

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

  16. Effect of enzymatic hydrolysis on native starch granule structure.

    PubMed

    Blazek, Jaroslav; Gilbert, Elliot Paul

    2010-12-13

    Enzymatic digestion of six starches of different botanical origin was studied in real time by in situ time-resolved small-angle neutron scattering (SANS) and complemented by the analysis of native and digested material by X-ray diffraction, differential scanning calorimetry, small-angle X-ray scattering, and scanning electron microscopy with the aim of following changes in starch granule nanostructure during enzymatic digestion. This range of techniques enables coverage over five orders of length-scale, as is necessary for this hierarchically structured material. Starches studied varied in their digestibility and displayed structural differences in the course of enzymatic digestion. The use of time-resolved SANS showed that solvent-drying of digested residues does not induce any structural artifacts on the length scale followed by small-angle scattering. In the course of digestion, the lamellar peak intensity gradually decreased and low-q scattering increased. These trends were more substantial for A-type than for B-type starches. These observations were explained by preferential digestion of the amorphous growth rings. Hydrolysis of the semicrystalline growth rings was explained on the basis of a liquid-crystalline model for starch considering differences between A-type and B-type starches in the length and rigidity of amylopectin spacers and branches. As evidenced by differing morphologies of enzymatic attack among varieties, the existence of granular pores and channels and physical penetrability of the amorphous growth ring affect the accessibility of the enzyme to the substrate. The combined effects of the granule microstructure and the nanostructure of the growth rings influence the opportunity of the enzyme to access its substrate; as a consequence, these structures determine the enzymatic digestibility of granular starches more than the absolute physical densities of the amorphous growth rings and amorphous and crystalline regions of the semicrystalline

  17. Silicon tetrachloride plasma induced grafting for starch-based composites

    NASA Astrophysics Data System (ADS)

    Ma, Yonghui C.

    Non-modified virgin starch is seldom used directly in industrial applications. Instead, it is often physically and/or chemically modified to achieve certain enhanced properties. For many of the non-food applications, these modifications involve changing its hydrophilicity to create hydrophobic starch. In this study, the hydrophobic starch was produced through silicon tetrachloride (SiCl4) plasma induced graft polymerization, so that it could be used as a renewable and biodegradable component of, or substitute for, the petrochemical-based plastics. It was suggested that this starch graft-copolymer might be used as reinforcing components in silicone-rubber materials for starch-based composites. To make this starch graft-copolymer, the ethyl ether-extracted starch powders were surface functionalized by SiCl4 plasma using a 13.56 MHz radio frequency rotating plasma reactor and subsequently stabilized by either ethylene diamine or dichlorodimethylsilane (DCDMS). The functionalized starch was then graft-polymerized with DCDMS to form polydimethylsiloxane (PDMS) layers around the starch granules. The presence of this PDMS layer was demonstrated by electron spectroscopy for chemical analysis (ESCA/XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GC-MS), thermo gravimetry/differential thermal analysis (TG/DTA), and other analyses. It was shown that the surface morphology, thermal properties, swelling characteristic, and hydrophilicity of starch were all changed due to the existence of this protective hydrophobic PDMS layer. Several different procedures to carry out the functionalization and graft polymerization steps were evaluated to improve the effectiveness of the reactions and to prevent the samples from being hydrolyzed by the grafting byproduct HCl. Actinometry, GC-MS, and residual gas analyzer (RGA) were used to investigate the mechanisms of the SiCl4 discharge and to optimize the plasma

  18. Middle Stone Age starch acquisition in the Niassa Rift, Mozambique

    NASA Astrophysics Data System (ADS)

    Mercader, Julio; Bennett, Tim; Raja, Mussa

    2008-09-01

    The quest for direct lines of evidence for Paleolithic plant consumption during the African Middle Stone Age has led scientists to study residues and use-wear on flaked stone tools. Past work has established lithic function through multiple lines of evidence and the spatial breakdown of use-wear and microscopic traces on tool surfaces. This paper focuses on the quantitative analysis of starch assemblages and the botanical identification of grains from flake and core tools to learn about human ecology of carbohydrate use around the Niassa woodlands, in the Mozambican Rift. The processing of starchy plant parts is deduced from the occurrence of starch assemblages that presumably got attached to stone tool surfaces by actions associated with extractive or culinary activities. Specifically, we investigate starch grains from stone tools recently excavated in northern Mozambique at the site of Mikuyu; which presumably spans the middle to late Pleistocene and represents similar sites found along the Malawi/Niassa corridor that links East, Southern, and Central Africa. Starch was extracted and processed with a diverse tool kit consisting of scrapers, cores, points, flakes, and other kinds of tools. The microbotanical data suggests consumption of seeds, legumes, caryopses, piths, underground storage organs, nuts, and mesocarps from more than a dozen families. Our data suggest a great antiquity for starch use in Africa as well as an expanded diet and intensification.

  19. Termination Documentation

    ERIC Educational Resources Information Center

    Duncan, Mike; Hill, Jillian

    2014-01-01

    In this study, we examined 11 workplaces to determine how they handle termination documentation, an empirically unexplored area in technical communication and rhetoric. We found that the use of termination documentation is context dependent while following a basic pattern of infraction, investigation, intervention, and termination. Furthermore,…

  20. Declassified Documents.

    ERIC Educational Resources Information Center

    Brown, Karen M.

    Journalists and other investigators are daily using declassified government documents to shed light on historical and current events, but few have discovered how to tap the wealth of documents once classified but now in the public realm. An executive order from President Reagan eliminating declassification procedures and allowing released…

  1. Phosphoglucan-bound structure of starch phosphatase Starch Excess4 reveals the mechanism for C6 specificity.

    PubMed

    Meekins, David A; Raththagala, Madushi; Husodo, Satrio; White, Cory J; Guo, Hou-Fu; Kötting, Oliver; Vander Kooi, Craig W; Gentry, Matthew S

    2014-05-20

    Plants use the insoluble polyglucan starch as their primary glucose storage molecule. Reversible phosphorylation, at the C6 and C3 positions of glucose moieties, is the only known natural modification of starch and is the key regulatory mechanism controlling its diurnal breakdown in plant leaves. The glucan phosphatase Starch Excess4 (SEX4) is a position-specific starch phosphatase that is essential for reversible starch phosphorylation; its absence leads to a dramatic accumulation of starch in Arabidopsis, but the basis for its function is unknown. Here we describe the crystal structure of SEX4 bound to maltoheptaose and phosphate to a resolution of 1.65 Å. SEX4 binds maltoheptaose via a continuous binding pocket and active site that spans both the carbohydrate-binding module (CBM) and the dual-specificity phosphatase (DSP) domain. This extended interface is composed of aromatic and hydrophilic residues that form a specific glucan-interacting platform. SEX4 contains a uniquely adapted DSP active site that accommodates a glucan polymer and is responsible for positioning maltoheptaose in a C6-specific orientation. We identified two DSP domain residues that are responsible for SEX4 site-specific activity and, using these insights, we engineered a SEX4 double mutant that completely reversed specificity from the C6 to the C3 position. Our data demonstrate that the two domains act in consort, with the CBM primarily responsible for engaging glucan chains, whereas the DSP integrates them in the catalytic site for position-specific dephosphorylation. These data provide important insights into the structural basis of glucan phosphatase site-specific activity and open new avenues for their biotechnological utilization.

  2. The barley amo1 locus is tightly linked to the starch synthase IIIa gene and negatively regulates expression of granule-bound starch synthetic genes

    PubMed Central

    Li, Zhongyi; Li, Dehong; Du, Xihua; Wang, Hong; Larroque, Oscar; Jenkins, Colin L. D.; Jobling, Stephen A.; Morell, Matthew K.

    2011-01-01

    In this study of barley starch synthesis, the interaction between mutations at the sex6 locus and the amo1 locus has been characterized. Four barley genotypes, the wild type, sex6, amo1, and the amo1sex6 double mutant, were generated by backcrossing the sex6 mutation present in Himalaya292 into the amo1 ‘high amylose Glacier’. The wild type, amo1, and sex6 genotypes gave starch phenotypes consistent with previous studies. However, the amo1sex6 double mutant yielded an unexpected phenotype, a significant increase in starch content relative to the sex6 phenotype. Amylose content (as a percentage of starch) was not increased above the level observed for the sex6 mutation alone; however, on a per seed basis, grain from lines containing the amo1 mutation (amo1 mutants and amo1sex6 double mutants) synthesize significantly more amylose than the wild-type lines and sex6 mutants. The level of granule-bound starch synthase I (GBSSI) protein in starch granules is increased in lines containing the amo1 mutation (amo1 and amo1sex6). In the amo1 genotype, starch synthase I (SSI), SSIIa, starch branching enzyme IIa (SBEIIa), and SBEIIb also markedly increased in the starch granules. Genetic mapping studies indicate that the ssIIIa gene is tightly linked to the amo1 locus, and the SSIIIa protein from the amo1 mutant has a leucine to arginine residue substitution in a conserved domain. Zymogram analysis indicates that the amo1 phenotype is not a consequence of total loss of enzymatic activity although it remains possible that the amo1 phenotype is underpinned by a more subtle change. It is therefore proposed that amo1 may be a negative regulator of other genes of starch synthesis. PMID:21813797

  3. Starch Applications for Delivery Systems

    NASA Astrophysics Data System (ADS)

    Li, Jason

    2013-03-01

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

  4. Characterization of potato leaf starch.

    PubMed

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

    2004-04-07

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

  5. Responsive starch-based materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Brucite nanoplate reinforced starch bionanocomposites

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Physicochemical properties of maca starch.

    PubMed

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

    2017-03-01

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

  8. 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...

  9. Microbial starch-binding domain.

    PubMed

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

    2005-06-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  12. Hydroxyethyl starch - the importance of being earnest

    PubMed Central

    2013-01-01

    Despite ongoing controversial expert discussions the European Medicines Agency (EMA) recently recommended to suspend marketing authorisations for hydroxyethyl starch. This comment critically evaluates the line of arguments. Basically, the only indication for a colloid is intravascular hypovolemia. Crystalloid use appears reasonable to compensate ongoing extracellular losses beyond. In the hemodynamically instable patient this leads to the distinction between an initial resuscitation phase where colloids might be indicated and a crystalloidal maintenance phase thereafter. It is important to bear this in mind when reevaluating the studies the EMA referred to in the context of its recent decision: i) VISEP compared ringer’s lactate to 10% HES 200/0.5 in septic patients and found an increased incidence of renal failure in HES receivers. Unfortunately, study treatment was started only after initial stabilization with HES, randomizing hemodynamically stable patients into a rational (crystalloids) and an irrational (high dose starch until ICU discharge) maintenance treatment. ii) 6S compared ringer’s acetate to 6% HES 130/0.42 for fluid resuscitation in septic patients and found an increased need of renal replacement therapy and a higher mortality in the HES group. However, patients of both groups were again randomized only after initial stabilization with colloids, the actual comparison was, therefore, again rational vs. irrational. Beyond that, the documentation is partly fragmentary, leaving many important questions around the fate of the patients unanswered. iii) CHEST randomized ICU patients to receive saline or 6% HES 130/0.4 for fluid resuscitation. Actually, despite partly discussed in a different way, this trial showed no relevant differences in outcome. In all, two studies showed what happens to septic patients if starches are used in a way we do not observe in daily practice. The third one actually proves their safety. The benefit of perioperative goal

  13. Mixed biopolymer systems based on starch.

    PubMed

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

    2012-01-09

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

  14. Sago starch and its utilisation.

    PubMed

    Abd-Aziz, Suraini

    2002-01-01

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

  15. Glucose content in the liquid hydrolysate after dilute acid pretreatment is affected by the starch content in rice straw.

    PubMed

    Teramura, Hiroshi; Oshima, Tomoko; Matsuda, Fumio; Sasaki, Kengo; Ogino, Chiaki; Yamasaki, Masanori; Kondo, Akihiko

    2013-12-01

    Lignocellulosic biomass, such as rice straw, is often utilized as a bioresource after being hydrolyzed using dilute acid and separated into liquid hydrolysate and acid-insoluble residue. However, the biomass component that determines the distribution between liquid hydrolysate and acid-insoluble residue has not yet been clarified. In this study, the glucose content in the liquid hydrolysate and weight of acid-insoluble residue of 13 rice cultivars were analyzed. Starch content was positively correlated with glucose content in the liquid hydrolysate, and negatively correlated with acid-insoluble residue weight. These results indicate that the glucose in the liquid hydrolysate is mainly liberated from starch rather than cellulose in the rice straw. These observations suggest that starch content is a good indicator of the glucose distribution between the liquid hydrolysate and insoluble residue.

  16. 2015 Survey of Non-Starch Ethanol and Renewable Hydrocarbon Biofuels Producers

    SciTech Connect

    Schwab, Amy; Warner, Ethan; Lewis, John

    2016-01-22

    In order to understand the anticipated status of the industry for non-starch ethanol and renewable hydrocarbon biofuels as of the end of calendar year 2015, the National Renewable Energy Laboratory (NREL) conducted its first annual survey update of U.S. non-starch ethanol and renewable hydrocarbon biofuels producers. This report presents the results of this survey, describes the survey methodology, and documents important changes since the 2013 survey.

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

    PubMed

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

    2014-08-13

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

  18. Document Monitor

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The charters of Freedom Monitoring System will periodically assess the physical condition of the U.S. Constitution, Declaration of Independence and Bill of Rights. Although protected in helium filled glass cases, the documents are subject to damage from light vibration and humidity. The photometer is a CCD detector used as the electronic film for the camera system's scanning camera which mechanically scans the document line by line and acquires a series of images, each representing a one square inch portion of the document. Perkin-Elmer Corporation's photometer is capable of detecting changes in contrast, shape or other indicators of degradation with 5 to 10 times the sensitivity of the human eye. A Vicom image processing computer receives the data from the photometer stores it and manipulates it, allowing comparison of electronic images over time to detect changes.

  19. Effect of nylon bag and protozoa on in vitro corn starch disappearance.

    PubMed

    van Zwieten, J T; van Vuuren, A M; Dijkstra, J

    2008-03-01

    An in vitro experiment was carried out to study whether the presence of protozoa in nylon bags can explain the underestimation of the in situ degradation of slowly degradable starch. Corn of a high (flint) and a low (dent) vitreousness variety was ground over a 3-mm screen, weighed in nylon bags with a pore size of 37 microm, and washed in cold water. Samples of washed cornstarch were incubated in 40-mL tubes with faunated and defaunated ruminal fluid. An additional amount of washed corn, in nylon bags, was inserted in each incubation tube. Incubations were carried out for 0, 2, 4, 6, 12, and 24 h, and starch residue in tube and nylon bag was determined. In general, starch disappearance from the nylon bag was less than from the tube, and was less with faunated than defaunated rumen fluid, but corn variety did not affect starch disappearance. When no protozoa were present, the disappearance of starch from the bags was higher after 6 and 12 h incubation compared with presence of protozoa. However, in the tubes, there was no difference in starch disappearance due to presence or absence of protozoa. Estimated lag time was higher in presence (4.6 h) then absence (3.6 h) of protozoa. It was concluded that the effect of presence or absence of protozoa on starch disappearance differs within or outside nylon bags. The reduced disappearance rate of starch inside the nylon bags in the presence of protozoa helps to explain the underestimation of starch degradation based on the in sacco procedure when compared with in vivo data upon incubation of slowly degradable starch sources.

  20. Microscopic analysis of corn fiber using starch- and cellulose-specific molecular probes.

    PubMed

    Porter, Stephanie E; Donohoe, Bryon S; Beery, Kyle E; Xu, Qi; Ding, Shi-You; Vinzant, Todd B; Abbas, Charles A; Himmel, Michael E

    2007-09-01

    Ethanol is the primary liquid transportation fuel produced from renewable feedstocks in the United States today. The majority of corn grain, the primary feedstock for ethanol production, has been historically processed in wet mills yielding products such as gluten feed, gluten meal, starch, and germ. Starch extracted from the grain is used to produce ethanol in saccharification and fermentation steps; however the extraction of starch is not 100% efficient. To better understand starch extraction during the wet milling process, we have developed fluorescent probes that can be used to visually localize starch and cellulose in samples using confocal microscopy. These probes are based on the binding specificities of two types of carbohydrate binding modules (CBMs), which are small substrate-specific protein domains derived from carbohydrate degrading enzymes. CBMs were fused, using molecular cloning techniques, to a green fluorescent protein (GFP) or to the red fluorescent protein DsRed (RFP). Using these engineered probes, we found that the binding of the starch-specific probe correlates with starch content in corn fiber samples. We also demonstrate that there is starch internally localized in the endosperm that may contribute to the high starch content in corn fiber. We also surprisingly found that the cellulose-specific probe did not bind to most corn fiber samples, but only to corn fiber that had been hydrolyzed using a thermochemical process that removes the residual starch and much of the hemicellulose. Our findings should be of interest to those working to increase the efficiency of the corn grain to ethanol process.

  1. Microscopic Analysis of Corn Fiber Using Corn Starch- and Cellulose-Specific Molecular Probes

    SciTech Connect

    Porter, S. E.; Donohoe, B. S.; Beery, K. E.; Xu, Q.; Ding, S.-Y.; Vinzant, T. B.; Abbas, C. A.; Himmel, M. E.

    2007-09-01

    Ethanol is the primary liquid transportation fuel produced from renewable feedstocks in the United States today. The majority of corn grain, the primary feedstock for ethanol production, has been historically processed in wet mills yielding products such as gluten feed, gluten meal, starch, and germ. Starch extracted from the grain is used to produce ethanol in saccharification and fermentation steps; however the extraction of starch is not 100% efficient. To better understand starch extraction during the wet milling process, we have developed fluorescent probes that can be used to visually localize starch and cellulose in samples using confocal microscopy. These probes are based on the binding specificities of two types of carbohydrate binding modules (CBMs), which are small substrate-specific protein domains derived from carbohydrate degrading enzymes. CBMs were fused, using molecular cloning techniques, to a green fluorescent protein (GFP) or to the red fluorescent protein DsRed (RFP). Using these engineered probes, we found that the binding of the starch-specific probe correlates with starch content in corn fiber samples. We also demonstrate that there is starch internally localized in the endosperm that may contribute to the high starch content in corn fiber. We also surprisingly found that the cellulose-specific probe did not bind to most corn fiber samples, but only to corn fiber that had been hydrolyzed using a thermochemical process that removes the residual starch and much of the hemicellulose. Our findings should be of interest to those working to increase the efficiency of the corn grain to ethanol process.

  2. "Notable Documents."

    ERIC Educational Resources Information Center

    Government Publications Review, 1990

    1990-01-01

    This annotated bibliography lists 569 documents from local, state, provincial, and national governments and from international organizations that have been selected on the basis of their reference value and/or subject coverage. Topics covered include health sciences, business and economics, government and politics, social problems, education,…

  3. Scientific Documentation.

    ERIC Educational Resources Information Center

    Pieper, Gail W.

    1980-01-01

    Describes how scientific documentation is taught in three 50-minute sessions in a technical writing course. Tells how session one distinguishes between in-text notes, footnotes, and reference entries; session two discusses the author-year system of citing references; and session three is concerned with the author-number system of reference…

  4. The biosynthesis of starch granules.

    PubMed

    Smith, A M

    2001-01-01

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

  5. Starch granules: structure and biosynthesis.

    PubMed

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

    1998-08-01

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

  6. The ASCE Residuals Transport Manual

    SciTech Connect

    Albertson, O.E.; Bizier, P.A.; Brown, J.; Koch, C.; Sadick, T.

    1999-07-01

    This presentation will highlight the ASCE Residuals Transport Manual, which has been published by ASCE this year. This document, which represents the state of the art in information on residuals transport, is designed to be used by both the active practitioner, as well as for instructional purposes. The authors will present the various chapters which cover the following topics: Conveyance of Water and Wastewater Residuals, Rheology, Sludge Characteristics, Quality and Quantity, Overview of Residuals Conveyance Devices, Pumping of Viscous Sludges and Slurries, Transport of Thickened Residuals, Conveyance of Dewatered Residuals, Transport of Granular and Compactable Residuals, and Case Studies. The Objective of the Transport Monograph is to summarize in one concise volume the general state of knowledge regarding residuals transport from both water and wastewater residuals. The presentation will cover each chapter and will review the pertinent information contained in the manual.

  7. Preparation and characterization of starch-based loose-fill packaging foams

    NASA Astrophysics Data System (ADS)

    Fang, Qi

    difference existed in water absorption characteristics between foams made of regular and waxy starches. Empirical models were developed to correlate foam water absorption characteristics with relative humidity and polymer content. The developed models fit the data well with relatively small standard errors and uniformly scattered residual plots. Foams with higher polymer content had better abrasion resistance than did foams with lower polymer content.

  8. Starch digestibility of foods: a nutritional perspective.

    PubMed

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

    1984-01-01

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

  9. Structure of Waxy Maize Starch Hydrolyzed by Maltogenic α-Amylase in Relation to Its Retrogradation.

    PubMed

    Grewal, Navneet; Faubion, Jon; Feng, Guohua; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2015-04-29

    Maltogenic α-amylase is widely used as an antistaling agent in bakery foods. The objective of this study was to determine the degree of hydrolysis (DH) and starch structure after maltogenic amylase treatments in relation to its retrogradation. Waxy maize starch was cooked and hydrolyzed to different degrees by a maltogenic amylase. High-performance anion-exchange chromatography and size exclusion chromatography were used to determine saccharides formed and the molecular weight (Mw) distributions of the residual starch structure, respectively. Chain length (CL) distributions of debranched starch samples were further related to amylopectin (AP) retrogradation. Differential scanning calorimetry (DSC) results showed the complete inhibition of retrogradation when starches were hydrolyzed to >20% DH. Mw and CL distributions of residual AP structure indicated that with an increase in %DH, a higher proportion of unit chains with degree of polymerization (DP) ≤9 and a lower proportion of unit chains with DP ≥17 were formed. A higher proportion of short outer AP chains that cannot participate in the formation of double helices supports the decrease in and eventual inhibition of retrogradation observed with the increase in %DH. These results suggest that the maltogenic amylase could play a powerful role in inhibiting the staling of baked products even at limited starch hydrolysis.

  10. Starch-binding domains in the post-genome era.

    PubMed

    Machovic, M; Janecek, S

    2006-12-01

    Starch belongs to the most abundant biopolymers on Earth. As a source of energy, starch is degraded by a large number of various amylolytic enzymes. However, only about 10% of them are capable of binding and degrading raw starch. These enzymes usually possess a distinct sequence-structural module, the so-called starchbinding domain (SBD). In general, all carbohydrate-binding modules (CBMs) have been classified into the CBM families. In this sequence-based classification the individual types of SBDs have been placed into seven CBM families: CBM20, CBM21, CBM25, CBM26, CBM34, CBM41 and CBM45. The family CBM20, known also as a classical C-terminal SBD of microbial amylases, is the most thoroughly studied. The three-dimensional structures have already been determined by X-ray crystallography or nuclear magnetic resonance for SBDs from five CBM families (20, 25, 26, 34 and 41), and the structure of the CBM21 has been modelled. Despite differences among the amino acid sequences, the fold of a distorted beta-barrel seems to be conserved together with a similar way of substrate binding (mainly stacking interactions between aromatic residues and glucose rings). SBDs have recently been discovered in many non-amylolytic proteins. These may, for example, have regulatory functions in starch metabolism in plants or glycogen metabolism in mammals. SBDs have also found practical uses.

  11. Improving starch for food and industrial applications.

    PubMed

    Jobling, Steve

    2004-04-01

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

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

    PubMed

    Schupp, Nicole; Ziegler, Paul

    2004-10-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Role of the N-terminal starch-binding domains in the kinetic properties of starch synthase III from Arabidopsis thaliana.

    PubMed

    Valdez, Hugo A; Busi, Maria V; Wayllace, Nahuel Z; Parisi, Gustavo; Ugalde, Rodolfo A; Gomez-Casati, Diego F

    2008-03-04

    Starch synthase III (SSIII), one of the SS isoforms involved in plant starch synthesis, has been reported to play a regulatory role in the synthesis of transient starch. SSIII from Arabidopsis thaliana contains 1025 amino acid residues and has an N-terminal transit peptide for chloroplast localization which is followed by three repeated starch-binding domains (SBDs; SSIII residues 22-591) and a C-terminal catalytic domain (residues 592-1025) similar to bacterial glycogen synthase. In this work, we constructed recombinant full-length and truncated isoforms of SSIII, lacking one, two, or three SBDs, and recombinant proteins, containing three, two, or one SBD, to investigate the role of these domains in enzyme activity. Results revealed that SSIII uses preferentially ADPGlc, although UDPGlc can also be used as a sugar donor substrate. When ADPGlc was used, the presence of the SBDs confers particular properties to each isoform, increasing the apparent affinity and the V max for the oligosaccharide acceptor substrate. However, no substantial changes in the kinetic parameters for glycogen were observed when UDPGlc was the donor substrate. Under glycogen saturating conditions, the presence of SBDs increases progressively the apparent affinity and V max for ADPGlc but not for UDPGlc. Adsorption assays showed that the N-terminal region of SSIII, containing three, two, or one SBD module have increased capacity to bind starch depending on the number of SBD modules, with the D23 protein (containing the second and third SBD module) being the one that makes the greatest contribution to binding. The results presented here suggest that the N-terminal SBDs have a regulatory role, showing a starch binding capacity and modulating the catalytic properties of SSIII.

  16. A Study of the Work of Daniel Starch: A Chapter in the History of the Application of Psychology and Statistics to Education and Other Areas.

    ERIC Educational Resources Information Center

    Johanningmeier, Erwin V.

    This document examines the work of Daniel Starch, emphasizing his work in educational psychology and advertising. After earning his doctorate in psychology (1906), Starch attempted to apply the findings of the new science to education and to advertising. This application met with much success. In advertising, he devised new sampling techniques and…

  17. Starch Products. Learning Activity Pack and Instructor's Guide 5.9. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with some basic information about starches and with three starch products found throughout the world: cereals and rice, potatoes, and pasta. Illustrated…

  18. Orbitmpi Documentation

    SciTech Connect

    Lisa L. Lowe

    2000-10-05

    Orbitmpi is a parallelized version of Roscoe White's Orbit code. The code has been parallelized using MPI, which makes it portable to many types of machines. The guidelines used for the parallelization were to increase code performance with minimal changes to the code's original structure. This document gives a general description of how the parallel sections of the code run. It discusses the changes made to the original code and comments on the general procedure for future additions to Orbitmpi, as well as describing the effects of a parallelized random number generator on the code's output. Finally, the scaling results from Hecate and from Puffin are presented. Hecate is a 64-processor Origin 2000 machine, with MIPS R12000 processors and 16GB of memory, and Puffin is a PC cluster with 9 dual-processor 450 MHz Pentium III (18 processors max.), with 100Mbits ethernet communication.

  19. Studies of Amylose Content in Potato Starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Structural and physicochemical characterisation of rye starch.

    PubMed

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

    2011-12-13

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

  1. 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. ...

  2. Esterification of Starch in Ionic Liquids

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Maltase-glucoamylase: Mucosal regulator of prandial starch glucogenesis and complementary hepatic gluconeogenesis of mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It was hypothesized that the slower rate of starch digestion by residual sucraseisomaltase (Si) maltase failed to fully regulate gluconeogenesis. In the present study the rate of gluconeogenesis was measured directly (J Appl Physiol 104: 944-951, 2008) and compared with exogenous glucose derived fro...

  4. RESIDUAL RISK ASSESSMENT: MAGNETIC TAPE ...

    EPA Pesticide Factsheets

    This document describes the residual risk assessment for the Magnetic Tape Manufacturing source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Magnetic Tape Manufacturing source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

  5. RESIDUAL RISK ASSESSMENT: ETHYLENE OXIDE ...

    EPA Pesticide Factsheets

    This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Resistant starch: promise for improving human health.

    PubMed

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

    2013-11-01

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

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

    PubMed

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

    2017-02-01

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

  9. Structural basis for the glucan phosphatase activity of Starch Excess4

    SciTech Connect

    Vander Kooi, Craig W.; Taylor, Adam O.; Pace, Rachel M.; Meekins, David A.; Guo, Hou-Fu; Kim, Youngjun; Gentry, Matthew S.

    2010-11-12

    Living organisms utilize carbohydrates as essential energy storage molecules. Starch is the predominant carbohydrate storage molecule in plants while glycogen is utilized in animals. Starch is a water-insoluble polymer that requires the concerted activity of kinases and phosphatases to solubilize the outer surface of the glucan and mediate starch catabolism. All known plant genomes encode the glucan phosphatase Starch Excess4 (SEX4). SEX4 can dephosphorylate both the starch granule surface and soluble phosphoglucans and is necessary for processive starch metabolism. The physical basis for the function of SEX4 as a glucan phosphatase is currently unclear. Herein, we report the crystal structure of SEX4, containing phosphatase, carbohydrate-binding, and C-terminal domains. The three domains of SEX4 fold into a compact structure with extensive interdomain interactions. The C-terminal domain of SEX4 integrally folds into the core of the phosphatase domain and is essential for its stability. The phosphatase and carbohydrate-binding domains directly interact and position the phosphatase active site toward the carbohydrate-binding site in a single continuous pocket. Mutagenesis of the phosphatase domain residue F167, which forms the base of this pocket and bridges the two domains, selectively affects the ability of SEX4 to function as a glucan phosphatase. Together, these results reveal the unique tertiary architecture of SEX4 that provides the physical basis for its function as a glucan phosphatase.

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

    PubMed

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

    2012-12-15

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

  11. Solvent effects on starch dissolution and gelatinization.

    PubMed

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

    2011-08-08

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

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

    PubMed

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

    2014-05-25

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

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

    PubMed

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

    2016-01-20

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

  14. Starch composites with aconitic acid.

    PubMed

    Gilfillan, William Neil; Doherty, William O S

    2016-05-05

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

  15. Limiting factors of starch hydrolysis.

    PubMed

    Colonna, P; Leloup, V; Buléon, A

    1992-10-01

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

  16. Properties and applications of starch-converting enzymes of the alpha-amylase family.

    PubMed

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

    2002-03-28

    Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. A large-scale starch processing industry has emerged in the last century. In the past decades, we have seen a shift from the acid hydrolysis of starch to the use of starch-converting enzymes in the production of maltodextrin, modified starches, or glucose and fructose syrups. Currently, these enzymes comprise about 30% of the world's enzyme production. Besides the use in starch hydrolysis, starch-converting enzymes are also used in a number of other industrial applications, such as laundry and porcelain detergents or as anti-staling agents in baking. A number of these starch-converting enzymes belong to a single family: the alpha-amylase family or family13 glycosyl hydrolases. This group of enzymes share a number of common characteristics such as a (beta/alpha)(8) barrel structure, the hydrolysis or formation of glycosidic bonds in the alpha conformation, and a number of conserved amino acid residues in the active site. As many as 21 different reaction and product specificities are found in this family. Currently, 25 three-dimensional (3D) structures of a few members of the alpha-amylase family have been determined using protein crystallization and X-ray crystallography. These data in combination with site-directed mutagenesis studies have helped to better understand the interactions between the substrate or product molecule and the different amino acids found in and around the active site. This review illustrates the reaction and product diversity found within the alpha-amylase family, the mechanistic principles deduced from structure-function relationship structures, and the use of the enzymes of this family in industrial applications.

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

    PubMed

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

    2015-12-01

    Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X-ray diffraction analysis revealed that bracken starch exhibited a typical C-type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch.

  18. Rheological and textural properties of pulse starch gels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The properties of starch gels from black beans, chickpeas, lentils and navy beans were investigated. Differences were shown between starch sources, and effect of starch concentration was studied. Navy bean starch had the highest peak and final viscosities in pasting tests, while black bean starch h...

  19. Thermal and rheological properties of breadfruit starch.

    PubMed

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

    2011-01-01

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

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

    PubMed

    Wang, Shujun; Copeland, Les

    2013-11-01

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

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

    PubMed

    Janaswamy, Srinivas

    2014-01-30

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

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

    PubMed

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

    2016-03-01

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

  3. 75 FR 879 - National Starch and Chemical Company Specialty Starches Division Including On-Site Leased Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-06

    ... Employment and Training Administration National Starch and Chemical Company Specialty Starches Division..., applicable to workers of National Starch and Chemical Company, Specialty Starches Division, Island Falls.... The workers were engaged in the production of drum dried and modified food starches. New...

  4. Mutations Affecting Starch Synthase III in Arabidopsis Alter Leaf Starch Structure and Increase the Rate of Starch Synthesis1

    PubMed Central

    Zhang, Xiaoli; Myers, Alan M.; James, Martha G.

    2005-01-01

    The role of starch synthase (SS) III (SSIII) in the synthesis of transient starch in Arabidopsis (Arabidopsis thaliana) was investigated by characterizing the effects of two insertion mutations at the AtSS3 gene locus. Both mutations, termed Atss3-1 and Atss3-2, condition complete loss of SSIII activity and prevent normal gene expression at both the mRNA and protein levels. The mutations cause a starch excess phenotype in leaves during the light period of the growth cycle due to an apparent increase in the rate of starch synthesis. In addition, both mutations alter the physical structure of leaf starch. Significant increases were noted in the mutants in the frequency of linear chains in amylopectin with a degree of polymerization greater than approximately 60, and relatively small changes were observed in chains of degree of polymerization 4 to 50. Furthermore, starch in the Atss3-1 and Atss3-2 mutants has a higher phosphate content, approximately two times that of wild-type leaf starch. Total SS activity is increased in both Atss3 mutants and a specific SS activity appears to be up-regulated. The data indicate that, in addition to its expected direct role in starch assembly, SSIII also has a negative regulatory function in the biosynthesis of transient starch in Arabidopsis. PMID:15908598

  5. Starch gelatinization in coiled heaters.

    PubMed

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  6. Characterisation and disintegration properties of irradiated starch.

    PubMed

    De Kerf, M; Mondelaers, W; Lahorte, P; Vervaet, C; Remon, J P

    2001-06-19

    Irradiation treatment could provide a quick and simple way to modify the physical, chemical and pharmaceutical properties of biopolymers such as starch. Corn, potato and drum dried corn starch were exposed to X-ray and electron beam (e-beam) irradiation treatment at doses of 10, 50 and 100 kGy. The disintegration properties of these starches were compared using alpha-lactose monohydrate tablets containing 5% (w/w) starch as disintegrant. Starch solubility increased, while its swelling capacity decreased with increasing irradiation dose. The irradiation treatment caused fragmentation of the amylopectin fraction. Irradiation modified the different starches thoroughly, showing remarkable differences in disintegration properties after X-ray treatment and e-beam modification. The e-beam modification resulted in significantly higher disintegration times of the tablets.

  7. The effects of starches on mechanical properties of paracetamol tablet formulations. I. Pregelatinization of starch binders.

    PubMed

    Alebiowu, Gbenga; Itiola, Oludele Adelanwa

    2003-09-01

    A study has been made of the effects of pregelatinization of native sorghum and plantain starches on the mechanical properties of a paracetamol tablet formulation in comparison with corn starch BP. The mechanical properties tested, viz. tensile strength (T) and brittle fracture index (BFI) of the paracetamol tablets were affected by pregelatinization of the starch. The results suggest that pregelatinized starches may be useful as binders when a particular degree of bond strength and brittleness is desired.

  8. Structural and functional properties of C-type starches.

    PubMed

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

    2014-01-30

    This study investigated the structural and functional properties of C-type starches from pea seeds, faba bean seeds, yam rhizomes and water chestnut corms. These starches were mostly oval in shape with significantly different sizes and contents of amylose, damaged starch and phosphorus. Pea, faba bean and water chestnut starches had central hila, and yam starch had eccentric hilum. Water chestnut and yam starches had higher amylopectin short and long chain, respectively. Water chestnut and faba bean starches showed CA-type crystallinities, and pea and yam starches had C-type crystallinities. Water chestnut starch had the highest swelling power, granule swelling and pasting viscosity, lowest gelatinization temperatures and enthalpy. Faba bean starch had the lowest pasting viscosity, whereas yam starch had the highest gelatinization temperatures. Water chestnut and yam starches possessed significantly higher and lower susceptibility to acid and enzyme hydrolysis, the highest and lowest RDS contents, and the lowest and highest RS contents, respectively.

  9. Insights into molecular structure and digestion rate of oat starch.

    PubMed

    Xu, Jinchuan; Kuang, Qirong; Wang, Kai; Zhou, Sumei; Wang, Shuo; Liu, Xingxun; Wang, Shujun

    2017-04-01

    The in vitro digestibility of oat starch and its relationship with starch molecular structure was investigated. The in vitro digestion results showed that the first-order kinetic constant (k) of oat starches (OS-1 and OS-2) was lower than that of rice starch. The size of amylose chains, amylose content and degree of branching (DB) of amylopectin in oat starch were significantly higher than the corresponding parameters in rice starch. The larger molecular size of oat starch may account for its lower digestion rate. The fine structure of amylopectin showed that oat starch had less chains of DP 6-12 and DP>36, which may explain the small difference in digestion rate between oat and rice starch. The biosynthesis model from oat amylopectin fine structure data suggested a lower starch branching enzyme (SBE) activity and/or a higher starch synthase (SS) activity, which may decrease the DB of oat starch and increase its digestion rate.

  10. The diurnal metabolism of leaf starch.

    PubMed

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

    2007-01-01

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

  11. Issues of Starch in Sugarcane Processing and Prospects of Breeding for Low Starch Content in Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch is a sugarcane impurity that adversely affects the quantity and quality of sugar processes and products. The increased production of combine and green harvested sugarcane has increased delivery of starch to sugarcane factories. Starch occurs as granules composed of amylose and amylopectin p...

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

    PubMed

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

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends.

  13. Starch aerogel beads obtained from inclusion complexes prepared from high amylose starch and sodium palmitate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch aerogels are a class of low density highly porous renewable materials currently prepared from retrograded starch gels and are of interest for their good surface area, porosity, biocompatibility, and biodegradability. Recently, we have reported on starches containing amylose-fatty acid salt h...

  14. Improved method for detection of starch hydrolysis

    SciTech Connect

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

    1982-09-01

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

  15. Physical modification of food starch functionalities.

    PubMed

    BeMiller, James N; Huber, Kerry C

    2015-01-01

    Because, in general, native starches do not have properties that make them ideally suited for applications in food products, most starch is modified by dervatization to improve its functionality before use in processed food formulations, and because food processors would prefer not to have to use the modified food starch label designation required when chemically modified starches are used, there is considerable interest in providing starches with desired functionalities that have not been chemically modified. One investigated approach is property modification via physical treatments, that is, modifications of starches imparted by physical treatments that do not result in any chemical modification of the starch. Physical treatments are divided into thermal and nonthermal treatments. Thermal treatments include those that produce pregelatinized and granular cold-water-swelling starches, heat-moisture treatments, annealing, microwave heating, so-called osmotic pressure treatment, and heating of dry starch. Nonthermal treatments include ultrahigh-pressure treatments, instantaneous controlled pressure drop, use of high-pressure homogenizers, dynamic pulsed pressure, pulsed electric field, and freezing and thawing.

  16. Document Update and Compare

    NASA Technical Reports Server (NTRS)

    Knoch, C. F.; Caldwell, D. C.; Caldwell, D. L.

    1983-01-01

    Document Update and Compare programs provide simple computerized documentmaintenance system on Data General NOVA 840 computer. Document Update program allows user to update document either by batch or terminal input. Documents are modified and lists of modifications printed out.

  17. The Role of Pea Chloroplast [alpha]-Glucosidase in Transitory Starch Degradation.

    PubMed

    Sun, Z.; Duke, S. H.; Henson, C. A.

    1995-05-01

    Pea chloroplastic [alpha]-glucosidase (EC 3.2.1.20) involved in transitory starch degradation was purified to apparent homogeneity by ion exchange, reactive dye, hydroxylapatite, hydrophobic interaction, and gel filtration column chromatography. The native molecular mass and the subunit molecular mass were about 49.1 and 24.4 kD, respectively, suggesting that the enzyme is a homodimer. The enzyme had a Km of 7.18 mM for maltose. The enzyme's maximal activity at pH 7.0 and stability at pH 6.5 are compatible with the diurnal oscillations of the chloroplastic stromal pH and transitory starch accumulation. This pH modulation of the [alpha]-glucosidase's activity and stability is the only mechanism known to regulate starch degradative enzymes in leaves. Although the enzyme was specific for the [alpha]-D-glucose in the nonreducing end as the glycon, the aglycon moieties could be composed of a variety of groups. However, the hydrolysis rate was greatly influenced by the aglycon residues. Also, the enzyme could hydrolyze glucans in which carbon 1 of the glycon was linked to different carbon positions of the penultimate glucose residue. The ability of the [alpha]-glucosidase to hydrolyze [alpha]-1,2- and [alpha]-1,3-glucosidic bonds may be vital if these bonds exist in starch granules because they would be barriers to other starch degradative enzymes. This purified pea chloroplastic [alpha]-glucosidase was demonstrated to initiate attacks on native transitory chloroplastic starch granules.

  18. Phage display selects for amylases with improved low pH starch-binding.

    PubMed

    Verhaert, Raymond M D; Beekwilder, Jules; Olsthoorn, René; van Duin, Jan; Quax, Wim J

    2002-06-13

    Directed evolution of secreted industrial enzymes is hampered by the lack of powerful selection techniques. We have explored surface display to select for enzyme variants with improved binding performance on complex polymeric substrates. By a combination of saturation mutagenesis and phage display we selected alpha-amylase variants, which have the ability to bind starch substrate at industrially preferred low pH conditions. First we displayed active alpha-amylase on the surface of phage fd. Secondly we developed a selection system that is based on the ability of alpha-amylase displaying phages to bind to cross-linked starch. This system was used to probe the involvement of specific beta-strands in substrate interaction. Finally, a saturated library of alpha-amylase mutants with one or more amino acid residues changed in their Cbeta4 starch-binding domain was subjected to phage display selection. Mutant molecules with good starch-binding and hydrolytic capacity could be isolated from the phage library by repeated binding and elution of phage particles at lowered pH value. Apart from the wild type alpha-amylase a specific subset of variants, with only changes in three out of the seven possible positions, was selected. All selected variants could hydrolyse starch and heptamaltose at low pH. Interestingly, variants were found with a starch hydrolysis ratio at pH 4.5/7.5 that is improved relative to the wild type alpha-amylase. These data demonstrate that useful alpha-amylase mutants can be selected via surface display on the basis of their binding properties to starch at lowered pH values.

  19. Preparation and characterization of acetylated starch nanoparticles as drug carrier: Ciprofloxacin as a model.

    PubMed

    Mahmoudi Najafi, Seyed Heydar; Baghaie, Maryam; Ashori, Alireza

    2016-06-01

    The objective of this study was to characterize in-vitro the potential of acetylated corn starch (ACS) particles as a matrix for the delivery of ciprofloxacin (CFx). ACS was successfully synthesized and optimized by the reaction of native corn starch using acetic anhydride and acetic acid with low and high degrees of substitution (DS). The nanoprecipitation method was applied for the formation of the ACS-based nanoparticles, by the dropwise addition of water to acetone solution of ACS under stirring. The effects of acetylation and nanoprecipitation on the morphology and granular structure of ACS samples were examined by the FT-IR, XRD, DSL and SEM techniques. The efficiency of CFx loading was also evaluated via encapsulation efficiency (EE) in ACS nanoparticles. The average degree of acetyl substitution per glucose residue of corn starch was 0.33, 2.00, and 2.66. The nanoparticles size of the ACS and ACS-loaded with CFx were measured and analyzed relative to the solvent:non-solvent ratio. Based on the results, ACS nanoparticles with DS of 2.00 and water:acetone of 3:1 had 312nm diameter. Increasing DS in starch acetate led to increase in the EE from 67.7 to 89.1% and with increasing ratio of water/acetone from 1:1 to 3:1, the EE raised from 48.5 to 89.1%. X-ray diffraction indicated that A-type pattern of native starch was completely transformed into the V-type pattern of acetylated starch. The scanning electron microscopy showed that the different sizes of pores formed on the acetylated starch granules were utterly converted into the uniform-sized spherical nanoparticles after the nanoprecipitation.

  20. Degradation studies of hydrophilic, partially degradable and bioactive cements (HDBCs) incorporating chemically modified starch.

    PubMed

    Mendes, Ana C; Boesel, Luciano F; Reis, Rui L

    2012-03-01

    The degradation rate in Hydrophilic, Degradable and Bioactive Cements (HDBCs) containing starch/cellulose acetate blends (SCA) is still low. In order to increase degradation, higher amounts of starch are required to exceed the percolation threshold. In this work, gelatinization, acetylation and methacrylation of corn starch were performed and assessed as candidates to replace SCA in HDBCs. Formulations containing methacrylated starch were prepared with different molar ratios of 2-hydroxyethyl methacrylate and methyl methacrylate in the liquid component and the amount of residual monomer released into water was evaluated. The concentration of reducing sugars, percentage of weight loss and morphologic analyses after degradation all confirmed increased degradation of HDBC with α-amylase, with the appearance of pores and voids from enzymatic action. Methacrylated starch therefore is a better alternative to be used as the solid component of HDBC then SCA, since it leads to the formation of cements with a lower release of toxic monomers and more prone to hydrolytic degradation while keeping the other advantages of HDBCs.

  1. Starch-branching enzymes preferentially associated with A-type starch granules in wheat endosperm.

    PubMed

    Peng, M; Gao, M; Båga, M; Hucl, P; Chibbar, R N

    2000-09-01

    Two starch granule-bound proteins (SGP), SGP-140 and SGP-145, were preferentially associated with A-type starch granules (>10 microm) in developing and mature wheat (Triticum aestivum) kernels. Immunoblotting and N-terminal sequencing suggested that the two proteins were different variants of SBEIc, a 152-kD isoform of wheat starch-branching enzyme. Both SGP-140 and SGP-145 were localized to the endosperm starch granules but were not found in the endosperm soluble fraction or pericarp starch granules younger than 15 d post anthesis (DPA). Small-size starch granules (<10 microm) initiated before 15 DPA incorporated SGP-140 and SGP-145 throughout endosperm development and grew into full-size A-type starch granules (>10 microm). In contrast, small-size starch granules harvested after 15 DPA contained only low amounts of SGP-140 and SGP-145 and developed mainly into B-type starch granules (<10 microm). Polypeptides of similar mass and immunologically related to SGP-140 and/or SGP-145 were also preferentially incorporated into A-type starch granules of barley (Hordeum vulgare), rye (Secale cereale), and triticale (x Triticosecale Wittmack) endosperm, which like wheat endosperm have a bimodal starch granule size distribution.

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

    PubMed

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

    2015-05-01

    Taro starch nanoparticles (TSNPs) obtained by hydrolysis with pullulanase and the recrystallisation of gelatinised starch were used as reinforcing agents in corn starch films. The influence of TSNPs contents (0.5-15%) on the physical, mechanical, thermal, and structural properties of starch films was investigated. An increase in the concentration of TSNPs led to a significant decrease in the water vapour permeability (WVP) of films. The addition of TSNPs increased the tensile strength (TS) of films from 1.11 MPa to 2.87 MPa. Compared with pure starch films, the surfaces of nanocomposite films became uneven. The onset temperature (To) and melting temperature (Tm) of films containing TSNPs were higher than those of pure starch films. The addition of TSNPs improved the thermal stability of starch films.

  3. A starch-accumulating mutant of Arabidopsis thaliana deficient in a chloroplastic starch-hydrolysing enzyme.

    PubMed

    Zeeman, S C; Northrop, F; Smith, A M; Rees, T

    1998-08-01

    The aim of this work was to identify enzymes that participate in the degradation of transitory starch in Arabidopsis. A mutant line was isolated by screening leaves at the end of the night for the presence of starch. The mutant had a higher starch content than the wild-type throughout the diurnal cycle. This accumulation was due to a reduction in starch breakdown, leading to an imbalance between the rates of synthesis and degradation. No reduction in the activity of endo-amylase (alpha-amylase), beta-amylase, starch phosphorylase, maltase, pullulanase or D-enzyme could be detected in crude extracts of leaves of the mutant. However, native PAGE in gels containing amylopectin revealed that a starch-hydrolysing activity, putatively identified as an endo-amylase and present in wild-type chloroplasts, was absent or appreciably reduced in the mutant. This is the first time that a specific enzyme required for starch degradation has been identified in leaves.

  4. Production and physicochemical characterization of resistant starch type III derived from pea starch.

    PubMed

    Lehmann, Undine; Rössler, Christine; Schmiedl, Detlef; Jacobasch, Gisela

    2003-02-01

    Smooth pea starch was used for the production of physiological important resistant starch type III. For reduction of the molecular weight of the starch, different strategies including enzymatic debranching and acid hydrolysis (lintnerization), were tested to obtain an optimal starting material for retrogradation. The resulting polymer chain lengths were analyzed by high-performance anion-exchange chromatography. Temperature regimes and starch concentrations in gel were optimized during the retrogradation with the aim to obtain a high yield of resistant starch. Optimal conditions led to resistant starch contents up to 74%. The products were thermostable and showed no loss of resistant structures after autoclaving. The peak temperatures of the thermal transition were at approximately 147 degrees C. The resulting resistant starch products are suitable for the generation of functional foods.

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

    PubMed

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

    2010-01-01

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

  6. Acetylation and characterization of banana (Musa paradisiaca) starch.

    PubMed

    Bello-Pérez, L A; Contreras-Ramos, S M; Jìmenez-Aparicio, A; Paredes-López, O

    2000-01-01

    Banana native starch was acetylated and some of its functional properties were evaluated and compared to corn starch. In general, acetylated banana starch presented higher values in ash, protein and fat than corn acetylated starch. The modified starches had minor tendency to retrogradation assessed as % transmittance of starch pastes. At high temperature acetylated starches presented a water retention capacity similar to their native counterpart. The acetylation considerably increased the solubility of starches, and a similar behavior was found for swelling power. When freeze-thaw stability was studied, acetyl banana starch drained approximately 60% of water in the first and second cycles, but in the third and fourth cycles the percentage of separated water was low. However, acetyl corn starch showed lower freeze-thaw stability than the untreated sample. The modification increased the viscosity of banana starch pastes.

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

    PubMed

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

    2003-08-01

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

  8. New type of starch-binding domain: the direct repeat motif in the C-terminal region of Bacillus sp. no. 195 alpha-amylase contributes to starch binding and raw starch degrading.

    PubMed Central

    Sumitani, J; Tottori, T; Kawaguchi, T; Arai, M

    2000-01-01

    The alpha-amylase from Bacillus sp. no. 195 (BAA) consists of two domains: one is the catalytic domain similar to alpha-amylases from animals and Streptomyces in the N-terminal region; the other is the functionally unknown domain composed of an approx. 90-residue direct repeat in the C-terminal region. The gene coding for BAA was expressed in Streptomyces lividans TK24. Three active forms of the gene products were found. The pH and thermal profiles of BAAs, and their catalytic activities for p-nitrophenyl maltopentaoside and soluble starch, showed almost the same behaviours. The largest, 69 kDa, form (BAA-alpha) was of the same molecular mass as that of the mature protein estimated from the nucleotide sequence, and had raw-starch-binding and -degrading abilities. The second largest, 60 kDa, form (BAA-beta), whose molecular mass was the same as that of the natural enzyme from Bacillus sp. no. 195, was generated by proteolytic processing between the two repeat sequences in the C-terminal region, and had lower activities for raw starch binding and degrading than those of BAA-alpha. The smallest, 50 kDa, form (BAA-gamma) contained only the N-terminal catalytic domain as a result of removal of the C-terminal repeat sequence, which led to loss of binding and degradation of insoluble starches. Thus the starch adsorption capacity and raw-starch-degrading activity of BAAs depends on the existence of the repeat sequence in the C-terminal region. BAA-alpha was specifically adsorbed on starch or dextran (alpha-1,4 or alpha-1,6 glucan), and specifically desorbed with maltose or beta-cyclodextrin. These observations indicated that the repeat sequence of the enzyme was functional in the starch-binding domain (SBD). We propose the designation of the homologues to the SBD of glucoamylase from Aspergillus niger as family I SBDs, the homologues to that of glucoamylase from Rhizopus oryzae as family II, and the homologues of this repeat sequence of BAA as family III. PMID:10947962

  9. New type of starch-binding domain: the direct repeat motif in the C-terminal region of Bacillus sp. no. 195 alpha-amylase contributes to starch binding and raw starch degrading.

    PubMed

    Sumitani, J; Tottori, T; Kawaguchi, T; Arai, M

    2000-09-01

    The alpha-amylase from Bacillus sp. no. 195 (BAA) consists of two domains: one is the catalytic domain similar to alpha-amylases from animals and Streptomyces in the N-terminal region; the other is the functionally unknown domain composed of an approx. 90-residue direct repeat in the C-terminal region. The gene coding for BAA was expressed in Streptomyces lividans TK24. Three active forms of the gene products were found. The pH and thermal profiles of BAAs, and their catalytic activities for p-nitrophenyl maltopentaoside and soluble starch, showed almost the same behaviours. The largest, 69 kDa, form (BAA-alpha) was of the same molecular mass as that of the mature protein estimated from the nucleotide sequence, and had raw-starch-binding and -degrading abilities. The second largest, 60 kDa, form (BAA-beta), whose molecular mass was the same as that of the natural enzyme from Bacillus sp. no. 195, was generated by proteolytic processing between the two repeat sequences in the C-terminal region, and had lower activities for raw starch binding and degrading than those of BAA-alpha. The smallest, 50 kDa, form (BAA-gamma) contained only the N-terminal catalytic domain as a result of removal of the C-terminal repeat sequence, which led to loss of binding and degradation of insoluble starches. Thus the starch adsorption capacity and raw-starch-degrading activity of BAAs depends on the existence of the repeat sequence in the C-terminal region. BAA-alpha was specifically adsorbed on starch or dextran (alpha-1,4 or alpha-1,6 glucan), and specifically desorbed with maltose or beta-cyclodextrin. These observations indicated that the repeat sequence of the enzyme was functional in the starch-binding domain (SBD). We propose the designation of the homologues to the SBD of glucoamylase from Aspergillus niger as family I SBDs, the homologues to that of glucoamylase from Rhizopus oryzae as family II, and the homologues of this repeat sequence of BAA as family III.

  10. Occurrence of amylose-lipid complexes in teff and maize starch biphasic pastes.

    PubMed

    Wokadala, Obiro Cuthbert; Ray, Suprakas Sinha; Emmambux, Mohammad Naushad

    2012-09-01

    The occurrence of amylose-lipid complexes was determined in maize and teff starch biphasic pastes i.e. peak viscosity pastes at short and prolonged pasting times. Maize and teff starches were pasted for 11.5 and 130 min with or without added stearic acid followed by thermo-stable alpha-amylase hydrolysis in a rapid visco-analyzer. X-ray diffraction analysis of pastes before and residues after hydrolysis showed crystalline V-amylose diffraction patterns for the starches pasted for a prolonged time with added stearic acid while less distinct V-amylose patterns with non-complexed stearic acid peaks were observed with a short pasting time. Differential scanning calorimetry of pastes before and residues after paste hydrolysis showed that Type I amylose-lipid complexes were formed after pasting for the short duration with added stearic acid, while Type II complexes are formed after pasting for the prolonged time. The present research provides evidence that amylose-lipid complexes play an important role in starch biphasic pasting.

  11. 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...

  12. Antimicrobial nanostructured starch based films for packaging.

    PubMed

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

    2015-09-20

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

  13. 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. ...

  14. Properties of corn starch subjected hydrothermal modification

    NASA Astrophysics Data System (ADS)

    Gryszkin, Artur; Zięba, Tomasz; Kapelko-Żeberska, Małgorzata

    2017-01-01

    The objective of this study was to determine the effect of heating a water dispersion of corn starch to various temperatures, followed by its freezing and defrosting, on selected properties of re-formed starch pastes. A suspension of starch was heated to various temperatures ranging from 59 to 94°C, and afterwards frozen and defrosted. The differential scanning calorimetry (Mettler Toledo, 822E) thermal characteristics of starch pre-heated to temperatures not inducing complete pasting revealed transitions of: (I) retrograded amylopectin, (II) non-pasted starch, (III) amylose-lipid complexes, (IV) retrograded amylose, and (V) highly thermostable starch structures. The application of higher temperatures during heating caused disappearance of transitions II and V. The increase of pre-heating temperature induced firstly a decrease and then stabilization of the swelling power as well as a successive decrease in starch solubility. Pastes pre-heated to temperatures over 79°C contained large macroparticles that were increasing viscosity of the re-formed starch paste (their size was positively correlated with viscosity value).

  15. Centrality based Document Ranking

    DTIC Science & Technology

    2014-11-01

    approach. We model the documents to be ranked as nodes in a graph and place edges between documents based on their similarity. Given a query, we compute...similarity of the query with respect to every document in the graph . Based on these similarity values, documents are ranked for a given query...clinical documents using centrality based approach. We model the documents to be ranked as nodes in a graph and place edges between documents based on their

  16. Starch nanoparticles formation via high power ultrasonication.

    PubMed

    Bel Haaj, Sihem; Magnin, Albert; Pétrier, Christian; Boufi, Sami

    2013-02-15

    Nano-sized starch particles (NSP) were prepared from starch granules using a purely physical method of high-intensity ultrasonication. Particle size distribution, Field Effect Scanning Electron Microscopy (FE-SEM), Raman spectroscopy, and Wide-Angle X-ray Diffraction (WAXD) were used to characterize the morphology and crystal structure of the ensuing nanoparticles. The results revealed that ultrasound treatment of the starch suspension in water and at low temperature for 75 min results in the formation of starch nanoparticles between 30 and 100 nm in size. An attempt to explain the generation of starch nanoparticles was made on the basis of WAXD, Raman analysis and FE-SEM observation. Compared to acid hydrolysis, which is the most commonly adopted process, the present approach has the advantage of being quite rapid, presenting a higher yield and not requiring any chemical treatment.

  17. Understanding starch gelatinization: The phase diagram approach.

    PubMed

    Carlstedt, Jonas; Wojtasz, Joanna; Fyhr, Peter; Kocherbitov, Vitaly

    2015-09-20

    By constructing a detailed phase diagram for the potato starch-water system based on data from optical microscopy, synchrotron X-ray scattering and differential scanning calorimetry, we show that gelatinization can be interpreted in analogy with a eutectic transition. The phase rule explains why the temperature of the gelatinization transition (G) is independent on water content. Furthermore, the melting (M1) endotherm observed in DSC represents a liquidus line; the temperature for this event increases with increasing starch concentration. Both the lamellar spacing and the inter-helix distance were observed to decrease with increasing starch content for starch concentrations between approximately 65 wt% and 75 wt%, while the inter-helix distance continued decreasing upon further dehydration. Understanding starch gelatinization has been a longstanding challenge. The novel approach presented here shows interpretation of this phenomenon from a phase equilibria perspective.

  18. Preparation and characterization of octenylsuccinylated plantain starch.

    PubMed

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

    2014-09-01

    Plantain starch was esterified with octenylsuccinic anhydride (OSA) at two concentrations (3 and 15% w/w) of OSA. The morphology, granule size distribution, pasting, gelatinization, swelling, and solubility of granules and structural features of the starch polymers were evaluated. Granules of the OSA-modified starches increased in size during cooking more than did the granules of the native starch, and the effect was greater at the higher OSA concentration. Pasting viscosities also increased, but gelatinization and pasting temperatures and enthalpy of gelatinization decreased in the OSA-modified starches. It was concluded that insertion of OS groups effected disorder in the granular structure. Solubility, weight average molar mass, Mw¯, and z-average radius of gyration, RGz, of the amylopectin decreased as the OSA concentration increased, indicating a decrease in molecular size.

  19. Effects of waxy rice starch and short chain amylose (SCA) on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in a model system.

    PubMed

    Yu, Di; Yu, Shu-Juan

    2016-03-01

    Starch is a glucose polymer of vast importance to mankind. It forms the major component of all our staple foods. Starch is often used as an important material in cooking meat. In this study, the effects of waxy rice starch and short chain amylose (SCA) from debranched waxy rice starch on the formation of PhIP in a model system were investigated and compared. The results showed that the addition of waxy rice starch and SCA significantly decreased PhIP, and the effect of SCA was more pronounced than that of waxy rice starch. This decrease may be attributed to the fact that the glucose residues of starch condense with the amino group of the creatinine formed N-glycosyl conjugate. This reaction path could disturb the reaction of creatinine with phenylacetaldehyde, subsequently influence the aldol condensation product formation, and finally suppress the formation of PhIP. Furthermore, the complex spatial structure of waxy rice starch disturbs the reaction of the glucosyl hydroxyl groups of glucose with the amino group of creatinine in the model reaction. So the effect of SCA was more pronounced than that of waxy rice starch on suppressing PhIP formation. A possible mechanism of waxy rice starch and SCA for inhibiting PhIP formation in the model system is also proposed.

  20. Structure of lintnerized starch is related to X-ray diffraction pattern and susceptibility to acid and enzyme hydrolysis of starch granules.

    PubMed

    Srichuwong, Sathaporn; Isono, Naoto; Mishima, Takashi; Hisamatsu, Makoto

    2005-11-15

    Acid-resistant residues (lintnerized starches, Ls) were prepared from starches showing A-, B- and C- X-ray diffraction patterns. Ls retained the same X-ray crystalline type as their native counterparts with an improvement in diffraction intensity. Fluorophore-assisted capillary electrophoresis (FACE) study indicated that structural characteristics of Ls were associated with X-ray diffraction patterns. Double helices originated from linear chains with an approximate average degree of polymerisation (DP) 14, 16, and 15 would span the entire length of crystalline lamellae of A-, B-, and C-type starches, respectively. The proportion of singly branched materials (SB) with DP 25 protected in Ls was higher for A-type Ls (10-17%) than for B-type Ls (4-6%) and C-type Ls (8%). The structures of SB were similar in which branched chain (DP 13-15) was longer than main chain (DP 10-12). The structural characteristics of Ls are discussed in relation to acid and enzymatic degradations of starch granules.

  1. Catalytically-inactive beta-amylase BAM4 required for starch breakdown in Arabidopsis leaves is a starch-binding-protein.

    PubMed

    Li, Jing; Francisco, Perigio; Zhou, Wenxu; Edner, Christoph; Steup, Martin; Ritte, Gerhard; Bond, Charles S; Smith, Steven M

    2009-09-01

    Of the four chloroplast beta-amylase (BAM) proteins identified in Arabidopsis, BAM3 and BAM4 were previously shown to play the major roles in leaf starch breakdown, although BAM4 apparently lacks key active site residues and beta-amylase activity. Here we tested multiple BAM4 proteins with different N-terminal sequences with a range of glucan substrates and assay methods, but detected no alpha-1,4-glucan hydrolase activity. BAM4 did not affect BAM1, BAM2 or BAM3 activity even when added in 10-fold excess, nor the BAM3-catalysed release of maltose from isolated starch granules in the presence of glucan water dikinase. However, BAM4 binds to amylopectin and to amylose-Sepharose whereas BAM2 has very low beta-amylase activity and poor glucan binding. The low activity of BAM2 may be explained by poor glucan binding but absence of BAM4 activity is not. These results suggest that BAM4 facilitates starch breakdown by a mechanism involving direct interaction with starch or other alpha-1,4-glucan.

  2. Molecular disassembly of rice and lotus starches during thermal processing and its effect on starch digestibility.

    PubMed

    Wang, Shujun; Sun, Yue; Wang, Jinrong; Wang, Shuo; Copeland, Les

    2016-02-01

    The molecular disassembly of starch during thermal processing is a major determinant for the susceptibility of starch to enzymatic digestion. In the present study, the effects of thermal processing on the disassembly of the granular structure and the in vitro enzymatic digestibility of rice and lotus starches were investigated. After heating at 50 °C, rice and lotus starches did not show significant changes in granular morphology, long-range crystallinity and short-range molecular order. As the temperature increased to 60 °C, rice starch underwent a partial gelatinization followed by an incomplete disruption of granular morphology, crystallites and molecular order. In contrast, lotus starch was almost completely gelatinized at 60 °C. At 70 °C or higher, both starches were fully gelatinized with complete disruption of the micro and macro structures. Our results show that gelatinization greatly increased the in vitro enzymatic digestibility of both starches, but that the degree of disassembly of the starch structure during thermal processing was not a major determinant of the digestibility of gelatinized starch.

  3. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  4. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  5. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  6. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Industrial starch-modified. 178.3520 Section 178... § 178.3520 Industrial starch-modified. Industrial starch-modified may be safely used as a component of..., transporting, or holding food, subject to the provisions of this section. (a) Industrial starch-modified...

  7. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  8. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  9. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  10. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Food starch-modified. 172.892 Section 172.892 Food... Multipurpose Additives § 172.892 Food starch-modified. Food starch-modified as described in this section may be... limitation prescribed. To insure safe use of the food starch-modified, the label of the food...

  11. 21 CFR 172.892 - Food starch-modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Food starch-modified. 172.892 Section 172.892 Food... starch-modified. Food starch-modified as described in this section may be safely used in food. The... insure safe use of the food starch-modified, the label of the food additive container shall bear the...

  12. 21 CFR 178.3520 - Industrial starch-modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Industrial starch-modified. 178.3520 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3520 Industrial starch-modified. Industrial starch... provisions of this section. (a) Industrial starch-modified is identified as follows: (1) A food...

  13. Generic safety documentation model

    SciTech Connect

    Mahn, J.A.

    1994-04-01

    This document is intended to be a resource for preparers of safety documentation for Sandia National Laboratories, New Mexico facilities. It provides standardized discussions of some topics that are generic to most, if not all, Sandia/NM facilities safety documents. The material provides a ``core`` upon which to develop facility-specific safety documentation. The use of the information in this document will reduce the cost of safety document preparation and improve consistency of information.

  14. Study of Selected Petroleum Refining Residuals

    EPA Pesticide Factsheets

    The document describes EPA's approach to conducting the industry study required by the Environmental Defense Fund (EDF)/EPA consent decree and characterizes the study residuals and how they are managed.

  15. Model approach to starch functionality in bread making.

    PubMed

    Goesaert, Hans; Leman, Pedro; Delcour, Jan A

    2008-08-13

    We used modified wheat starches in gluten-starch flour models to study the role of starch in bread making. Incorporation of hydroxypropylated starch in the recipe reduced loaf volume and initial crumb firmness and increased crumb gas cell size. Firming rate and firmness after storage increased for loaves containing the least hydroxypropylated starch. Inclusion of cross-linked starch had little effect on loaf volume or crumb structure but increased crumb firmness. The firming rate was mostly similar to that of control samples. Presumably, the moment and extent of starch gelatinization and the concomitant water migration influence the structure formation during baking. Initial bread firmness seems determined by the rigidity of the gelatinized granules and leached amylose. Amylopectin retrogradation and strengthening of a long-range network by intensifying the inter- and intramolecular starch-starch and possibly also starch-gluten interactions (presumably because of water incorporation in retrograded amylopectin crystallites) play an important role in firming.

  16. Native starch in tablet formulations: properties on compaction.

    PubMed

    Bos, C E; Bolhuis, G K; Van Doorne, H; Lerk, C F

    1987-10-16

    Maize, potato, rice and tapioca (cassava) starch were evaluated with respect to their properties on direct compression. Rice starch showed much better compactibility as compared to maize, potato and tapioca starch. Moreover, its binding capacity proved to be almost insensitive to mixing with magnesium stearate. This in contrast to the dramatic decrease in crushing strength of potato starch tablets containing the lubricant. The compactibility of the starches was found to be strongly affected by the equilibrium moisture content of the starches, which is dependent on the relative humidity of the atmosphere under which the powders were stored. All starches showed adequate capacity for water uptake to act as a disintegrant. Rice starch exhibited worst flowability, caused by its fine particle size as compared to the other starches. Granulation of rice starch changed it into a potential filler-binder in tablets prepared by direct compression.

  17. Effect of pressure and temperature on the gelatinization of starch at various starch concentrations.

    PubMed

    Baks, Tim; Bruins, Marieke E; Janssen, Anja E M; Boom, Remko M

    2008-01-01

    The effects of pressure, temperature, and treatment time on the degree of gelatinization were determined with differential scanning calorimetry measurements for wheat starch-water mixtures with starch concentrations varying between 5 and 80 w/w %. Although simple models could be used to describe the degree of starch gelatinization as a function of pressure or temperature, a more complex model based on the Gibbs energy difference had to be used to describe the degree of gelatinization as a function of both pressure and temperature. The experimental and model data were used to construct a phase diagram for 5, 30, and 60 w/w % wheat starch-water mixtures. Data obtained from literature were in accordance with our phase diagrams. These phase diagrams can be used to estimate the degree of gelatinisation after applying a certain pressure and temperature on a starch-water mixture with starch concentrations in the range of 5 and 60 w/w %.

  18. Applicability, Commercial Utility and Recent Patents on Starch and Starch Derivative as Pharmaceutical Drug Delivery Carrier.

    PubMed

    Pandey, Shreya; Malviya, Rishabha; Sharma, Pramod K

    2015-01-01

    Natural polymers are widely utilized in pharmaceutical and food industries. Starch, a major carbohydrate is a staple food in human and animal diets which is simply extractable from various sources, like potato, maize, corn, wheat, etc. It is widely used as a raw material in various food and non food industries as well as in paper, textile and other industries. This article summarizes the starch and modification of starch and to produce a novel molecule with various applications in industries including number of advances in pharmaceutical industry. The unique characteristics of starch and their modified form can be successfully used as drug delivery carriers in various pharmaceutical preparations. It is widely used as controlled and sustained release polymer, tablet disintegrant, drug delivery carrier, plasma volume expander and also finds its applicability in bone tissue engineering and in artificial red cells. It also includes the patents related to starch and modified starch based products and their commercial utility.

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

    PubMed

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

    2013-10-15

    Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials.

  20. Effects of salts on the gelatinization and retrogradation properties of maize starch and waxy maize starch.

    PubMed

    Wang, Wei; Zhou, Hongxian; Yang, Hong; Zhao, Siming; Liu, Youming; Liu, Ru

    2017-01-01

    The objective of this study was to evaluate the effects of salts on the gelatinization and retrogradation of maize and waxy maize starch. Experimental results showed that the salting-out or structure-making ions, such as F(-) and SO4(2-), decreased the swelling power, solubility and transparency of both starches, but increased the gelatinization temperature, enthalpy, and syneresis, due to the tendency of these ions to protect the hydrogen bond links among starch molecules. On the other hand, the salting-in or structure-breaking ions, such as I(-) and SCN(-), exhibited the opposite effects. Microscopic observations confirmed such effects of salts on both starches. Furthermore, the effects of salts were more significant on waxy maize and on normal maize starch. Generally, salts could significantly influence on the gelatinization and retrogradation of maize and waxy maize starch, following the order of the Hofmeister series.

  1. Starch synthesis in Arabidopsis. Granule synthesis, composition, and structure.

    PubMed

    Zeeman, Samuel C; Tiessen, Axel; Pilling, Emma; Kato, K Lisa; Donald, Athene M; Smith, Alison M

    2002-06-01

    The aim of this work was to characterize starch synthesis, composition, and granule structure in Arabidopsis leaves. First, the potential role of starch-degrading enzymes during starch accumulation was investigated. To discover whether simultaneous synthesis and degradation of starch occurred during net accumulation, starch was labeled by supplying (14)CO(2) to intact, photosynthesizing plants. Release of this label from starch was monitored during a chase period in air, using different light intensities to vary the net rate of starch synthesis. No release of label was detected unless there was net degradation of starch during the chase. Similar experiments were performed on a mutant line (dbe1) that accumulates the soluble polysaccharide, phytoglycogen. Label was not released from phytoglycogen during the chase indicating that, even when in a soluble form, glucan is not appreciably degraded during accumulation. Second, the effect on starch composition of growth conditions and mutations causing starch accumulation was studied. An increase in starch content correlated with an increased amylose content of the starch and with an increase in the ratio of granule-bound starch synthase to soluble starch synthase activity. Third, the structural organization and morphology of Arabidopsis starch granules was studied. The starch granules were birefringent, indicating a radial organization of the polymers, and x-ray scatter analyses revealed that granules contained alternating crystalline and amorphous lamellae with a periodicity of 9 nm. Granules from the wild type and the high-starch mutant sex1 were flattened and discoid, whereas those of the high-starch mutant sex4 were larger and more rounded. These larger granules contained "growth rings" with a periodicity of 200 to 300 nm. We conclude that leaf starch is synthesized without appreciable turnover and comprises similar polymers and contains similar levels of molecular organization to storage starches, making Arabidopsis

  2. Automated document analysis system

    NASA Astrophysics Data System (ADS)

    Black, Jeffrey D.; Dietzel, Robert; Hartnett, David

    2002-08-01

    A software application has been developed to aid law enforcement and government intelligence gathering organizations in the translation and analysis of foreign language documents with potential intelligence content. The Automated Document Analysis System (ADAS) provides the capability to search (data or text mine) documents in English and the most commonly encountered foreign languages, including Arabic. Hardcopy documents are scanned by a high-speed scanner and are optical character recognized (OCR). Documents obtained in an electronic format bypass the OCR and are copied directly to a working directory. For translation and analysis, the script and the language of the documents are first determined. If the document is not in English, the document is machine translated to English. The documents are searched for keywords and key features in either the native language or translated English. The user can quickly review the document to determine if it has any intelligence content and whether detailed, verbatim human translation is required. The documents and document content are cataloged for potential future analysis. The system allows non-linguists to evaluate foreign language documents and allows for the quick analysis of a large quantity of documents. All document processing can be performed manually or automatically on a single document or a batch of documents.

  3. Microwave-accelerated methylation of starch.

    PubMed

    Singh, Vandana; Tiwari, Ashutosh

    2008-01-14

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

  4. Protein Phosphorylation in Amyloplasts Regulates Starch Branching Enzyme Activity and Protein–Protein Interactions

    PubMed Central

    Tetlow, Ian J.; Wait, Robin; Lu, Zhenxiao; Akkasaeng, Rut; Bowsher, Caroline G.; Esposito, Sergio; Kosar-Hashemi, Behjat; Morell, Matthew K.; Emes, Michael J.

    2004-01-01

    Protein phosphorylation in amyloplasts and chloroplasts of Triticum aestivum (wheat) was investigated after the incubation of intact plastids with γ-32P-ATP. Among the soluble phosphoproteins detected in plastids, three forms of starch branching enzyme (SBE) were phosphorylated in amyloplasts (SBEI, SBEIIa, and SBEIIb), and both forms of SBE in chloroplasts (SBEI and SBEIIa) were shown to be phosphorylated after sequencing of the immunoprecipitated 32P-labeled phosphoproteins using quadrupole-orthogonal acceleration time of flight mass spectrometry. Phosphoamino acid analysis of the phosphorylated SBE forms indicated that the proteins are all phosphorylated on Ser residues. Analysis of starch granule–associated phosphoproteins after incubation of intact amyloplasts with γ-32P-ATP indicated that the granule-associated forms of SBEII and two granule-associated forms of starch synthase (SS) are phosphorylated, including SSIIa. Measurement of SBE activity in amyloplasts and chloroplasts showed that phosphorylation activated SBEIIa (and SBEIIb in amyloplasts), whereas dephosphorylation using alkaline phosphatase reduced the catalytic activity of both enzymes. Phosphorylation and dephosphorylation had no effect on the measurable activity of SBEI in amyloplasts and chloroplasts, and the activities of both granule-bound forms of SBEII in amyloplasts were unaffected by dephosphorylation. Immunoprecipitation experiments using peptide-specific anti-SBE antibodies showed that SBEIIb and starch phosphorylase each coimmunoprecipitated with SBEI in a phosphorylation-dependent manner, suggesting that these enzymes may form protein complexes within the amyloplast in vivo. Conversely, dephosphorylation of immunoprecipitated protein complex led to its disassembly. This article reports direct evidence that enzymes of starch metabolism (amylopectin synthesis) are regulated by protein phosphorylation and indicate a wider role for protein phosphorylation and protein

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

    PubMed

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

    2013-04-01

    Gelatinized waxy and normal corn starches (40% starch) were subjected to temperature cycling between 4 and 30°C (1 day at each temperature) or isothermal storage (4°C) to induce retrogradation. The in vitro analysis methods that are currently used for the measurement of resistant starch (RS), i.e. Englyst, AACC 32-40 and Goni methods, were compared with homogenized retrograded starch gels and freeze-dried powders of the gels. RS contents obtained by the three analysis methods were in the following order: Goni>Englyst>AACC. Although different RS values were obtained among the analysis methods, similar trends in regards to the starch type and storage conditions could be observed. Little or no RS was found in freeze-dried powders of the retrograded starch gels and storage conditions had no effect, indicating that the physical state for RS analysis is important. More RS was found in normal corn starch gels than in waxy corn starch gels under identical storage conditions and in the gels stored under temperature cycling than those under isothermal storage (4°C), indicating that the presence of amylose inhibits starch digestion and the level of crystalline structure of re-crystallized amylopectin also affects the RS formation during retrogradation.

  6. Electron microscopy and composition of raw acorn starch in relation to in vivo starch digestibility.

    PubMed

    Cappai, Maria Grazia; Alesso, Giuseppe Andrea; Nieddu, Giuseppa; Sanna, Marina; Pinna, Walter

    2013-06-01

    The structure and composition of starch play an important role as co-factors affecting raw starch digestibility: such features were investigated in raw acorn starch from the most diffused oak trees in the Mediterranean basin. A total of 620 whole ripe acorns from Holm (Quercus ilex L., n = 198), Downy (Quercus pubescens Willd., n = 207) and Cork (Quercus suber L., n = 215) oaks sampled on the Sardinia Isle (40° 56' 0'' N; 9° 4' 0'' E; 545 m above the mean sea level) in the same geographical area, were analyzed for their chemical composition. The starch contents ranged between 51.2% and 53.5% of dry matter. The starch granules displayed a spheroid/ovoid and cylindrical shape; on scanning electron microscopic (SEM) analyses, a bimodal distribution of starch granule size was observed both for Holm and Cork oak acorns, whereas the starch granules of Downy oak acorns showed diameters between 10.2 and 13.8 μm. The specific amylose to amylopectin ratio of acorn starch was 25.8%, 19.5% and 34.0% in the Holm, Downy and Cork oaks, respectively. The (13)C Nuclear Magnetic Resonance (NMR) signal analysis displayed a pivotal spectrum for the identification of the amylose peaks in raw acorn starch, as a basis for the amylose to amylopectin ratio determination.

  7. Distribution of branches in whole starches from maize mutants deficient in starch synthase III.

    PubMed

    Zhu, Fan; Bertoft, Eric; Seetharaman, Koushik

    2014-05-21

    An earlier study explored the possibility of analyzing the distribution of branches directly in native, whole starch without isolating the amylopectin component. The aim of this study was to explore if this approach can be extended to include starch mutants. Whole starches from du1 maize mutants deficient in starch synthase III (SSIII) with amylose content of ∼30-40% were characterized and compared with the wild type of the common genetic background W64A. Clusters were produced from whole starch by hydrolysis with α-amylase of Bacillus amyloliquefaciens. Their compositions of building blocks and chains were analyzed further by complete α-amylolysis and by debranching, respectively, whereafter the products were subjected to gel permeation and anion exchange chromatography. The size and structure of the clusters were compared with those of their isolated amylopectin component. Whereas the whole starch of the wild type sample had a branched structure similar to that of its amylopectin component, the results showed that the du1 mutation resulted in more singly branched building blocks in the whole starch compared to the isolated amylopectin. This suggested that amylose and/or intermediate materials in whole du1 starches likely contributed to the composition of branches. This study explored an alternative procedure to characterize the composition of branches in the whole starch without fractionating the components.

  8. Resistant starch improvement of rice starches under a combination of acid and heat-moisture treatments.

    PubMed

    Hung, Pham Van; Vien, Ngo Lam; Lan Phi, Nguyen Thi

    2016-01-15

    The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1-39.0%, significantly higher than those of native rice starches (6.3-10.2%) and those of heat-moisture treated rice starches (18.5-23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application.

  9. Dilute solution properties of canary seed (Phalaris canariensis) starch in comparison to wheat starch.

    PubMed

    Irani, Mahdi; Razavi, Seyed M A; Abdel-Aal, El-Sayed M; Hucl, Pierre; Patterson, Carol Ann

    2016-06-01

    Dilute solution properties of an unknown starch are important to understand its performance and applications in food and non-food industries. In this paper, rheological and molecular properties (intrinsic viscosity, molecular weight, shape factor, voluminosity, conformation and coil overlap parameters) of the starches from two hairless canary seed varieties (CO5041 & CDC Maria) developed for food use were evaluated in the dilute regime (Starch dispersions in DMSO (0.5g/dl)) and compared with wheat starch (WS). The results showed that Higiro model is the best among five applied models for intrinsic viscosity determination of canary seed starch (CSS) and WS on the basis of coefficient of determination (R(2)) and root mean square error (RMSE). WS sample showed higher intrinsic viscosity value (1.670dl/g) in comparison to CSS samples (1.325-1.397dl/g). Berry number and the slope of master curve demonstrated that CSS and WS samples were in dilute domain without entanglement occurrence. The shape factor suggested spherical and ellipsoidal structure for CO5041 starch and ellipsoidal for CDC Maria starch and WS. The molecular weight, coil radius and coil volume of CSSs were smaller than WS. The behavior and molecular characterization of canary seed starch showed its unique properties compared with wheat starch.

  10. The molecular structure of waxy maize starch nanocrystals.

    PubMed

    Angellier-Coussy, Hélène; Putaux, Jean-Luc; Molina-Boisseau, Sonia; Dufresne, Alain; Bertoft, Eric; Perez, Serge

    2009-08-17

    The insoluble residues obtained by submitting amylopectin-rich native starch granules from waxy maize to a mild acid hydrolysis consist of polydisperse platelet nanocrystals that have retained the allomorphic type of the parent granules. The present investigation is a detailed characterization of their molecular composition. Two major groups of dextrins were found in the nanocrystals and were isolated. Each group was then structurally characterized using beta-amylase and debranching enzymes (isoamylase and pullulanase) in combination with anion-exchange chromatography. The chain lengths of the dextrins in both groups corresponded with the thickness of the crystalline lamellae in the starch granules. Only approximately 62 mol% of the group of smaller dextrins with an average degree of polymerization (DP) 12.2 was linear, whereas the rest consisted of branched dextrins. The group of larger dextrins (DP 31.7) apparently only consisted of branched dextrins, several of which were multiply branched molecules. It was shown that many of the branch linkages were resistant to the action of the debranching enzymes. The distribution of branched molecules in the two populations of dextrins suggested that the nanocrystals possessed a regular and principally homogeneous molecular structure.

  11. Cooking behavior and starch digestibility of NUTRIOSE® (resistant starch) enriched noodles from sweet potato flour and starch.

    PubMed

    Menon, Renjusha; Padmaja, G; Sajeev, M S

    2015-09-01

    The effect of a resistant starch source, NUTRIOSE® FB06 at 10%, 15% and 20% in sweet potato flour (SPF) and 5% and 10% in sweet potato starch (SPS) in reducing the starch digestibility and glycaemic index of noodles was investigated. While NUTRIOSE (10%) significantly reduced the cooking loss in SPF noodles, this was enhanced in SPS noodles and guar gum (GG) supplementation reduced CL of both noodles. In vitro starch digestibility (IVSD) was significantly reduced in test noodles compared to 73.6g glucose/100g starch in control SPF and 65.9 g in SPS noodles. Resistant starch (RS) was 54.96% for NUTRIOSE (15%)+GG (1%) fortified SPF noodles and 53.3% for NUTRIOSE (5%)+GG (0.5%) fortified SPS noodles, as against 33.8% and 40.68%, respectively in SPF and SPS controls. Lowest glycaemic index (54.58) and the highest sensory scores (4.23) were obtained for noodles with 15% NUTRIOSE+1% GG.

  12. Computer software documentation

    NASA Technical Reports Server (NTRS)

    Comella, P. A.

    1973-01-01

    A tutorial in the documentation of computer software is presented. It presents a methodology for achieving an adequate level of documentation as a natural outgrowth of the total programming effort commencing with the initial problem statement and definition and terminating with the final verification of code. It discusses the content of adequate documentation, the necessity for such documentation and the problems impeding achievement of adequate documentation.

  13. Production of modified starches by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

    1999-04-01

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch.

  14. [Characterisation of Dioscorea bulbifera native starch].

    PubMed

    Araujo de Vizcarrondo, Consuelo; Rincón, Alicia Mariela; Padilla, Fanny

    2004-06-01

    A non conventional source of starch, bulbs of Dioscorea bulbifera, was evaluated. Giving a yield of 28.48 g/100 g on dry weight, chemical composition, physical, physico-chemical and morphological characteristics were assessed, as well as its rheological properties. Chemical analysis showed a amylose content of 29.37%. Micrographies showed that most of the starch granules were of irregular shape, similar to a pyramid with rounded vertices, and a smaller number were elongated with smooth surface. Dioscorea starch showed a gelatinization temperature of 70.8 degrees C and maximum viscosity at 88.6 degrees C of 435 Brabender units (BU). It presented a relatively stable consistency to the cooking process and a low tendency to retrogradation; which suggest the starch possible use in food products that need a fast viscosity and a gel with a stable consistency.

  15. Starch-Poly(Hydroxylalkanoate) Composites and Blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper summarizes research on starch-polyhydroxyalkanoate (PHA) blends and composites. Efforts to increase compatibility, characterize mechanical and biodegradation properties are described. A range of blend products have been prepared including molded plastics, films and foams. Finally, futu...

  16. Rheological behaviour of heated potato starch dispersions

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    The study was designed to investigate the rheological properties of heated potato starch dispersions. Water suspensions of starch were heated at 65, 80 or 95°C for 5, 15, 30 or 60 min. The dispersions obtained were examined for granule size distribution and rheology. It was found that the starch dispersions significantly differed in both respects. The mean diameters of starch granules were largest for the dispersion heated at 65°C and smallest for that heated at 95°C. As the heating temperature was raised, the yield stresses and consistency coefficients decreased, while the flow behaviour indexes and Casson plastic viscosities increased. There were also differences in the viscoelastic properties of the dispersions: for those heated at 65°C the storage and loss moduli increased with heating time whereas for those heated at 80°C both moduli decreased.

  17. Biotechnological relevance of starch-degrading enzymes

    SciTech Connect

    Stewart, G.G.

    1987-01-01

    Traditional enzymes, such as the amylases and the proteases, have been improved, novel applications have been found and new and valuable products have been marketed. The enzymatic hydrolysis of starch is described in some detail. (Refs. 8).

  18. Formation of starch in plant cells.

    PubMed

    Pfister, Barbara; Zeeman, Samuel C

    2016-07-01

    Starch-rich crops form the basis of our nutrition, but plants have still to yield all their secrets as to how they make this vital substance. Great progress has been made by studying both crop and model systems, and we approach the point of knowing the enzymatic machinery responsible for creating the massive, insoluble starch granules found in plant tissues. Here, we summarize our current understanding of these biosynthetic enzymes, highlighting recent progress in elucidating their specific functions. Yet, in many ways we have only scratched the surface: much uncertainty remains about how these components function together and are controlled. We flag-up recent observations suggesting a significant degree of flexibility during the synthesis of starch and that previously unsuspected non-enzymatic proteins may have a role. We conclude that starch research is not yet a mature subject and that novel experimental and theoretical approaches will be important to advance the field.

  19. Physicochemical properties and digestibility of hydrothermally treated waxy rice starch.

    PubMed

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

    2015-04-01

    Waxy rice starch was subjected to annealing (ANN) and heat-moisture treatment (HMT). These starches were also treated by a combination of ANN and HMT. The impact of single and dual modifications (ANN-HMT and HMT-ANN) on the molecular weight (M(w)), crystalline structure, thermal properties, and the digestibility were investigated. The relative crystallinity and short-range order on the granule surface increased on ANN, whereas decreased on HMT. All treated starches showed lower M(w) than that of the native starch. Gelatinization onset temperature, peak temperature and conclusion temperature increased for both single and dual treatments. Increased slowly digestible starch content was found on HMT and ANN-HMT. However, resistant starch levels decreased in all treated starches as compared with native starch. The results would imply that hydrothermal treatment induced structural changes in waxy rice starch significantly affected its digestibility.

  20. Morphological features and physicochemical properties of waxy wheat starch.

    PubMed

    Zhang, Huanxin; Zhang, Wei; Xu, Chunzhong; Zhou, Xing

    2013-11-01

    Morphological features, granule composition, and physicochemical properties of waxy wheat starch were compared with those of normal wheat starch. The morphologies and granule populations were found to be similar for the two starches. However, waxy wheat starch contained a smaller proportion of B-type granules, had a larger average granule diameter, and a higher degree of crystallinity than normal wheat starch, as measured by particle size analysis and differential scanning calorimetry. These differences resulted in a higher gelatinization temperature, transition enthalpy, peak viscosity, breakdown, swelling power, lower peak viscosity temperature and final viscosity in waxy wheat starch. These points suggest that waxy wheat starch should have greater resistance to retrogradation during cooling and higher water-holding capacity under dry conditions. Highlighting the differences in physicochemical properties of waxy and normal wheat starches should help point toward effective applications of waxy wheat starch in the food industry.

  1. Phosphoglucan phosphatase function sheds light on starch degradation.

    PubMed

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

    2014-07-01

    Phosphoglucan phosphatases are novel enzymes that remove phosphates from complex carbohydrates. In plants, these proteins are vital components in the remobilization of leaf starch at night. Breakdown of starch is initiated through reversible glucan phosphorylation to disrupt the semi-crystalline starch structure at the granule surface. The phosphoglucan phosphatases starch excess 4 (SEX4) and like-SEX4 2 (LSF2) dephosphorylate glucans to provide access for amylases that release maltose and glucose from starch. Another phosphatase, LSF1, is a putative inactive scaffold protein that may act as regulator of starch degradative enzymes at the granule surface. Absence of these phosphatases disrupts starch breakdown, resulting in plants accumulating excess starch. Here, we describe recent advances in understanding the biochemical and structural properties of each of these starch phosphatases.

  2. Preparation of indigestible pyrodextrins from different starch sources.

    PubMed

    Laurentin, Alexander; Cárdenas, Marité; Ruales, Jenny; Pérez, Elevina; Tovar, Juscelino

    2003-08-27

    Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl. The enzymatically available starch content of all preparations decreased by 55-65% after modification. Thus, pyrodextrinization seems to be an effective way to produce indigestible glucans from different starches. Pyrodextrins obtained were complex mixtures of starch derivatives with a wide range of molecular weight as estimated by gel filtration chromatography. Both their molecular weight profiles and contents of indigestible fractions varied with starch source. Experiments with lentil and cassava starches showed that changing dextrinization conditions also affects the susceptibility to enzymatic hydrolysis of the product.

  3. Heat expanded starch-based compositions.

    PubMed

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

    2007-05-16

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

  4. The Other Double Helix--The Fascinating Chemistry of Starch

    NASA Astrophysics Data System (ADS)

    Hancock, Robert D.; Tarbet, Bryon J.

    2000-08-01

    Current textbooks deal only briefly with the chemistry of starch. A short review with 21 references is presented, describing the structure of starch and indicating the double helix structure of A-type and B-type starch. The structure of the starch granule is examined, pointing out the existence of growth rings of alternating crystalline and noncrystalline starch, with growing amylopectin molecules extending from the hilum (point of origin) to the surface of the starch granule. The swelling of starch granules in water, above the gelatinization temperature of about 60 °C, is discussed. The process of gelatinization involves unraveling of the starch helix and a manyfold increase in volume of the starch granule as water is imbibed and bound to the unraveled starch polymer by hydrogen bonding. Baking bread or pastries causes unraveling of the starch helix, and the process by which these products become stale corresponds primarily to the re-forming of the starch helix. The importance of this phenomenon in food science is discussed. The absorption of nonpolar linear molecules such as I2, or linear nonpolar portions of molecules such as n-butanol or fats and phospholipids, by the C-type helix of starch is examined. The way in which starch is structurally modified to retard staling is discussed in relation to food technology.

  5. Engineering Potato Starch with a Higher Phosphate Content

    PubMed Central

    Xu, Xuan; Huang, Xing-Feng; Visser, Richard G. F.

    2017-01-01

    Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a carbohydrate-binding module and a dual-specificity phosphatase domain, is involved in the dephosphorylation of glycogen. To modify phosphate content and better understand starch (de)phosphorylation in storage starch, laforin was engineered and introduced into potato (cultivar Kardal). Interestingly, expression of an (engineered) laforin in potato resulted in significantly higher phosphate content of starch, and this result was confirmed in amylose-free potato genetic background (amf). Modified starches exhibited altered granule morphology and size compared to the control. About 20–30% of the transgenic lines of each series showed red-staining granules upon incubation with iodine, and contained higher phosphate content than the blue-stained starch granules. Moreover, low amylose content and altered gelatinization properties were observed in these red-stained starches. Principle component and correlation analysis disclosed a complex correlation between starch composition and starch physico-chemical properties. Ultimately, the expression level of endogenous genes involved in starch metabolism was analysed, revealing a compensatory response to the decrease of phosphate content in potato starch. This study provides a new perspective for engineering starch phosphate content in planta by making use of the compensatory mechanism in the plant itself. PMID:28056069

  6. Degraded document image enhancement

    NASA Astrophysics Data System (ADS)

    Agam, G.; Bal, G.; Frieder, G.; Frieder, O.

    2007-01-01

    Poor quality documents are obtained in various situations such as historical document collections, legal archives, security investigations, and documents found in clandestine locations. Such documents are often scanned for automated analysis, further processing, and archiving. Due to the nature of such documents, degraded document images are often hard to read, have low contrast, and are corrupted by various artifacts. We describe a novel approach for the enhancement of such documents based on probabilistic models which increases the contrast, and thus, readability of such documents under various degradations. The enhancement produced by the proposed approach can be viewed under different viewing conditions if desired. The proposed approach was evaluated qualitatively and compared to standard enhancement techniques on a subset of historical documents obtained from the Yad Vashem Holocaust museum. In addition, quantitative performance was evaluated based on synthetically generated data corrupted under various degradation models. Preliminary results demonstrate the effectiveness of the proposed approach.

  7. RESIDUAL RISK ASSESSMENTS - RESIDUAL RISK ...

    EPA Pesticide Factsheets

    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  8. Size separations of starch of different botanical origin studied by asymmetrical-flow field-flow fractionation and multiangle light scattering.

    PubMed

    Wahlund, Karl-Gustav; Leeman, Mats; Santacruz, Stalin

    2011-02-01

    Asymmetrical-flow field-flow fractionation combined with multiangle light scattering and refractive index detection has been revealed to be a powerful tool for starch characterization. It is based on size separation according to the hydrodynamic diameter of the starch components. Starch from a wide range of different botanical sources were studied, including normal starch and high-amylose and high-amylopectin starch. The starch was dissolved by heat treatment at elevated pressure in a laboratory autoclave. This gave clear solutions with no granular residues. Amylose retrogradation was prevented by using freshly dissolved samples. Programmed cross flow starting at 1.0 mL min(-1) and decreasing exponentially with a half-life of 4 min was utilised. The starches showed two size populations representing mainly amylose and mainly amylopectin with an overlapping region where amylose and amylopectin were possibly co-eluted. Most of the first population had molar masses below 10(6) g mol(-1), and most of the second size population had molar masses above 10(7) g mol(-1). Large differences were found in the relative amounts of the two populations, the molar mass, and hydrodynamic diameters, depending on the plant source and its varieties.

  9. Production of a freeze-thaw-stable potato starch by antisense inhibition of three starch synthase genes.

    PubMed

    Jobling, Stephen A; Westcott, Roger J; Tayal, Akash; Jeffcoat, Roger; Schwall, Gerhard P

    2002-03-01

    The use of unmodified starches in frozen foods is severely limited by the undesirable textural changes that occur after freezing and thawing. Retrogradation of glucan chains leads to syneresis, a separation of the starch gel and water phases. Stabilization of the starch structure is normally achieved by chemical modification to prevent these changes from occurring. We have now created a freeze-thaw-stable potato starch by alteration of starch composition and structure by genetic modification. An amylose-free starch with short-chain amylopectin was produced by simultaneous antisense downregulation of three starch synthase genes. This starch is extremely freeze-thaw-stable and shows no syneresis even after five freeze-thaw cycles. The use of this starch has potential for environmental and consumer benefits because its production requires no chemical modification.

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

    NASA Astrophysics Data System (ADS)

    Cieśla, Krystyna; Watzeels, Nick; Rahier, Hubert

    2014-06-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2014-07-15

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2011-06-22

    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. α- and β-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 α-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.

  15. Effects of β-amylolysis on the resistant starch formation of debranched corn starches.

    PubMed

    Luckett, Curtis R; Wang, Ya-Jane

    2012-05-09

    Retrograded amylose is resistant to digestion by amylolytic enzymes, which is known as resistant starch type III (RS3). In this study we investigated the effect of β-amylase hydrolysis on the formation and physicochemical properties of RS3 from debranched corn starches. Three types of corn starch (Hylon VII, Hylon V, and common corn) were first gelatinized and then hydrolyzed using β-amylase to varying degrees. The resultant hydrolyzed starch was debranched with isoamylase and then exposed to temperature cycling to promote RS formation. A broad endotherm from approximately 45 to 120 °C and a small endotherm above 150 °C were noted for all retrograded starches. All three corn starches had increased RS contents after moderate β-amylolysis, with Hylon V having the highest RS content at 70.7% after 4 h of β-amylolysis. The results suggest that RS3 formation is affected by the starch composition as well as the starch structure and can be increased by moderate β-amylolysis.

  16. Resistant-starch Formation in High-amylose Maize Starch During Kernel Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to understand the resistant-starch (RS) formation during the kernel development of high-amylose maize, GEMS-0067 line. RS content of the starch, determined using AOAC Method 991.43 for total dietary fiber, increased with kernel maturation and the increase in amylose/...

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

    PubMed

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

    2013-04-01

    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.

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

    PubMed

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

    2012-06-01

    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.

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

    PubMed

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

    2008-11-12

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

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

    PubMed

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

    2016-01-15

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

  1. Documentation and knowledge acquisition

    NASA Technical Reports Server (NTRS)

    Rochowiak, Daniel; Moseley, Warren

    1990-01-01

    Traditional approaches to knowledge acquisition have focused on interviews. An alternative focuses on the documentation associated with a domain. Adopting a documentation approach provides some advantages during familiarization. A knowledge management tool was constructed to gain these advantages.

  2. JSC document index

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Johnson Space Center (JSC) document index is intended to provide a single source listing of all published JSC-numbered documents their authors, and the designated offices of prime responsibility (OPR's) by mail code at the time of publication. The index contains documents which have been received and processed by the JSC Technical Library as of January 13, 1988. Other JSC-numbered documents which are controlled but not available through the JSC Library are also listed.

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

    PubMed

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

    2013-07-01

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

  4. Guidelines for Document Designers.

    ERIC Educational Resources Information Center

    Felker, Daniel B.; And Others

    Intended to improve the quality of public documents by making them clearer to the people who use them, this book contains document design principles concerned with writing documents that are visually distinct, attractive, and easily understood. Following an introduction, the major portion of the book presents the 25 principles, each of which…

  5. Documenting Employee Conduct

    ERIC Educational Resources Information Center

    Dalton, Jason

    2009-01-01

    One of the best ways for a child care program to lose an employment-related lawsuit is failure to document the performance of its employees. Documentation of an employee's performance can provide evidence of an employment-related decision such as discipline, promotion, or discharge. When properly implemented, documentation of employee performance…

  6. Program analysis for documentation

    NASA Technical Reports Server (NTRS)

    Lolmaugh, G. H.

    1970-01-01

    A program analysis for documentation (PAD) written in FORTRAN has three steps: listing the variables, describing the structure and writing the program specifications. Technical notes on editing criteria for reviewing program documentation, technical notes for PAD, and FORTRAN program analyzer for documentation are appended.

  7. Automated Management Of Documents

    NASA Technical Reports Server (NTRS)

    Boy, Guy

    1995-01-01

    Report presents main technical issues involved in computer-integrated documentation. Problems associated with automation of management and maintenance of documents analyzed from perspectives of artificial intelligence and human factors. Technologies that may prove useful in computer-integrated documentation reviewed: these include conventional approaches to indexing and retrieval of information, use of hypertext, and knowledge-based artificial-intelligence systems.

  8. Documents and Civic Duties

    ERIC Educational Resources Information Center

    Potter, Lee Ann

    2005-01-01

    All of the documents featured in this article come from the holdings of the National Archives and Records Administration. Primary source documents illustrate what is meant by responsible citizenship. The people who create documents as well as those who are featured in them can serve as models of civic behavior--both appropriate and…

  9. Grain processing effects on starch utilization by ruminants.

    PubMed

    Theurer, C B

    1986-11-01

    Starch utilization may be markedly enhanced by proper grain processing; however, extent of improvement is primarily dependent upon the ruminant species, grain source and method of processing. Grain processing has less impact on starch digestion by sheep than cattle. The magnitude of improvement is inverse to the starch digestion values for nonprocessed (or minimally processed) grains. Utilization of sorghum grain starch is improved most by extensive processing, and then corn, with little improvement in barley starch digestion. Studies comparing processing effects on barley or wheat starch utilization by cattle were not found. Steam-flaking consistently improves digestibility of starch by cattle fed corn- or sorghum grain-based diets over whole, ground or dry-rolled processes. Other extensive processing methods appear to enhance starch digestibility of corn and sorghum grain to a similar extent as steam-flaking, but comparative data are too limited to quantitate adequately effects of these methods. This improvement in starch utilization appears to be the primary reason for enhanced feed conversion of cattle fed diets high in these processed grains. The major site of cereal grain starch digestion is usually the rumen. Processing increases microbial degradation of starch in the rumen and decreases amounts of starch digested post-ruminally. Rates of in vitro amylolytic attack of starch in cereal grains by both ruminal microbial and pancreatic enzyme sources are improved by processing methods employing proper combinations of moisture, heat and pressure. In vitro and in situ studies suggest that much of the increase in ruminal starch fermentation with steam-flaking is due to changes in starch granular structure, which produces additive effects beyond those of decreasing particle size. Thus, efficiency of ruminal starch fermentation by cattle appears to be improved by proper processing of corn and sorghum grain. Processing and grain source studies both suggest that

  10. Starches of varied digestibilities differentially modify intestinal function in rats.

    PubMed

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

    1993-12-01

    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.

  11. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths.

    PubMed

    Holst, Irene; Moreno, J Enrique; Piperno, Dolores R

    2007-11-06

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals.

  12. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths

    PubMed Central

    Holst, Irene; Moreno, J. Enrique; Piperno, Dolores R.

    2007-01-01

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals. PMID:17978176

  13. Cloning and extracellular expression of a raw starch digesting α-amylase (Blamy-I) and its application in bioethanol production from a non-conventional source of starch.

    PubMed

    Roy, Jetendra K; Manhar, Ajay K; Nath, Dhrubajyoti; Mandal, Manabendra; Mukherjee, Ashis K

    2015-11-01

    The aim of this study was to clone and efficiently express a raw starch-digesting α-amylase enzyme in the culture media and also to investigate the potential application of this recombinant enzyme in the digestion of non-conventional raw starch for bioethanol production. A raw starch digesting α-amylase gene isolated from Bacillus licheniformis strain AS08E was cloned and extracellularly expressed in E. coli cells using the native signal peptide. The mature recombinant α-amylase (Blamy-I) consisting of 483 amino acid residues was found to be homogenous with a mass of 55.3 kDa (by SDS-PAGE analysis) and a predicted pI of 6.05. Structural and functional analysis of Blamy-I revealed the presence of an extra Ca(2+) -binding region between the A and C domains responsible for higher thermostability of this enzyme. The statistical optimization of E. coli culture conditions resulted in an approximately eightfold increase in extracellular expression of Blamy-I as compared to its production under non-optimized conditions. Blamy-I demonstrated optimum enzyme activity at 80 °C and pH 10.0, and efficiently hydrolyzed raw starch isolated from a non-conventional, underutilized jack fruit seeds. Further utilization of this starch for bioethanol production using Blamy-I and Saccharomyces cerevisiae also proved to be highly promising.

  14. Fermentation RS3 derived from sago and rice starch with Clostridium butyricum BCC B2571 or Eubacterium rectale DSM 17629.

    PubMed

    Purwani, Endang Yuli; Purwadaria, Tresnawati; Suhartono, Maggy Thenawidjaja

    2012-02-01

    Resistant starch type 3 (RS3) is retrograded starch which is not digested by human starch degrading enzyme, and will thus undergo bacterial degradation in the colon. The main fermentation products are the Short Chain Fatty Acid (SCFA): acetate, propionate and butyrate. SCFA has significant benefit impact on the metabolism of the host. The objectives of this research were to study the SCFA profile produced by colonic butyrate producing bacteria grown in medium containing RS3. RS3 was made from sago or rice starch treated with amylase, pullulanase and the combination of amylase and pullulanase. Fermentation study was performed by using Clostridium butyricum BCC B2571 or Eubacterium rectale DSM 17629, which has been identified as capable of degradation of starch residue and also regarded as beneficial bacteria. Experimental result revealed that enzyme hydrolysis of retrograded sago or rice starch was beneficial to RS formation. RS3 derived from sago contained higher RS (31-38%) than those derived from rice starch (21-26%). This study indicated that C. butyricum BCC B2571 produced acetate, propionate and butyrate at molar ratio of 1.8 : 1 : 1, when the medium was supplemented with RSSA at concentration 1%. In the medium containing similar substrate, E. rectale DSM 17629 produced acetate, propionate and butyrate at molar ratio of 1.7 : 1 : 1.2. High levels of acetate, propionate and butyrate at molar ratio of 1.8 : 1 : 1.1 was also produced by E. rectale DSM 17629 in medium supplemented with RSSP at concentration 1%. The results showed that both bacteria responded differently to the RS3 supplementation. Such result provided insight into the possibility of designing RS3 as prebiotic with featured regarding SCFA released in the human colon with potential health implication.

  15. Starlink Document Styles

    NASA Astrophysics Data System (ADS)

    Lawden, M. D.

    This document describes the various styles which are recommended for Starlink documents. It also explains how to use the templates which are provided by Starlink to help authors create documents in a standard style. This paper is concerned mainly with conveying the ``look and feel" of the various styles of Starlink document rather than describing the technical details of how to produce them. Other Starlink papers give recommendations for the detailed aspects of document production, design, layout, and typography. The only style that is likely to be used by most Starlink authors is the Standard style.

  16. PSD Guidance Document

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  17. 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...

  18. Fermentation of corn starch to ethanol with genetically engineered yeast.

    PubMed

    Inlow, D; McRae, J; Ben-Bassat, A

    1988-07-05

    Expression of the glucoamylase gene from Aspergillus awamori by laboratory and distiller's strains of Saccharomyces cerevisiae allowed them to ferment soluble starch. Approximately 95% of the carbohydrates in the starch were utilized. Glycerol production was significantly decreased when soluble starch was used instead of glucose. Ethanol yield on soluble starch was higher than that on glucose. The rate of starch fermentation was directly related to the level of glucoamylase activity. Strains with higher levels of glucoamylase expression fermented starch faster. The decline in starch fermentation rates toward the end of the fermentation was associated with accumulation of disaccharides and limit dextrins, poor substrates for glucoamylase. The buildup of these products in continuous fermentations inhibited glucoamylase activity and complete utilization of the starch. Under these conditions maltose-fermenting strains had a significant advantage over nonfermenting strains. The synthesis and secretion of glucoamylase showed no deleterious effects on cell growth rates, fermetation rates, and fermentation products.

  19. Enzymatic modification of cassava starch by bacterial lipase.

    PubMed

    Rajan, Akhila; Abraham, T Emilia

    2006-06-01

    Enzymatic modification of starch using long chain fatty acid makes it thermoplastic suitable for a myriad of industrial applications. An industrial lipase preparation produced by Burkholderia cepacia (lipase PS) was used for modification of cassava starch with two acyl donors, lauric acid and palmitic acid. Reactions performed with palmitic acid by liquid-state and microwave esterification gave a degree of substitution (DS) of 62.08% (DS 1.45) and 42.06% (DS 0.98), respectively. Thermogravimetric analysis showed that onset of decomposition is at a higher temperature (above 600 degrees Celsius) for modified starch than the unmodified starch (280 degrees Celsius). Modified starch showed reduction in alpha-amylase digestibility compared to native starch (76.5-18%). Swelling power lowered for modified starch as esterification renders starch more hydrophobic, making it suitable for biomedical applications as materials for bone fixation and replacements, carriers for controlled release of drugs and bioactive agents. Thus enzymatic esterification is ecofriendly.

  20. Molecular structure, functionality and applications of oxidized starches: A review.

    PubMed

    Vanier, Nathan Levien; El Halal, Shanise Lisie Mello; Dias, Alvaro Renato Guerra; da Rosa Zavareze, Elessandra

    2017-04-15

    During oxidation, the hydroxyl groups of starch molecules are first oxidized to carbonyl groups, then to carboxyl groups. The contents of the carbonyl and carboxyl groups in a starch molecule therefore indicate the extent of starch oxidation. The mechanisms of starch oxidation with different oxidizing agents, including sodium hypochlorite, hydrogen peroxide, ozone and sodium periodate, are described in this review. The effects of these oxidizing agents on the molecular, physicochemical, thermal, pasting and morphological properties of starch are described as well. In addition, the main industrial applications of oxidized starches are presented. The present review is important for understanding the effects of oxidation on starch properties, and this information may facilitate the development of novel oxidized starches for both food and non-food applications.

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

    PubMed

    Lin, Da-Gin; Jeang, Chii-Ling

    2005-10-05

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

  2. Regulation of starch synthesis in potato tubers

    SciTech Connect

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

    1990-05-01

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

  3. Probing starch-iodine interaction by atomic force microscopy.

    PubMed

    Du, Xiongwei; An, Hongjie; Liu, Zhongdong; Yang, Hongshun; Wei, Lijuan

    2014-01-01

    We explored the interaction of iodine with three crystalline type starches, corn, potato, and sweet potato starches using atomic force microscopy. Results revealed that starch molecules aggregated through interaction with iodine solution as well as iodine vapor. Detailed fine structures such as networks, chains, and super-helical structures were found in iodide solution tests. The nanostructures formed due to iodine adsorption could help to understand the formation and properties of the starch-iodine complex.

  4. Starch Catabolism by a Prominent Human Gut Symbiont Is Directed by the Recognition of Amylose Helices

    SciTech Connect

    Koropatkin, Nicole M.; Martens, Eric C.; Gordon, Jeffrey I.; Smith, Thomas J.

    2009-01-12

    The human gut microbiota performs functions that are not encoded in our Homo sapiens genome, including the processing of otherwise undigestible dietary polysaccharides. Defining the structures of proteins involved in the import and degradation of specific glycans by saccharolytic bacteria complements genomic analysis of the nutrient-processing capabilities of gut communities. Here, we describe the atomic structure of one such protein, SusD, required for starch binding and utilization by Bacteroides thetaiotaomicron, a prominent adaptive forager of glycans in the distal human gut microbiota. The binding pocket of this unique {alpha}-helical protein contains an arc of aromatic residues that complements the natural helical structure of starch and imposes this conformation on bound maltoheptaose. Furthermore, SusD binds cyclic oligosaccharides with higher affinity than linear forms. The structures of several SusD/oligosaccharide complexes reveal an inherent ligand recognition plasticity dominated by the three-dimensional conformation of the oligosaccharides rather than specific interactions with the composite sugars.

  5. Starch-bound 2S proteins and kernel texture in einkorn, Triticum monococcum ssp monococcum.

    PubMed

    Taddei, Federica; Gazza, Laura; Conti, Salvatore; Muccilli, Vera; Foti, Salvatore; Pogna, Norberto Edgar

    2009-11-01

    The starch granule proteins from 113 einkorn wheat (Triticum monococcum ssp monococcum) accessions were analyzed by acidic, polyacrylamide gel electrophoresis (A-PAGE), and two-dimensional A-PAGE x SDS-PAGE. All accessions were confirmed to contain equal amounts of two polypeptide chains corresponding to puroindoline B (Pin-B), as well as a prominent component plus a faint band corresponding to puroindoline A (Pin-A). When compared with soft-textured common wheat, "monococcum" accessions showed an increase of 3.2- and 2.7-fold in Pin-A and Pin-B levels on the starch granules, respectively. In addition, all accessions contained a novel component of the 2S super-family of seed proteins named Einkorn Trypsin Inhibitor (ETI), which was found to be encoded as a pre-protein 148 residues long. Wild-type ETI encoded by allele Eti-A(m) 1a and "valine-type" ETI encoded by allele Eti-A(m) 1b, which occurred in 107 and six einkorn accessions, respectively, were found to accumulate on starch granules as a mature protein of 121 amino acids with a hydrophobic central domain. The einkorn accessions exhibited an average SKCS index as low as -2.05 +/- 11.4, which is typical of extra-soft kernels. The total surface area of starch granules in "monococcum" wheat, as determined by visual assessments in counting chambers, was estimated at 764 mm(2)/mg of starch, and was about 1.5 times higher than that for common wheat. The results are discussed in relation to the identification of factors that cause the extra-soft texture of einkorn kernels.

  6. Acetylated adipate of retrograded starch as RS 3/4 type resistant starch.

    PubMed

    Kapelko-Żeberska, M; Zięba, T; Spychaj, R; Gryszkin, A

    2015-12-01

    This study was aimed at producing acetylated adipate of retrograded starch (ADA-R) with various degrees of substitution with functional groups and at determining the effect of esterification degree on resistance and pasting characteristics of the produced preparations. Paste was prepared from native potato starch, and afterwards frozen and defrosted. After drying and disintegration, the paste was acetylated and crosslinked using various doses of reagents. An increase in the total degree of esterification of the produced ADA-R-preparation caused an increase in its resistance to the action of amyloglucosidase. Viscosity of the paste produced from ADA-R-preparation in a wide range of acetylation degrees was increasing along with increasing crosslinking of starch. The study demonstrated that acetylated adipate of retrograded starch may be classified as a preparation of RS 3/4 type resistant starch (retrograded starch/chemically-modified starch) with good texture-forming properties. The conducted modification offers the possibility of modeling the level of resistance of the produced preparation.

  7. Association mapping of starch physicochemical properties with starch biosynthesizing genes in waxy rice (Oryza sativa L.).

    PubMed

    Xu, Feifei; Zhang, Gan; Tong, Chuan; Sun, Xiao; Corke, Harold; Sun, Mei; Bao, Jinsong

    2013-10-23

    Waxy (glutinous) rice is widely used in traditional foods, and understanding the genetic bases of its diverse physicochemical properties will contribute to breeding of new waxy rice with unique qualities. The objective of this study was to investigate the genetic relationship between the starch biosynthesis related genes and the physicochemical properties of waxy rice using association mapping. A total of 36 molecular markers representing 18 genes were used to genotype 50 waxy rice accessions for which starch properties were previously available. Most of the starch properties differed between high and low gelatinization temperature (GT) groups, whereas most traits were similar between the low-GT indica rice and low-GT japonica rice, suggesting GT was the main determinant of the starch quality of waxy rice. Association mapping indicated that the starch properties of waxy rice were mainly controlled by starch synthase IIa (SSIIa or SSII-3, a major gene responsible for the gelatinization temperature) and SSI. It was found that gene-gene interactions were also important for the genetic control of starch properties of waxy rice. This study suggests that application of the functional SNPs of SSIIa in molecular breeding may facilitate quality improvement of waxy rice.

  8. Production of resistant starch by extrusion cooking of acid-modified normal-maize starch.

    PubMed

    Hasjim, Jovin; Jane, Jay-Lin

    2009-09-01

    The objective of this study was to utilize extrusion cooking and hydrothermal treatment to produce resistant starch (RS) as an economical alternative to a batch-cooking process. A hydrothermal treatment (110 degrees C, 3 d) of batch-cooked and extruded starch samples facilitated propagation of heat-stable starch crystallites and increased the RS contents from 2.1% to 7.7% up to 17.4% determined using AOAC Method 991.43 for total dietary fiber. When starch samples were batch cooked and hydrothermally treated at a moisture content below 70%, acid-modified normal-maize starch (AMMS) produced a greater RS content than did native normal-maize starch (NMS). This was attributed to the partially hydrolyzed, smaller molecules in the AMMS, which had greater mobility and freedom than the larger molecules in the NMS. The RS contents of the batch-cooked and extruded AMMS products after the hydrothermal treatment were similar. A freezing treatment of the AMMS samples at -20 degrees C prior to the hydrothermal treatment did not increase the RS content. The DSC thermograms and the X-ray diffractograms showed that retrograded amylose and crystalline starch-lipid complex, which had melting temperatures above 100 degrees C, accounted for the RS contents.

  9. Morphological, Thermal, and Rheological Properties of Starches from Maize Mutants Deficient in Starch Synthase III.

    PubMed

    Zhu, Fan; Bertoft, Eric; Li, Guantian

    2016-08-31

    Morphological, thermal, and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ∼11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, whereas additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 °C during heating and increased it when the paste was cooled to 25 °C at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional bases responsible for these changes in physical properties of the starches are discussed. This study highlighted the relationship between SSIII and some physicochemical properties of maize starch.

  10. Amylose Content in Tuber Starch of Potato Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Extraction of starch from wheat flour by alkaline solution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Separation of starch from wheat flour with high purity is very important for the analysis of starch such as amylose and amylopectin determination by size exclusion HPLC (SE-HPLC). A procedure that extracts starch from flour by ethanol precipitation after dissolving flour in KOH and urea solution wa...

  12. Amylose Content in Tuber Starch of Wild Potato Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Starch-based Foam Composite Materials: processing and bioproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch is an abundant, biodegradable, renewable and low-cost commodity that has been explored as a replacement for petroleum-based plastics. By itself, starch is a poor replacement for plastics because of its moisture sensitivity and brittle properties. Efforts to improve starch properties and funct...

  14. Starch as a feedstock for bioproducts and packaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much progress has been achieved in developing starch-based feedstocks as a partial replacement for petroleum-based feedstocks. Although starch remains a poor direct substitute for plastics, composite starch-based materials have useful functional properties and are in commercial production as a repla...

  15. HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Adsorption of Polyethylene from Solution onto Starch Film Surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch films were prepared by jet cooking aqueous dispersions of high-amylose starch and then allowing the jet cooked dispersions to air-dry on Teflon surfaces. When the starch films were immersed in 1 % solutions of PE in 1-dodecanol, dodecane and xylene at 120º C and the solutions were allowed to...

  18. Evaluation of sorghum starch as a tablet disintegrant and binder.

    PubMed

    Deshpande, A V; Panya, L B

    1987-06-01

    The starch prepared from the seeds of Sorghum bicolor, Moench has been evaluated as a disintegrant and binder in tablets of magnesium sulphate, calcium carbonate, sulphadimidine, and chloroquine phosphate to represent soluble and insoluble inorganic and organic substances. The starch performed as well as maize starch in binding and disintegrating properties and better than acacia as binder.

  19. Effect of hydrocolloids on functional properties of navy bean starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of hydrocolloid replacement on the pasting properties of navy bean starch and on the properties of navy bean starch gels were studied. Navy bean starch was isolated, and blends were prepared with beta-glucan, guar gum, pectin and xanthan gum solutions. The total solids concentration was ...

  20. Composition, structure, physicochemical properties, and modifications of cassava starch.

    PubMed

    Zhu, Fan

    2015-05-20

    Cassava is highly tolerant to harsh climatic conditions and has great productivity on marginal lands. The supply of cassava starch, the major component of the root, is thus sustainable and cheap. This review summarizes the current knowledge of the composition, physical and chemical structures, physicochemical properties, nutritional quality, and modifications of cassava starch. Research opportunities to better understand this starch are provided.

  1. Thermoplastic starch films reinforced with talc nanoparticles.

    PubMed

    Castillo, Luciana; López, Olivia; López, Cintia; Zaritzky, Noemí; García, M Alejandra; Barbosa, Silvia; Villar, Marcelo

    2013-06-20

    Nanocomposite films of thermoplastic corn starch (TPS) with talc particles were obtained by thermo-compression in order to study the effect of filler on structure, optical, and thermal properties. Talc increased the films rigid phase, thus their cross-sections resulted more irregular. Talc preferential orientation within matrix and good compatibility between particles and TPS was observed by SEM. Slight crystalline structure changes in TPS matrix were measured by XRD and DSC, due to talc nucleating effect. Randomly dispersed talc nanoagglomerates and individual platelets were assessed by TEM. Laminar morphology and nano-sized particles allowed that nanocomposite films were optically transparent. TPS-talc films resulted heterogeneous materials, presenting domains rich in glycerol and others rich in starch. Talc incorporation higher than 3%, w/w increased softening resistance of the nanocomposites as stated by DMA. Relaxation temperatures of glycerol-rich phase shifted to higher values since talc reduces the mobility of starch chains.

  2. Retention of Cationic Starch onto Cellulose Fibres

    NASA Astrophysics Data System (ADS)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  3. Polymorphism of starch pathway genes in cassava.

    PubMed

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

    2016-12-02

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

  4. Starch Grain Distribution in Taproots of Defoliated Medicago sativa L.

    PubMed

    Habben, J E; Volenec, J J

    1990-11-01

    Defoliation of alfalfa (Medicago sativa L.) results in a cyclic pattern of starch degradation followed by reaccumulation in taproots. Characterization of changes in anatomical distribution of starch grains in taproots will aid our understanding of biochemical and physiological mechanisms involved in starch metabolism in taproots of this species. Our objectives were to determine the influence of defoliation on starch grain distribution and size variation in taproots of two alfalfa lines selected for contrasting concentrations of taproot starch. In addition, we used electron microscopy to examine the cellular environment of starch grains, and computer-based image optical analysis to determine how cross-sectional area of tissues influenced starch accumulation. Taproots of field-grown plants were sampled at defoliation and weekly thereafter over a 28-day period. Taproot segments were fixed in glutaraldehyde and prepared for either light or electron microscopy. Transverse sections were examined for number and size of starch grains and tissue areas were measured. Starch grains were located throughout bark tissues, but were confined primarily to ray parenchyma cells in wood tissues. During the first week of foliar regrowth after defoliation, starch grains in ray cells near the cambium disappeared first, while degradation of those near the center of the taproot was delayed. During the third and fourth weeks of regrowth, there was a uniform increase in number of starch grains per cell profile across the rays, but by 28 days after defoliation there were more starch grains in ray cells near the cambium than in cells near the center of the taproot (low starch line only). Bark tissues from both lines showed synchronous degradation and synthesis of starch grains that was not influenced greatly by cell location. Diameter of starch grains varied with cell location in medullary rays during rapid starch degradation, but was not influenced by cell position in bark tissues. Therefore

  5. Toward Parallel Document Clustering

    SciTech Connect

    Mogill, Jace A.; Haglin, David J.

    2011-09-01

    A key challenge to automated clustering of documents in large text corpora is the high cost of comparing documents in a multimillion dimensional document space. The Anchors Hierarchy is a fast data structure and algorithm for localizing data based on a triangle inequality obeying distance metric, the algorithm strives to minimize the number of distance calculations needed to cluster the documents into “anchors” around reference documents called “pivots”. We extend the original algorithm to increase the amount of available parallelism and consider two implementations: a complex data structure which affords efficient searching, and a simple data structure which requires repeated sorting. The sorting implementation is integrated with a text corpora “Bag of Words” program and initial performance results of end-to-end a document processing workflow are reported.

  6. Tobacco documents research methodology

    PubMed Central

    McCandless, Phyra M; Klausner, Kim; Taketa, Rachel; Yerger, Valerie B

    2011-01-01

    Tobacco documents research has developed into a thriving academic enterprise since its inception in 1995. The technology supporting tobacco documents archiving, searching and retrieval has improved greatly since that time, and consequently tobacco documents researchers have considerably more access to resources than was the case when researchers had to travel to physical archives and/or electronically search poorly and incompletely indexed documents. The authors of the papers presented in this supplement all followed the same basic research methodology. Rather than leave the reader of the supplement to read the same discussion of methods in each individual paper, presented here is an overview of the methods all authors followed. In the individual articles that follow in this supplement, the authors present the additional methodological information specific to their topics. This brief discussion also highlights technological capabilities in the Legacy Tobacco Documents Library and updates methods for organising internal tobacco documents data and findings. PMID:21504933

  7. Starch Biosynthesis in Developing Wheat Grain 1

    PubMed Central

    Keeling, Peter L.; Wood, John R.; Tyson, R. Huw; Bridges, Ian G.

    1988-01-01

    We have used 13C-labeled sugars and nuclear magnetic resonance (NMR) spectrometry to study the metabolic pathway of starch biosynthesis in developing wheat grain (Triticum aestivum cv Mardler). Our aim was to examine the extent of redistribution of 13C between carbons atoms 1 and 6 of [1-13C] or [6-13C]glucose (or fructose) incorporated into starch, and hence provide evidence for or against the involvement of triose phosphates in the metabolic pathway. Starch synthesis in the endosperm tissue was studied in two experimental systems. First, the 13C sugars were supplied to isolated endosperm tissue incubated in vitro, and second the 13C sugars were supplied in vivo to the intact plant. The 13C starch produced by the endosperm tissue of the grain was isolated and enzymically degraded to glucose using amyloglucosidase, and the distribution of 13C in all glucosyl carbons was quantified by 13C-NMR spectrometry. In all of the experiments, irrespective of the incubation time or incubation conditions, there was a similar pattern of partial (between 15 and 20%) redistribution of label between carbons 1 and 6 of glucose recovered from starch. There was no detectable increase over background 13C incidence in carbons 2 to 5. Within each experiment, the same pattern of partial redistribution of label was found in the glucosyl and fructosyl moieties of sucrose extracted from the tissue. Since it is unlikely that sucrose is present in the amyloplast, we suggest that the observed redistribution of label occurred in the cytosolic compartment of the endosperm cells and that both sucrose and starch are synthesized from a common pool of intermediates, such as hexose phosphate. We suggest that redistribution of label occurs via a cytosolic pathway cycle involving conversion of hexose phosphate to triose phosphate, interconversion of triose phosphate by triose phosphate isomerase, and resynthesis of hexose phosphate in the cytosol. A further round of triose phosphate interconversion in

  8. Deformation mechanisms of plasticized starch materials.

    PubMed

    Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P

    2014-12-19

    The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch.

  9. Slowly digestible starch from heat-moisture treated waxy potato starch: preparation, structural characteristics, and glucose response in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat-moisture treatment (HMT) was optimized to increase the formation of slowly digestible starch (SDS) in waxy potato starch, and the structural and physiological properties of this starch were investigated. A maximum SDS content (41.8%) consistent with the expected value (40.1%) was obtained after...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Structural characteristics of slowly digestible starch and resistant starch isolated from heat-moisture treated waxy potato starch.

    PubMed

    Lee, Chang Joo; Moon, Tae Wha

    2015-07-10

    The objective of this study was to investigate the structural characteristics of slowly digestible starch (SDS) and resistant starch (RS) fractions isolated from heat-moisture treated waxy potato starch. The waxy potato starch with 25.7% moisture content was heated at 120°C for 5.3h. Scanning electron micrographs of the cross sections of RS and SDS+RS fractions revealed a growth ring structure. The branch chain-length distribution of debranched amylopectin from the RS fraction had a higher proportion of long chains (DP ≥ 37) than the SDS+RS fraction. The X-ray diffraction intensities of RS and SDS+RS fractions were increased compared to the control. The SDS+RS fraction showed a lower gelatinization enthalpy than the control while the RS fraction had a higher value than the SDS+RS fraction. In this study we showed the RS fraction is composed mainly of crystalline structure and the SDS fraction consists of weak crystallites and amorphous regions.

  13. Mechanical Properties of Isotactic Polypropylene Modified with Thermoplastic Potato Starch

    NASA Astrophysics Data System (ADS)

    Knitter, M.; Dobrzyńska-Mizera, M.

    2015-05-01

    In this paper selected mechanical properties of isotactic polypropylene (iPP) modified with potato starch have been presented. Thermoplastic starch (TPS) used as a modifier in the study was produced from potato starch modified with glycerol. Isotactic polypropylene/thermoplastic potato starch composites (iPP/TPS) that contained 10, 30, 50 wt.% of modified starch were examined using dynamic mechanical-thermal analysis, static tensile, Brinell hardness, and Charpy impact test. The studies indicated a distinct influence of a filler content on the mechanical properties of composites in comparison with non-modified polypropylene.

  14. Step-reduced synthesis of starch-silver nanoparticles.

    PubMed

    Raghavendra, Gownolla Malegowd; Jung, Jeyoung; Kim, Dowan; Seo, Jongchul

    2016-05-01

    In the present process, silver nanoparticles were directly synthesized in a single step by microwave irradiation of a mixture of starch, silver nitrate, and deionized water. This is different from the commonly adopted procedure for starch-silver nanoparticle synthesis in which silver nanoparticles are synthesized by preparing a starch solution as a reaction medium first. Thus, the additional step associated with the preparation of the starch solution was eliminated. In addition, no additional reducing agent was utilized. The adopted method was facile and straight forward, affording spherical silver nanoparticles with diameter below 10nm that exhibited good antibacterial activity. Further, influence of starch on the size of the silver nanoparticles was noticed.

  15. Thermal properties of barley starch and its relation to starch characteristics.

    PubMed

    Källman, Anna; Vamadevan, Varatharajan; Bertoft, Eric; Koch, Kristine; Seetharaman, Koushik; Åman, Per; Andersson, Roger

    2015-11-01

    Amylopectin fine structure and starch gelatinization and retrogradation were studied in 10 different barley cultivars/breeding lines. Clusters and building blocks were isolated from the amylopectin by α-amylase from Bacillus amyloliquefaciens and their structure was characterized. Gelatinization was studied at a starch:water ratio of 1:3, and retrogradation was studied on gelatinized starch at starch:water ratio of 1:2, by differential scanning calorimetry. Three barley cultivars/breeding lines possessed the amo1 mutation, and they all had a lower molar proportion of chains of DP ≥38 and more of large building blocks. The amo1 mutation also resulted in a higher gelatinization temperature and a broader temperature interval during gelatinization. Overall, small clusters with a dense structure resulted in a higher gelatinization temperature while retrogradation was promoted by short chains in the amylopectin and many large building blocks.

  16. Effects of homoeologous wheat starch synthase IIa genes on starch properties.

    PubMed

    Shimbata, Tomoya; Ai, Yongfeng; Fujita, Masaya; Inokuma, Takayuki; Vrinten, Patricia; Sunohara, Ai; Saito, Mika; Takiya, Toshiyuki; Jane, Jay-lin; Nakamura, Toshiki

    2012-12-05

    Near-isogenic lines (NILs) of the eight haplotypes of starch synthase IIa (SSIIa) were used to analyze the effects of SSIIa gene dosage on branch chain length, gelatinization, pasting, retrogradation, and enzymatic hydrolysis of starches. Compared to wild-type, the amylopectin of lines missing one or more active SSIIa enzymes had increases in the proportion of short branch chains (DP6-10) and decreases in midlength chains (DP11-24), and the size of these differences depended on the dosage of active SSIIa enzymes. Of the three loci, SSIIa-A1 had the smallest contribution to amylopectin structure and SSIIa-B1 the largest. The different effects of the three SSIIa enzymes on starch properties were also seen in gelatinization, retrogradation, pasting, and enzymatic hydrolysis properties. Such differences in starch properties might be useful in influencing the texture and shelf life of food products.

  17. Starch nanocrystals and starch nanoparticles from waxy maize as nanoreinforcement: A comparative study.

    PubMed

    Bel Haaj, Sihem; Thielemans, Wim; Magnin, Albert; Boufi, Sami

    2016-06-05

    The morphological, structural and thermal behavior of starch nanocrystals (SNCs) extracted from waxy maize starch through an acid hydrolysis were compared with those of starch nanoparticles (SNPs) obtained through an ultrasound treatment starting from the same waxy maize starch. The SNPs were found to be completely amorphous, slightly smaller and had no surface charge, whereas the SNCs had the expected platelet-like morphology with a negative surface charge introduced as a result of the use of sulphuric acid in the acid hydrolysis step. SNCs also showed better thermal stability than SNPs in the presence of water. As a result of their platelet-like morphology, the SNCs performed better in reinforcing a polymer film. On the other hand, SNPs reduced the transparency of the nanocomposite films to a lesser extent than the SNCs due to their smaller size.

  18. Effects of chemical modification on in vitro rate and extent of food starch digestion: an attempt to discover a slowly digested starch.

    PubMed

    Wolf, B W; Bauer, L L; Fahey, G C

    1999-10-01

    Differences in glycemic and insulinemic responses to dietary starch are directly related to the rate of starch digestion. Chemical modification of starch may allow for the production of a slowly digested starch that could be used for the treatment of certain medical modalities. An in vitro method was utilized to evaluate the effects of chemical modification on the rate and extent of raw and cooked starch digestion. The extent of starch digestion was significantly reduced by dextrinization, etherification, and oxidation. However, the rate of starch digestion was not significantly affected by chemical modification. For most modified starches, as the degree of modification increased, the extent of digestion decreased, suggesting an increase in the amount of resistant starch. The results of this study suggest that chemically modified starch has a metabolizable energy value of <16.7 kJ/g. Chemically modified starch ingredients may serve as a good source of resistant starch in human and animal diets.

  19. Project LEAF Documents

    EPA Pesticide Factsheets

    Project LEAF has a goal of educating farmworkers about how to reduce pesticide exposure to their families from pesticide residues they may be inadvertently taking home on their clothing, etc. Find outreach materials.

  20. System Documentation Manual.

    ERIC Educational Resources Information Center

    Semmel, Melvyn I.; Olson, Jerry

    The document is a system documentation manual of the Computer-Assisted Teacher Training System (CATTS) developed by the Center for Innovation in Teaching the Handicapped (Indiana University). CATTS is characterized as a system capable of providing continuous, instantaneous, and/or delayed feedback of relevant teacher-student interaction data to a…

  1. IDC System Specification Document.

    SciTech Connect

    Clifford, David J.

    2014-12-01

    This document contains the system specifications derived to satisfy the system requirements found in the IDC System Requirements Document for the IDC Reengineering Phase 2 project. Revisions Version Date Author/Team Revision Description Authorized by V1.0 12/2014 IDC Reengineering Project Team Initial delivery M. Harris

  2. Document Design: Part 1.

    ERIC Educational Resources Information Center

    Andrews, Deborah C., Ed.; Dyrud, Marilyn, Ed.

    1996-01-01

    Presents four articles that provide suggestions for teaching document design: (1) "Teaching the Rhetoric of Document Design" (Michael J. Hassett); (2) "Teaching by Example: Suggestions for Assignment Design" (Marilyn A. Dyrud); (3) "Teaching the Page as a Visual Unit" (Bill Hart-Davidson); and (4) "Designing a…

  3. NASA Software Documentation Standard

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The NASA Software Documentation Standard (hereinafter referred to as "Standard") is designed to support the documentation of all software developed for NASA; its goal is to provide a framework and model for recording the essential information needed throughout the development life cycle and maintenance of a software system. The NASA Software Documentation Standard can be applied to the documentation of all NASA software. The Standard is limited to documentation format and content requirements. It does not mandate specific management, engineering, or assurance standards or techniques. This Standard defines the format and content of documentation for software acquisition, development, and sustaining engineering. Format requirements address where information shall be recorded and content requirements address what information shall be recorded. This Standard provides a framework to allow consistency of documentation across NASA and visibility into the completeness of project documentation. The basic framework consists of four major sections (or volumes). The Management Plan contains all planning and business aspects of a software project, including engineering and assurance planning. The Product Specification contains all technical engineering information, including software requirements and design. The Assurance and Test Procedures contains all technical assurance information, including Test, Quality Assurance (QA), and Verification and Validation (V&V). The Management, Engineering, and Assurance Reports is the library and/or listing of all project reports.

  4. Water dynamics and retrogradation of ultrahigh pressurized wheat starch.

    PubMed

    Doona, Christopher J; Feeherry, Florence E; Baik, Moo-Yeol

    2006-09-06

    The water dynamics and retrogradation kinetics behavior of gelatinized wheat starch by either ultrahigh pressure (UHP) processing or heat are investigated. Wheat starch completely gelatinized in the condition of 90, 000 psi at 25 degrees C for 30 min (pressurized gel) or 100 degrees C for 30 min (heated gel). The physical properties of the wheat starches were characterized in terms of proton relaxation times (T2 times) measured using time-domain nuclear magnetic resonance spectroscopy and evaluated using commercially available continuous distribution modeling software. Different T2 distributions in both micro- and millisecond ranges between pressurized and heated wheat starch gels suggest distinctively different water dynamics between pressurized and heated wheat starch gels. Smaller water self-diffusion coefficients were observed for pressurized wheat starch gels and are indicative of more restricted translational proton mobility than is observed with heated wheat starch gels. The physical characteristics associated with changes taking place during retrogradation were evaluated using melting curves obtained with differential scanning calorimetry. Less retrogradation was observed in pressurized wheat starch, and it may be related to a smaller quantity of freezable water in pressurized wheat starch. Starches comprise a major constituent of many foods proposed for commercial potential using UHP, and the present results furnish insight into the effect of UHP on starch gelatinization and the mechanism of retrogradation during storage.

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

    PubMed

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

    2010-02-01

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

  6. Resistant Starch: Promise for Improving Human Health12

    PubMed Central

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

    2013-01-01

    Ongoing research to develop digestion-resistant starch for human health promotion integrates the disciplines of starch chemistry, agronomy, analytical chemistry, food science, nutrition, pathology, and microbiology. The objectives of this research include identifying components of starch structure that confer digestion resistance, developing novel plants and starches, and modifying foods to incorporate these starches. Furthermore, recent and ongoing studies address the impact of digestion-resistant starches on the prevention and control of chronic human diseases, including diabetes, colon cancer, and obesity. This review provides a transdisciplinary overview of this field, including a description of types of resistant starches; factors in plants that affect digestion resistance; methods for starch analysis; challenges in developing food products with resistant starches; mammalian intestinal and gut bacterial metabolism; potential effects on gut microbiota; and impacts and mechanisms for the prevention and control of colon cancer, diabetes, and obesity. Although this has been an active area of research and considerable progress has been made, many questions regarding how to best use digestion-resistant starches in human diets for disease prevention must be answered before the full potential of resistant starches can be realized. PMID:24228189

  7. Prospects for increasing starch and sucrose yields for bioethanol production.

    PubMed

    Smith, Alison M

    2008-05-01

    In the short term, the production of bioethanol as a liquid transport fuel is almost entirely dependent on starch and sugars from existing food crops. The sustainability of this industry would be enhanced by increases in the yield of starch/sugar per hectare without further inputs into the crops concerned. Efforts to achieve increased yields of starch over the last three decades, in particular via manipulation of the enzyme ADPglucose pyrophosphorylase, have met with limited success. Other approaches have included manipulation of carbon partitioning within storage organs in favour of starch synthesis, and attempts to manipulate source-sink relationships. Some of the most promising results so far have come from manipulations that increase the availability of ATP for starch synthesis. Future options for achieving increased starch contents could include manipulation of starch degradation in organs in which starch turnover is occurring, and introduction of starch synthesis into the cytosol. Sucrose accumulation is much less well understood than starch synthesis, but recent results from research on sugar cane suggest that total sugar content can be greatly increased by conversion of sucrose into a non-metabolizable isomer. A better understanding of carbohydrate storage and turnover in relation to carbon assimilation and plant growth is required, both for improvement of starch and sugar crops and for attempts to increase biomass production in second-generation biofuel crops.

  8. Evaluation of a high throughput starch analysis optimised for wood.

    PubMed

    Bellasio, Chandra; Fini, Alessio; Ferrini, Francesco

    2014-01-01

    Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11) was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood) of four species (coniferous and flowering plants). The optimised protocol proved to be remarkably precise and accurate (3%), suitable for a high throughput routine analysis (35 samples a day) of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes.

  9. Pressure-induced gelatinization of starch in excess water.

    PubMed

    Vallons, Katleen J R; Ryan, Liam A M; Arendt, Elke K

    2014-01-01

    High pressure processing is a promising non-thermal technology for the development of fresh-like, shelf-stable foods. The effect of high pressure on starch has been explored by many researchers using a wide range of techniques. In general, heat and pressure have similar effects: if sufficiently high, they both induce gelatinization of starch in excess water, resulting in a transition of the native granular structure to a starch paste or gel. However, there are significant differences in the structural and rheological properties between heated and pressurized starches. These differences offer benefits with respect to new product development. However, in order to implement high-pressure technology to starch and starch-containing products, a good understanding of the mechanism of pressure-induced gelatinization is necessary. Studies that are published in this area are reviewed, and the similarities and differences between starches gelatinized by pressure and by temperature are summarized.

  10. Characterization of normal and waxy corn starch for bioethanol production.

    PubMed

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

    2013-01-16

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

  11. Drying and cracking mechanisms in a starch slurry.

    PubMed

    Goehring, Lucas

    2009-09-01

    Starch-water slurries are commonly used to study fracture dynamics. Drying starch cakes benefit from being simple, economical, and reproducible systems, and have been used to model desiccation fracture in soils, thin-film fracture in paint, and columnar joints in lava. In this paper, the physical properties of starch-water mixtures are studied, and used to interpret and develop a multiphase transport model of drying. Starch cakes are observed to have a nonlinear elastic modulus, and a desiccation strain that is comparable to that generated by their maximum achievable capillary pressure. It is shown that a large material porosity is divided between pore spaces between starch grains, and pores within starch grains. This division of pore space leads to two distinct drying regimes, controlled by liquid and vapor transport of water, respectively. The relatively unique ability for drying starch to generate columnar fracture patterns is shown to be linked to the unusually strong separation of these two transport mechanisms.

  12. Sedimentation field flow fractionation monitoring of rice starch amylolysis.

    PubMed

    Morelon, X; Battu, S; Salesse, C; Begaud-Grimaud, G; Cledat, D; Cardot, P J P

    2005-11-04

    Enzymatic starch granule hydrolysis is one of the most important reactions in many industrial processes. In this work, we investigated the capacity of SdFFF to monitor the native rice starch amylolysis. In order to determine if fractogram changes observed were correlated to granule biophysical modifications which occurred during amylolysis, SdFFF separation was associated with particle size distribution analysis. The results showed that SdFFF is an effective tool to monitor amylolysis of native rice starch. SdFFF analysis was a rapid (less than 10 min), simple and specific method to follow biophysical modifications of starch granules. These results suggested many different applications such as testing series of enzymes and starches. By using sub-population sorting, SdFFF could be also used to better understand starch hydrolysis mechanisms or starch granule structure.

  13. Drying and cracking mechanisms in a starch slurry

    NASA Astrophysics Data System (ADS)

    Goehring, Lucas

    2009-09-01

    Starch-water slurries are commonly used to study fracture dynamics. Drying starch cakes benefit from being simple, economical, and reproducible systems, and have been used to model desiccation fracture in soils, thin-film fracture in paint, and columnar joints in lava. In this paper, the physical properties of starch-water mixtures are studied, and used to interpret and develop a multiphase transport model of drying. Starch cakes are observed to have a nonlinear elastic modulus, and a desiccation strain that is comparable to that generated by their maximum achievable capillary pressure. It is shown that a large material porosity is divided between pore spaces between starch grains, and pores within starch grains. This division of pore space leads to two distinct drying regimes, controlled by liquid and vapor transport of water, respectively. The relatively unique ability for drying starch to generate columnar fracture patterns is shown to be linked to the unusually strong separation of these two transport mechanisms.

  14. Starch-lipid composites containing cimmamaldehyde

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The formulation of a starch-lipid composite containing cinnamaldehyde as antimicrobial agent has been studied. Cinnamaldehyde was incorporated as an emulsion using Acetem 90-50K as a carrier and Tween 60 as the emulsifier. Oil in water emulsions were prepared by direct emulsification using a high sh...

  15. Breadmaking with zein-starch dough

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mixtures of maize prolamins (zein) and starch form a cohesive, extensible, viscoelastic dough when mixed above zein's glass transition temperature, e.g. at 35-40 degrees Celsius. Although this phenomenon has long been known, it has not yet been successfully used for gluten-free breadmaking. We fou...

  16. Iodine catalyzed acetylation of starch and cellulose

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Reactions of Starch in Ionic Liquids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We found that starches are found to be soluble at 80 ºC in ionic liquids such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-butyl-3-methylimidazolium dicyanamide (BMIMdca) in concentration up to 10% (w/w). Higher concentrations of biopolymers in these novel solvents resulted in solutions w...

  18. Resistant starch in food: a review.

    PubMed

    Raigond, Pinky; Ezekiel, Rajarathnam; Raigond, Baswaraj

    2015-08-15

    The nutritional property of starch is related to its rate and extent of digestion and absorption in the small intestine. For nutritional purposes, starch is classified as rapidly available, slowly available and resistant starch (RS). The exact underlying mechanism of relative resistance of starch granules is complicated because those factors are often interconnected. The content of RS in food is highly influenced by food preparation manner and processing techniques. Physical or chemical treatments also alter the level of RS in a food. Commercial preparations of RS are now available and can be added to foods as an ingredient for lowering the calorific value and improving textural and organoleptic characteristics along with increasing the amount of dietary fiber. RS has assumed great importance owing to its unique functional properties and health benefits. The beneficial effects of RS include glycemic control and control of fasting plasma triglyceride and cholesterol levels and absorption of minerals. This review attempts to analyze the information published, especially in the recent past, on classification, structure, properties, applications and health benefits of RS.

  19. Starch digestion and absorption in nonruminants.

    PubMed

    Gray, G M

    1992-01-01

    Starch digestion and absorption is augmented appreciably by physical processing of grain or legume and by heating to 100 degrees C for several minutes before its ingestion. Starch, a polysaccharide composed of alpha 1,4-linked glucose units (amylose) and alpha 1,4-1,6-linked branched structure (amylopectin), is cleaved in the duodenal cavity by secreted pancreatic alpha-amylase to a disaccharide (maltose), trisaccharide (maltotriose), and branched alpha-dextrins. These final oligosaccharides are hydrolyzed efficiently by complimentary action of three integral brush border enzymes at the intestinal surface: glucoamylase (maltase-glucoamylase, amyloglucosidase), sucrase (maltase-sucrase) and alpha-dextrinase (isomaltase). The final monosaccharide glucose product is then cotransported into the enterocyte along with Na+ by a specific brush border 75-kDa transport protein in the rate-limiting step for overall starch assimilation. By virtue of this sequential luminal and membrane digestion followed by glucose transport, starch is assimilated in a very efficient manner in nonruminants.

  20. Novel products from starch based feedstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There has been progress in the utilization of starch as a partial replacement for petroleum based plastics, but it remains a poor direct substitute for plastics, and a moderate one for composites. Our research focuses on using polymers produced from direct fermentation such as poly(lactic acid) or m...

  1. Characterization of Proteins in Filtrate from Biodegradation of Crop Residue

    NASA Technical Reports Server (NTRS)

    Horton, Wileatha; Trotman, A. A.

    1997-01-01

    Biodegradation of plant biomass is a feasible path for transformation of crop residue and recycling of nutrients for crop growth. The need to model the effects of factors associated with recycling of plant biomass resulting from hydroponic sweet potato production has led to investigation of natural soil isolates with the capacity for starch hydrolysis. This study sought to use nondenaturing gel electrophoresis to characterize the proteins present in filtered effluent from bioreactors seeded with starch hydrolyzing bacterial culture used in the biodegradation of senesced sweet potato biomass. The study determined the relative molecular weight of proteins in sampled effluent and the protein banding pattern was characterized. The protein profiles of effluent were similar for samples taken from independent runs under similar conditions of starch hydrolysis. The method can be used as a quality control tool for confirmation of starch hydrolysis of crop biomass. In addition, this method will allow monitoring for presence of contaminants within the system-protein profiles indicative of new enzymes in the bioreactors.

  2. PROTEIN TARGETING TO STARCH is required for localising GRANULE-BOUND STARCH SYNTHASE to starch granules and for normal amylose synthesis in Arabidopsis.

    PubMed

    Seung, David; Soyk, Sebastian; Coiro, Mario; Maier, Benjamin A; Eicke, Simona; Zeeman, Samuel C

    2015-02-01

    The domestication of starch crops underpinned the development of human civilisation, yet we still do not fully understand how plants make starch. Starch is composed of glucose polymers that are branched (amylopectin) or linear (amylose). The amount of amylose strongly influences the physico-chemical behaviour of starchy foods during cooking and of starch mixtures in non-food manufacturing processes. The GRANULE-BOUND STARCH SYNTHASE (GBSS) is the glucosyltransferase specifically responsible for elongating amylose polymers and was the only protein known to be required for its biosynthesis. Here, we demonstrate that PROTEIN TARGETING TO STARCH (PTST) is also specifically required for amylose synthesis in Arabidopsis. PTST is a plastidial protein possessing an N-terminal coiled coil domain and a C-terminal carbohydrate binding module (CBM). We discovered that Arabidopsis ptst mutants synthesise amylose-free starch and are phenotypically similar to mutants lacking GBSS. Analysis of granule-bound proteins showed a dramatic reduction of GBSS protein in ptst mutant starch granules. Pull-down assays with recombinant proteins in vitro, as well as immunoprecipitation assays in planta, revealed that GBSS physically interacts with PTST via a coiled coil. Furthermore, we show that the CBM domain of PTST, which mediates its interaction with starch granules, is also required for correct GBSS localisation. Fluorescently tagged Arabidopsis GBSS, expressed either in tobacco or Arabidopsis leaves, required the presence of Arabidopsis PTST to localise to starch granules. Mutation of the CBM of PTST caused GBSS to remain in the plastid stroma. PTST fulfils a previously unknown function in targeting GBSS to starch. This sheds new light on the importance of targeting biosynthetic enzymes to sub-cellular sites where their action is required. Importantly, PTST represents a promising new gene target for the biotechnological modification of starch composition, as it is exclusively involved

  3. Functional characterization of alpha-glucan,water dikinase, the starch phosphorylating enzyme.

    PubMed Central

    Mikkelsen, René; Baunsgaard, Lone; Blennow, Andreas

    2004-01-01

    GWD (alpha-glucan,water dikinase) is the enzyme that catalyses the phosphorylation of starch by a dikinase-type reaction in which the beta-phosphate of ATP is transferred to either the C-6 or the C-3 position of the glycosyl residue of amylopectin. GWD shows similarity in both sequence and reaction mechanism to bacterial PPS (pyruvate,water dikinase) and PPDK (pyruvate,phosphate dikinase). Amino acid sequence alignments identified a conserved histidine residue located in the putative phosphohistidine domain of potato GWD. Site-directed mutagenesis of this histidine residue resulted in an inactive enzyme and loss of autophosphorylation. Native GWD is a homodimer and shows a strict requirement for the presence of alpha-1,6 branch points in its polyglucan substrate, and exhibits a sharp 20-fold increase in activity when the degree of polymerization is increased from 27.8 to 29.5. In spite of the high variability in the degree of starch phosphorylation, GWD proteins are ubiquitous in plants. The overall reaction mechanism of GWD is similar to that of PPS and PPDK, but the GWD family appears to have arisen after divergence of the plant kingdom. The nucleotide-binding domain of GWD exhibits a closer phylogenetic relationship to prokaryotic PPSs than to PPDKs. PMID:14525539

  4. Thermostability enhancement and change in starch hydrolysis profile of the maltohexaose-forming amylase of Bacillus stearothermophilus US100 strain

    PubMed Central

    Ben Ali, Mamdouh; Khemakhem, Bassem; Robert, Xavier; Haser, Richard; Bejar, Samir

    2005-01-01

    The implications of Asn315 and Val450 in the atypical starch hydrolysis profile of Bacillus stearothermophilus Amy (α-amylase) US100 have been suggested previously [Ben Ali, Mhiri, Mezghani and Bejar (2001) Enzyme Microb. Tech. 28, 537–542]. In order to confirm this hypothesis, three mutants were generated. Of these two have a single mutation, N315D or V450G, whereas the third contains both mutations. Analysis of the starch breakdown-profile of these three mutants, as well as of the wild-type, allowed us to conclude that each single mutation induces a small variation in the hydrolysis product. However, the major end product produced by the double mutant shifts from maltopentaose/maltohexaose to maltose/maltotriose, confirming the involvement of these two residues in starch hydrolysis. The superimposition of AmyUS100 model with that of Bacillus licheniformis shows in AmyUS100 an additional loop containing residues Ile214 and Gly215. Remarkably, the deletion of these two residues increases the half-life at 100 °C from 15 min to approx. 70 min. Moreover, this engineered amylase requires less calcium, 25 p.p.m. instead of 100 p.p.m., to reach maximal thermostability. PMID:16197365

  5. C-type starch from high-amylose rice resistant starch granules modified by antisense RNA inhibition of starch branching enzyme.

    PubMed

    Wei, Cunxu; Xu, Bin; Qin, Fengling; Yu, Huaguang; Chen, Chong; Meng, Xianglen; Zhu, Lijia; Wang, Youping; Gu, Minghong; Liu, Qiaoquan

    2010-06-23

    High-amylose starch is a source of resistant starch (RS) which has a great benefit on human health. A transgenic rice line (TRS) enriched amylose and RS had been developed by antisense RNA inhibition of starch branching enzymes. In this study, the native starch granules were isolated from TRS grains as well as the wild type, and their crystalline type was carefully investigated before and after acid hydrolysis. In high-amylose TRS rice, the C-type starch, which might result from the combination of both A-type and B-type starch, was observed and subsequently confirmed by multiple physical techniques, including X-ray powder diffraction, solid-state nuclear magnetic resonance, and Fourier transform infrared. Moreover, the change of starch crystalline structure from C- to B-type during acid hydrolysis was also observed in this RS-rich rice. These data could add to our understanding of not only the polymorph structure of cereal starch but also why high-amylose starch is more resistant to digestion.

  6. Continuous enzymatic liquefaction of starch for saccharification.

    PubMed

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

    1982-11-01

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

  7. Continuous enzymatic liquefaction of starch for saccharification

    SciTech Connect

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

    1982-01-01

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

  8. Deficiency of Starch Synthase IIIa and IVb Alters Starch Granule Morphology from Polyhedral to Spherical in Rice Endosperm1

    PubMed Central

    Toyosawa, Yoshiko; Kawagoe, Yasushi; Matsushima, Ryo; Ogawa, Masahiro; Fukuda, Masako; Kumamaru, Toshihiro; Okazaki, Yozo; Kusano, Miyako; Saito, Kazuki; Toyooka, Kiminori; Sato, Mayuko; Ai, Yongfeng; Fujita, Naoko

    2016-01-01

    Starch granule morphology differs markedly among plant species. However, the mechanisms controlling starch granule morphology have not been elucidated. Rice (Oryza sativa) endosperm produces characteristic compound-type granules containing dozens of polyhedral starch granules within an amyloplast. Some other cereal species produce simple-type granules, in which only one starch granule is present per amyloplast. A double mutant rice deficient in the starch synthase (SS) genes SSIIIa and SSIVb (ss3a ss4b) produced spherical starch granules, whereas the parental single mutants produced polyhedral starch granules similar to the wild type. The ss3a ss4b amyloplasts contained compound-type starch granules during early developmental stages, and spherical granules were separated from each other during subsequent amyloplast development and seed dehydration. Analysis of glucan chain length distribution identified overlapping roles for SSIIIa and SSIVb in amylopectin chain synthesis, with a degree of polymerization of 42 or greater. Confocal fluorescence microscopy and immunoelectron microscopy of wild-type developing rice seeds revealed that the majority of SSIVb was localized between starch granules. Therefore, we propose that SSIIIa and SSIVb have crucial roles in determining starch granule morphology and in maintaining the amyloplast envelope structure. We present a model of spherical starch granule production. PMID:26747287

  9. Degradation of Glucan Primers in the Absence of Starch Synthase 4 Disrupts Starch Granule Initiation in Arabidopsis*

    PubMed Central

    Lu, Kuan-Jen; Stettler, Michaela; Streb, Sebastian

    2016-01-01

    Arabidopsis leaf chloroplasts typically contain five to seven semicrystalline starch granules. It is not understood how the synthesis of each granule is initiated or how starch granule number is determined within each chloroplast. An Arabidopsis mutant lacking the glucosyl-transferase, STARCH SYNTHASE 4 (SS4) is impaired in its ability to initiate starch granules; its chloroplasts rarely contain more than one large granule, and the plants have a pale appearance and reduced growth. Here we report that the chloroplastic α-amylase AMY3, a starch-degrading enzyme, interferes with granule initiation in the ss4 mutant background. The amy3 single mutant is similar in phenotype to the wild type under normal growth conditions, with comparable numbers of starch granules per chloroplast. Interestingly, the ss4 mutant displays a pleiotropic reduction in the activity of AMY3. Remarkably, complete abolition of AMY3 (in the amy3 ss4 double mutant) increases the number of starch granules produced in each chloroplast, suppresses the pale phenotype of ss4, and nearly restores normal growth. The amy3 mutation also restores starch synthesis in the ss3 ss4 double mutant, which lacks STARCH SYNTHASE 3 (SS3) in addition to SS4. The ss3 ss4 line is unable to initiate any starch granules and is thus starchless. We suggest that SS4 plays a key role in granule initiation, allowing it to proceed in a way that avoids premature degradation of primers by starch hydrolases, such as AMY3. PMID:27458017

  10. Hydrolysis of native and heat-treated starches at sub-gelatinization temperature using granular starch hydrolyzing enzyme.

    PubMed

    Uthumporn, U; Shariffa, Y N; Karim, A A

    2012-03-01

    The effect of heat treatment below the gelatinization temperature on the susceptibility of corn, mung bean, sago, and potato starches towards granular starch hydrolysis (35°C) was investigated. Starches were hydrolyzed in granular state and after heat treatment (50°C for 30 min) by using granular starch hydrolyzing enzyme for 24 h. Hydrolyzed heat-treated starches showed a significant increase in the percentage of dextrose equivalent compared to native starches, respectively, with corn 53% to 56%, mung bean 36% to 47%, sago 15% to 26%, and potato 12% to 15%. Scanning electron microscopy micrographs showed the presence of more porous granules and surface erosion in heat-treated starch compared to native starch. X-ray analysis showed no changes but with sharper peaks for all the starches, suggested that hydrolysis occurred on the amorphous region. The amylose content and swelling power of heat-treated starches was markedly altered after hydrolysis. Evidently, this enzyme was able to hydrolyze granular starches and heat treatment before hydrolysis significantly increased the degree of hydrolysis.

  11. NACA documents database project

    NASA Technical Reports Server (NTRS)

    Smith, Ruth S.

    1991-01-01

    The plan to get all the National Advisory Committee on Aeronautics (NACA) collection online, with quality records, led to the NACA Documents Data base Project. The project has a two fold purpose: (1) to develop the definitive bibliography of NACA produced and/or held documents; and (2) to make that bibliography and the associated documents available to the aerospace community. This study supports the first objective by providing an analysis of the NACA collection and its bibliographic records, and supports the second objective by defining the NACA archive and recommending methodologies for meeting the project objectives.

  12. Carbon transitions from either Calvin cycle or transitory starch to heteroglycans as revealed by (14) C-labeling experiments using protoplasts from Arabidopsis.

    PubMed

    Malinova, Irina; Steup, Martin; Fettke, Joerg

    2013-09-01

    Plants metabolize transitory starch by precisely coordinated plastidial and cytosolic processes. The latter appear to include the action of water-soluble heteroglycans (SHGin ) whose monosaccharide pattern is similar to that of apoplastic glycans (SHGex ) but, unlike SHGex , SHGin strongly interacts with glucosyl transferases. In this study, we analyzed starch metabolism using mesophyll protoplasts from wild-type plants and two knock-out mutants [deficient in the cytosolic transglucosidase, disproportionating isoenzyme 2 (DPE2) or the plastidial phosphoglucomutase (PGM1)] from Arabidopsis thaliana. Protoplasts prelabeled by photosynthetic (14) CO2 fixation were transferred to an unlabeled medium and were darkened or illuminated. Carbon transitions from the Calvin cycle or from starch to both SHGin and SHGex were analyzed. In illuminated protoplasts, starch turn-over was undetectable but darkened protoplasts continuously degraded starch. During illumination, neither the total (14) C content nor the labeling patterns of the sugar residues of SHGin were significantly altered but both the total amount and the labeling of the constituents of SHGex increased with time. In darkened protoplasts, the (14) C-content of most of the sugar residues of SHGin transiently and strongly increased and then declined. This effect was not observed in any SHGex constituent. In darkened DPE2-deficient protoplasts, none of the SHGin constituents exhibited an essential transient increase in labeling. In contrast, some residues of SHGin from the PGM1 mutant exhibited a transient increase in label but this effect significantly differed from that of the wild type. Two conclusions are reached: first, SHGin and SHGex exert different metabolic functions and second, SHGin is directly involved in starch degradation.

  13. Development of oxidised and heat-moisture treated potato starch film.

    PubMed

    Zavareze, Elessandra da Rosa; Pinto, Vânia Zanella; Klein, Bruna; El Halal, Shanise Lisie Mello; Elias, Moacir Cardoso; Prentice-Hernández, Carlos; Dias, Alvaro Renato Guerra

    2012-05-01

    This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.

  14. Effect of maize starch concentration in the diet on starch and cell wall digestion in the dairy cow.

    PubMed

    van Vuuren, A M; Hindle, V A; Klop, A; Cone, J W

    2010-06-01

    An in vivo experiment was performed to determine the effect of level of maize starch in the diet on digestion and site of digestion of organic matter, starch and neutral detergent fibre (NDF). In a repeated change-over design experiment, three cows fitted with a rumen cannula and T-piece cannulae in duodenum and ileum received a low-starch (12% of ration dry matter) and a high-starch (33% of ration dry matter) diet. Starch level was increased by exchanging dried sugar beet pulp by ground maize. After a 2-week adaptation period, feed intake, rumen fermentation parameters (in vivo and in situ), intestinal flows, faecal excretion of organic matter, starch and NDF were estimated. When the high-starch diet was fed, dry matter intake was higher (19.0 kg/day vs. 17.8 kg/day), and total tract digestibility of organic matter, starch and NDF was lower when the low-starch diet was fed. Maize starch concentration had no significant effect on rumen pH and volatile fatty acid concentration nor on the site of digestion of organic matter and starch and rate of passage of ytterbium-labelled forage. On the high-starch diet, an extra 1.3 kg of maize starch was supplied at the duodenum in relation to the low-starch diet, but only an extra 0.3 kg of starch was digested in the small intestine. Digestion of NDF was only apparent in the rumen and was lower on the high-starch diet than on the low-starch diet, mainly attributed to the reduction in sugar beet pulp in the high-starch diet. It was concluded that without the correction for the reduction in NDF digestion in the rumen, the extra supply of glucogenic (glucose and propionic acid) and ketogenic nutrients (acetic and butyric acid) by supplemented starch will be overestimated. The mechanisms responsible for these effects need to be addressed in feed evaluation.

  15. Impact of dry heating on physicochemical properties of corn starch and lysine mixture.

    PubMed

    Ji, Ying; Yu, Jicheng; Xu, Yongbin; Zhang, Yinghui

    2016-10-01

    Corn starch was modified with lysine by dry heat treatment and to investigate how they can affect the pasting and structural properties of the treated starches. Dry heating with lysine reduced the pasting temperature and resulting in viscosity increase. The particle size of heated starch-lysine mixture increased, suggesting that starch granules were cross-linked to lysine. After dry heating, the onset temperature, peak temperature and conclusion temperature of corn starch-lysine mixture were lower than those of other starches. The degree of crystallinity decreased for the starch after dry heat treatment while these heated starch samples still have the same X-ray diffraction types as the original starch.

  16. Transportation System Requirements Document

    SciTech Connect

    Not Available

    1993-09-01

    This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification.

  17. Geochemistry Technical Basis Document

    SciTech Connect

    Benedict, Jr., F. Christopher; Rose, Timothy P.; Thomas, James M.; Waddell, Richard; Jacobson, Roger

    2003-12-01

    This document presents a methodology whereby geochemical data can more effectively contribute to the development , calibration, and verification of groundwater flow and slute transport models for the Underground Test Area (UGTA) Project.

  18. Microbiological Production of Surfactant from Agricultural Residuals for IOR Application

    SciTech Connect

    Bala, Greg Alan; Bruhn, Debby Fox; Fox, Sandra Lynn; Noah, Karl Scott; Thompson, David Neal

    2002-04-01

    Utilization of surfactants for improved oil recovery (IOR) is an accepted technique with high potential. However, technology application is frequently limited by cost. Biosurfactants (surface-active molecules produced by microorganisms) are not widely utilized in the petroleum industry due to high production costs associated with use of expensive substrates and inefficient product recovery methods. The economics of biosurfactant production could be significantly impacted through use of media optimization and application of inexpensive carbon substrates such as agricultural process residuals. Utilization of biosurfactants produced from agricultural residuals may 1) result in an economic advantage for surfactant production and technology application, and 2) convert a substantial agricultural waste stream to a value-added product for IOR. A biosurfactant with high potential for use is surfactin, a lipopeptide biosurfactant, produced by Bacillus subtilis. Reported here is the production and potential IOR utilization of surfactin produced by Bacillus subtilis (American Type Culture Collection (ATCC) 21332) from starch-based media. Production of surfactants from microbiological growth media based on simple sugars, chemically pure starch medium, simulated liquid and solid potato-process effluent media, a commercially prepared potato starch in mineral salts, and process effluent from a potato processor is discussed. Additionally, the effect of chemical and physical pretreatments on starchy feedstocks is discussed.

  19. Impact of full range of amylose contents on the architecture of starch granules.

    PubMed

    Goldstein, Avi; Annor, George; Putaux, Jean-Luc; Hebelstrup, Kim H; Blennow, Andreas; Bertoft, Eric

    2016-08-01

    The effects of amylose deposition on crystalline regions of barley starch granules were studied in granules containing zero to 99.1% amylose using "waxy" (WBS, 0% amylose), normal (NBS, 18% amylose) and amylose-only barley lines (AOS, 99.1% amylose). The effects were probed after hydrolysis of amorphous regions of starch granules in dilute HCl generating lintners, which typically represent the crystalline lamella of starch granules. Compared to NBS and WBS, AOS granules exhibited an irregular, multilobular morphology with a rough surface texture. AOS displayed lower rates of acid hydrolysis than WBS, and AOS reached a plateau at ∼45wt% acid hydrolysis. High-performance anion-exchange chromatography of lintners at equivalent levels of hydrolysis (45wt%) revealed the average degree of polymerization (DP) of AOS lintners was 21, substantially smaller than that of NBS and WBS (DP 42). AOS lintners contained the lowest number of chains (NC) per molecule (1.1) compared to NBS (2.8) and WBS (3.3) and the average chain length of AOS, NBS and WBS lintners was 19, 15 and 13, respectively. Hence, both NC and the average chain length correlated with amylose content. The size distribution profile of AOS lintners revealed a repeat motif in the molecules corresponding to 5-6 glucose residues.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Sites, rates, and limits of starch digestion and glucose metabolism in growing cattle.

    PubMed

    Huntington, G B; Harmon, D L; Richards, C J

    2006-04-01

    Growing cattle in the United States consume up to 6 kg of starch daily, mainly from corn or sorghum grain. Total tract apparent digestibility of starch usually ranges from 90 to 100% of starch intake. Ruminal starch digestion ranges from 75 to 80% of starch intake and is not greatly affected by intake over a range of 1 to 5 kg of starch/d. Starch apparently digested in the small intestine decreases from 80 to 34% as starch entering the small intestine increases from 0.2 to 2 kg/d. Starch apparently digested in the large intestine ranges from 44 to 46% of starch entering the large intestine. Approximately 70% of starch digested in the small intestine appears as glucose in the bloodstream. Within the range of starch intakes that do not cause rumen upsets, increasing starch (and energy) intake increases the amount of starch digested in the rumen, increases the supply of starch to the small intestine, increases starch digested in small intestine (albeit at reduced efficiency), and increases starch digested in the large intestine, such that total tract digestibility remains relatively constant. With increased starch intake, most of the starch is still digested in the rumen, but increasing amounts of starch escape ruminal and intestinal digestion, and disappear distal to the ileocecal junction. Again, within the range of starch intakes that do not cause rumen upsets, as starch intake increases, hepatic gluconeogenesis increases, glucose entry increases, and glucose irreversible loss increases, with a significant portion lost as CO2. The ability to increase use of dietary starch to support greater weight gains or improved marbling could come from increasing starch digestion in a healthy rumen or in the small intestine, but we conclude that the main limit to use of dietary starch to support live weight gain is digestion and absorption from the small intestine. Increased oxidation of glucose at greater starch intakes may alter energetic efficiency by sparing other

  2. LCS Content Document Application

    NASA Technical Reports Server (NTRS)

    Hochstadt, Jake

    2011-01-01

    My project at KSC during my spring 2011 internship was to develop a Ruby on Rails application to manage Content Documents..A Content Document is a collection of documents and information that describes what software is installed on a Launch Control System Computer. It's important for us to make sure the tools we use everyday are secure, up-to-date, and properly licensed. Previously, keeping track of the information was done by Excel and Word files between different personnel. The goal of the new application is to be able to manage and access the Content Documents through a single database backed web application. Our LCS team will benefit greatly with this app. Admin's will be able to login securely to keep track and update the software installed on each computer in a timely manner. We also included exportability such as attaching additional documents that can be downloaded from the web application. The finished application will ease the process of managing Content Documents while streamlining the procedure. Ruby on Rails is a very powerful programming language and I am grateful to have the opportunity to build this application.

  3. Characters related to higher starch accumulation in cassava storage roots

    PubMed Central

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-01-01

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed. PMID:26892156

  4. The potential of resistant starch as a prebiotic.

    PubMed

    Zaman, Siti A; Sarbini, Shahrul R

    2016-01-01

    Resistant starch is defined as the total amount of starch and the products of starch degradation that resists digestion in the small intestine. Starches that were able to resist the digestion will arrive at the colon where they will be fermented by the gut microbiota, producing a variety of products which include short chain fatty acids that can provide a range of physiological benefits. There are several factors that could affect the resistant starch content of a carbohydrate which includes the starch granule morphology, the amylose-amylopectin ratio and its association with other food component. One of the current interests on resistant starch is their potential to be used as a prebiotic, which is a non-digestible food ingredient that benefits the host by stimulating the growth or activity of one or a limited number of beneficial bacteria in the colon. A resistant starch must fulfill three criterions to be classified as a prebiotic; resistance to the upper gastrointestinal environment, fermentation by the intestinal microbiota and selective stimulation of the growth and/or activity of the beneficial bacteria. The market of prebiotic is expected to reach USD 198 million in 2014 led by the export of oligosaccharides. Realizing this, novel carbohydrates such as resistant starch from various starch sources can contribute to the advancement of the prebiotic industry.

  5. Preparation of cassava starch grafted with polystyrene by suspension polymerization.

    PubMed

    Kaewtatip, Kaewta; Tanrattanakul, Varaporn

    2008-09-05

    Cassava starch grafted with polystyrene (PS-g-starch) copolymer was synthesized via free-radical polymerization of styrene by using suspension polymerization technique. Potassium persulfate (PPS) was used as an initiator and water was used as a medium. The graft copolymer was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, X-ray diffraction and scanning electron microscopy. The sub-micron spherical beads of PS were observed on the surface of starch granules. SEM micrographs showed porous patches of PS adhering on the starch granules after Soxhlet extraction. FTIR spectra also indicated the presence of PS-g-starch copolymer. XRD analysis exhibited insignificant changes in crystalline structure and degree of crystallinity. The effects of starch:styrene weight ratio, amount of PPS, reaction time and reaction temperature on the percentage of grafting - G (%), were investigated. G (%) increased with increasing starch content. Other variables showed their own individual optimal values. The optimum condition yielding 31.47% of G (%) was derived when the component ratio was 1:3 and reaction temperature and time were 50°C and 2h, respectively. Graft copolymerization did not change granular shape and crystallinity of starch. This study demonstrated the capability of polymerization of styrene monomer on the granular starch without emulsifier and the synthesis of graft copolymer without gelatinization of starch.

  6. Characters related to higher starch accumulation in cassava storage roots.

    PubMed

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-02-19

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed.

  7. Susceptibility of glutinous rice starch to digestive enzymes.

    PubMed

    Guo, Li; Zhang, Juanjuan; Hu, Jian; Li, Xueling; Du, Xianfeng

    2015-09-05

    To understand the susceptibility of glutinous rice starch to digestive enzymes and its potential impact on glycemic response, enzyme kinetics and in vitro digestibility of the native and gelatinized starches were investigated. The results showed that the Km values of the native and gelatinized starch were 10.35 mg/mL and 9.92 mg/mL, respectively. The digestion rate coefficients k values of the native and gelatinized starches were 2.0 × 10(-3)min(-1) and 1.1 × 10(-2)min(-1), respectively. The contents of rapid digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) in native glutinous rice starch were 8.92%, 21.52% and 69.56%, respectively. After gelatinization, the amounts of RDS, SDS and RS were 18.47%, 29.75% and 51.78%, respectively. The native and gelatinized glutinous rice starches were 10.34% and 14.07% for hydrolysis index (HI), as well as 43.14% and 45.92% for glycemic index (GI), respectively. During the in vitro digestion, the crystallinity of native glutinous rice starch was increased from 34.7% to 35.8% and 38.4% after 20 and 120 min, respectively.

  8. Selected properties of acetylated adipate of retrograded starch.

    PubMed

    Zięba, T; Gryszkin, A; Kapelko, M

    2014-01-01

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

  9. Production and characterization of cellulose reinforced starch (CRT) films.

    PubMed

    Sudharsan, K; Chandra Mohan, C; Azhagu Saravana Babu, P; Archana, G; Sabina, K; Sivarajan, M; Sukumar, M

    2016-02-01

    Starch from Tamarind seed is considered to be a nonedible and inexpensive component, with many industrial applications. Extraction and characterization of tamarind seed starch was carried out for the synthesis of biopolymer. Tamarind seeds were collected, cleaned and further roasted, decorticated, and pulverized to get starch powder. Total starch content present in each tamarind seed is estimated to be around 65-70%. About 84.68% purified starch can be recovered from the tamarind seed. Defatted Tamarind seed starch has an amylose content of 27.55 wt.% and 72.45 wt.% of amylopectin. Morphological (SEM) and X-ray diffraction were used to evaluate crystallinity. Likewise, TGA and DSC of starch have also been analyzed. Thermal properties of starch obtained from tamarind seeds showed good thermal stability when compared to other starch sources such as Mesquite seed and Mango kernel. This study proved that the tamarind seed starch can be used as a potential biopolymer material. Thermo-stable biofilms were produced through initial optimization studies. Predictive response surface quadratic models were constructed for prediction and optimization of biofilm mechanical properties. Correlation coefficient values were calculated to me more than 0.90 for mechanical responses which implies the fitness of constructed model with experimental data.

  10. Zinc chloride aqueous solution as a solvent for starch.

    PubMed

    Lin, Meiying; Shang, Xiaoqin; Liu, Peng; Xie, Fengwei; Chen, Xiaodong; Sun, Yongyi; Wan, Junyan

    2016-01-20

    It is important to obtain starch-based homogeneous systems for starch modification. Regarding this, an important key point is to find cheap, low-cost and low-toxicity solvents to allow complete dissolution of starch and its easy regeneration. This study reveals that a ZnCl2 aqueous solution is a good non-derivatizing solvent for starch at 50 °C, and can completely dissolve starch granules. The possible formation of a "zinc-starch complex" might account for the dissolution; and the degradation of starch, which was caused by the H(+) inZnCl2 aqueous solution, could not contribute to full dissolution. From polarized light microscopic observation combined with the solution turbidity results, it was found that the lowest ZnCl2 concentration for full dissolution was 29.6 wt.% at 50 °C, with the dissolving time being 4h. Using Fourier-transform infrared (FTIR), solid state (13)C nuclear magnetic resonance (NMR), and X-ray diffraction (XRD), it was revealed that ZnCl2 solution had no chemical reaction with starch glucosides, but only weakened starch hydrogen bonding and converted the crystalline regions to amorphous regions. In addition, as shown by intrinsic viscosity and thermogravimetric analysis (TGA), ZnCl2 solution caused degradation of starch macromolecules, which was more serious with a higher concentration of ZnCl2 solution.

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

    PubMed

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

    2015-02-01

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

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

    PubMed

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

    2015-01-01

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

  13. Characterization of Starch Degradation Related Genes in Postharvest Kiwifruit

    PubMed Central

    Hu, Xiong; Kuang, Sheng; Zhang, Ai-Di; Zhang, Wang-Shu; Chen, Miao-Jin; Yin, Xue-Ren; Chen, Kun-Song

    2016-01-01

    Starch is one of the most important storage carbohydrates in plants. Kiwifruit typically accumulate large amounts of starch during development. The fruit retain starch until commercial maturity, and its postharvest degradation is essential for consumer acceptance. The activity of genes related to starch degradation has, however, rarely been investigated. Based on the kiwifruit genome sequence and previously reported starch degradation-related genes, 17 novel genes were isolated and the relationship between their expression and starch degradation was examined using two sets of materials: ethylene-treated (100 µL/L, 20 °C; ETH) vs. control (20 °C; CK) and controlled atmosphere stored (CA, 5% CO2 + 2% O2, 0 °C) vs. normal atmosphere in cold storage (NA, 0 °C). Physiological analysis indicated that ETH accelerated starch degradation and increased soluble solids content (SSC) and soluble sugars (glucose, fructose and sucrose), while CA inhibited starch reduction compared with NA. Using these materials, expression patterns of 24 genes that may contribute to starch degradation (seven previously reported and 17 newly isolated) were analyzed. Among the 24 genes, AdAMY1, AdAGL3 and AdBAM3.1/3L/9 were significantly induced by ETH and positively correlated with starch degradation. Furthermore, these five genes were also inhibited by CA, conforming the likely involvement of these genes in starch degradation. Thus, the present study has identified the genes with potential for involvement in starch degradation in postharvest kiwifruit, which will be useful for understanding the regulation of kiwifruit starch content and metabolism. PMID:27983700

  14. Characterization of Starch Degradation Related Genes in Postharvest Kiwifruit.

    PubMed

    Hu, Xiong; Kuang, Sheng; Zhang, Ai-Di; Zhang, Wang-Shu; Chen, Miao-Jin; Yin, Xue-Ren; Chen, Kun-Song

    2016-12-15

    Starch is one of the most important storage carbohydrates in plants. Kiwifruit typically accumulate large amounts of starch during development. The fruit retain starch until commercial maturity, and its postharvest degradation is essential for consumer acceptance. The activity of genes related to starch degradation has, however, rarely been investigated. Based on the kiwifruit genome sequence and previously reported starch degradation-related genes, 17 novel genes were isolated and the relationship between their expression and starch degradation was examined using two sets of materials: ethylene-treated (100 µL/L, 20 °C; ETH) vs. control (20 °C; CK) and controlled atmosphere stored (CA, 5% CO₂ + 2% O₂, 0 °C) vs. normal atmosphere in cold storage (NA, 0 °C). Physiological analysis indicated that ETH accelerated starch degradation and increased soluble solids content (SSC) and soluble sugars (glucose, fructose and sucrose), while CA inhibited starch reduction compared with NA. Using these materials, expression patterns of 24 genes that may contribute to starch degradation (seven previously reported and 17 newly isolated) were analyzed. Among the 24 genes, AdAMY1, AdAGL3 and AdBAM3.1/3L/9 were significantly induced by ETH and positively correlated with starch degradation. Furthermore, these five genes were also inhibited by CA, conforming the likely involvement of these genes in starch degradation. Thus, the present study has identified the genes with potential for involvement in starch degradation in postharvest kiwifruit, which will be useful for understanding the regulation of kiwifruit starch content and metabolism.

  15. Critical roles of soluble starch synthase SSIIIa and granule-bound starch synthase Waxy in synthesizing resistant starch in rice

    PubMed Central

    Zhou, Hongju; Wang, Lijun; Liu, Guifu; Meng, Xiangbing; Jing, Yanhui; Shu, Xiaoli; Kong, Xiangli; Sun, Jian; Yu, Hong; Smith, Steven M.; Wu, Dianxing; Li, Jiayang

    2016-01-01

    Changes in human lifestyle and food consumption have resulted in a large increase in the incidence of type-2 diabetes, obesity, and colon disease, especially in Asia. These conditions are a growing threat to human health, but consumption of foods high in resistant starch (RS) can potentially reduce their incidence. Strategies to increase RS in rice are limited by a lack of knowledge of its molecular basis. Through map-based cloning of a RS locus in indica rice, we have identified a defective soluble starch synthase gene (SSIIIa) responsible for RS production and further showed that RS production is dependent on the high expression of the Waxya (Wxa) allele, which is prevalent in indica varieties. The resulting RS has modified granule structure; high amylose, lipid, and amylose–lipid complex; and altered physicochemical properties. This discovery provides an opportunity to increase RS content of cooked rice, especially in the indica varieties, which predominates in southern Asia. PMID:27791174

  16. Optimization of resistant starch formation from high amylose corn starch by microwave irradiation treatments and characterization of starch preparations.

    PubMed

    Mutlu, Selime; Kahraman, Kevser; Öztürk, Serpil

    2017-02-01

    The effects of microwave irradiation on resistant starch (RS) formation and functional properties in high-amylose corn starch, Hylon VII, by applying microwave-storing cycles and drying processes were investigated. The Response Surface Methodology (RSM) was used to optimize the reaction conditions, microwave time (2-4min) and power (20-100%), for RS formation. The starch:water (1:10) mixtures were cooked and autoclaved and then different microwave-storing cycles and drying (oven or freeze drying) processes were applied. The RS contents of the samples increased with increasing microwave-storing cycle. The highest RS (43.4%) was obtained by oven drying after 3 cycles of microwave treatment at 20% power for 2min. The F, p (<0.05) and R(2) values indicated that the selected models were consistent. Linear equations were obtained for oven-dried samples applied by 1 and 3 cycles of microwave with regression coefficients of 0.65 and 0.62, respectively. Quadratic equation was obtained for freeze-dried samples applied by 3 cycles of microwave with a regression coefficient of 0.83. The solubility, water binding capacity (WBC) and RVA viscosity values of the microwave applied samples were higher than those of native Hylon VII. The WBC and viscosity values of the freeze-dried samples were higher than those of the oven-dried ones.

  17. REGULATIONS ON THE DISPOSAL OF ARSENIC RESIDUALS FROM DRINKING WATER TREATMENT PLANTS

    EPA Science Inventory

    This report summarizes federal and selected state regulations that govern the management of residuals produced by small water treatment systems removing arsenic from drinking water. The document focuses on the residuals produced by five treatment processes: anion exchange, activa...

  18. Partial characterization of chayotextle starch-based films added with ascorbic acid encapsulated in resistant starch.

    PubMed

    Martínez-Ortiz, Miguel A; Vargas-Torres, Apolonio; Román-Gutiérrez, Alma D; Chavarría-Hernández, Norberto; Zamudio-Flores, Paul B; Meza-Nieto, Martín; Palma-Rodríguez, Heidi M

    2017-05-01

    Chayotextle starch was modified by subjecting it to a dual treatment with acid and heating-cooling cycles. This caused a decrease in the content of amylose, which showed values of 30.22%, 4.80%, 3.27% and 3.57% for native chayotextle starch (NCS), starch modified by acid hydrolysis (CMS), and CMS with one (CMS1AC) and three autoclave cycles (CMS3AC), respectively. The percentage of crystallinity showed an increase of 36.9%-62% for NCS and CMS3AC. The highest content of resistant starch (RS) was observed in CMS3AC (37.05%). The microcapsules were made with CMS3AC due to its higher RS content; the total content of ascorbic acid of the microcapsules was 82.3%. The addition of different concentrations of CMS3AC microcapsules (0%, 2.5%, 6.255% and 12.5%) to chayotextle starch-based films (CSF) increased their tensile strength and elastic modulus. The content of ascorbic acid and RS in CSF was ranged from 0% to 59.4% and from 4.84% to 37.05% in the control film and in the film mixed with CMS3AC microcapsules, respectively. Water vapor permeability (WVP) values decreased with increasing concentrations of microcapsules in the films. Microscopy observations showed that higher concentrations of microcapsules caused agglomerations due their poor distribution in the matrix of the films.

  19. Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages

    PubMed Central

    Ning, Tingting; Wang, Huili; Zheng, Mingli; Niu, Dongze; Zuo, Sasa; Xu, Chuncheng

    2017-01-01

    Objective This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion The microbial amylase contributes to starch hydrolysis during the ensiling process

  20. Document Concurrence System

    NASA Technical Reports Server (NTRS)

    Muhsin, Mansour; Walters, Ian

    2004-01-01

    The Document Concurrence System is a combination of software modules for routing users expressions of concurrence with documents. This system enables determination of the current status of concurrences and eliminates the need for the prior practice of manually delivering paper documents to all persons whose approvals were required. This system runs on a server, and participants gain access via personal computers equipped with Web-browser and electronic-mail software. A user can begin a concurrence routing process by logging onto an administration module, naming the approvers and stating the sequence for routing among them, and attaching documents. The server then sends a message to the first person on the list. Upon concurrence by the first person, the system sends a message to the second person, and so forth. A person on the list indicates approval, places the documents on hold, or indicates disapproval, via a Web-based module. When the last person on the list has concurred, a message is sent to the initiator, who can then finalize the process through the administration module. A background process running on the server identifies concurrence processes that are overdue and sends reminders to the appropriate persons.

  1. Synthesis of resistant starches in plants.

    PubMed

    Morell, Matthew K; Konik-Rose, Christine; Ahmed, Regina; Li, Zhongyi; Rahman, Sadiq

    2004-01-01

    The increased incidence in many countries in lifestyle diseases such as colorectal cancer, cardiovascular disease, and diabetes has led to an enhanced interest in disease-prevention measures that can be delivered to target populations through diet. Resistant starch (RS) is emerging as an important dietary component that has the potential to reduce the incidence of bowel health disorders. However, the range of crop species that can serve as effective sources of RS is limited. In this paper the state of knowledge of the starch biosynthesis pathway is reviewed and opportunities to manipulate crop genetics in order to generate additional sources of RS are discussed. The need for a "whole of chain" approach to delivery of RS to the consumer is highlighted because of the impact that different food-processing technologies can have in maintaining, enhancing, or destroying the RS potential of a raw material or food.

  2. Slowly digestible starch--a review.

    PubMed

    Miao, Ming; Jiang, Bo; Cui, Steve W; Zhang, Tao; Jin, Zhengyu

    2015-01-01

    The link between carbohydrate intake and health is becoming increasingly important for consumers, particularly in the areas of glycemic index (GI) and extended energy-releasing starches. From a physiological point of view, slowly digestible starch (SDS) delivers a slow and sustained release of blood glucose along with the benefits resulting from low glycemic and insulinemic response. SDS has been implicated in several health problems, including diabetes, obesity, and cardiovascular diseases (metabolic syndromes). It may also have commercial potential as a novel functional ingredient in a variety of fields, such as nutrition, medicine, and agriculture. The present review assesses this form of digestion by analyzing methods to prepare and evaluate SDS, and factors affecting its transformation, its health benefits, and its applications.

  3. Enzymatic Hydrogen Production from Starch and Water

    SciTech Connect

    Zhang, Y.-H. Percival; Evans, Barbara R; Mielenz, Jonathan R; Hopkins, Robert C.; Adams, Michael W. W.

    2007-01-01

    A novel enzymatic reaction was conducted for producing hydrogen from starch and water at 30oC. The overall reaction comprised of 13 enzymes, 1 cofactor (NADP+), and phosphate was driven by energy stored in carbohydrate starch according to the overall stoichiometry stoichiometric reaction of C6H10O5 (l) + 7 H2O (l) --> 12 H2 (g) + 6 CO2 (g). It is spontaneous and unidirectional because of negative Gibbs free energy and the removal of gaseous products from the aqueous reaction solution. With technology improvement and integration with fuel cells, this technology would be suitable for mobile applications and also solve the challenges associated with hydrogen storage, distribution, and infrastructure in a hydrogen economy.

  4. Prebiotic properties of potato starch dextrins.

    PubMed

    Barczyńska, Renata; Śliżewska, Katarzyna; Libudzisz, Zdzisława; Kapuśniak, Kamila; Kapuśniak, Janusz

    2015-09-08

    The objective of the present study was to compare the prebiotic properties of starch dextrins, that is, resistant dextrins obtained from potato starch in the process of simultaneous thermolysis and chemical modification, which were selected based on previous research. Both prepared dextrins met the definition criterion of dietary fiber and also the basic prebiotic criterion - they were not degraded by the digestive enzymes of the initial sections of the gastrointestinal tract. The growth of probiotic lactobacilli and bifidobacteria, as well as Escherichia coli, Enterococcus, Bacteroides, and Clostridium strains isolated from feces of healthy people, showed that both studied dextrins were utilized as a source of assimilable carbon and energy by the strains. Furthermore, better growth (higher numbers of cells) counts of probiotic bacteria than those of fecal isolates indicated that the studied resistant dextrins showed a selective effect. Both dextrins might be considered as substances with prebiotic properties due to their chemical and physical properties and selectivity towards the studied probiotic bacterial strains.

  5. Recreating the synthesis of starch granules in yeast.

    PubMed

    Pfister, Barbara; Sánchez-Ferrer, Antoni; Diaz, Ana; Lu, Kuanjen; Otto, Caroline; Holler, Mirko; Shaik, Farooque Razvi; Meier, Florence; Mezzenga, Raffaele; Zeeman, Samuel C

    2016-11-22

    Starch, as the major nutritional component of our staple crops and a feedstock for industry, is a vital plant product. It is composed of glucose polymers that form massive semi-crystalline granules. Its precise structure and composition determine its functionality and thus applications; however, there is no versatile model system allowing the relationships between the biosynthetic apparatus, glucan structure and properties to be explored. Here, we expressed the core Arabidopsis starch-biosynthesis pathway in Saccharomyces cerevisiae purged of its endogenous glycogen-metabolic enzymes. Systematic variation of the set of biosynthetic enzymes illustrated how each affects glucan structure and solubility. Expression of the complete set resulted in dense, insoluble granules with a starch-like semi-crystalline organization, demonstrating that this system indeed simulates starch biosynthesis. Thus, the yeast system has the potential to accelerate starch research and help create a holistic understanding of starch granule biosynthesis, providing a basis for the targeted biotechnological improvement of crops.

  6. Soybean cotyledon starch metabolism is sensitive to altered gravity conditions

    NASA Astrophysics Data System (ADS)

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

    1994-08-01

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

  7. High throughput screening of starch structures using carbohydrate microarrays

    PubMed Central

    Tanackovic, Vanja; Rydahl, Maja Gro; Pedersen, Henriette Lodberg; Motawia, Mohammed Saddik; Shaik, Shahnoor Sultana; Mikkelsen, Maria Dalgaard; Krunic, Susanne Langgaard; Fangel, Jonatan Ulrik; Willats, William George Tycho; Blennow, Andreas

    2016-01-01

    In this study we introduce the starch-recognising carbohydrate binding module family 20 (CBM20) from Aspergillus niger for screening biological variations in starch molecular structure using high throughput carbohydrate microarray technology. Defined linear, branched and phosphorylated maltooligosaccharides, pure starch samples including a variety of different structures with variations in the amylopectin branching pattern, amylose content and phosphate content, enzymatically modified starches and glycogen were included. Using this technique, different important structures, including amylose content and branching degrees could be differentiated in a high throughput fashion. The screening method was validated using transgenic barley grain analysed during development and subjected to germination. Typically, extreme branching or linearity were detected less than normal starch structures. The method offers the potential for rapidly analysing resistant and slowly digested dietary starches. PMID:27468930

  8. Synergistic effect of starch on the antibacterial activity of honey.

    PubMed

    Boukraâ, Laïd; Amara, Karim

    2008-03-01

    The role of amylase present in honey in enhancing its antibacterial activity was evaluated in the presence and absence of starch. Two strains of pathogenic bacteria have been used: Staphylococcus aureus and Escherichia coli. For S. aureus, the minimum inhibitory concentration (MIC) for the three varieties of honey tested without starch was 11%, 24%, and 29% (vol/vol), respectively. When starch was added with honey to the media the MIC obtained was 5%, 19%, and 25% (vol/vol), respectively. For E. coli, the MIC for the three varieties without starch was 23%, 28%, and 25% (vol/vol), respectively. When starch was added with honey to media, the MIC was 19%, 26%, and 23% (vol/vol), respectively. It is speculated that the amylase present in honey hydrolyzed the starch chains to randomly produce dextrin and maltose and that this increased the osmotic effect of the media, which consequently increased the antibacterial activity.

  9. Soybean cotyledon starch metabolism is sensitive to altered gravity conditions

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  10. Hydrophobic starch nanocrystals preparations through crosslinking modification using citric acid.

    PubMed

    Zhou, Jiang; Tong, Jin; Su, Xingguang; Ren, Lili

    2016-10-01

    Biodegradable starch nanocrystals prepared by an acid treatment process were modified through crosslinking modification using citric acid as reactant by a dry reaction method. The occurrence of crosslinking modification was evaluated by Fourier transform infrared spectroscopy and swelling degree. X-ray diffraction, wettability tests and contact angle measurements were used to characterize the modified starch nanocrystals. It was found that the crosslinked starch nanocrystals displayed a higher affinity for low polar solvents such as dichloromethane. The surface of starch nanocrystals became more roughness after crosslinking modification with citric acid and the size decreased as revealed by scanning electron microscopy and dynamic light scattering results. XRD analysis showed that the crystalline structure of starch nanocrystals was basically not changed after the crosslinking modification with shorter heating time. The resulting hydrophobic starch nanocrystals are versatile precursors to the development of nanocomposites.

  11. Regulation of starch metabolism: the age of enlightenment?

    PubMed

    Kötting, Oliver; Kossmann, Jens; Zeeman, Samuel C; Lloyd, James R

    2010-06-01

    Starch and sucrose are the primary products of photosynthesis in the leaves of most plants. Starch represents the major plant storage carbohydrate providing energy during the times of heterotrophic growth. Starch metabolism has been studied extensively, leading to a good knowledge of the numerous enzymes involved. In contrast, understanding of the regulation of starch metabolism is fragmentary. This review summarises briefly the known steps in starch metabolism, highlighting recent discoveries. We also focus on evidence for potential regulatory mechanisms of the enzymes involved. These mechanisms include allosteric regulation by metabolites, redox regulation, protein-protein interactions and reversible protein phosphorylation. Modern systems biology and bioinformatic approaches are uncovering evidence for extensive post-translational protein modifications that may underlie enzyme regulation and identify novel proteins which may be involved in starch metabolism.

  12. System Documentation: A Symposium on Printer Documentation for Computer Systems.

    ERIC Educational Resources Information Center

    Kaplan, Denise, Ed.

    1989-01-01

    This symposium on printed documentation covers (1) Tacoma Public Library's documentation (Lare Mischo); (2) characteristics of bad documentation (Linda Bills); (3) GEAC manuals (Joe Matthews); (4) Personal Bibliographic Software manuals (Victor Rosenberg); (5) DIALOG documentation (Barbara E. Anderson); (6) documentation problems and improvements…

  13. Process of converting starch to glucose and glucose to lactic acid

    SciTech Connect

    Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

    1990-12-31

    This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

  14. Process of converting starch to glucose and glucose to lactic acid

    SciTech Connect

    Tsai, TenLin; Sanville, C.Y.; Coleman, R.D.; Schertz, W.W.

    1990-01-01

    This document describes a method for converting starch into lactic acid of sufficient purity for use as a substrate for biodegradable plastics. The process is designed to work on industrial food waste streams such as potato wastes or cheese whey permeate. For potato waste, {alpha}-amylase and calcium chloride are added to the starch containing waste and incubated at a pH of 4--7, a temperature of 90--130{degree}C, and a pressure above 15 psi for not less than 15 minutes. At this point, glucoamylase is added and the mixture is incubated at a temperature of 50--70{degree}C and a pH below 6.5 for 4 hours. This results in the conversion of more than 90% of the starch into glucose, which is substantially free of microbial contamination. The hydrolysate is filtered, and introduced with additional nutrients to a fermentor containing a lactose producing microorganism to form a fermentation broth. This results in the fermentation of glucose to lactose, which is filtered and subjected to electrodialysis for purification. Conversion of glucose to lactic acid or lactate occurs with an efficiency of over 95%. 1 fig. (MHB)

  15. Starch grains on human teeth reveal early broad crop diet in northern Peru

    PubMed Central

    Piperno, Dolores R.; Dillehay, Tom D.

    2008-01-01

    Previous research indicates that the Ñanchoc Valley in northern Peru was an important locus of early and middle Holocene human settlement, and that between 9200 and 5500 14C yr B.P. the valley inhabitants adopted major crop plants such as squash (Cucurbita moschata), peanuts (Arachis sp.), and cotton (Gossypium barbadense). We report here an examination of starch grains preserved in the calculus of human teeth from these sites that provides direct evidence for the early consumption of cultivated squash and peanuts along with two other major food plants not previously detected. Starch from the seeds of Phaseolus and Inga feuillei, the flesh of Cucurbita moschata fruits, and the nuts of Arachis was routinely present on numerous teeth that date to between 8210 and 6970 14C yr B.P. Early plant diets appear to have been diverse and stable through time and were rich in cultivated foods typical of later Andean agriculture. Our data provide early archaeological evidence for Phaseolus beans and I. feuillei, an important tree crop, and indicate that effective food production systems that contributed significant dietary inputs were present in the Ñanchoc region by 8000 14C yr B.P. Starch grain studies of dental remains document plants and edible parts of them not normally preserved in archaeological records and can assume primary roles as direct indicators of ancient human diets and agriculture. PMID:19066222

  16. Resistant starch content of Indian foods.

    PubMed

    Platel, K; Shurpalekar, K S

    1994-01-01

    Resistant starch (RS) was determined in a few selected cereals, legumes and vegetables after processing. Higher RS contents were observed in foods subjected to dry heat treatment compared to wet processed ones. Among the foods studied, sorghum, green gram dhal, and green plantain showed relatively higher RS content. Based on the RS content thus determined in individual foods and the known composition of the Indian diet, RS content of Indian diets were computed.

  17. Computer integrated documentation

    NASA Technical Reports Server (NTRS)

    Boy, Guy

    1991-01-01

    The main technical issues of the Computer Integrated Documentation (CID) project are presented. The problem of automation of documents management and maintenance is analyzed both from an artificial intelligence viewpoint and from a human factors viewpoint. Possible technologies for CID are reviewed: conventional approaches to indexing and information retrieval; hypertext; and knowledge based systems. A particular effort was made to provide an appropriate representation for contextual knowledge. This representation is used to generate context on hypertext links. Thus, indexing in CID is context sensitive. The implementation of the current version of CID is described. It includes a hypertext data base, a knowledge based management and maintenance system, and a user interface. A series is also presented of theoretical considerations as navigation in hyperspace, acquisition of indexing knowledge, generation and maintenance of a large documentation, and relation to other work.

  18. Perceptions of document relevance

    PubMed Central

    Bruza, Peter; Chang, Vivien

    2014-01-01

    This article presents a study of how humans perceive and judge the relevance of documents. Humans are adept at making reasonably robust and quick decisions about what information is relevant to them, despite the ever increasing complexity and volume of their surrounding information environment. The literature on document relevance has identified various dimensions of relevance (e.g., topicality, novelty, etc.), however little is understood about how these dimensions may interact. We performed a crowdsourced study of how human subjects judge two relevance dimensions in relation to document snippets retrieved from an internet search engine. The order of the judgment was controlled. For those judgments exhibiting an order effect, a q–test was performed to determine whether the order effects can be explained by a quantum decision model based on incompatible decision perspectives. Some evidence of incompatibility was found which suggests incompatible decision perspectives is appropriate for explaining interacting dimensions of relevance in such instances. PMID:25071622

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

    PubMed

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

    2013-02-15

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

  20. Effects of citric acid esterification on digestibility, structural and physicochemical properties of cassava starch.

    PubMed

    Mei, Ji-Qiang; Zhou, Da-Nian; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

    2015-11-15

    In this study, citric acid was used to react with cassava starch in order to compare the digestibility, structural and physicochemical properties of citrate starch samples. The results indicated that citric acid esterification treatment significantly increased the content of resistant starch (RS) in starch samples. The swelling power and solubility of citrate starch samples were lower than those of native starch. Compared with native starch, a new peak at 1724 cm(-1) was appeared in all citrate starch samples, and crystalline peaks of all starch citrates became much smaller or even disappeared. Differential scanning calorimetry results indicated that the endothermic peak of citrate starches gradually shrank or even disappeared. Moreover, the citrate starch gels exhibited better freeze-thaw stability. These results suggested that citric acid esterification induced structural changes in cassava starch significantly affected its digestibility and it could be a potential method for the preparation of RS with thermal stability.

  1. Recent advances of starch-based excipients used in extended-release tablets: a review.

    PubMed

    Hong, Yan; Liu, Guodong; Gu, Zhengbiao

    2016-01-01

    In recent years, polysaccharides, including starch and its derivatives, have been widely used in the pharmaceutical industry, including as diluents, fillers, binders, disintegrants and glidants. The use of native starch as excipient in extended-release tablets is limited due to its low compactibility and enzymatic degradability, leading to the formation of weakly structured tablets. To overcome these limitations and expand the application of starch as an excipient, researchers have modified starch by physical and chemical methods, as well as by enzymatic hydrolysis. Some starch derivatives, including retrograded starch, pregelatinized starch, carboxymethyl starch, starch acetate, cross-linked starch and grafted starch have recently been introduced as excipients in oral tablets to control drug release. In this review, applications of starch and its derivatives as extended release excipients are reviewed and future frontiers are described.

  2. Dual modification of taro starch by microwave and other heat moisture treatments.

    PubMed

    Deka, Dhritiman; Sit, Nandan

    2016-11-01

    Effect of heat moisture treatment on the physicochemical properties of taro starch with 25% moisture (w/w) modified by single treatments of microwave (HMT1), autoclave (HMT2) and hot air oven (HMT3), and dual treatments of microwave followed by autoclave (HMT4) and microwave followed by hot air oven (HMT5) were investigated. Amylose contents of the modified starches increased except for HMT3. A loss of physical integrity of the starch granules were observed for dual modified starches. The swelling and solubility of all the modified starches increased. The peak viscosities of starches modified by HMT1 and HMT5 were found to be higher whereas for other modified starches it was lower than that of native starch. The holding and final viscosities of all the modified starches except HMT4 were higher than native starch. The freeze-thaw stabilities of the modified starches were also found to be better than that of native starch.

  3. Effect of acetylation, oxidation and annealing on physicochemical properties of bean starch.

    PubMed

    Simsek, Senay; Ovando-Martínez, Maribel; Whitney, Kristin; Bello-Pérez, Luis A

    2012-10-15

    Black and Pinto bean starches were physically and chemically modified to investigate the effect of modification on digestibility and physicochemical properties of bean starch. The impact of acetylation, oxidation (ozonation) and annealing on the chemical composition, syneresis, swelling volume, pasting, thermal properties and digestibility of starches was evaluated. The physicochemical and estimated glycemic index (eGI) of the Black and Pinto bean starches treated with ozone were not significantly (P>0.05) different than that of their respective control starches. Annealed starches had improved thermal and pasting properties compared to native starches. Acetylated starches presented reduced syneresis, good pasting properties and lower eGI. Also, all modified starches had increased levels of resistant starch (RS). Therefore, the digestibility and physicochemical properties of bean starch were affected by the type of modification but there were no significant (P>0.05) differences between the Black and Pinto bean starches.

  4. Starch-related cytosolic heteroglycans in roots from Arabidopsis thaliana.

    PubMed

    Malinova, Irina; Steup, Martin; Fettke, Joerg

    2011-08-15

    Both photoautotrophic and heterotrophic plant cells are capable of accumulating starch inside the plastid. However, depending on the metabolic state of the respective cell the starch-related carbon fluxes are different. The vast majority of the transitory starch biosynthesis relies on the hexose phosphate pools derived from the reductive pentose phosphate cycle and, therefore, is restricted to ongoing photosynthesis. Transitory starch is usually degraded in the subsequent dark period and mainly results in the formation of neutral sugars, such as glucose and maltose, that both are exported into the cytosol. The cytosolic metabolism of the two carbohydrates includes reversible glucosyl transfer reactions to a heteroglycan that are mediated by two glucosyl transferases, DPE2 and PHS2 (or, in all other species, Pho2). In heterotrophic cells, accumulation of starch mostly depends on the long distance transport of reduced carbon compounds from source to sink organs and, therefore, includes as an essential step the import of carbohydrates from the cytosol into the starch forming plastids. In this communication, we focus on starch metabolism in heterotrophic tissues from Arabidopsis thaliana wild type plants (and in various starch-related mutants as well). By using hydroponically grown A. thaliana plants, we were able to analyse starch-related biochemical processes in leaves and roots from the same plants. Within the roots we determined starch levels and the morphology of native starch granules. Cytosolic and apoplastic heteroglycans were analysed in roots and compared with those from leaves of the same plants. A. thaliana mutants lacking functional enzymes either inside the plastid (such as phosphoglucomutase) or in the cytosol (disproportionating isoenzyme 2 or the phosphorylase isozyme, PHS2) were included in this study. In roots and leaves from the three mutants (and from the respective wild type organ as well), starch and heteroglycans as well as enzyme patterns were

  5. Simple organocatalytic route for the synthesis of starch esters.

    PubMed

    Tupa, Maribel; Maldonado, Lorena; Vázquez, Analía; Foresti, María L

    2013-10-15

    Starch acetates and starch butyrates with degree of substitution (DS) in the range of 0.06-1.54 were prepared by a simple direct solvent-free organocatalytic methodology of starch acylation. The starch esters synthesized have important applications in the food and pharmaceutical industries, among others. The acylation methodology used involves a non-toxic biobased α-hydroxycarboxylic acid as catalyst, and proceeds with high efficiency in absence of solvents. The effect of reaction time on the advance of starch modification was studied as a simple way to control the level of substitution achieved, when all other reaction parameters were kept constant. Starch esters were characterized by means of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). FTIR spectroscopy qualitatively confirmed the esterification of starch by the appearance of bands which are associated with esters groups. Scanning electron microscopy showed that the granular structure of the polysaccharide was preserved upon acylation, although acylated granules had rougher surfaces; and wrinkles, grooves and deformed zones appeared in some granules at high DS. Thermogravimetric analysis showed a gradual reduction in the water content of acylated starches, as well as noticeable changes in their thermal properties at increasing DS. X-ray diffraction analysis showed that the acetylation treatment led to lower crystallinity at increasing DS, although characteristic corn starch A-type patterns could be identified even at the highest DS achieved (DS=1.23). Specific bands and weight losses derived from FTIR and TGA data could be very well correlated with the substitution degree achieved in acetylated starches at DS lower/equal than 0.6. The organocatalytic methodology described for the synthesis of starch acetates and butyrates has the potential to be easily extended to the synthesis of other starch esters using a

  6. Enzymatic transformation of nonfood biomass to starch

    PubMed Central

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

    2013-01-01

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

  7. Starch composites reinforced by bamboo cellulosic crystals.

    PubMed

    Liu, Dagang; Zhong, Tuhua; Chang, Peter R; Li, Kaifu; Wu, Qinglin

    2010-04-01

    Using a method of combined HNO(3)-KClO(3) treatment and sulfuric acid hydrolysis, bamboo cellulose crystals (BCCs) were prepared and used to reinforce glycerol plasticized starch. The structure and morphology of BCCs were investigated using X-ray diffraction, electron microscopy, and solid-state (13)C NMR. Results showed that BCCs were of typical cellulose I structure, and the morphology was dependent on its concentration in the suspension. BCC of 50-100 nm were assembled into leaf nervations at low concentration (i.e. 0.1 wt.% of solids), but congregated into a micro-sized "flower" geometry at high concentration (i.e. 10.0 wt.% of solids). Tensile strength and Young's modulus of the starch/BCC composite films (SBC) were enhanced by the incorporation of the crystals due to reinforcement of BCCs and reduction of water uptake. BCCs at the optimal 8% loading level exhibited a higher reinforcing efficiency for plasticized starch plastic than any other loading level.

  8. Enzymatic transformation of nonfood biomass to starch.

    PubMed

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

    2013-04-30

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

  9. [Hydroxyethyl starch--an interim report].

    PubMed

    Weidhase, R; Faude, K; Weidhase, R

    1998-01-01

    Since the beginning of this century, a few biopolymers have been used as basic materials for volume substitution. Aside from gelatin and dextran, modified starch (hydroxyethyl starch, HES) is currently the first-choice means. Due to special manufacturing processes, different hydroxyethyl starches are now available. They have several different characteristics and produce different clinical effects. These clinical properties depend on the average molecular weight and the distribution of molecular weight as well as on the degree and pattern of substitution. The duration of volume effect, one of the most important parameters for the effectiveness of a volume substitute, depends to a large degree on the substitution. Elimination of HES from serum is delayed by a high degree of substitution and a high C2/C6 ratio of the substitution pattern. The molecular parameters of HES also influence other effects, such as cumulation in various organs and hemostasis. Critical reading of current HES literature shows that many questions still have to be answered. At the same time ways and means of optimizing differential volume substitution therapy and hemodilution therapy are emerging.

  10. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    DOEpatents

    Sanfilippo, Antonio; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset of the documents of the document set, using a plurality of terms of the documents, providing a cluster label indicative of subject matter content of the documents of the cluster, wherein the cluster label comprises a plurality of word senses, and selecting one of the word senses of the cluster label.

  11. Customer Communication Document

    NASA Technical Reports Server (NTRS)

    2009-01-01

    This procedure communicates to the Customers of the Automation, Robotics and Simulation Division (AR&SD) Dynamics Systems Test Branch (DSTB) how to obtain services of the Six-Degrees-Of-Freedom Dynamic Test System (SDTS). The scope includes the major communication documents between the SDTS and its Customer. It established the initial communication and contact points as well as provides the initial documentation in electronic media for the customer. Contact the SDTS Manager (SM) for the names of numbers of the current contact points.

  12. Related environmental documents

    SciTech Connect

    1995-10-01

    This portion of the Energy Vision 2020 draft report is a listing of related environmental documents used in the drafting of this report. Specifically, the documents are the final environmental impact statements for: (1) Bellefonte Nuclear Plant 1 & 2, (2) Browns Ferry Nuclear Plant 1, 2, & 3, (3) Sequoyah Nuclear Plant 1 & 2, (4) Watts Bar Nuclear Plant 1 & 2, (5) Raccoon Mountain Pumped Storage Facility, (6) Policies relating to rates, (7) Tennessee River and reservoir system operation and planning, (8) Policies related to the use of coal.

  13. Inhibition of buckwheat starch digestion by the formation of starch/bile salt complexes: possibility of its occurrence in the intestine.

    PubMed

    Takahama, Umeo; Hirota, Sachiko

    2011-06-08

    During the digestion of starch in foods, starch is mixed with bile in the duodenum. Because fatty acids and some kinds of polyphenols could bind to starch, it was postulated that bile salts might also bind to starch. The purpose of this paper is to study the effects of bile and bile salts on starch/iodine complex formation and pancreatin-induced starch digestion. Bile suppressed starch/iodine complex formation and inhibited pancreatin-induced starch digestion slightly in control buckwheat starch, but did so significantly in buckwheat starch from which fatty acids and polyphenols had been extracted. Such significant suppression and inhibition by bile were also observed in a reagent soluble starch. The effects of cholate and taurocholate on the starch/iodine complex formation and the pancreatin-induced starch digestion were essentially the same as those of bile. Bile, cholate, and taurocholate suppressed amylose/iodine complex formation more significantly than amylopectin/iodine complex formation and inhibited pancreatin-induced amylose digestion more effectively than the digestion of amylopectin. It is concluded from the results that bile salts could bind to starch, especially amylose, the helical structures of which were not occupied by other molecules such as fatty acids and polyphenols, and that the binding resulted in the inhibition of starch digestion by pancreatin. The conclusion suggests that the function of bile salts can be discussed from the point of not only lipid digestion but also starch digestion.

  14. Methodology for Evaluating Encapsulated Beneficial Uses of Coal Combustion Residuals

    EPA Pesticide Factsheets

    The primary purpose of this document is to present an evaluation methodology developed by the EPA for making determinations about environmental releases from encapsulated products containing coal combustion residuals.

  15. Thermal and rheological properties of nixtamalized maize starch.

    PubMed

    Mendez-Montealvo, G; Sánchez-Rivera, M M; Paredes-López, O; Bello-Pérez, L A

    2006-12-15

    The effect of nixtamalization process on thermal and rheological characteristics of corn starch was studied. Starch of raw sample had higher gelatinization temperature than its raw counterpart, because, the Ca(2+) ions stabilize starch structure of nixtamalized sample; however, the enthalpy values were not different in both samples. The temperature of the phase transition of the retrograded starches (raw and nixtamalized) were not different at the storage times assessed, but the enthalpy values of the above mentioned transition was different, indicating a lower reorganization of the starch structure in the nixtamalized sample. The viscoamylographic profile showed differences between both starches, since raw starch had higher peak viscosity than the nixtamalized sample due to partial gelatinization of some granules during this heat treatment. Rheological test showed that at low temperature (25 degrees C) the raw and nixtamalized starches presented different behaviour; however, the elastic characteristic was more important in the starch gel structure. The nixtamalization process produced changes in thermal and rheological characteristics becoming important in those products elaborated from nixtamalized maize.

  16. Characterization of acetylated corn starch prepared under ultrahigh pressure (UHP).

    PubMed

    Kim, Hyun-Seok; Choi, Hyun-Shik; Kim, Byung-Yong; Baik, Moo-Yeol

    2010-03-24

    To investigate the impact of ultrahigh pressure (UHP) on the physicochemical properties of the UHP-assisted starch acetate, common corn starch was subjected to either conventional (0.1 MPa, 30 degrees C, 60 min) or UHP-assisted (400 MPa, 25 degrees C, 15 min) acetylation reactions at three levels (4, 8, or 12%) of acetic anhydride. Without significant changes in starch granule crystal structure, UHP-assisted reaction exhibited lower degree of substitution values than conventional reaction across reagent addition levels. An increase in reagent addition levels exhibited common trends in starch solubility/swelling power, gelatinization, and pasting properties for the conventional and UHP-assisted starch acetates relative to native starch. Within an equivalent derivatization level, however, the UHP-assisted (relative to conventional) starch acetates revealed restricted starch solubility/swelling power, reduced gelatinization temperatures, and lower pasting viscosities. Overall, this result suggested that UHP treatment in acetylation reaction might influence the physicochemical properties of starch acetate by facilitating the formation of lipid-complexed amylose or altering granular reaction patterns to acetic anhydride.

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

    PubMed

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

    2015-05-05

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

  18. Structural investigations and morphology of tomato fruit starch.

    PubMed

    Luengwilai, Kietsuda; Beckles, Diane M

    2009-01-14

    The physicochemical properties of starch from tomato (Solanum lycopersicum L.) pericarp and columella of cv. Moneymaker fruit at 28 days post anthesis (DPA) were investigated, providing the first description of the composition and structure of tomato fruit starch. Starch granules from pericarp were mainly polygonal, 13.5-14.3 microm, and increased in size through development, being largest in ripening fruit. Amylopectin content was 81-83% and was of molecular weight 1.01 x 10(8) g/mol; the phosphorus content was 139 ppm, and starch showed a C-type pattern with crystallinity of 30%. Starch characteristics were similar in columella except granule size (16.8-17.8 microm) and crystallinity (40%), although 6-fold more starch accumulated in the pericarp. Solara, a high-sugar tomato cultivar, was also studied to determine if this affects starch granule architecture. There were few differences from Moneymaker, except that Solara columella starch crystallinity was lower (26%), and more starch granule-intrinsic proteins could be extracted by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

  19. The structure and interactions of starch with food constituents.

    PubMed

    Biliaderis, C G

    1991-01-01

    For most starch-containing foods, the physical and functional properties can be traced to characteristic molecular species being present, their interactions with each other, and modifications caused by environmental conditions (moisture, temperature, shear) during processing and storage. In the present paper, the chemistry and physical chemistry of starch are discussed with an emphasis on how structure (molecular and supermolecular) and composition influence the functionality of this polysaccharide. New experimental findings brought forward on structure indicate that this polymeric carbohydrate is found in various metastable states, depending on the thermomechanical history of the product. Even more important to processing and quality attributes of starch products is the recognition that the dynamics of the supermolecular structure and interactions between starch and other food constituents are governed by the mobility of the amorphous phase of each particular system. In this respect, water, acting as a plasticizer, depresses the glass transition temperature (Tg) and thereby alters the kinetics of state transformations (e.g., gelatinization, retrogradation) and reactivity of starch. The effects of water on phase transition behavior of starch as well as the underlying molecular mechanisms to the phenomena of gelatinization, gelation, retrogradation, and starch-lipid interactions are reviewed herein. Finally, consideration is given to factors affecting the digestibility of starch from the viewpoint of processing-related changes in the susceptibility of starch to alpha-amylase.

  20. Effect of gelatinization and starch-emulsifier interactions on aroma release from starch-rich model systems.

    PubMed

    Lopes Da Silva, J A; Castro, Sónia M; Delgadillo, Ivonne

    2002-03-27

    Release of selected volatile aldehyde compounds from starch-rich matrices was studied by headspace extraction, using solid-phase microextraction, and gas chromatography. Changes in the rheological properties of the starch-based matrices, due to starch concentration, gelatinization, and interactions with emulsifiers, were studied by steady shear and dynamic methods. The degree of volatile retention was found to depend on the compound properties, starch concentration, native structure of the granules, and presence of emulsifiers. The nongelatinized starch granules were more effective in lowering the volatile headspace quantities. Loss of the native structural integrity of the granules decreases the retention ability. For the nongelatinized starch dispersions, the more hydrophilic emulsifier showed a more pronounced effect on the matrix rheology and also on the aroma retention. A different behavior was observed for the gelatinized systems. Interpretation of the volatile release profiles was made on the basis of the matrix physical properties and interactions among components.

  1. Processing effects on susceptibility of starch to digestion in some dietary starch sources.

    PubMed

    Niba, Lorraine L

    2003-01-01

    Maize flour, potato flour, cocoyam flour, plantain flour, yam flour, and rice flour were assayed for starch digestibility by an established enzymatic procedure. These were either autoclaved, microwaved, or parboiled and then freeze-dried. Freeze-dried samples were stored for 10 days either below freezing or at ambient temperature. Parameters assessed were readily digestible starch (RDS), slowly digestible starch (SDS), and total starch (TS). Data was analyzed by t-test (P < or = 0.05). RDS levels among raw flours ranged from 1.01 g/100g in rice flour to 8.16 g/100 g in cocoyam flour. Autoclaving and parboiling increased RDS levels in most flours, while microwaving significantly reduced RDS compared with raw flour. Ambient temperature storage reduced the RDS content. SDS levels ranged from 4.95 g/100 g in yam flour to 22.2 g/100 g in maize flour. SDS levels were increased by autoclaving and parboling, but significantly reduced by microwaving, compared with the raw flour. Storage at ambient temperature resulted in lower SDS. The TS content in raw flour ranged from 28.0 g/100 g in plantain flour to 68.4 g/100 g in rice flour. Autoclaving resulted in reduced TS levels insome flours. Moist heat processing and the post-process storage temperature therefore result in significant changes in starch susceptibility to enzymic digestion. This information will be useful in developing food processing and storage procedures that modify starch resistance to digestion in order to optimize its nutritional quality and to enhance the physiological benefits.

  2. Evaluation of starch obtained from Ensete ventricosum as a binder and disintegrant for compressed tablets.

    PubMed

    Gebre-Mariam, T; Nikolayev, A S

    1993-04-01

    The binding and disintegrant properties of starch obtained from Ensete ventricosum Musaceae have been evaluated. The effect of the starch on the physical properties such as crushing strength, friability and disintegration time of tablets of chloroquine phosphate, dipyrone and paracetamol was compared with tablets prepared with potato starch. The results show that enset starch can be used both as a tablet binder and disintegrant and the indication is that enset starch has a better binding ability and less disintegrating power than potato starch.

  3. Transitory and storage starch metabolism: two sides of the same coin?

    PubMed

    Lloyd, James Richard; Kossmann, Jens

    2015-04-01

    The industrially important polymer, starch, is manufactured through a complex process involving multiple isoforms of several different enzymes. These contribute to alter the structure of starch which, in turn, affects its downstream industrial use. This review compares recent advances in our knowledge of starch metabolism in leaves and storage organs. Starch granule initiation and formation, enzyme complexes involved in starch metabolism and control of flux in starch synthesis and degradation are examined.

  4. Motivation through Routine Documentation

    ERIC Educational Resources Information Center

    Koth, Laurie J.

    2016-01-01

    This informed commentary article offers a simple, effective classroom management strategy in which the teacher uses routine documentation to motivate students both to perform academically and to behave in a manner consistent with established classroom rules and procedures. The pragmatic strategy is grounded in literature, free to implement,…

  5. Teaching America's Founding Documents.

    ERIC Educational Resources Information Center

    Tucker, James

    1993-01-01

    Reflects on the author's experiences teaching a course on great documents in American history to high school students, concentrating on teaching the Declaration of Independence and the "Federalist Papers." Countering the students' tendencies toward superficial reading and encouraging deep analysis are the teacher's primary goals. (SLD)

  6. Automating clinical dietetics documentation.

    PubMed

    Grace-Farfaglia, P; Rosow, P

    1995-06-01

    A review of commonly used charting formats discussed in the dietetics literature revealed that the subjective, objective assessment and planning (SOAP) approach is most frequently used by dietitians. Formats reported in the nursing literature were charting by exception (CBE); problem, intervention, evaluation (PIE); and focus/data, action, response (Focus/DAR). The strengths and weaknesses of the charting styles as they apply to the needs of clinical dietetic specialists were reviewed. We then decided to test in house the Focus/DAR format by assessing chart entries for adherence to style, brevity, and physician response. Dietitians pilot tested all the methods, but found them time consuming to use. The consensus was that SOAP could be adapted to the documentation needs of the individual situation and required little additional staff training. Often because of time limitations, a narrative summary was most appropriate. Chart entry length was reduced as much as 200% when staff were given brief clinical communication as a goal, and a further reduction when line limits were imposed. The physician response was positive, with recommendations followed in 50% of charts, compared with 34% in a previous audit. A nutrition documentation system was developed by the researchers by reviewing medical chart structure, documentation standards, methods of risk identification, and terminology for clinical documentation style. The resulting system affected the decision making of physicians, who could now scan notes more quickly and implement nutrition recommendations in a more timely fashion.

  7. Using Primary Source Documents.

    ERIC Educational Resources Information Center

    Mintz, Steven

    2003-01-01

    Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

  8. Extremely secure identification documents

    SciTech Connect

    Tolk, K.M.; Bell, M.

    1997-09-01

    The technology developed in this project uses biometric information printed on the document and public key cryptography to ensure that an adversary cannot issue identification documents to unauthorized individuals or alter existing documents to allow their use by unauthorized individuals. This process can be used to produce many types of identification documents with much higher security than any currently in use. The system is demonstrated using a security badge as an example. This project focused on the technologies requiring development in order to make the approach viable with existing badge printing and laminating technologies. By far the most difficult was the image processing required to verify that the picture on the badge had not been altered. Another area that required considerable work was the high density printed data storage required to get sufficient data on the badge for verification of the picture. The image processing process was successfully tested, and recommendations are included to refine the badge system to ensure high reliability. A two dimensional data array suitable for printing the required data on the badge was proposed, but testing of the readability of the array had to be abandoned due to reallocation of the budgeted funds by the LDRD office.

  9. The Iranian Documentation Centre.

    ERIC Educational Resources Information Center

    Harvey, John F.

    The purpose of the Iranian Documentation Centr (Irandoc) was to collect that portion of the world's literature which was pertinent to Iran's research interests, to organize that material, and to promote its use by Iranian researchers. Stated more succinctly, Irandoc's purpose was to obtain ready access to the world's scientific literature in order…

  10. ELT Documents, January 1975.

    ERIC Educational Resources Information Center

    British Council, London (England). English-Teaching Information Centre.

    The theme of this issue of ELT Documents is the use of the language laboratory in language learning. An article by A. Maley summarizes the conference on the use of the language laboratory for advanced learners, held in Paris, 2-4 Oct. 1974, from which two main perspectives emerged. One is critical of the structuralist audio-lingual assumptions…

  11. Documenting Early Science Learning.

    ERIC Educational Resources Information Center

    Jones, Jacqueline; Courtney, Rosalea

    2002-01-01

    Three principles that guide documentation and assessment of children's early science understanding are: collect a variety of forms of evidence, collect evidence over a period of time, and collect evidence on the understanding of groups of children as well as individuals. Information and insights gained from this process help teachers plan future…

  12. Novel polymer blends with thermoplastic starch

    NASA Astrophysics Data System (ADS)

    Taghizadeh, Ata

    A new class of polymers known as "bioplastics" has emerged and is expanding rapidly. This class consists of polymers that are either bio-based or biodegradable, or both. Among these, polysaccharides, namely starch, are of great interest for several reasons. By gelatinizing starch via plasticizers, it can be processed in the same way as thermoplastic polymers with conventional processing equipment. Hence, these bio-based and biodegradable plastics, with their low source and refinery costs, as well as relatively easy processability, have made them ideal candidates for incorporation into various current plastic products. Four different plasticizers have been chosen here for gelatinization of thermoplastic starch (TPS): glycerol, sorbitol, diglycerol and polyglycerol, with the latter two being used for the first time in such a process. Two methodological categories are used. The first involves a calorimetric method (Differential Scanning Calorimetry) as well as optical microscopy; these are "static" methods where no shear is applied A wide range of starch/water/plasticizer compositions were prepared to explore the gelatinization regime for each plasticizer. The onset and conclusion gelatinization temperatures for sorbitol and glycerol were found to be in the same vicinity, while diglycerol and polyglycerol showed significantly higher transition temperatures. The higher molecular weight and viscosity of polyglycerol allow this transition to occur at an even higher temperature than with diglycerol. This is due to the increase in molecular weight and viscosity of the two new plasticizers, as well as their significant decrease in water solubility. It is demonstrated that the water/plasticizer ratio has a pronounced effect on gelatinization temperatures. When plasticizer content was held constant and water content was increased, it was found that the gelatinization temperature decreased for all the plasticizers. Meanwhile, when the water content was held constant and the

  13. Technical approach document

    SciTech Connect

    Not Available

    1989-12-01

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604 (PL95-604), grants the Secretary of Energy the authority and responsibility to perform such actions as are necessary to minimize radiation health hazards and other environmental hazards caused by inactive uranium mill sites. This Technical Approach Document (TAD) describes the general technical approaches and design criteria adopted by the US Department of Energy (DOE) in order to implement remedial action plans (RAPS) and final designs that comply with EPA standards. It does not address the technical approaches necessary for aquifer restoration at processing sites; a guidance document, currently in preparation, will describe aquifer restoration concerns and technical protocols. This document is a second revision to the original document issued in May 1986; the revision has been made in response to changes to the groundwater standards of 40 CFR 192, Subparts A--C, proposed by EPA as draft standards. New sections were added to define the design approaches and designs necessary to comply with the groundwater standards. These new sections are in addition to changes made throughout the document to reflect current procedures, especially in cover design, water resources protection, and alternate site selection; only minor revisions were made to some of the sections. Sections 3.0 is a new section defining the approach taken in the design of disposal cells; Section 4.0 has been revised to include design of vegetated covers; Section 8.0 discusses design approaches necessary for compliance with the groundwater standards; and Section 9.0 is a new section dealing with nonradiological hazardous constituents. 203 refs., 18 figs., 26 tabs.

  14. Starch grain evidence for the preceramic dispersals of maize and root crops into tropical dry and humid forests of Panama

    PubMed Central

    Dickau, Ruth; Ranere, Anthony J.; Cooke, Richard G.

    2007-01-01

    The Central American isthmus was a major dispersal route for plant taxa originally brought under cultivation in the domestication centers of southern Mexico and northern South America. Recently developed methodologies in the archaeological and biological sciences are providing increasing amounts of data regarding the timing and nature of these dispersals and the associated transition to food production in various regions. One of these methodologies, starch grain analysis, recovers identifiable microfossils of economic plants directly off the stone tools used to process them. We report on new starch grain evidence from Panama demonstrating the early spread of three important New World cultigens: maize (Zea mays), manioc (Manihot esculenta), and arrowroot (Maranta arundinacea). Maize starch recovered from stone tools at a site located in the Pacific lowlands of central Panama confirms previous archaeobotanical evidence for the use of maize there by 7800–7000 cal BP. Starch evidence from preceramic sites in the less seasonal, humid premontane forests of Chiriquí province, western Panama, shows that maize and root crops were present by 7400–5600 cal BP, several millennia earlier than previously documented. Several local starchy resources, including Zamia and Dioscorea spp., were also used. The data from both regions suggest that crop dispersals took place via diffusion or exchange of plant germplasm rather than movement of human populations practicing agriculture. PMID:17360697

  15. Starch grain evidence for the preceramic dispersals of maize and root crops into tropical dry and humid forests of Panama.

    PubMed

    Dickau, Ruth; Ranere, Anthony J; Cooke, Richard G

    2007-02-27

    The Central American isthmus was a major dispersal route for plant taxa originally brought under cultivation in the domestication centers of southern Mexico and northern South America. Recently developed methodologies in the archaeological and biological sciences are providing increasing amounts of data regarding the timing and nature of these dispersals and the associated transition to food production in various regions. One of these methodologies, starch grain analysis, recovers identifiable microfossils of economic plants directly off the stone tools used to process them. We report on new starch grain evidence from Panama demonstrating the early spread of three important New World cultigens: maize (Zea mays), manioc (Manihot esculenta), and arrowroot (Maranta arundinacea). Maize starch recovered from stone tools at a site located in the Pacific lowlands of central Panama confirms previous archaeobotanical evidence for the use of maize there by 7800-7000 cal BP. Starch evidence from preceramic sites in the less seasonal, humid premontane forests of Chiriquí province, western Panama, shows that maize and root crops were present by 7400-5600 cal BP, several millennia earlier than previously documented. Several local starchy resources, including Zamia and Dioscorea spp., were also used. The data from both regions suggest that crop dispersals took place via diffusion or exchange of plant germplasm rather than movement of human populations practicing agriculture.

  16. Tartary buckwheat (Fagopyrum tataricum Gaertn.) starch, a side product in functional food production, as a potential source of retrograded starch.

    PubMed

    Gao, Jinfeng; Kreft, Ivan; Chao, Guimei; Wang, Ying; Liu, Xiaojin; Wang, Li; Wang, Pengke; Gao, Xiaoli; Feng, Baili

    2016-01-01

    A starch rich fraction is a side product in Tartary buckwheat processing. This study investigated the fractions that are of technological and nutritional interest. Tartary buckwheat starch granules had a diameter of 3-14 μm, and presented a typical type "A" X-ray diffraction pattern. They contained nearly 39.0% amylose. The solubility of Tartary buckwheat starch was much lower at 70-90 °C (ranging within 9.9-10.4% at 90 °C) than that in maize (up to 49.3%) and potato (up to 85.0%) starch. The starch of one variety of Tartary buckwheat had significantly lower solubility at 70 °C and 80 °C than that of common buckwheat. The starch peak viscosity and breakdown were higher and pasting time was shorter in Tartary buckwheat than in that of the starch of common buckwheat. Tartary buckwheat starch had unique pasting and physicochemical properties, and is thereby capable of being exploited as a suitable raw material of retrograded starch in food processing.

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

    PubMed

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

    2008-03-26

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

  18. Multigene engineering of starch biosynthesis in maize endosperm increases the total starch content and the proportion of amylose.

    PubMed

    Jiang, Lili; Yu, Xiaoming; Qi, Xin; Yu, Qian; Deng, Sen; Bai, Bing; Li, Ning; Zhang, Ai; Zhu, Changfu; Liu, Bao; Pang, Jinsong

    2013-12-01

    Maize (Zea mays spp. mays) is a staple crop for more than 900 million people. The seeds or kernels provide a rich source of calories because ~70% of the weight is carbohydrate, mostly in the form of starch. The content and composition of starch are complex traits controlled by many genes, offering multiple potential targets for intervention. We used a multigene engineering approach combining the overexpression of Bt2, Sh2, Sh1 and GbssIIa (to enhance the activity of sucrose synthase, AGPase and granule-bound starch synthase) with the suppression of SbeI and SbeIIb by RNA interference (to reduce the activity of starch branching enzyme). Maize plants expressing all six genes plus the selectable marker showed a 2.8-7.7% increase in the endosperm starch content and a 37.8-43.7% increase in the proportion of amylose, which was significant compared to untransformed control plants. We also observed improvements in other agronomic traits, such as a 20.1-34.7% increase in 100-grain weight, a 13.9-19.0% increase in ear weight, and larger kernels with a better appearance, presumably reflecting the modified starch structure within the kernels. Our results confirm that multigene engineering applied to the starch biosynthesis pathway can not only modulate the quality and quantity of starch but can also improve starch-dependent agronomic traits.

  19. Effects of starches on the mechanical properties of paracetamol tablet formulations. II. Sorghum and plantain starches as disintegrants.

    PubMed

    Alebiowu, Gbenga; Itiola, Oludele Adelanwa

    2003-12-01

    This study evaluates the disintegrant properties--tablet disintegration time (DT) and crushing strength--friability/disintegration time (CSFR/DT) ratio of a paracetamol tablet formulation prepared with sorghum and plantain starches in comparison with corn starch BP. The effects of disintegrant concentration, relative density of tablets and the mode of disintegrants addition were studied. The study revealed that the rank order of effectiveness of the starches as disintegrants was corn > plantain > sorghum. The mode of addition of disintegrants, disintegrant concentration and relative density had a significant impact on the disintegrant properties. The tested starches, namely, sorghum and plantain, showed promising results.

  20. Effects of Arabinoxylan and Resistant Starch on Intestinal Microbiota and Short-Chain Fatty Acids in Subjects with Metabolic Syndrome: A Randomised Crossover Study

    PubMed Central

    Moore, Mary E.; Dige, Anders; Lærke, Helle Nygaard; Agnholt, Jørgen; Bach Knudsen, Knud Erik; Hermansen, Kjeld; Marco, Maria L.; Gregersen, Søren; Dahlerup, Jens F.

    2016-01-01

    Recently, the intestinal microbiota has been emphasised as an important contributor to the development of metabolic syndrome. Dietary fibre may exert beneficial effects through modulation of the intestinal microbiota and metabolic end products. We investigated the effects of a diet enriched with two different dietary fibres, arabinoxylan and resistant starch type 2, on the gut microbiome and faecal short-chain fatty acids. Nineteen adults with metabolic syndrome completed this randomised crossover study with two 4-week interventions of a diet enriched with arabinoxylan and resistant starch and a low-fibre Western-style diet. Faecal samples were collected before and at the end of the interventions for fermentative end-product analysis and 16S ribosomal RNA bacterial gene amplification for identification of bacterial taxa. Faecal carbohydrate residues were used to verify compliance. The diet enriched with arabinoxylan and resistant starch resulted in significant reductions in the total species diversity of the faecal-associated intestinal microbiota but also increased the heterogeneity of bacterial communities both between and within subjects. The proportion of Bifidobacterium was increased by arabinoxylan and resistant starch consumption (P<0.001), whereas the proportions of certain bacterial genera associated with dysbiotic intestinal communities were reduced. Furthermore, the total short-chain fatty acids (P<0.01), acetate (P<0.01) and butyrate concentrations (P<0.01) were higher by the end of the diet enriched with arabinoxylan and resistant starch compared with those resulting from the Western-style diet. The concentrations of isobutyrate (P = 0.05) and isovalerate (P = 0.03) decreased in response to the arabinoxylan and resistant starch enriched diet, indicating reduced protein fermentation. In conclusion, arabinoxylan and resistant starch intake changes the microbiome and short-chain fatty acid compositions, with potential beneficial effects on colonic health

  1. Enhancement of photoassimilate utilization by manipulation of starch regulatory enzymes

    SciTech Connect

    Okita, Thomas W.

    2016-05-11

    ADPglucose pyrophosphorylase (AGPase) and the plastidial starch phosphorylase1 (Pho1) are two regulatory enzymes whose catalytic activities are essential for starch granule synthesis. Conversion of the pre-starch granule to the mature form is dependent on AGPase, which produces ADPglucose, the substrate used by starch synthases. The catalytic activity of AGPase is controlled by small effector molecules and a prime goal of this project was to decipher the role of the two subunit types that comprise the heterotetrameric enzyme structure. Extensive genetic and biochemical studies showed that catalysis was contributed mainly by the small subunit although the large subunit was required for maximum activity. Both subunits were needed for allosteric regulatory properties. We had also demonstrated that the AGPase catalyzed reaction limits the amount of starch accumulation in developing rice seeds and that carbon flux into rice seed starch can be increased by expression of a cytoplasmic-localized, up-regulated bacterial AGPase enzyme form. Results of subsequent physiological and metabolite studies showed that the AGPase reaction is no longer limiting in the AGPase transgenic rice lines and that one or more downstream processes prevent further increases in starch biosynthesis. Further studies showed that over-production of ADPglucose dramatically alters the gene program during rice seed development. Although the expression of nearly all of the genes are down-regulated, levels of a starch binding domain containing protein (SBDCP) are elevated. This SBDCP was found to bind to and inhibit the catalytic activity of starch synthase III and, thereby preventing maximum starch synthesis from occurring. Surprisingly, repression of SBDCP elevated expression of starch synthase III resulting in increasing rice grain weight. A second phase of this project examined the structure-function of Pho1, the enzyme required during the initial phase of pre-starch granule formation and its

  2. Relationships among Genetic, Structural, and Functional Properties of Rice Starch.

    PubMed

    Kong, Xiangli; Chen, Yaling; Zhu, Ping; Sui, Zhongquan; Corke, Harold; Bao, Jinsong

    2015-07-15

    We determined the relationships among the structural properties, in vitro digestibility, and genetic factors in starches of 14 rice cultivars. Weight-based chain-length distributions in amylopectin ranged from 18.07% to 24.71% (fa, DP 6-12), 45.01% to 55.67% (fb1, DP 13-24), 12.72% to 14.05% (fb2, DP 25-36), and 10.80 to 20.72% (fb3, DP > 36), respectively. The contents of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) ranged from 78.5% to 87.5%, 1.2% to 6.0%, and 10.1% to 18.0%, respectively. AAC was negatively correlated with RDS content but positively correlated with RS content in rice starch. The proportion of short chains in amylopectin, i.e. the amount of fraction IIa (FrIIa) fractionated by gel permeation chromatography (GPC), was positively correlated with RDS. Starch synthase IIa (SSIIa) gene controlled the degree of crystallinity, the amount of fa chains of amylopectin. SSIIIa gene controlled the amount of fb1 chains. Wx gene controlled the FrI, FrIIa, RDS, and RS. Starch debranching enzyme isoamylase II (ISA2) gene also controlled the RDS, which may suggest that RDS was also affected by amylopectin structure, although no correlation between them was found. This study indicated that genetics (i.e., starch biosynthesis related genes) controlled the structural properties of starch, and both amylose content and amylopectin fine structure determined functional properties of rice starch (i.e., the digestion), each in a different way. Understanding the "genetics-structure-function" relationships in rice starches will assist plant breeders and food processors in developing new rice varieties and functional foods.

  3. The deposition and characterization of starch in Brachypodium distachyon.

    PubMed

    Tanackovic, Vanja; Svensson, Jan T; Jensen, Susanne L; Buléon, Alain; Blennow, Andreas

    2014-10-01

    Brachypodium distachyon is a non-domesticated cereal. Nonetheless, Brachypodium was recently introduced as a model plant for temperate cereals. This study compares grain starch metabolism in Brachypodium and barley (Hordeum vulgare). In Brachypodium, we identified and annotated 28 genes involved in starch metabolism and identified important motifs including transit peptides and putative carbohydrate-binding modules (CBMs) of the families CBM20, CBM45, CBM48, and CBM53. Starch content was markedly lower in Brachypodium grains (12%) compared to barley grains (47%). Brachypodium starch granules were doughnut shaped and bimodally distributed into distinct small B-type (2.5-10 µm) and very small C-type (0.5-2.5 µm) granules. Large A-type granules, typical of cereals, were absent. Starch-bound phosphate, important for starch degradation, was 2-fold lower in Brachypodium compared with barley indicating different requirements for starch mobilization. The amylopectin branch profiles were similar and the amylose content was only slightly higher compared with barley cv. Golden Promise. The crystallinity of Brachypodium starch granules was low (10%) compared to barley (20%) as determined by wide-angle X-ray scattering (WAXS) and molecular disorder was confirmed by differential scanning calorimetry (DSC). The expression profiles in grain for most genes were distinctly different for Brachypodium compared to barley, typically showing earlier decline during the course of development, which can explain the low starch content and differences in starch molecular structure and granule characteristics. High transitory starch levels were observed in leaves of Brachypodium (2.8% after 14h of light) compared to barley (1.9% after 14h of light). The data suggest important pre-domesticated features of cereals.

  4. Do informed consent documents matter?

    PubMed

    Resnik, David B

    2009-03-01

    This commentary argues that, despite extensive critiques of informed consent documents, there are several ethical and legal reasons for investigators and IRB members to take these documents seriously.

  5. Sequential document visualization.

    PubMed

    Mao, Yi; Dillon, Joshua; Lebanon, Guy

    2007-01-01

    Documents and other categorical valued time series are often characterized by the frequencies of short range sequential patterns such as n-grams. This representation converts sequential data of varying lengths to high dimensional histogram vectors which are easily modeled by standard statistical models. Unfortunately, the histogram representation ignores most of the medium and long range sequential dependencies making it unsuitable for visualizing sequential data. We present a novel framework for sequential visualization of discrete categorical time series based on the idea of local statistical modeling. The framework embeds categorical time series as smooth curves in the multinomial simplex summarizing the progression of sequential trends. We discuss several visualization techniques based on the above framework and demonstrate their usefulness for document visualization.

  6. SANSMIC design document.

    SciTech Connect

    Weber, Paula D.; Rudeen, David Keith

    2015-07-01

    The United States Strategic Petroleum Reserve (SPR) maintains an underground storage system consisting of caverns that were leached or solution mined in four salt domes located near the Gulf of Mexico in Texas and Louisiana. The SPR comprises more than 60 active caverns containing approximately 700 million barrels of crude oil. Sandia National Labo- ratories (SNL) is the geotechnical advisor to the SPR. As the most pressing need at the inception of the SPR was to create and fill storage volume with oil, the decision was made to leach the caverns and fill them simultaneously (leach-fill). Therefore, A.J. Russo developed SANSMIC in the early 1980s which allows for a transient oil-brine interface (OBI) making it possible to model leach-fill and withdrawal operations. As the majority of caverns are currently filled to storage capacity, the primary uses of SANSMIC at this time are related to the effects of small and large withdrawals, expansion of existing caverns, and projecting future pillar to diameter ratios. SANSMIC was identified by SNL as a priority candidate for qualification. This report continues the quality assurance (QA) process by documenting the "as built" mathematical and numerical models that comprise this document. The pro- gram flow is outlined and the models are discussed in detail. Code features that were added later or were not documented previously have been expounded. No changes in the code's physics have occurred since the original documentation (Russo, 1981, 1983) although recent experiments may yield improvements to the temperature and plume methods in the future.

  7. Cadmium technical support document

    SciTech Connect

    Not Available

    1986-09-01

    This Position Document addresses the risks and benefits of pesticide products containing the subject active ingredient. The Agency has determined that the use of products containing the subject active ingredient may meet or exceed a risk criterion described in 40 CFR Part 154. Potential hazards will be examined further to determine the nature and extent of the risk, and considering the benefits of the subject active ingredient, whether such risks cause unreasonable adverse effects on the environment.

  8. The surface-associated proteins of wheat starch granules: suitability of wheat starch for celiac patients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat starch is used to make baked products for celiac patients in several European countries, but is avoided in the US because of uncertainty about the amounts of associated grain storage (gluten) proteins. People with celiac disease (CD) must avoid wheat, rye and barley proteins and products that...

  9. Toughening polylactide with polyether-block-amide and thermoplastic starch acetate: Influence of starch esterification degree.

    PubMed

    Zhou, Linyao; Zhao, Guiyan; Feng, Yulin; Yin, Jinghua; Jiang, Wei

    2015-01-01

    Native corn starch was esterified with acetic anhydride and plasticized with glycerol to give the thermoplastic starch acetate (TPSA). TPSA was blended with polylactide (PLA) and polyether-block-amide-graft-glycidyl methacrylate (PEBA-g-GMA) to obtain biodegradable PLA/PEBA-g-GMA/TPSA blends with high notched impact resistance and low cost. Compared with PLA/PEBA-g-GMA blends, as much as 9 wt% expensive PEBA-g-GMA elastomer could be substituted by the slightly acetylated thermoplastic starch while retaining high impact strength. The mechanical properties depended on the esterification degree of starch acetate. The impact strength, tensile strength and elongation at break increased to the peak value with increasing the esterification degree from 0 to 0.04, thereafter they decreased on further increasing the esterification degree. The morphological results showed that the TPSA particles were smaller and more uniform at the optimum esterification degree of 0.04, leading to the peak value of the mechanical properties.

  10. Identification and characterization of granule bound starch synthase I (GBSSI) gene of tartary buckwheat (Fagopyrum tataricum Gaertn.).

    PubMed

    Wang, Xun; Feng, Bo; Xu, Zhibin; Sestili, Francesco; Zhao, Guojun; Xiang, Chao; Lafiandra, Domenico; Wang, Tao

    2014-01-25

    Tartary buckwheat (Fagopyrum tataricum Gaertn.) is increasingly considered as an important functional food material because of its rich nutraceutical compounds. Reserve starch is the major component of tartary buckwheat seed. However, the gene sequences and the molecular mechanism of tartary buckwheat starch synthesis are unknown so far. In this study, the complete genomic sequence and full-size cDNA coding tartary buckwheat granule-bound starch synthase I (FtGBSSI), which is responsible for amylose synthesis, were isolated and analyzed. The genomic sequence of the FtGBSSI contained 3947 nucleotides and was composed of 14 exons and 13 introns. The cDNA coding sequence of FtGBSSI shared 63.3%-75.1% identities with those of dicots and 56.6%-57.5% identities with monocots (Poaceae). In deduced amino acid sequence of FtGBSSI, eight motifs conserved among plant starch synthases were identified. A cleavage at the site IVC↓G of FtGBSSI protein produces the chloroplast transit sequence of 78 amino acids and the mature protein of 527 amino acids. The FtGBSSI mature protein showed an identity of 73.4%-77.8% with dicot plants, and 67.6%-70.4% with monocot plants (Poaceae). The mature protein was composed of 20 α-helixes and 16 β-strands, and folds into two main domains, N- and C-terminal domains. The critical residues which are involved in ADP and sugar binding were predicted. These results will be useful to modulate starch composition of buckwheat kernels with the aim to produce novel improved varieties in future breeding programs.

  11. (1)H-(13)C NMR-Based Profiling of Biotechnological Starch Utilization.

    PubMed

    Sundekilde, Ulrik K; Meier, Sebastian

    2016-10-04

    Starch is used in food- and nonfood applications as a renewable and degradable source of carbon and energy. Insight into the chemical detail of starch degradation remains challenging as the starch constituents amylose and amylopectin are homopolymers. We show that considerable molecular detail of starch fragmentation can be obtained from multivariate analysis of spectral features in optimized (1)H-(13)C NMR spectroscopy of starch fragments to identify relevant features that distinguish processes in starch utilization. As a case study, we compare the profiles of starch fragments in commercial beer samples. Spectroscopic profiles of homooligomeric starch fragments can be excellent indicators of process conditions. In addition, differences in the structure and composition of starch fragments have predictive value for downstream process output such as ethanol production from starch. Thus, high-resolution (1)H-(13)C NMR spectroscopic profiles of homooligomeric fragment mixtures in conjunction with chemometric methods provide a useful addition to the analytical chemistry toolbox of biotechnological starch utilization.

  12. Content Documents Management

    NASA Technical Reports Server (NTRS)

    Muniz, R.; Hochstadt, J.; Boelke J.; Dalton, A.

    2011-01-01

    The Content Documents are created and managed under the System Software group with. Launch Control System (LCS) project. The System Software product group is lead by NASA Engineering Control and Data Systems branch (NEC3) at Kennedy Space Center. The team is working on creating Operating System Images (OSI) for different platforms (i.e. AIX, Linux, Solaris and Windows). Before the OSI can be created, the team must create a Content Document which provides the information of a workstation or server, with the list of all the software that is to be installed on it and also the set where the hardware belongs. This can be for example in the LDS, the ADS or the FR-l. The objective of this project is to create a User Interface Web application that can manage the information of the Content Documents, with all the correct validations and filters for administrator purposes. For this project we used one of the most excellent tools in agile development applications called Ruby on Rails. This tool helps pragmatic programmers develop Web applications with Rails framework and Ruby programming language. It is very amazing to see how a student can learn about OOP features with the Ruby language, manage the user interface with HTML and CSS, create associations and queries with gems, manage databases and run a server with MYSQL, run shell commands with command prompt and create Web frameworks with Rails. All of this in a real world project and in just fifteen weeks!

  13. Association of alpha-amylase and the R1 protein with starch granules precedes the initiation of net starch degradation in turions of Spirodela polyrhiza.

    PubMed

    Reimann, Rezarta; Ritte, Gerhard; Steup, Martin; Appenroth, Klaus-J

    2002-01-01

    In turions of Spirodela polyrhiza (L.) Schleiden, net degradation of storage starch is controlled by a special low fluence response of phytochrome requiring illumination for several days. This light effect has been used to study protein-starch interactions that occur prior to and during net degradation of starch. Following various pretreatments on S. polyrhiza turions, native starch granules were isolated and two fractions of starch-related proteins were distinguished: proteins enclosed within the starch particles (starch-internalized proteins) and those attached to the surface (starch-associated proteins). The pattern of starch-associated proteins as resolved by SDS-PAGE was more complex than that of starch-internalized proteins and varied depending upon the pretreatment of the turions. Two starch associated proteins were identified immunochemically as alpha-amylase (EC 3.2.1.1) and the R1 protein (Lorberth et al. (1998) Nature Biotechnology 16: 473-477). Dark-pretreatment of non-dormant turions does not induce starch net degradation. Under these conditions, alpha-amylase and R1 were bound to the surface of the starch granules. Continuous illumination with red light induces a rapid degradation of starch. Within the first 24 h of illumination the level of starch-associated alpha-amylase transiently increased and subsequently decreased rapidly. Similarly, the amount of the starch-associated R1 also decreased during illumination. The dissociation of both alpha-amylase and R1 from the starch granules preceded the decrease in starch content. However, binding of the two proteins to starch granules remained unchanged when the turions did not perform net starch degradation (as observed during continuous darkness, orthophosphate deficiency, or dormancy of the turions). Thus, during net starch degradation, so far unidentified changes are postulated to occur at the surface of the starch particles that are relevant for protein binding. This conclusion was supported by in

  14. Analysis of Cereal Starches by High Performance Size Exclusion Chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch has unique physicochemical characteristics among carbohydrates. Most starch granules are a mixture of two sugar polymers: a highly branched polysaccharide named amylopectin, and a basically linear polysaccharide named amylose. The objective of this study was to develop a simple, one-step and ...

  15. Potential Targets for Seed Improvement through Bioengineering Starch Synthesis Pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Flocculation of Kaolin by Waxy Maize Starch Phosphates

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Flocculation of Kaolin by Waxy Maize Starch Phosphates

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. Alternative utilization of wheat starch, Grafton, North Dakota

    SciTech Connect

    Not Available

    1981-02-01

    In 1978, North Dakota State University (NDSU), in cooperation with the Economic Development Administration, completed a study of the feasibility of a vital wheat gluten starch processing plant in North Dakota. The overall objective of this study is to determine the most feasible alternatives for utilizing the by-product starch slurry from a vital wheat gluten processing plant.

  19. In vitro starch digestion in sorghum flour from Algerian cultivars.

    PubMed

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

    2014-05-01

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

  20. In vitro starch digestion in sorghum flour from Algerian cultivars

    PubMed Central

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

    2014-01-01

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

  1. Immobilization of urease on grafted starch by radiation method

    NASA Astrophysics Data System (ADS)

    Dung, Nguyen anh; Huyen, Nguyen dinh; Hang, Nguyen duy; Canh, Tran tich

    1995-09-01

    The acrylamide was grafted by radiation onto starch which is a kind polymeric biomaterial. The urease was immobilized on the grafted starch. Some experiments to observe the quantitative relationships between the percent grafl and the activity of immobilized enzyme were determined. The enzyme activity was maintained by more than seven batch enzyme reactions.

  2. Evaluation of the emulsifying properties of some cationic starches.

    PubMed

    Vermeire, A; Kiekens, F; Corveleyn, S; Remon, J P

    1999-03-01

    Different cationic potato, maize, and waxy maize starches were evaluated for their emulsifying properties. Emulsions were prepared using 20% (w/w) arachidic oil and 80% (w/w) water. Emulsions with the cationic starches as emulsifier in a concentration ranging from 1% to 5% (w/w) were prepared and characterized by droplet size and viscosity measurements, and the stability was evaluated visually and by electrical conductance measurements. None of the cationic potato, waxy maize starches, and maize starches with a low degree of substitution (DS) showed adequate emulsifying properties. Emulsions prepared using non-pregelatinized (C [symbol: see text] bond 05914, 2% and 5% w/w; C [symbol: see text] bond 05907, 5% w/w) and pregelatinized (C [symbol: see text] bond 12504, 5% w/w) cationic maize starches with high-DS were visually stable. The initial mean droplet volume diameter of the emulsions prepared with these cationic starches in a 5% (w/w) concentration was similar and ranged from 2.40 to 2.84 microns; however, there was an important difference in droplet size distribution. The droplet size distribution of the emulsions prepared using the non-pregelatinized high-DS cationic starches was markedly narrower than in the case of the emulsions prepared using the pregelatinized high-DS cationic starches. The droplet size of the emulsions remained almost constant during 120 days of storage. Visual inspection and electrical conductance measurements showed that these emulsions were stable for at least 120 days.

  3. Physicochemical properties of quinoa flour as affected by starch interactions.

    PubMed

    Li, Guantian; Zhu, Fan

    2017-04-15

    There has been growing interest in whole grain quinoa flour for new product development due to the unique nutritional benefits. The quality of quinoa flour is much determined by the properties of its major component starch as well as non-starch components. In this study, composition and physicochemical properties of whole grain flour from 7 quinoa samples have been analyzed. Flour properties have been correlated to the flour composition and the properties of isolated quinoa starches through chemometrics. Great variations in chemical composition, swelling power, water soluble index, enzyme susceptibility, pasting, gel texture, and thermal properties of the flour have been observed. Correlation analysis showed that thermal properties and enzyme susceptibility of quinoa flour are highly influenced by the starch. Interactions of starch with non-starch components, including lipids, protein, dietary fibre, phenolics, and minerals, greatly impacted the flour properties. For example, peak gelatinization temperature of the flour is positively correlated to that of the starch (r=0.948, p<0.01) and negatively correlated to the lipid content (r=-0.951, p<0.01). Understanding the roles of starch and other components in physicochemical properties of quinoa flour provides a basis for better utilization of this specialty crop.

  4. Thermal dissolution of maize starches in aqueous medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. Humidity-responsive starch-poly (methyl acrylate) films.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blown films prepared from starch-poly(methyl acrylate) graft copolymers plasticized with urea and water display shrinkage at relative humidities greater than 50%. Shrinkage at relative humidities below approximately 75% is strongly correlated with the urea/starch weight ratio, which controls the eq...

  6. Individual mammalian mucosal glucosidase subunits digest various starch structures differently

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch digestion in the human body requires two luminal enzymes,salivary and pancreatic alpha-amylase (AMY), and four small intestinal mucosal enzyme activities related to the maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) complexes. Starch consists of two polysaccharides, amylose (AM) and ...

  7. Autophagy Contributes to Leaf Starch Degradation[C][W

    PubMed Central

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

    2013-01-01

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

  8. Effect of hydrocolloids on functional properties of navy bean starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pulses are recognized as a low-fat source of gluten-free protein, soluble fiber, B-vitamins and minerals, and their use in foods has increased in recent years. The functional properties of pulse starches have received relatively little attention, but they are important since starch is the major comp...

  9. A rapid method to determine starch damage in sorghum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a major component of cereal grains including sorghum, starch plays an important role not only in grain development but also post-maturation processing and end-product quality. Because milling can result in the inadvertent disruption of starch granules, in turn negatively affecting dough rheology...

  10. Starch-binding domain shuffling in Aspergillus niger glucoamylase.

    PubMed

    Cornett, Catherine A G; Fang, Tsuei-Yun; Reilly, Peter J; Ford, Clark

    2003-07-01

    Aspergillus niger glucoamylase (GA) consists mainly of two forms, GAI [from the N-terminus, catalytic domain + linker + starch-binding domain (SBD)] and GAII (catalytic domain + linker). These domains were shuffled to make RGAI (SBD + linker + catalytic domain), RGAIDeltaL (SBD + catalytic domain) and RGAII (linker + catalytic domain), with domains defined by function rather than by tertiary structure. In addition, Paenibacillus macerans cyclomaltodextrin glucanotransferase SBD replaced the closely related A.niger GA SBD to give GAE. Soluble starch hydrolysis rates decreased as RGAII approximately GAII approximately GAI > RGAIDeltaL approximately RGAI approximately GAE. Insoluble starch hydrolysis rates were GAI > RGAIDeltaL > RGAI > GAE approximately RGAII > GAII, while insoluble starch-binding capacities were GAI > RGAI > RGAIDeltaL > RGAII > GAII > GAE. These results indicate that: (i) moving the SBD to the N-terminus or replacing the native SBD somewhat affects soluble starch hydrolysis; (ii) SBD location significantly affects insoluble starch binding and hydrolysis; (iii) insoluble starch hydrolysis is imperfectly correlated with its binding by the SBD; and (iv) placing the P.macerans cyclomaltodextrin glucanotransferase SBD at the end of a linker, instead of closely associated with the rest of the enzyme, severely reduces its ability to bind and hydrolyze insoluble starch.

  11. Enzyme-Catalyzed Regioselective Modification of Starch Nanoparticles

    SciTech Connect

    Chakraborty, Soma; Sahoo, Bishwabhusan; Teraoka, Iwao; Miller, Lisa M.; Gross, Richard A.

    2004-12-13

    The selective esterification of starch nanoparticles was performed using as catalyst Candida antartica Lipase B (CAL-B) in its immobilized (Novozym 435) and free (SP-525) forms. The starch nanoparticles were made accessible for acylation reactions by formation of Aerosol-OT (AOT, bis(2-ethylhexyl)sodium sulfosuccinate) stabilized microemulsions. Starch nanoparticles in microemulsions were reacted with vinyl stearate, ε-caprolactone, and maleic anhydride at 40 °C for 48 h to give starch esters with degrees of substitution (DS) of 0.8, 0.6, and 0.4, respectively. Substitution occurred regioselectively at the C-6 position of the glucose repeat units. Infrared microspectroscopy (IRMS) revealed that AOT-coated starch nanoparticles diffuse into the outer 50 μm shell of catalyst beads. Thus, even though CAL-B is immobilized within a macroporous resin, CAL-B is sufficiently accessible to the starch nanoparticles. When free CAL-B was incorporated along with starch within AOT-coated reversed micelles, CAL-B was also active and catalyzed the acylation with vinyl stearate (24 h, 40 °C) to give DS = 0.5. After removal of surfactant from the modified starch nanoparticles, they were dispersed in DMSO or water and were shown to retain their nanodimensions.

  12. Milk glucosidase activity enables suckled pup starch digestion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch requires six enzymes for digestion to free glucose: two amylases (salivary and pancreatic) and four mucosal maltase activities; sucrase-isomaltase and maltase-glucoamylase. All are deficient in suckling rodents. The objective of this study is to test (13)C-starch digestion before weaning by m...

  13. Structures, physicochemical properties, and applications of amaranth starch.

    PubMed

    Zhu, Fan

    2017-01-22

    Amaranth as a rediscovered "new" crop is becoming a research focus in the recent two decades. The major carbohydrate of some amaranth species is starch, which accounts up to around 60% of the dry grains. This review summarizes the present knowledge of the isolation, composition, structures, physiochemical properties, modifications, and applications of amaranth starches, and provides suggestions for research to further improve the utilization.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Films based on oxidized starch and cellulose from barley.

    PubMed

    El Halal, Shanise Lisie Mello; Colussi, Rosana; Deon, Vinícius Gonçalves; Pinto, Vânia Zanella; Villanova, Franciene Almeida; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2015-11-20

    Starch and cellulose fibers were isolated from grains and the husk from barley, respectively. Biodegradable films of native starch or oxidized starches and glycerol with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. Cellulose fibers isolated from the barley husk were obtained with 75% purity and high crystallinity. The morphology of the films of the oxidized starches, regardless of the fiber addition, was more homogeneous as compared to the film of the native starch. The addition of cellulose fibers in the films increased the tensile strength and decreased elongation. The water vapor permeability of the film of oxidized starch with 20% of cellulose fibers was lower than the without fibers. However the films with cellulose fibers had the highest decomposition with the initial temperature and thermal stability. The oxidized starch and cellulose fibers from barley have a good potential for use in packaging. The addition of cellulose fibers in starch films can contribute to the development of films more resistant that can be applied in food systems to maintain its integrity.

  16. [Insect pests dissemination by extruded starch packages].

    PubMed

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

    2009-01-01

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

  17. Dry media blasting with wheat starch

    NASA Astrophysics Data System (ADS)

    Foster, Terry

    1995-04-01

    The brand name TECHNOSTRIP covers several types of installations and facilities. These were developed mainly to meet the requirements of customers in the aeronautic field. The range of products includes: complete self-supporting and semi-automated system for aircraft stripping; large-size blasting booth for semi-automatic stripping; manual blasting booth; and sealed and portable manual stripping head. Wheat starch media was developed for particle blasting stripping and is used in TECHNOSTRIP. This paper reviews its origins and use as well as use of automated facilities, reliability, effects on materials, effects on environment, and utilization examples.

  18. Biophysical features of cereal endosperm that decrease starch digestibility.

    PubMed

    Roman, Laura; Gomez, Manuel; Li, Cheng; Hamaker, Bruce R; Martinez, Mario M

    2017-06-01

    The influence of the physical structure of cereal endosperm on the natural structural integrity (intact cells) and starch bioaccessibility of the resultant flours was studied using maize as example. Endosperm hardness, defined by its intracellular (protein matrix) and extracellular (cell walls) constituents, affected the granular and molecular damage of the starch of the resultant flours leading to higher digestibility of raw hard than soft endosperm flours, but comparatively lower digestibility after cooking. After milling, hard endosperm possessed more damaged starch (radial splitting of amylopectin clusters) in the periphery of the resultant particles that increased in vitro starch digestibility of raw flours. Conversely, the hard endosperm plant tissue matrix significantly limited water availability and heat transfer on starch gelatinisation, thereby decreasing the digestion rate after hydrothermal processing (in particle size flours >80μm). This study provides a unique mechanistic understanding to obtain cereal flours with slow digestion property for commercial utilisation.

  19. Inhibition of wheat starch retrogradation by tea derivatives.

    PubMed

    Zhang, Haihua; Sun, Binghua; Zhang, Shikang; Zhu, Yuejin; Tian, Yaoqi

    2015-12-10

    The effect of four industrial tea derivatives (tea polyphenols [TPS], tea water-soluble extracts [TSE], tea polysaccharides [TSS], and green tea powder [GTP]), on the retrogradation of wheat starch was investigated using texture profile analysis (TPA), differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and the α-amylase-iodine method. The addition of the four tea derivatives resulted in decreased hardness and increased cohesiveness of the starch gel as shown by the TPA test. The DSC data demonstrated an increase in the enthalpy change of starch gelatinization and a decrease in the enthalpy change of starch recrystallite dissociation. The RVA results indicated that the peak viscosity, representing the intermolecular forces of wheat starch, was reduced after addition of TPS, TSE, and TSS, respectively, but was increased by GTP. Furthermore, the half crystallization time in the Avrami equation almost doubled after the separate addition of the tea derivatives.

  20. Preamylopectin Processing: A Mandatory Step for Starch Biosynthesis in Plants.

    PubMed Central

    Mouille, G.; Maddelein, M. L.; Libessart, N.; Talaga, P.; Decq, A.; Delrue, B.; Ball, S.

    1996-01-01

    It has been generally assumed that the [alpha]-(1->4)-linked and [alpha]-(1->6)-branched glucans of starch are generated by the coordinated action of elongation (starch synthases) and branching enzymes. We have identified a novel Chlamydomonas locus (STA7) that when defective leads to a wipeout of starch and its replacement by a small amount of glycogen-like material. Our efforts to understand the enzymological basis of this phenotype have led us to determine the selective disappearance of an 88-kD starch hydrolytic activity. We further demonstrate that this enzyme is a debranching enzyme. Cleavage of the [alpha]-(1->6) linkage in a branched precursor of amylopectin (preamylopectin) has provided us with the ground rules for understanding starch biosynthesis in plants. Therefore, we propose that amylopectin clusters are synthesized by a discontinuous mechanism involving a highly specific glucan trimming mechanism. PMID:12239416

  1. Sedimentation field flow fractionation monitoring of bimodal wheat starch amylolysis.

    PubMed

    Salesse, C; Battu, S; Begaud-Grimaud, G; Cledat, D; Cook-Moreau, J; Cardot, P J P

    2006-10-06

    Enzymatic starch granule hydrolysis is one of the most important reactions in many industrial processes. In this study, we investigated the capacity of sedimentation field flow fractionation (SdFFF) to monitor the amylolysis of a bimodal starch population: native wheat starch. Results demonstrated a correlation between fractogram changes and enzymatic hydrolysis. Furthermore, SdFFF was used to sort sub-populations which enhanced the study of granule size distribution changes occurring during amylolysis. These results show the interest in coupling SdFFF with particle size measurement methods to study complex starch size/density modifications associated to hydrolysis. These results suggested different applications such as the association of SdFFF with structural investigations to better understand the specific mechanisms of amylolysis or starch granule structure.

  2. Enzymatic esterification of starch using recovered coconut oil.

    PubMed

    Rajan, Akhila; Prasad, V S; Abraham, T Emilia

    2006-11-15

    Modification of maize and cassava starches was done using recovered coconut oil and microbial lipase. Microwave esterification was advantageous as it gave a DS 1.55 and 1.1 for maize starch and cassava starch, respectively. Solution state esterification of cassava starch for 36 h at 60 degrees C gave a DS of 0.08 and semi-solid state esterification gave a DS of 0.43. TGA and DSC studies showed that the higher DS attributed to the thermostability, since onset of decomposition is at a higher temperature (492 degrees C) than the unmodified (330 degrees C) and was stable above 600 degrees C. alpha-Amylase digestibility and viscosity reduced for modified starch.

  3. A review of the chemical modification techniques of starch.

    PubMed

    Masina, Nonhlanhla; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Govender, Mershen; Indermun, Sunaina; Pillay, Viness

    2017-02-10

    Starch is a naturally occurring storage copolymer with unique physicochemical properties. There are, however, some key structural properties of starch that can be modified in order to functionalize the copolymer to meet specific requirements. Specifically, the chemical modification of starch provides a variety of physicochemical benefits, some of which have been used previously to functionalize preformed drug delivery systems. Of the three main chemical modification methods reviewed (namely: oxidation, esterification and etherification), surface chemical oxidation introduces more pertinent physicochemical properties that increase overall drug delivery system efficacy and applicability. Surface oxidation evidently is the more preferable chemical modification method of pre-formed starch particles and has the greatest potential for further development when compared to the other reviewed chemical modification methods. The use of modified starch in clinical trials as well as the potential future implications of these systems is also included in this review.

  4. Kinetic expression for hydrolysis of soluble starch by glucoamylase

    SciTech Connect

    Koichiro, K.; Koel, K.; Fumihide, S.; Keiichi, K.; Mayumi, K.

    1982-01-01

    As the hydrolysis of starch by glucoamylase proceeds with stepwise removal of glucose units from the nonreducing ends of the starch chain, the number of available substrate molecules is essentially unchanged in the course of the degradation. In view of this aspect, a simple practical kinetic expression, which consists of a modified Michaelis-Menten form with product inhibition, is presented for the hydrolysis of soluble starch. It is assumed that the values of kinetic parameters Vm and Km vary linearly from the values for starch toward those for maltose. The applicability of this kinetic expression is verified through the simulation with the experimental results for the hydrolysis of two soluble starches with different average molecular weights of 3 X 10 to the power of 4 and 3 X 10 to the power of 6. (Refs. 12)>

  5. Enzymatic modification of corn starch with 4-α-glucanotransferase results in increasing slow digestible and resistant starch.

    PubMed

    Jiang, Huan; Miao, Ming; Ye, Fan; Jiang, Bo; Zhang, Tao

    2014-04-01

    In this study, partial 4-α-glucanotransferase (4αGT) treatment was used to modulate the fine structure responsible for the slow digestion and resistant property of starch. Normal corn starch modified using 4αGT for 4h showed an increase of slowly digestible starch from 9.40% to 20.92%, and resistant starch from 10.52 to 17.63%, respectively. The 4αGT treatment decreased the content of amylose from 32.6% to 26.8%. The molecular weight distribution and chain length distribution of 4αGT-treated starch showed a reduction of molecular weight and a great number of short (DP<13) and long (DP>30) chains through cleaving and reorganization of starch molecules. Both the short and long chain fractions of modified amylopectin were attributed to the low in vitro digestibility. The viscosity was inversely related to the digestibility of the 4αGT-treated starch. These results suggested that the 4αGT modified starch synthesized the novel amylopectin clusters with slow digestible and resistant character.

  6. Teaching portfolios: documenting teaching.

    PubMed

    Regan-Smith, M G

    1998-01-01

    In recent years, teaching portfolios have been developed as a way teachers can document teaching scholarship and demonstrate their teaching accomplishments, skills, and strategies. Most medical schools reward good teaching, often with promotion on clinician-teacher tracks, thereby acknowledging the contributions made by clinical faculty who serve the academic mission as teachers. Teaching portfolios provide a means for teachers to demonstrate their teaching achievements and display their best work. This article gives recommendations for constructing a teaching portfolio and includes examples of what can be included.

  7. Simultaneous saccharification and cofermentation of lignocellulosic residues from commercial furfural production and corn kernels using different nutrient media

    PubMed Central

    2011-01-01

    Background As the supply of starch grain and sugar cane, currently the main feedstocks for bioethanol production, become limited, lignocelluloses will be sought as alternative materials for bioethanol production. Production of cellulosic ethanol is still cost-inefficient because of the low final ethanol concentration and the addition of nutrients. We report the use of simultaneous saccharification and cofermentation (SSCF) of lignocellulosic residues from commercial furfural production (furfural residue, FR) and corn kernels to compare different nutritional media. The final ethanol concentration, yield, number of live yeast cells, and yeast-cell death ratio were investigated to evaluate the effectiveness of integrating cellulosic and starch ethanol. Results Both the ethanol yield and number of live yeast cells increased with increasing corn-kernel concentration, whereas the yeast-cell death ratio decreased in SSCF of FR and corn kernels. An ethanol concentration of 73.1 g/L at 120 h, which corresponded to a 101.1% ethanol yield based on FR cellulose and corn starch, was obtained in SSCF of 7.5% FR and 14.5% corn kernels with mineral-salt medium. SSCF could simultaneously convert cellulose into ethanol from both corn kernels and FR, and SSCF ethanol yield was similar between the organic and mineral-salt media. Conclusions Starch ethanol promotes cellulosic ethanol by providing important nutrients for fermentative organisms, and in turn cellulosic ethanol promotes starch ethanol by providing cellulosic enzymes that convert the cellulosic polysaccharides in starch materials into additional ethanol. It is feasible to produce ethanol in SSCF of FR and corn kernels with mineral-salt medium. It would be cost-efficient to produce ethanol in SSCF of high concentrations of water-insoluble solids of lignocellulosic materials and corn kernels. Compared with prehydrolysis and fed-batch strategy using lignocellulosic materials, addition of starch hydrolysates to cellulosic

  8. Mango starch degradation. II. The binding of alpha-amylase and beta-amylase to the starch granule.

    PubMed

    Peroni, Fernanda Helena Gonçalves; Koike, Claudia; Louro, Ricardo Pereira; Purgatto, Eduardo; do Nascimento, João Roberto Oliveira; Lajolo, Franco Maria; Cordenunsi, Beatriz Rosana

    2008-08-27

    During mango ripening, soluble sugars that account for mango sweetening are accumulated through carbon supplied by both photosynthesis and starch degradation. The cultivar Keitt has a characteristic dependence on sugar accumulation during starch degradation, which takes place during ripening, only a few days after detachment from the tree. Most knowledge about starch degradation is based on seeds and leaves currently used as models. However, information about the mango fruit is scarce. This work presents the evaluation of alpha- and beta-amylases in the starch granule surface during fruit development and ripening. Extractable proteins were assayed for amylase activity and detected by immunofluorescence microscopy and correlated to gene expression. The results suggest that both amylases are involved in starch degradation during mango ripening, probably under the dependence of another signal triggered by the detachment from the mother-plant.

  9. Structure of raw starch-digesting Bacillus cereus beta-amylase complexed with maltose.

    PubMed

    Mikami, B; Adachi, M; Kage, T; Sarikaya, E; Nanmori, T; Shinke, R; Utsumi, S

    1999-06-01

    The crystals of beta-amylase from Bacillus cereus belong to space group P21 with the following cell dimensions: a = 57.70 A, b = 92.87 A, c = 65.93 A, and beta =101.95 degrees. The structures of free and maltose-bound beta-amylases were determined by X-ray crystallography at 2.1 and 2.5 A with R-factors of 0.170 and 0.164, respectively. The final model of the maltose-bound form comprises 516 amino acid residues, four maltose molecules, 275 water molecules, one Ca2+, one acetate, and one sulfate ion. The enzyme consists of a core (beta/alpha)8-barrel domain (residues 5-434) and a C-terminal starch-binding domain (residues 435-613). Besides the active site in the core where two maltose molecules are bound in tandem, two novel maltose-binding sites were found in the core L4 region and in the C-terminal domain. The structure of the core domain is similar to that of soybean beta-amylase except for the L4 maltose-binding site, whereas the C-terminal domain has the same secondary structure as domain E of cyclodextrin glucosyltransferase. These two maltose-binding sites are 32-36 A apart from the active site. These results indicate that the ability of B. cereus beta-amylase to digest raw starch can be attributed to the additional two maltose-binding sites.

  10. Regulatory guidance document

    SciTech Connect

    1994-05-01

    The Office of Civilian Radioactive Waste Management (OCRWM) Program Management System Manual requires preparation of the OCRWM Regulatory Guidance Document (RGD) that addresses licensing, environmental compliance, and safety and health compliance. The document provides: regulatory compliance policy; guidance to OCRWM organizational elements to ensure a consistent approach when complying with regulatory requirements; strategies to achieve policy objectives; organizational responsibilities for regulatory compliance; guidance with regard to Program compliance oversight; and guidance on the contents of a project-level Regulatory Compliance Plan. The scope of the RGD includes site suitability evaluation, licensing, environmental compliance, and safety and health compliance, in accordance with the direction provided by Section 4.6.3 of the PMS Manual. Site suitability evaluation and regulatory compliance during site characterization are significant activities, particularly with regard to the YW MSA. OCRWM`s evaluation of whether the Yucca Mountain site is suitable for repository development must precede its submittal of a license application to the Nuclear Regulatory Commission (NRC). Accordingly, site suitability evaluation is discussed in Chapter 4, and the general statements of policy regarding site suitability evaluation are discussed in Section 2.1. Although much of the data and analyses may initially be similar, the licensing process is discussed separately in Chapter 5. Environmental compliance is discussed in Chapter 6. Safety and Health compliance is discussed in Chapter 7.

  11. ExactPack Documentation

    SciTech Connect

    Singleton, Jr., Robert; Israel, Daniel M.; Doebling, Scott William; Woods, Charles Nathan; Kaul, Ann; Walter, Jr., John William; Rogers, Michael Lloyd

    2016-05-09

    For code verification, one compares the code output against known exact solutions. There are many standard test problems used in this capacity, such as the Noh and Sedov problems. ExactPack is a utility that integrates many of these exact solution codes into a common API (application program interface), and can be used as a stand-alone code or as a python package. ExactPack consists of python driver scripts that access a library of exact solutions written in Fortran or Python. The spatial profiles of the relevant physical quantities, such as the density, fluid velocity, sound speed, or internal energy, are returned at a time specified by the user. The solution profiles can be viewed and examined by a command line interface or a graphical user interface, and a number of analysis tools and unit tests are also provided. We have documented the physics of each problem in the solution library, and provided complete documentation on how to extend the library to include additional exact solutions. ExactPack’s code architecture makes it easy to extend the solution-code library to include additional exact solutions in a robust, reliable, and maintainable manner.

  12. Effect of cultivar, location and year on total starch, amylose, phosphorus content and starch grain size of high starch potato cultivars for food and industrial processing.

    PubMed

    Šimková, Dagmar; Lachman, Jaromír; Hamouz, Karel; Vokál, Bohumil

    2013-12-15

    In recent time the interest of industry increases particularly in processing and use of potato high amylopectin (AMP) starches. Therefore the plant breeders effort to obtain "waxy" potato cultivars with low amylose (AMS) content. In this four-year study sixteen potato cultivars grown on five experimental locations were evaluated on the percentage of AMS/AMP by enzymatic method, starch content by the underwater weight method, phosphorus (P) content in starch digests spectrophotometrically, and starch granule size determined by laser diffraction method. Between enzymatic and iodine-potassium iodide method good correlation has been revealed (r=0.71). The correlation analysis between AMS and P levels showed a clear negative correlation. For all measured parameters (starch, AMS, P, starch granule size) significant impact of cultivar has been determined. Location and year have lower, but significant impact. No statistically significant effect of year on AMS has been found. The cultivar Amado distinguished with the highest AMP and P contents and the cultivar Westamyl showed all positive values interesting for growers and processors.

  13. Effect of compression force and corn starch on tablet disintegration time.

    PubMed

    Hill, P M

    1976-11-01

    An unusual occurrence of decreasing tablet disintegration time with increasing tablet hardness was explored. Tablets were made with varying ratios of starch disintegrant to starch paste and compressed with eight different forces. This unusual disintegration pattern is modified by changes in the starch ratios. The reason for this phenomenon is ascribed to gain swelling as the mechanism by which starch acts as a disintegrant.

  14. Preparation and Physical Properties of Starch Stearates of Low to High Degree of Substitution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch stearates of degree of substitution (DS) 0.07-2.40 were prepared by heating dry starch and vinyl stearate in the ionic liquid BMIM dca at 75 Degrees C. Starch stearate of low DS (0.07) was insoluble in water but formed a gel and absorbed over seven times its weight of water. Starch stearate...

  15. Effect of dietary starch source and concentration on equine fecal microbiota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assig...

  16. 40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... wheat starch and gluten subcategory. 406.100 Section 406.100 Protection of Environment ENVIRONMENTAL... Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten... operations utilizing wheat flour as a raw material for production of wheat starch and gluten...

  17. Slowly digestible starch diets alter proximal glucosidase activity and glucose absorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrase-isomaltase (Si) and maltase-glucoamylase (Mgam) are mucosal glucosidases required for digestion of starch to glucose. Ablation of maltase-Mgam reduces in vivo starch digestion. We tested whether slowly digestible starch diets induce changes in glucosidase activities. Rice starch was encaps...

  18. Influence of starch source on sporulation and enterotoxin production by Clostridium perfringens type A.

    PubMed

    Labbe, R; Somers, E; Duncan, C

    1976-03-01

    Of 16 different starch preparations tested, Clostridium perfringes NCTC 8798 yielded maximum sporulation and enterotoxin formation when ICN-soluble starch was included in Duncan and Strong sporulation medium. In general soluble starches were better than potato, corn, or arrowroot starch with regard to these two parameters.

  19. Chemical composition, mineral profile, and functional properties of Canna (Canna edulis) and Arrowroot (Maranta spp.) starches.

    PubMed

    Pérez, Elevina; Lares, Mary

    2005-09-01

    The aim of the present study was to evaluate some chemical and mineral characteristics and functional and rheological properties of Canna and Arrowroot starches produced in the Venezuelan Andes. Canna starch showed a higher (P < 0.05) moisture, ash, and crude protein content than arrowroot starch, while crude fiber, crude fat, and amylose content of this starch were higher (P < 0.05). Starches of both rhizomes own phosphorus, sodium, potassium, magnesium, iron, calcium, and zinc in their composition. Phosphorus, sodium, and potassium are the higher in both starches. Water absorption, swelling power, and solubility values revealed weak bonding forces in Canna starch granules; this explained the lower gelatinization temperature and the substantial viscosity development of Canna starch during heating. Arrowroot starch showed a higher gelatinization temperature measure by DSC, than Canna starch and exhibited a lower value of DeltaH. Both starches show negative syneresis. The apparent viscosity of Canna starch was higher (P < 0.05) than the Arrowroot starch values. The size (wide and large) of Canna starch granules was higher than arrowroot starch. From the previous results, it can be concluded that Canna and Arrowroot starches could become interesting alternatives for food developers, depending on their characteristics and functional properties.

  20. One minute after the detonation of the atomic bomb: the erased effects of residual radiation.

    PubMed

    Takahashi, Hiroko

    2009-01-01

    The U.S. Government's official narrative denies the effects of residual radiation which appeared one minute after the atomic bomb detonations in Hiroshima and Nagasaki. This paper explores declassified documents from the U.S. Atomic Energy Commission, the Atomic Bomb Casualties Commission, and others and shows that these documents actually suggested the existence of serious effects from residual radiation.

  1. Processing surface sizing starch using oxidation, enzymatic hydrolysis and ultrasonic treatment methods--Preparation and application.

    PubMed

    Brenner, Tobias; Kiessler, Birgit; Radosta, Sylvia; Arndt, Tiemo

    2016-03-15

    The surface application of starch is a well-established method for increasing paper strength. In surface sizing, a solution of degraded starch is applied to the paper. Two procedures have proved valuable for starch degradation in the paper mill: enzymatic and thermo-oxidative degradation. The objective of this study was to determine achievable efficiencies of cavitation in preparing degraded starch for surface application on paper. It was found that ultrasonic-assisted starch degradation can provide a starch solution that is suitable for surface sizing. The molecular composition of starch solutions prepared by ultrasonic treatment differed from that of starch solutions degraded by enzymes or by thermo-oxidation. Compared to commercial degradation processes, this resulted in intensified film formation and in greater penetration during surface sizing and ultimately in a higher starch content of the paper. Paper sized with ultrasonically treated starch solutions show the same strength properties compared to commercially sized paper.

  2. Structural features and thermal property of propionylated starches with different amylose/amylopectin ratio.

    PubMed

    Zhu, Jie; Zhang, Shuyan; Zhang, Binjia; Qiao, Dongling; Pu, Huayin; Liu, Siyuan; Li, Lin

    2017-04-01

    This work concerned the effects of amylose/amylopectin ratio on the structure and thermal stability of propionylated starches with high degree of substitution (DS). Four starches with different amylose content were used to obtain propionylated starches. Acylation partly disrupted granule morphology of native starches, and the imperfection and porous structures of starch granule were intensified along with the increased amylose content. It was noted that the crystalline structure of starch was destroyed and thus intense acylation occurred in both amorphous and crystalline regions. The acylated starch with high-amylose content displayed more ordered region compared to low-amylose starch. Acylation enhanced the thermal stability of starch, and this effect became more evident as the amylose content increased. Thus, the amylose/amylopectin ratio has been confirmed capable of affecting the structure and thermal behaviors of hydrophobic propionylated starch, which is of value for the design of starchy materials with tailored thermal stability.

  3. Effects of grain development on formation of resistant starch in rice.

    PubMed

    Shu, Xiaoli; Sun, Jian; Wu, Dianxing

    2014-12-01

    Three rice mutants with different contents of resistant starch (RS) were selected to investigate the effects of grain filling process on the formation of resistant starch. During grain development, the content of RS was increased with grain maturation and showed negative correlations with the grain weight and the starch molecular weight (Mn, Mw) and a positive correlation with the distribution of molecular mass (polydispersity, Pd). The morphologies of starch granules in high-RS rice were almost uniform in single starch granules and exhibited different proliferation modes from common rice. The lower activities of ADP-glucose pyrophosphorylase and starch branching enzyme and the higher activity of starch synthase and starch de-branching enzyme observed in high-RS rice might be responsible for the formation of small irregular starch granules with large spaces between them. In addition, the lower molecular weight and the broad distribution of molecular weights lead to differences in the physiochemical properties of starch.

  4. Structural properties and digestibility of pulsed electric field treated waxy rice starch.

    PubMed

    Zeng, Feng; Gao, Qun-Yu; Han, Zhong; Zeng, Xin-An; Yu, Shu-Juan

    2016-03-01

    Waxy rice starch was subjected to pulsed electric field (PEF) treatment at intensity of 30, 40 and 50kVcm(-1). The impact of PEF treatment on the granular morphology, molecular weight, semi-crystalline structure, thermal properties, and digestibility were investigated. The micrographs suggested that electric energy could act on the granule structure of starch granule, especially at high intensity of 50kVcm(-1). Gelatinization onset temperature, peak temperature, conclusion temperature and enthalpy value of PEF treated starches were lower than that of native starch. The 9nm lamellar peak of PEF treated starches decreased as revealed by small angle X-ray scattering. The relative crystallinity of treated starches decreased as the increase of electric field intensity. Increased rapidly digestible starch level and decreased slowly digestible starch level was found on PEF treated starches. These results would imply that PEF treatment induced structural changes in waxy rice starch significantly affected its digestibility.

  5. Characterization of starch from two ecotypes of andean achira roots (Canna edulis).

    PubMed

    Cisneros, Fausto H; Zevillanos, Roberto; Cisneros-Zevallos, Luis

    2009-08-26

    Starches from two ecotypes of achira roots (Canna edulis Ker-Gawler) were characterized and compared to commercial potato and corn starches. This included scanning electron microscopy (SEM) of starch granules and amylose content determination of starch. Starch solutions or gels were tested by rotational viscometry, Rapid Visco Analyzer (RVA), and texture analysis. Some starch samples were subjected to various treatments: pH reduction, autoclaving at high temperature, and high shear before testing by rotational viscometry. Achira starch showed some unusual properties, such as very large oblong granules (approximately 45-52 microm major axis and approximately 33-34 microm minor axis) and relatively high amylose content (approximately 33-39%). The San Gaban achira ecotype formed high-consistency gels upon cooling, both in RVA study (5% starch) and in texture analysis (8% starch), compared to other starch gels and also exhibited higher thermal resistance to viscosity breakdown.

  6. Structure and digestibility of debranched and repeatedly crystallized waxy rice starch.

    PubMed

    Zeng, Feng; Chen, Fuquan; Kong, Fansheng; Gao, Qunyu; Aadil, Rana Muhammad; Yu, Shujuan

    2015-11-15

    Debranched waxy rice starch was subjected to repeated crystallization (RC) treatment, and its physicochemical properties and digestion pattern were investigated. The A-type crystalline pattern of native starch was crystallized to a complex of B- and V-type patterns by debranching and RC treatment. Among the treated starches, the relative crystallinity of debranched starch reached its maximum (29.6%) after eight repetitions of crystallization. Changes in weight-average molar mass among treated starch samples were not significantly different. The repeated-crystallized starches showed higher thermal transition temperatures and melting enthalpy than that of debranched starch. As a result, slowly digestible starch (SDS) content of repeated-crystallized starches reached a very high level (57.8%). Results showed that RC treatment induced structural changes of waxy rice starch result in a great amount of SDS.

  7. Method and apparatus for imaging and documenting fingerprints

    DOEpatents

    Fernandez, Salvador M.

    2002-01-01

    The invention relates to a method and apparatus for imaging and documenting fingerprints. A fluorescent dye brought in intimate proximity with the lipid residues of a latent fingerprint is caused to fluoresce on exposure to light energy. The resulting fluorescing image may be recorded photographically.

  8. Rheological and biochemical properties of Solanum lycocarpum starch.

    PubMed

    Di-Medeiros, Maria Carolina B; Pascoal, Aline M; Batista, Karla A; Bassinello, Priscila Z; Lião, Luciano M; Leles, Maria Inês G; Fernandes, Kátia F

    2014-04-15

    This study was conducted to evaluate the rheological and physicochemical properties of Solanum lycocarpum starch. The thermogravimetric analysis of S. lycocarpum starch showed a typical three-step weight loss pattern. Microscopy revealed significant changes in the granule morphology after hydrothermal treatment. Samples hydrothermally treated at 50°C for 10 min lost 52% of their crystallinity, which was recovered after storage for 7 days at 4°C. However, samples hydrothermally treated at 65°C were totally amorphous. This treatment was sufficient to completely disrupt the starch granule, as evidenced by the absence of an endothermic peak in the DSC thermogram. The RVA of S. lycocarpum starch revealed 4440.7cP peak viscosity, 2660.5cP breakdown viscosity, 2414.1cP final viscosity, 834.3cP setback viscosity, and a pasting temperature of 49.6°C. The low content of resistant starch (10.25%) and high content of digestible starch (89.78%) in S. lycocarpum suggest that this starch may be a good source for the production of hydrolysates, such as glucose syrup and its derivatives.

  9. Extraction and chemical characterization of starch from S. lycocarpum fruits.

    PubMed

    Pascoal, Aline M; Di-Medeiros, Maria Carolina B; Batista, Karla A; Leles, Maria Inês Gonçalves; Lião, Luciano Moraes; Fernandes, Kátia F

    2013-11-06

    In this study the pulp from Solanum lycocarpum fruits was used as raw material for extraction of starch, resulting in a yield of 51%. The starch granules were heterogeneous in size, presenting a conical appearance, very similar to a high-amylose cassava starch. The elemental analysis (CHNS) revealed 64.33% carbon, 7.16% hydrogen and 0.80% nitrogen. FT-IR spectroscopy showed characteristic peaks of polysaccharides and NMR analysis confirmed the presence of the α-anomer of d-glucose. The S. lycocarpum starch was characterized by high value of intrinsic viscosity (3515 mPa s) and estimated molecular weight around 645.69 kDa. Furthermore, this starch was classified as a B-type and high amylose content starch, presenting 34.66% of amylose and 38% crystallinity. Endothermic transition temperatures (To=61.25 °C, Tp=64.5 °C, Tc=67.5 °C), gelatinization temperature (ΔT=6.3 °C) ranges and enthalpy changes (ΔH=13.21 J g(-1)) were accessed by DCS analysis. These results make the S. lycocarpum fruit a very promising source of starch for biotechnological applications.

  10. Thermal characteristics of ohmically heated rice starch and rice flours.

    PubMed

    An, H J; King, J M

    2007-01-01

    Thermal properties of conventionally and ohmically heated rice starch and rice flours at various frequencies and voltages were studied. There was an increase in gelatinization temperature for conventionally heated rice starches since they were pregelatinized and became more rigid due to starch-chain interactions. In addition, there was a decrease in enthalpy (energy needed) for conventionally and ohmically heated starches during gelatinization; thus, the samples required less energy for gelatinization during DSC analysis. Ohmically heated commercial starch showed the greatest decrease in enthalpy probably because of the greatest extent of pregelatinization through ohmic heating. Brown rice flour showed the greatest gelatinization temperature resulting from the delay of starch granule swelling by lipid and protein. Enthalpy of ohmically heated starches at 20 V/cm was the lowest, which was most likely due to the lower voltage resulting in a more complete pregelatinization from a longer heating time required to reach 100 degrees C. Ohmic treatment at 70 V/cm decreased onset gelatinization temperature of white flour; therefore, it produced rice flour that swelled faster, whereas the conventionally heated sample showed a better thermal resistance.

  11. Corn porous starch: preparation, characterization and adsorption property.

    PubMed

    Zhang, Bing; Cui, Dapeng; Liu, Mingzhu; Gong, Honghong; Huang, Yinjuan; Han, Fei

    2012-01-01

    This study was carried out to develop a new type of modified starch based on α-amylase and glucoamylase. The structural and chemical characteristics of the porous starch were determined by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The potential application of the porous starch as an adsorbent was evaluated using methyl violet as an adsorbed model. The adsorption capacity was optimized by investigating the reaction factors, including the mass ratio of α-amylase to glucoamylase (m(α-amylase)/m(glucoamylase)), the mass ratio of total amount of enzymes to starch (m(enzyme)/m(St)), the ratio of liquid volume to starch mass (V(H2O)/M(St)), pH value of the reaction solution, enzymatic reaction temperature, and enzymatic reaction time. The hydrolysis ratio of each sample was also determined to investigate the effect of different reaction conditions on the hydrolysis degree. The results suggest that the porous starch has a more excellent adsorption capacity than the native starch, and may be expected to have wide potential applications in many fields.

  12. Ovary starch reserves and pistil development in avocado (Persea americana).

    PubMed

    Alcaraz, M Librada; Hormaza, J Ignacio; Rodrigo, Javier

    2010-12-01

    In avocado, only a very small fraction of the flowers are able to set fruit. Previous work in other woody perennial plant species has shown the importance of carbohydrates accumulated in the flower in the reproductive process. Thus, in order to explore the implications of the nutritive status of the flower in the reproductive process in avocado, the starch content in the pistil has been examined in individual pollinated and non-pollinated flowers at anthesis and during the days following anthesis. Starch content in different pistilar tissues in each flower was quantified with the help of an image analysis system attached to a microscope. Flowers at anthesis were rich in highly compartmentalized starch. Although no external morphological differences could be observed among flowers, the starch content varied widely at flower opening. Starch content in the ovary is largely independent of flower size because these differences were not correlated with ovary size. Differences in the progress of starch accumulation within the ovule integuments between pollinated and non-pollinated flowers occurred concomitantly with the triggering of the progamic phase. The results suggest that starch reserves in the ovary could play a significant role in the reproductive process in avocado.

  13. Starch hydrolysis modeling: application to fuel ethanol production.

    PubMed

    Murthy, Ganti S; Johnston, David B; Rausch, Kent D; Tumbleson, M E; Singh, Vijay

    2011-09-01

    Efficiency of the starch hydrolysis in the dry grind corn process is a determining factor for overall conversion of starch to ethanol. A model, based on a molecular approach, was developed to simulate structure and hydrolysis of starch. Starch structure was modeled based on a cluster model of amylopectin. Enzymatic hydrolysis of amylose and amylopectin was modeled using a Monte Carlo simulation method. The model included the effects of process variables such as temperature, pH, enzyme activity and enzyme dose. Pure starches from wet milled waxy and high-amylose corn hybrids and ground yellow dent corn were hydrolyzed to validate the model. Standard deviations in the model predictions for glucose concentration and DE values after saccharification were less than ± 0.15% (w/v) and ± 0.35%, respectively. Correlation coefficients for model predictions and experimental values were 0.60 and 0.91 for liquefaction and 0.84 and 0.71 for saccharification of amylose and amylopectin, respectively. Model predictions for glucose (R2 = 0.69-0.79) and DP4+ (R2 = 0.8-0.68) were more accurate than the maltotriose and maltose for hydrolysis of high-amylose and waxy corn starch. For yellow dent corn, simulation predictions for glucose were accurate (R2 > 0.73) indicating that the model can be used to predict the glucose concentrations during starch hydrolysis.

  14. Modification of Cilembu sweet potato starch with ethanoic acid

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  15. Starch nanocrystals based hydrogel: Construction, characterizations and transdermal application.

    PubMed

    Bakrudeen, Haja Bava; Sudarvizhi, C; Reddy, B S R

    2016-11-01

    Bio-based nanocomposites were prepared using starch nanocrystals obtained by acid hydrolysis of native starches using different acid sources. In recent times, focuses on starch nanocrystals (SNCs) have been increasing in number of research works dedicated to the development of bio-nanocomposites by blending with different biopolymeric matrices. The work mainly deals with the preparation of starch nanocrystals using different native starches by acid hydrolysis using hydrochloric acid and trifluroacetic acid. The as-prepared starch nanocrystals are having high crystallinity and more platelet morphologies, and used as a drug carrying filler material in the hydrogel formulations with the care of different polymer matrices. The condensed work also concentrates on the dispersion of antiviral drug in the hydrogels, which are applied onto biocompatible bio-membrane to be formulating a complete transdermal patch. The acid hydrolysed starch nanocrystals were thoroughly characterized using TEM, SEM, particle size analysis and zeta potential. Their thermal stability and the crystalline properties were also characterized using TG-DSC and XRD respectively. The physiochemical interaction and compatibility between the drug and the SNCs filler in the polymeric hydrogels were evaluated using FT-IR analysis. The formulated hydrogels were subjected to evaluation of in vitro permeation studies using Franz diffusion studies. The in vitro study was indicated substantial guarantee for the fabrication of drug dispersed in polymeric hydrogels using SNCs as filler matrices for a successful transdermal drug delivery.

  16. Physicochemical Properties of Starch from Dioscorea pyrifolia tubers.

    PubMed

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

    2017-04-01

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

  17. Gravitropism in roots of intermediate-starch mutants of Arabidopsis

    NASA Technical Reports Server (NTRS)

    Kiss, J. Z.; Wright, J. B.; Caspar, T.

    1996-01-01

    Gravitropism was studied in roots of wild type (WT) Arabidopsis thaliana (L.) Heynh. (strain Wassilewskija) and three starch-deficient mutants that were generated by T-DNA insertional mutagenesis. One of these mutants was starchless while the other two were intermediate mutants, which had 51% and 60%, respectively, of the WT amount of starch as determined by light and electron microscopy. The four parameters used to assay gravitropism were: orientation during vertical growth, time course of curvature, induction, and intermittent stimulation experiments. WT roots were much more responsive to gravity than were roots of the starchless mutant, and the intermediate starch mutants exhibited an intermediate graviresponse. Our data suggest that lowered starch content in the mutants primarily affects gravitropism rather than differential growth because both phototropic curvature and growth rates were approximately equal among all four genotypes. Since responses of intermediate-starch mutants were closer to the WT response than to the starchless mutant, it appears that 51-60% of the WT level of starch is near the threshold amount needed for full gravitropic sensitivity. While other interpretations are possible, the data are consistent with the starch statolith hypothesis for gravity perception in that the degree of graviresponsiveness is proportional to the total mass of plastids per cell.

  18. Cereal Starch Nanoparticles- A Prospective Food Additive: A Review.

    PubMed

    Kaur, Jashandeep; Kaur, Gurkirat; Sharma, Savita; Jeet, Kiran

    2016-11-10

    Starch is one of the most abundant biopolymers in nature and is typically isolated from plants in the form of micro-scale granules. Raw starch has limited applications due to its innate disadvantages such as poor solubility in cold water, tendency to retrograde and high viscosity once it is gelatinized. Therefore, some degree of modification is required to enhance its functionality. Starch nanoparticle is one of the products of such modification. Chemical, enzymatic, and physical treatments are used for the preparation of starch nanoparticles and to study their granular and molecular structures. Characterization of starch nanoparticles on the size distribution, crystalline structure, and physical properties in relation to the starch sources and preparation methods can be done using various characterization tools e.g. Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Florescence Microscopy, etc. Starch nanoparticles can be used as a food additive as it has adverse range of uses in food such as emulsion stabilizer, fat replacer, Thickener or rheology modifier etc.

  19. Tribology of swollen starch granule suspensions from maize and potato.

    PubMed

    Zhang, Bin; Selway, Nichola; Shelat, Kinnari J; Dhital, Sushil; Stokes, Jason R; Gidley, Michael J

    2017-01-02

    The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications.

  20. [Unpublished documents concerning Dupuytren].

    PubMed

    Boulinier, G

    1996-01-01

    In the present paper is proposed a first incursion in various archives - mainly notarial ones - concerning Dupuytren and his close relatives, investigated by the author. They will be more thoroughly dealt with in a forthcoming book. These documents give us a better knowledge of various events of Dupuytren's public and private life. They namely disclose the great challenge shown by the surgeon-in-chief of the Hôtel-Dieu in marrying his daughter Adeline in the midst of the Paris cholera epidemic in 1832. They show moreover in this unusual character the essential role continually played by some preoccupations such as nobility, power, religion and wealth, amidst a family of which he is the only member to have shown the ambition to become famous in the medical field.

  1. Wind system documentation

    SciTech Connect

    Froggatt, J.R.; Tatum, C.P.

    1993-01-15

    Atmospheric transport and diffusion models have been developed by the Environmental Technology Section (ETS) of the Savannah River Technology Center to calculate the location and concentration of toxic or radioactive materials during an accidental release at the Savannah River Site (SRS). The output from these models has been used to support initial on-site and off-site emergency response activities such as protective action decision making and field monitoring coordination. These atmospheric transport and diffusion models have been incorporated into an automated computer-based system called the (Weather Information and Display) System and linked to real-time meteorological and radiological monitoring instruments to provide timely information for these emergency response activities (Hunter, 1990). This report documents various aspects of the WIND system.

  2. Hot-melt extrusion of sugar-starch-pellets.

    PubMed

    Yeung, Chi-Wah; Rein, Hubert

    2015-09-30

    Sugar-starch-pellets (syn. sugar spheres) are usually manufactured through fluidized bed granulation or wet extrusion techniques. This paper introduces hot-melt extrusion (HME) as an alternative method to manufacture sugar-starch-pellets. A twin-screw extruder coupled with a Leistritz Micro Pelletizer (LMP) cutting machine was utilized for the extrusion of different types (normal-, waxy-, and high-amlyose) of corn starch, blended with varying amounts of sucrose. Pellets were characterized for their physicochemical properties including crystallinity, particle size distribution, tensile strength, and swelling expansion. Furthermore, the influence of sugar content and humidity on the product was investigated. Both sucrose and water lowered the Tg of the starch system allowing a convenient extrusion process. Mechanical strength and swelling behavior could be associated with varying amylose and amylopectin. X-ray powder diffractometric (XRPD) peaks of increasing sucrose contents appeared above 30%. This signified the oversaturation of the extruded starch matrix system with sucrose. Otherwise, had the dissolved sucrose been embedded into the molten starch matrix, no crystalline peak could have been recognized. The replacement of starch with sucrose reduced the starch pellets' swelling effect, which resulted in less sectional expansion (SEI) and changed the surface appearance. Further, a nearly equal tensile strength could be detected for sugar spheres with more than 40% sucrose. This observation stands in good relation with the analyzed values of the commercial pellets. Both techniques (fluidized bed and HME) allowed a high yield of spherical pellets (less friability) for further layering processes. Thermal influence on the sugar-starch system is still an obstacle to be controlled.

  3. Eukaryotic starch degradation: integration of plastidial and cytosolic pathways.

    PubMed

    Fettke, Joerg; Hejazi, Mahdi; Smirnova, Julia; Höchel, Erik; Stage, Marion; Steup, Martin

    2009-01-01

    Starch is an important plant product widely used as a nutrient, as a source of renewable energy, and for many technological applications. In plants, starch is the almost ubiquitous storage carbohydrate whereas most heterotrophic prokaryotes and eukaryotes rely on glycogen. Despite close similarities in basic chemical features, starch and glycogen differ in both structural and physicochemical properties. Glycogen is a hydrosoluble macromolecule with evenly distributed branching points. Starch exists as a water-insoluble particle having a defined (and evolutionary conserved) internal structure. The biochemistry of starch requires the co-operation of up to 40 distinct (iso)enzymes whilst approximately 10 (iso)enzymes permit glycogen metabolism. The biosynthesis and degradation of native starch include the transition of carbohydrates from the soluble to the solid phase and vice versa. In this review, two novel aspects of the eukaryotic plastidial starch degradation are discussed: Firstly, biochemical reactions that take place at the surface of particulate glucans and mediate the phase transition of carbohydrates. Secondly, processes that occur downstream of the export of starch-derived sugars into the cytosol. Degradation of transitory starch mainly results in the formation of neutral sugars, such as glucose and maltose, that are transported into the cytosol via the respective translocators. The cytosolic metabolism of the neutral sugars includes the action of a hexokinase, a phosphoglucomutase, and a transglucosidase that utilizes high molecular weight glycans as a transient glucosyl acceptor or donor. Data are included on the transglucosidase (disproportionating isozyme 2) in Cyanophora paradoxa that accumulates storage carbohydrates in the cytosol rather than in the plastid.

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

    PubMed

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

    2011-01-01

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

  5. Isomalto/malto-polysaccharide, a novel soluble dietary fiber made via enzymatic conversion of starch.

    PubMed

    Leemhuis, Hans; Dobruchowska, Justyna M; Ebbelaar, Monique; Faber, Folkert; Buwalda, Pieter L; van der Maarel, Marc J E C; Kamerling, Johannis P; Dijkhuizen, Lubbert

    2014-12-10

    Dietary fibers are at the forefront of nutritional research because they positively contribute to human health. Much of our processed foods contain, however, only small quantities of dietary fiber, because their addition often negatively affects the taste, texture, and mouth feel. There is thus an urge for novel types of dietary fibers that do not cause unwanted sensory effects when applied as ingredient, while still positively contributing to the health of consumers. Here, we report the generation and characterization of a novel type of soluble dietary fiber with prebiotic properties, derived from starch via enzymatic modification, yielding isomalto/malto-polysaccharides (IMMPs), which consist of linear (α1 → 6)-glucan chains attached to the nonreducing ends of starch fragments. The applied Lactobacillus reuteri 121 GTFB 4,6-α-glucanotransferase enzyme synthesizes these molecules by transferring the nonreducing glucose moiety of an (α1 → 4)-glucan chain to the nonreducing end of another (α1 → 4)-α-glucan chain, forming an (α1 → 6)-glycosidic linkage. Once elongated in this way, the molecule becomes a better acceptor substrate and is then further elongated with (α1 → 6)-linked glucose residues in a linear way. Comparison of 30 starches, maltodextrins, and α-glucans of various botanical sources, demonstrated that substrates with long and linear (α1 → 4)-glucan chains deliver products with the highest percentage of (α1 → 6) linkages, up to 92%. In vitro experiments, serving as model of the digestive power of the gastrointestinal tract, revealed that the IMMPs, or more precisely the IMMP fraction rich in (α1 → 6) linkages, will largely pass the small intestine undigested and therefore end up in the large intestine. IMMPs are a novel type of dietary fiber that may have health promoting activity.

  6. Automated document content characterization for a multimedia document retrieval system

    NASA Astrophysics Data System (ADS)

    Koivusaari, Maija; Sauvola, Jaakko J.; Pietikaeinen, Matti

    1997-10-01

    We propose a new approach to automate document image layout extraction for an object- oriented database feature population using rapid low level feature analysis, preclassification and predictive coding. The layout information comprised of region location and classification data is transformed into 'feature object(s)'. The information is then fed into an intelligent document image retrieval system (IDIR) to be utilized in document retrieval schemes. The IDIR system consists of user interface, object-oriented database and a variety of document image analysis algorithms. In this paper the object-oriented storage model and the database system are presented in formal and functional domains. Moreover, the graphical user interface and a visual document image browser are described. The document analysis techniques used at document characterization are also presented. In this context the documents consist of text, picture and other media data. Documents are stored in the database as document, page and region objects. Our test systems has been implemented and tested using a document database of 10,000 documents.

  7. Crystal structure of an essential enzyme in seed starch degradation: barley limit dextrinase in complex with cyclodextrins.

    PubMed

    Vester-Christensen, Malene Bech; Abou Hachem, Maher; Svensson, Birte; Henriksen, Anette

    2010-11-12

    Barley limit dextrinase [Hordeum vulgare limit dextrinase (HvLD)] catalyzes the hydrolysis of α-1,6 glucosidic linkages in limit dextrins. This activity plays a role in starch degradation during germination and presumably in starch biosynthesis during grain filling. The crystal structures of HvLD in complex with the competitive inhibitors α-cyclodextrin (CD) and β-CD are solved and refined to 2.5 Å and 2.1 Å, respectively, and are the first structures of a limit dextrinase. HvLD belongs to glycoside hydrolase 13 family and is composed of four domains: an immunoglobulin-like N-terminal eight-stranded β-sandwich domain, a six-stranded β-sandwich domain belonging to the carbohydrate binding module 48 family, a catalytic (β/α)(8)-like barrel domain that lacks α-helix 5, and a C-terminal eight-stranded β-sandwich domain of unknown function. The CDs are bound at the active site occupying carbohydrate binding subsites +1 and +2. A glycerol and three water molecules mimic a glucose residue at subsite -1, thereby identifying residues involved in catalysis. The bulky Met440, a unique residue at its position among α-1,6 acting enzymes, obstructs subsite -4. The steric hindrance observed is proposed to affect substrate specificity and to cause a low activity of HvLD towards amylopectin. An extended loop (Asp513-Asn520) between β5 and β6 of the catalytic domain also seems to influence substrate specificity and to give HvLD a higher affinity for α-CD than pullulanases. The crystal structures additionally provide new insight into cation sites and the concerted action of the battery of hydrolytic enzymes in starch degradation.

  8. Gravimetric enrichment of high lipid and starch accumulating microalgae.

    PubMed

    Hassanpour, Morteza; Abbasabadi, Mahsa; Ebrahimi, Sirous; Hosseini, Maryam; Sheikhbaglou, Ahmad

    2015-11-01

    This study presents gravimetric enrichment of mixed culture to screen starch and lipid producing species separately in a sequencing batch reactor. In the enriched starch-producing mixed culture photobioreactor, the starch content at the end of steady state batch became 3.42 times the beginning of depletion. Whereas in the enriched lipid-producing photobioreactor, the lipid content at the end of steady state batch became 3 times the beginning of famine phase. The obtained results revealed that the gravimetric enrichment is a suitable screening method for specific production of storage compounds in none-sterile large-scaled condition.

  9. Adsorption depth profile of water on thermoplastic starch films

    SciTech Connect

    Bonno, B.; Laporte, J.L.; Paris, D.; D'Leon, R.T.

    2000-01-01

    It is well known that petroleum derived polymers are primary environmental contaminants. The study of new packing biodegradable materials has been the object of numerous papers in past years. Some of these new materials are the thermoplastic films derived from wheat starch. In the present paper, the authors study some of properties of wheat starch thermoplastic films, with various amounts of absorbed water, using photoacoustic spectroscopy techniques. The absorption depth profile of water in the starch substrate is determined for samples having a variable water level.

  10. Absorption depth profile of water on thermoplastic starch films

    SciTech Connect

    Bonno, B.; Laporte, J.L.; Paris, D.; D'Leon, R.T.

    2000-01-01

    It is well known that petroleum derived polymers are primary environmental contaminants. The study of new packing biodegradable materials has been the object of numerous papers in past years. Some of these new materials are the thermoplastic films derived from wheat starch. In the present paper, the authors study some of properties of wheat starch thermoplastic films, with various amounts of absorbed water, using photoacoustic spectroscopy techniques. The absorption depth profile of water in the starch substrate is determined for samples having a variable water level.

  11. The effect of vacuum frying on starch gelatinization and its in vitro digestibility in starch-gluten matrices.

    PubMed

    Contardo, Ingrid; Parada, Javier; Leiva, Angel; Bouchon, Pedro

    2016-04-15

    Starch digestibility in a food matrix depends on processing conditions that may affect its physical state and microstructure. Starch gelatinization is one critical change that takes place during frying which could be affected during low-pressure processing. This study assessed the effect of vacuum frying on starch gelatinization and its in vitro digestibility. Laminated dough was made of a reconstituted blend of wheat starch (88% d.b.) and gluten (12% d.b.). Samples were fried under vacuum (6.5 kPa, Twater-boiling-point=38°C) or atmospheric conditions up to bubble-end point, maintaining a thermal driving force of 70°C (Toil-Twater-boiling-point=70°C). Vacuum fried samples showed less starch gelatinization (28%), less rapidly available glucose (27%), and more unavailable glucose (70%) than their atmospheric counterparts (which presented 99% starch gelatinization, 40% rapidly available glucose, and 46% unavailable glucose), and the values were close to those of raw dough. These results show how vacuum processing may be used to control the degree of starch gelatinization and related digestibility.

  12. Proteome Profile of Starch Granules Purified from Rice (Oryza sativa) Endosperm

    PubMed Central

    Xing, Shihai; Meng, Xiaoxi; Zhou, Lihui; Mujahid, Hana; Zhao, Chunfang; Zhang, Yadong; Wang, Cailin; Peng, Zhaohua

    2016-01-01

    Starch is the most important food energy source in cereals. Many of the known enzymes involved in starch biosynthesis are partially or entirely granule-associated in the endosperm. Studying the proteome of rice starch granules is critical for us to further understand the mechanisms underlying starch biosynthesis and packaging of starch granules in rice amyloplasts, consequently for the improvement of rice grain quality. In this article, we developed a protocol to purify starch granules from mature rice endosperm and verified the quality of purified starch granules by microscopy observations, I2 staining, and Western blot analyses. In addition, we found the phenol extraction method was superior to Tris-HCl buffer extraction method with respect to the efficiency in recovery of starch granule associated proteins. LC-MS/MS analysis showed identification of already known starch granule associated proteins with high confidence. Several proteins reported to be involved in starch synthesis in prior genetic studies in plants were also shown to be enriched with starch granules, either directly or indirectly, in our studies. In addition, our results suggested that a few additional candidate proteins may also be involved in starch synthesis. Furthermore, our results indicated that some starch synthesis pathway proteins are subject to protein acetylation modification. GO analysis and KEGG pathway enrichment analysis showed that the identified proteins were mainly located in plastids and involved in carbohydrate metabolism. This study substantially advances the understanding of the starch granule associated proteome in rice and post translational regulation of some starch granule associated proteins. PMID:27992503

  13. Isolation and partial characterization of mango (Magnifera indica L.) starch: morphological, physicochemical and functional studies.

    PubMed

    Bello-Pérez, L A; Aparicio-Saguilán, A; Méndez-Montealvo, G; Solorza-Feria, J; Flores-Huicochea, E

    2005-03-01

    Mango (Mangifera indica) is a fruit that grows in tropical regions. The aim of this work was to isolate the starch from two varieties of mango highly consumed in Mexico ("criollo" and "manila"), and to evaluate its chemical composition, along with some morphological, physicochemical and functional properties. Mango starch had an amylose content of about 13%, the fat content of "criollo" variety starch (0.1-0.12%), was similar to that of commercial corn starch used as control (0.2%); both mango starches had higher ash amount (0.2-0.4%) than corn starch. Mango starches presented a smaller granule size (10 microm) than corn starch (15 microm), along with an A-type X-ray diffraction pattern with slight tendency to a C-type. All values of water retention capacity (WRC) increased with the temperature. When the temperature increased, solubility and swelling values increased and in general, mango starches had higher values than corn starch. Both mango starches had gelatinization temperatures lower than the control, but "criollo" variety starch presented higher enthalpy values than "manila" variety and corn starches. Overall, it was concluded that due to its morphological, physicochemical and functional properties, mango starches could be a feasible starch source with adequate properties, suitable for using in the food industry.

  14. Development of barley (Hordeum vulgare L.) lines with altered starch granule size distribution.

    PubMed

    Jaiswal, Sarita; Båga, Monica; Ahuja, Geetika; Rossnagel, Brian G; Chibbar, Ravindra N

    2014-03-12

    Microscope analysis of starches prepared from 139 barley genotypes identified a Japanese genotype, Kinai Kyoshinkai-2 (KK-2), with altered starch granule size distribution. Compared to normal barley starch, KK-2 produced consistently higher volumes of starch granules with 5-15 μm diameter and reduced volumes of starch granules with >15 μm diameter when grown in different environments. A cross between KK-2 and normal starch cultivar CDC Kendall was made and led to the production of 154 F5 lines with alterations to the normal 7:3:1 distribution for A-:B-:C-type starch granule volumes. Three F5 lines showed unimodal starch granule size distribution due to apparent lack of very small (<5.0 μm diameter) C-type starch granules, but the phenotype was accompanied by reduced grain weight and total starch concentration. Five F5 lines produced a significantly larger population of large (>15 μm diameter) A-type starch granules as compared to normal starch and showed on average a 10:4:1 distribution for A-:B-:C-type starch granule volumes. The unusual starch phenotypes displayed by the F5 lines confirm starch granule size distribution in barley can be genetically altered.

  15. Beta-AMYLASE4, a noncatalytic protein required for starch breakdown, acts upstream of three active beta-amylases in Arabidopsis chloroplasts.

    PubMed

    Fulton, Daniel C; Stettler, Michaela; Mettler, Tabea; Vaughan, Cara K; Li, Jing; Francisco, Perigio; Gil, Manuel; Reinhold, Heike; Eicke, Simona; Messerli, Gaëlle; Dorken, Gary; Halliday, Karen; Smith, Alison M; Smith, Steven M; Zeeman, Samuel C

    2008-04-01

    This work investigated the roles of beta-amylases in the breakdown of leaf starch. Of the nine beta-amylase (BAM)-like proteins encoded in the Arabidopsis thaliana genome, at least four (BAM1, -2, -3, and -4) are chloroplastic. When expressed as recombinant proteins in Escherichia coli, BAM1, BAM2, and BAM3 had measurable beta-amylase activity but BAM4 did not. BAM4 has multiple amino acid substitutions relative to characterized beta-amylases, including one of the two catalytic residues. Modeling predicts major differences between the glucan binding site of BAM4 and those of active beta-amylases. Thus, BAM4 probably lost its catalytic capacity during evolution. Total beta-amylase activity was reduced in leaves of bam1 and bam3 mutants but not in bam2 and bam4 mutants. The bam3 mutant had elevated starch levels and lower nighttime maltose levels than the wild type, whereas bam1 did not. However, the bam1 bam3 double mutant had a more severe phenotype than bam3, suggesting functional overlap between the two proteins. Surprisingly, bam4 mutants had elevated starch levels. Introduction of the bam4 mutation into the bam3 and bam1 bam3 backgrounds further elevated the starch levels in both cases. These data suggest that BAM4 facilitates or regulates starch breakdown and operates independently of BAM1 and BAM3. Together, our findings are consistent with the proposal that beta-amylase is a major enzyme of starch breakdown in leaves, but they reveal unexpected complexity in terms of the specialization of protein function.

  16. Mutagenesis of cysteine 81 prevents dimerization of the APS1 subunit of ADP-glucose pyrophosphorylase and alters diurnal starch turnover in Arabidopsis thaliana leaves.

    PubMed

    Hädrich, Nadja; Hendriks, Janneke H M; Kötting, Oliver; Arrivault, Stéphanie; Feil, Regina; Zeeman, Samuel C; Gibon, Yves; Schulze, Waltraud X; Stitt, Mark; Lunn, John E

    2012-04-01

    Many plants, including Arabidopsis thaliana, retain a substantial portion of their photosynthate in leaves in the form of starch, which is remobilized to support metabolism and growth at night. ADP-glucose pyrophosphorylase (AGPase) catalyses the first committed step in the pathway of starch synthesis, the production of ADP-glucose. The enzyme is redox-activated in the light and in response to sucrose accumulation, via reversible breakage of an intermolecular cysteine bridge between the two small (APS1) subunits. The biological function of this regulatory mechanism was investigated by complementing an aps1 null mutant (adg1) with a series of constructs containing a full-length APS1 gene encoding either the wild-type APS1 protein or mutated forms in which one of the five cysteine residues was replaced by serine. Substitution of Cys81 by serine prevented APS1 dimerization, whereas mutation of the other cysteines had no effect. Thus, Cys81 is both necessary and sufficient for dimerization of APS1. Compared to control plants, the adg1/APS1(C81S) lines had higher levels of ADP-glucose and maltose, and either increased rates of starch synthesis or a starch-excess phenotype, depending on the daylength. APS1 protein levels were five- to tenfold lower in adg1/APS1(C81S) lines than in control plants. These results show that redox modulation of AGPase contributes to the diurnal regulation of starch turnover, with inappropriate regulation of the enzyme having an unexpected impact on starch breakdown, and that Cys81 may play an important role in the regulation of AGPase turnover.

  17. Residential Demand Module - NEMS Documentation

    EIA Publications

    2014-01-01

    Model Documentation - Documents the objectives, analytical approach, and development of the National Energy Modeling System (NEMS) Residential Sector Demand Module. The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, and FORTRAN source code.

  18. Utilization of protein-rich residues in biotechnological processes.

    PubMed

    Pleissner, Daniel; Venus, Joachim

    2016-03-01

    A drawback of biotechnological processes, where microorganisms convert biomass constituents, such as starch, cellulose, hemicelluloses, lipids, and proteins, into wanted products, is the economic feasibility. Particularly the cost of nitrogen sources in biotechnological processes can make up a large fraction of total process expenses. To further develop the bioeconomy, it is of considerable interest to substitute cost-intensive by inexpensive nitrogen sources. The aim of this mini-review was to provide a comprehensive insight of utilization methods of protein-rich residues, such as fish waste, green biomass, hairs, and food waste. The methods described include (i) production of enzymes, (ii) recovery of bioactive compounds, and/or (iii) usage as nitrogen source for microorganisms in biotechnological processes. In this aspect, the utilization of protein-rich residues, which are conventionally considered as waste, allows the development of value-adding processes for the production of bioactive compounds, biomolecules, chemicals, and materials.

  19. Isolation and characterization of wheat bran starch and endosperm starch of selected soft wheats grown in Michigan and comparison of their physicochemical properties.

    PubMed

    Liu, Ya; Ng, Perry K W

    2015-06-01

    Three soft wheat varieties with relatively high crop yields and different levels of milling softness equivalence were studied to characterize bran starch properties compared with those of endosperm starch from the same wheat sample. Bran starch had more short chains than had endosperm starch, and was found to have a higher percentage of B-type granules, higher amylose content, higher crystallinity, broader gelatinization temperature range, higher enthalpy of gelatinization, lower retrogradation degree, and lower pasting peak and setback viscosities than had the counterpart endosperm starch. Bran starch of variety Aubrey had the highest crystallinity (21.75%) and gelatinization temperature (62.9°C), while bran starch of variety D8006 had the highest percentage of B-type granules and lowest retrogradation degree (21.7%). Results of this study provide a foundation for better utilization of bran starch during whole grain food processing.

  20. Changes in crystal structure of chickpea starch samples during processing treatments: an X-ray diffraction and starch moisture analysis study.

    PubMed

    Sun, Yongkang; Ye, Hong; Hu, Bing; Wang, Wei; Lei, Shicheng; Wang, Xiaoqing; Zhou, Li; Zeng, Xiaoxiong

    2015-05-05

    To detect more credibly the changes in the crystal structure of chickpea starch during processing treatments, two methods, a deconvolution method based on X-ray diffraction (XRD) pattern of starch and a moisture analysis method based on starch moisture content, were applied to determine the relative crystallinity (RC) of A- and B-type polymorphs (RCA and RCB) in the same chickpea starch sample. It was found that the values of RCA for chickpea starch samples determined by these two methods were close and showed similar trend. The results suggested that these two methods could be used to estimate RCA in the same chickpea starch sample and provide mutual corroboration. Based on the deconvolution method, it was observed that the crystalline region of chickpea starch was less susceptible to α-amylase hydrolysis than its amorphous region, and B-type polymorph in chickpea starch was more resistant to α-amylase hydrolysis than A-type polymorph.