The Experts below are selected from a list of 19542 Experts worldwide ranked by ideXlab platform
Jay-lin Jane - One of the best experts on this subject based on the ideXlab platform.
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chemical and physical properties of kiwifruit actinidia deliciosa starch
Starch-starke, 2006Co-Authors: David G Stevenson, Scott R Johnson, Jay-lin Jane, George E. InglettAbstract:Chemical and physical properties of kiwifruit (Actinidia deliciosa var. 'Hayward') starch were studied. Kiwifruit starch granules were compound, irregular or dome-shaped with diameters predominantly 4-5 μm or 7-9 μm. Kiwifruit starch exhibited B-type X-ray diffraction pattern, an apparent amylose content of 43.1% and absolute amylose content of 18.8%. Kiwifruit Amylopectins, relative to other starches, had low weight-average molecular weight (7.4 × 10 7 ), and gyration radius (200 nm). Average Amylopectin branch chain-length was long (DP 28.6). Onset and peak gelatinization temperatures were 68.9°C and 73.0°C, respectively, and gelatinization enthalpy was high (18.5 J/g). Amylose-lipid thermal transition was observed. Starch retrograded for 7 d at 4°C had a very high peak melting temperature (60.7°C). Peak (250 RVU), final (238 RVU) and setback (94 RVU) viscosity of 8% kiwifruit starch paste was high relative to other starches and pasting temperature (69.7°C) was marginally higher than onset gelatinization temperature. High paste viscosities and low pasting temperature could give kiwifruit starch some advantages over many cereal starches.
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structural and physicochemical characteristics of winter squash cucurbita maxima d fruit starches at harvest
Carbohydrate Polymers, 2005Co-Authors: David G Stevenson, Paul L Hurst, Jay-lin JaneAbstract:Abstract Structures and physicochemical properties of starch isolated from fruit (pepo) of seven winter squash cultivars ( Cucurbita maxima D.) were studied. Squash starches exhibited the B-type X-ray diffraction pattern and had most granules with diameters of 1.5–2.5, 6–8, and 11–13 μm. Squash Amylopectin had more long branch chains (25.4–29.3% DP≥37), and squash starch had relatively small absolute amylose contents (12.9–18.2%). Squash starch Amylopectins had weight-average molecular weights ranging from 2.03 to 3.22×10 8 g/mol, gyration radii of 294–337 nm, and unusually low polydispersity (1.21–1.81). Isoamylase-debranched Amylopectins showed average chain-length varied from DP 26.5 to 28.1. Squash starches had onset gelatinization temperature ranging from 60.6 to 63.5 °C and enthalpy changes (Δ H ) from 15.9 to 17.4 J/g. Retrogradation rate for squash starches ranged from 41 to 55% after 7 days at 4 °C. Squash starch pastes, measured by using a Rapid Visco-Analyzer, had peak viscosity of 174–233 RVU, final viscosity of 193–244 RVU, and setback of 79–100 RVU, with pasting temperature of 65.6–68.8 °C.
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Structures and Properties of Amylopectin and Phytoglycogen in the Endosperm of sugary-1 Mutants of Rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP
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structures and properties of Amylopectin and phytoglycogen in the endosperm of sugary 1 mutants of rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP<12 but fewer chains of DP13–24 than did wild-type Amylopectin, and the alterations reflected on lower molecular weights, smaller gyration radii, and denser molecules. These changes resulted in lower onset gelatinization temperature, lower peak viscosity, lesser degree of crystallinity, and smaller and cracked granules with rough surface of sugary starch granules as compared with that of the wild-type. These results indicate that changes in the fine structure of Amylopectin induced by lesion of DBE greatly influence the morphological and physicochemical properties of starch. Phytoglycogens from sugary-1 mutants were composed of multiple components of smaller molecular weights and gyration radii than sugary -Amylopectin and Amylopectin. The highly branched phytoglycogens were more tightly packed molecules exhibiting greater dispersed densities than sugary -Amylopectin and Amylopectin. These results suggest that the levels of DBE in rice endosperm control the biosynthetic pathway of branched α-glucans and produce Amylopectin, sugary -Amylopectin and phytoglycogen.
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molecular weights and gyration radii of Amylopectins determined by high performance size exclusion chromatography equipped with multi angle laser light scattering and refractive index detectors
Carbohydrate Polymers, 2002Co-Authors: Jay-lin JaneAbstract:Abstract High-performance size-exclusion chromatography (HPSEC) equipped with multi-angle laser-light scattering (MALLS) and refractive index (RI) detectors was used to determine weight-average molecular weight ( M w ) and z -average radius of gyration ( R z ) of Amylopectin of selected starches. Ranges of M w and R z values of Amylopectin were 7.0×10 7 –5.7×10 9 g/mol and 191–782 nm, respectively. Amylopectins of waxy starches had substantially larger M w than did those of normal starch counterparts. Based on the dispersed-molecular density ( M w / R z 3 ), waxy Amylopectins displayed, in general, larger dispersed-molecular density than did normal Amylopectin counterparts, and Amylopectins of the A-type starches had larger dispersed-molecular density than did those of the B-type starches. These results suggested that Amylopectins of waxy starches had more branch-chains and no extra long chains, which resulted in more densely packed molecules than did those of normal starch counterparts. The Amylopectin of B-type starch had longer but fewer branch-chains, which resulted in smaller dispersed density than did that of the A-type starch. M w and R z values of amylose isolated from amylomaize VII starch were also determined to be 2.8×10 5 and 43 nm, respectively.
Yasunori Nakamura - One of the best experts on this subject based on the ideXlab platform.
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the structure of starch can be manipulated by changing the expression levels of starch branching enzyme iib in rice endosperm
Plant Biotechnology Journal, 2004Co-Authors: Naoki Tanaka, Hikaru Satoh, Naoko Fujita, Aiko Nishi, Yuko Hosaka, Masashi Ugaki, Shinji Kawasaki, Yasunori NakamuraAbstract:Summary When the starch branching enzyme IIb (BEIIb) gene was introduced into a BEIIb-defective mutant, the resulting transgenic rice plants showed a wide range of BEIIb activity and the fine structure of their Amylopectins showed considerable variation despite having the two other BE isoforms, BEI and BEIIa, in their endosperm at the same levels as in the wild-type. The properties of the starch granules, such as their gelatinization behaviour, morphology and X-ray diffraction pattern, also changed dramatically depending on the level of BEIIb activity, even when this was either slightly lower or higher than that of the wild-type. The over-expression of BEIIb resulted in the accumulation of excessive branched, water-soluble polysaccharides instead of Amylopectin. These results imply that the manipulation of BEIIb activity is an effective strategy for the generation of novel starches for use in foodstuffs and industrial applications.
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Structures and Properties of Amylopectin and Phytoglycogen in the Endosperm of sugary-1 Mutants of Rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP
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structures and properties of Amylopectin and phytoglycogen in the endosperm of sugary 1 mutants of rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP<12 but fewer chains of DP13–24 than did wild-type Amylopectin, and the alterations reflected on lower molecular weights, smaller gyration radii, and denser molecules. These changes resulted in lower onset gelatinization temperature, lower peak viscosity, lesser degree of crystallinity, and smaller and cracked granules with rough surface of sugary starch granules as compared with that of the wild-type. These results indicate that changes in the fine structure of Amylopectin induced by lesion of DBE greatly influence the morphological and physicochemical properties of starch. Phytoglycogens from sugary-1 mutants were composed of multiple components of smaller molecular weights and gyration radii than sugary -Amylopectin and Amylopectin. The highly branched phytoglycogens were more tightly packed molecules exhibiting greater dispersed densities than sugary -Amylopectin and Amylopectin. These results suggest that the levels of DBE in rice endosperm control the biosynthetic pathway of branched α-glucans and produce Amylopectin, sugary -Amylopectin and phytoglycogen.
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differences in Amylopectin structure between two rice varieties in relation to the effects of temperature during grain filling
Starch-starke, 1999Co-Authors: Takayuki Umemoto, Yasunori Nakamura, Kazuo Terashima, Hikaru SatohAbstract:The structure of endosperm Amylopectin was compared between two rice varieties, Kinmaze (subspecies japonica) and IR36 (subspecies indica), as well as their waxy mutants, all grown under controlled temperature. The distinct varietal difference in chain length distribution of Amylopectin was confirmed by high performance anion-exchange chromatography equipped with pulsed amperometric detection. Amylopectin from Kinmaze contains more very short chains with degree of polymerization (DP) between 6 and 10 and less chains with DP from 13 to 22 than Amylopectin from IR36, while there is little difference in the distribution of longer chains with DP > 24 between the two varieties. Waxy mutation had little effect on chain length distribution of endosperm Amylopectin. The temperature during grain-filling affected the chain length distribution of Amylopectin in both varieties in a similar way; grain-filling at lower temperatures lead to an increased proportion of chains of DP 6—13 and decreased the percentage of chains with DP 20—27 and DP 44—54. However, the temperature-dependent changes in chain length distribution of Amylopectin were within the range of varietal difference between Kinmaze and IR36. These results strongly suggest that factors regulating the varietal difference in patterns of chain length of Amylopectin are dissimilar to those causing the temperature effects on Amylopectin fine structure in rice endosperm.
Paul Colonna - One of the best experts on this subject based on the ideXlab platform.
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molecular and supra molecular structure of waxy starches developed from cassava manihot esculenta crantz
Carbohydrate Polymers, 2013Co-Authors: Agnes Rollandsabate, Paul Colonna, Teresa Sanchez, Alain Buleon, Hernan Ceballos, Shanshan Zhao, Peng Zhang, Dominique DufourAbstract:Abstract The aim of this work was to characterize the Amylopectin of low amylose content cassava starches obtained from transgenesis comparatively with a natural waxy cassava starch (WXN) discovered recently in CIAT (International Center for Tropical Agriculture). Macromolecular features, starch granule morphology, crystallinity and thermal properties of these starches were determined. M ¯ w of Amylopectin from the transgenic varieties are lower than WXN. Branched and debranched chain distributions analyses revealed slight differences in the branching degree and structure of these Amylopectins, principally on DP 6–9 and DP > 37. For the first time, a deep structural characterization of a series of transgenic lines of waxy cassava was carried out and the link between structural features and the mutated gene expression approached. The transgenesis allows to silenced partially or totally the GBSSI, without changing deeply the starch granule ultrastructure and allows to produce clones with similar Amylopectin as parental cassava clone.
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Molecular and supra-molecular structure of waxy starches developed from cassava (Manihot esculenta Crantz)
Carbohydrate Polymers, 2013Co-Authors: Agnes Sabate, Paul Colonna, Teresa Sanchez, Alain Buleon, Hernan Ceballos, Shanshan Zhao, Peng Zhang, Dominique DufourAbstract:The aim of this work was to characterize the Amylopectin of low amylose content cassava starches obtained from transgenesis comparatively with a natural waxy cassava starch (WXN) discovered recently in CIAT (International Center for Tropical Agriculture). Macromolecular features, starch granule morphology, crystallinity and thermal properties of these starches were determined. (M) over bar (w) of Amylopectin from the transgenic varieties are lower than WXN. Branched and debranched chain distributions analyses revealed slight differences in the branching degree and structure of these Amylopectins, principally on DP 6-9 and DP > 37. For the first time, a deep structural characterization of a series of transgenic lines of waxy cassava was carried out and the link between structural features and the mutated gene expression approached. The transgenesis allows to silenced partially or totally the GBSSI, without changing deeply the starch granule ultrastructure and allows to produce clones with similar Amylopectin as parental cassava clone. (C) 2012 Elsevier Ltd. All rights reserved.
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molecular size and mass distributions of native starches using complementary separation methods asymmetrical flow field flow fractionation a4f and hydrodynamic and size exclusion chromatography hdc sec
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Agnes Rollandsabate, Sophie Guilois, Benoit Jaillais, Paul ColonnaAbstract:Starch consists of a mixture of two α-glucans built mainly upon α-(1,4) linkages: amylose, an essentially linear polymer, and Amylopectin, a branched polymer containing 5–6% of α-(1,6) linkages. The aim of the present work was to analyze the structural properties of native starches displaying different amylose-to-Amylopectin ratios and arising from different botanical sources, using asymmetrical flow field flow fractionation (A4F) and a combination of hydrodynamic and size-exclusion chromatography (HDC-SEC) coupled with multiangle laser light scattering, online quasi-elastic light scattering, and differential refractive index techniques. The procedure, based upon dimethyl sulfoxide pretreatment and then solubilization in water, generates a representative injected sample without altering the initial degree of polymerization. The Amylopectin weight-average molar masses and radii of gyration were around 1.0 × 108–4.8 × 108 g mol-1 and 110–267 nm, respectively. For each starch sample, the hydrodynamic radius (RH) distributions and the molar mass distributions obtained from the two fractionation systems coupled with light scattering techniques were analyzed. The size determination scales were extended by means of RH calibration curves. HDC-SEC and A4F data could be matched. However, A4F enabled a better separation of Amylopectins and therefore an enhanced structural characterization of the starches. The two advantages of this experimental approach are (1) it can directly obtain distributions as a function of both molar mass and size, while taking account of sample heterogeneity, and (2) it is possible to compare the results obtained using the different techniques through the direct application of RH distributions.
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branching features of Amylopectins and glycogen determined by asymmetrical flow field flow fractionation coupled with multiangle laser light scattering
Biomacromolecules, 2007Co-Authors: Agnes Rollandsabate, Maria Guadalupe Mendezmontealvo, Paul Colonna, Veronique PlanchotAbstract:The aim of this work was to characterize starch polysaccharides using asymmetrical flow field flow fractionation coupled with multiangle laser light scattering. Amylopectins from eight different botanical sources and rabbit liver glycogen were studied. Amylopectins and glycogen were completely solubilized and analyzed, and high mass recoveries were achieved (81.7−100.0%). Amylopectin Mw, RG, and the hydrodynamic coefficient νG (the slope of the log−log plot of RGi vs Mi) were within the ranges 1.05−3.18 × 108 g mol-1, 163−229 nm, 0.37−0.49, respectively. The data were also considered in terms of structural parameters. The results were analyzed by comparison with the theory of hyperbranched polymers (Flory, P. J. Principles of Polymer Chemistry; Cornell University Press: Ithaca, NY, 1953; Burchard, W. Macromolecules, 1977, 10, 919−927). This theory, based upon the ABC model, has been shown to underestimate the branching degrees of Amylopectins. However, quantitative agreement with the data in the litera...
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Branching features of Amylopectins and glycogen determined by asymmetrical flow field flow fractionation coupled with multiangle laser light scattering
Biomacromolecules, 2007Co-Authors: Agnes Rolland-sabaté, Paul Colonna, Maria Guadalupe Mendez-montealvo, Veronique PlanchotAbstract:The aim of this work was to characterize starch polysaccharides using asymmetrical flow field flow fractionation coupled with multiangle laser light scattering. Amylopectins from eight different botanical sources and rabbit liver glycogen were studied. Amylopectins and glycogen were completely solubilized and analyzed, and high mass recoveries were achieved (81.7-100.0%). Amylopectin (M) over bar (W), (R) over bar (G), and the hydrodynamic coefficient nu(G) (the slope of the log-log plot of R-Gi vs M-i) were within the ranges 1.05-3.18 x 10(8) g mol(-1), 163-229 nm, 0.370.49, respectively. The data were also considered in terms of structural parameters. The results were analyzed by comparison with the theory of hyperbranched polymers (Flory, P. J. Principles of Polymer Chemistry; Cornell University Press: Ithaca, NY, 1953; Burchard, W. Macromolecules, 1977, 10, 919-927). This theory, based upon the ABC model, has been shown to underestimate the branching degrees of amylopec! tins. However, quantitative agreement with the data in the literature was found for Amylopectins when using the ABC model modified by the introduction of a multiplying factor, determined from previously described Amylopectin structures in terms of the number of branching point calculations.
Eric Bertoft - One of the best experts on this subject based on the ideXlab platform.
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Unit and Internal Chain Profile of Millet Amylopectin
Cereal Chemistry, 2014Co-Authors: George Amponsah Annor, Massimo F. Marcone, Eric Bertoft, Koushik SeetharamanAbstract:ABSTRACT The unit chain compositions of debranched foxtail, proso, pearl, and finger millet Amylopectins and their ϕ,β-limit dextrins were analyzed by high-performance anion-exchange chromatography. The ϕ,β-limit dextrins reflected Amylopectin internal chain profiles. The Amylopectins had average chain lengths ranging from 17.94 to 18.12. The ranges of external chain length, internal chain length, and total internal chain length of the millet Amylopectins were 11.85–12.33, 4.75–5.09, and 11.64–12.28, respectively. The relative molar concentration of B-chains in the Amylopectins was close to 50% in all samples. Significant differences were, however, observed in the proportions of very short “fingerprint” B-chains (Bfp, degree of polymerization 3–7) and the major group of short B-chains (BSmajor): foxtail and proso millets possessed high amounts of Bfp-chains, whereas finger and pearl millets had higher amounts of BSmajor-chains, suggesting possible differences in the fine structure of the clusters and buil...
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composition of clusters and building blocks in Amylopectins from maize mutants deficient in starch synthase iii
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Eric Bertoft, Koushik SeetharamanAbstract:Branches in Amylopectin are distributed along the backbone. Units of the branches are building blocks (smaller) and clusters (larger) based on the distance between branches. In this study, composition of clusters and building blocks of Amylopectins from dull1 maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were characterized and compared with the wild type. Clusters were produced from Amylopectins by partial hydrolysis using α-amylase of Bacillus amyloliquefaciens and were subsequently treated with phosphorylase a and β-amylase to produce φ,β-limit dextrins. Clusters were further extensively hydrolyzed with the α-amylase to produce building blocks. Structures of clusters and building blocks were analyzed by diverse chromatographic techniques. The results showed that the dull1 mutation resulted in larger clusters with more singly branched building blocks. The average cluster contained ∼5.4 blocks in dull1 mutants and ∼4.2 blocks in the wild type. The results a...
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Building block organisation of clusters in Amylopectin from different structural types.
International journal of biological macromolecules, 2012Co-Authors: Eric Bertoft, Kristine Koch, Per AmanAbstract:Abstract Clusters of chains consisting of tightly branched units of building blocks were isolated from 10 Amylopectin samples possessing the 4 types of Amylopectin with different internal unit chain profiles previously described. It was shown that clusters in types 1 and 2 Amylopectins are larger than in types 3 and 4, but the average cluster size did not correspond to the ratio of short to long chains of the Amylopectins. The size-distribution of the building blocks, having one or several branches, possessed generally only small differences between samples. However, the length of the interblock segments followed the type of Amylopectin structure, so that type 1 Amylopectins had shortest and type 4 the longest segments. The chains in the clusters were divided into characteristic groups probably being involved in the interconnection of two, three, and four – or more – building blocks. Long chains were typically found in high amounts in clusters from type 4 Amylopectins, however, all cluster samples contained long chains. The results are discussed in terms of the building block structure of Amylopectin, in which the blocks together with the interblock segments participate in a branched backbone building up the amorphous lamellae inside growth rings of the starch granules. In such a model, Amylopectins with proportionally less long chains (types 1 and 2) possess a more extensively branched backbone compared to those with more long chains (types 3 and 4).
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The building block structure of barley Amylopectin
International Journal of Biological Macromolecules, 2011Co-Authors: Eric Bertoft, Anna Källman, Kristine Koch, Roger Andersson, Per AmanAbstract:Amylopectin branchpoints are present in amorphous lamellae of starch granules and organised into densely branched areas, referred to as building blocks. One single Amylopectin cluster contains several building blocks. This study investigated the building block structure of domains (groups of clusters) and clusters in four different barley genotypes. Two of the barleys possessed the amo1 mutation, Glacier Ac38 and the double recessive SW 49427 with both wax and amo1 mutations, and were compared with the two waxy type barleys Cinnamon and Cindy. A previous detailed study on these four barley genotypes showed that the amo1 mutation affected the internal structure of Amylopectin as manifested in the composition of clusters. In this work the building blocks were isolated from domains and clusters by extensive treatment with liquefying α-amylase of Bacillus subtilis and structurally characterised with enzymatic and chromatographic techniques. The proportion of large building blocks with a high number of chains was increased in the amo1 barleys, and the chain length between the blocks was short, which explained the previous findings of large clusters with more dense structure in the amo1 Amylopectins.
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Amylopectin internal molecular structure in relation to physical properties of sweetpotato starch
Carbohydrate Polymers, 2011Co-Authors: Fan Zhu, Harold Corke, Eric BertoftAbstract:Abstract Unit chain length distributions of Amylopectins and their φ,β-limit dextrins (reflecting Amylopectin internal part) from 11 Chinese sweetpotato genotypes were characterized by high performance anion-exchange chromatography after debranching, and were related to the thermal and pasting properties of granular starches. The weight-based unit chain length profiles of whole Amylopectin and their internal parts both had three distinguishable major groups with approximate range of DP 6–36, 37–68, and >69 for Amylopectins and DP 3–25, 26–55, and >55 for φ,β-limit dextrins. Among different genotypes, two different patterns of B fp (fingerprint B-chains, DP 3–7) were observed for φ,β-limit dextrins, whereas A fp (fingerprint A-chains, DP 6–8) for whole Amylopectins were consistent. Reconstruction of Amylopectins from their φ,β-limit dextrins revealed that B-chains with internal DP > 20 possessed an external chain length corresponding to the average value DP 12.8. Wide genetic variations were recorded among structural parameters, of which several concerning the Amylopectin internal part were highly correlated to the thermal and pasting parameters of sweetpotato starches, and suggested that the internal part of Amylopectin is critical to the physical behavior of granular starch.
Hikaru Satoh - One of the best experts on this subject based on the ideXlab platform.
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relationship between chain length distributions of waxy rice Amylopectins and physical properties of rice grains
Journal of applied glycoscience, 2006Co-Authors: Keitaro Suzuki, Sumiko Nakamura, Hikaru Satoh, Ken'ichi OhtsuboAbstract:Chain-length distributions of Amylopectins by HPAEC-PAD from japonica and indica waxy-rice samples were characterized, and the relationship between the chain-length distributions and pasting properties of rice flour by RVA and the physical properties of cooked rice grains by Tensipresser were studied. In comparison with jaonica and indica types, the pattern of chain-length distribution of indica Amylopectin typically differed, and the ratio of degree of polymerization (DP) 6-12, fa short chains of indica type was clearly lower, while the ratio of DP>13, fb1+2+3 long chains was clearly higher. The physical properties of cooked rice grains and powder pasting of the indica type showed clearly as hard type starch. There were differences in the chain-length distribution among japonica waxy-rice starches. The ratios of fb3, DP>37 for japonica waxy Amylopectins were positively correlated with RVA paste viscosity parameters, such as minimum viscosity, final viscosity, pasting temperature and setback, and iodine absorbance. Iodine absorbance was negatively correlated with properties of cooked rice grains, such as overall adhered mass, L6. The results showed the possibility that the long chain portion of the Amylopectin structure is a factor in regulating its starch physical properties.
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the structure of starch can be manipulated by changing the expression levels of starch branching enzyme iib in rice endosperm
Plant Biotechnology Journal, 2004Co-Authors: Naoki Tanaka, Hikaru Satoh, Naoko Fujita, Aiko Nishi, Yuko Hosaka, Masashi Ugaki, Shinji Kawasaki, Yasunori NakamuraAbstract:Summary When the starch branching enzyme IIb (BEIIb) gene was introduced into a BEIIb-defective mutant, the resulting transgenic rice plants showed a wide range of BEIIb activity and the fine structure of their Amylopectins showed considerable variation despite having the two other BE isoforms, BEI and BEIIa, in their endosperm at the same levels as in the wild-type. The properties of the starch granules, such as their gelatinization behaviour, morphology and X-ray diffraction pattern, also changed dramatically depending on the level of BEIIb activity, even when this was either slightly lower or higher than that of the wild-type. The over-expression of BEIIb resulted in the accumulation of excessive branched, water-soluble polysaccharides instead of Amylopectin. These results imply that the manipulation of BEIIb activity is an effective strategy for the generation of novel starches for use in foodstuffs and industrial applications.
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Structures and Properties of Amylopectin and Phytoglycogen in the Endosperm of sugary-1 Mutants of Rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP
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structures and properties of Amylopectin and phytoglycogen in the endosperm of sugary 1 mutants of rice
Journal of Cereal Science, 2003Co-Authors: Kit-sum Wong, Hikaru Satoh, Kyuya Harada, Akiko Kubo, Jay-lin Jane, Yasunori NakamuraAbstract:Starch debranching enzyme (DBE)-deficient, sugary-1 mutations of rice caused the biosynthesis of more highly branched α-glucan in the form of phytoglycogen and sugary -Amylopectin rather than wild-type Amylopectin. Phytoglycogen and sugary -Amylopectin are located in the inner and outer regions of the rice endosperm, respectively. Detailed analyses of these glucans from a variety of allelic mutants with different severity of sugary phenotype revealed that sugary -Amylopectins consisted of more short chains of DP<12 but fewer chains of DP13–24 than did wild-type Amylopectin, and the alterations reflected on lower molecular weights, smaller gyration radii, and denser molecules. These changes resulted in lower onset gelatinization temperature, lower peak viscosity, lesser degree of crystallinity, and smaller and cracked granules with rough surface of sugary starch granules as compared with that of the wild-type. These results indicate that changes in the fine structure of Amylopectin induced by lesion of DBE greatly influence the morphological and physicochemical properties of starch. Phytoglycogens from sugary-1 mutants were composed of multiple components of smaller molecular weights and gyration radii than sugary -Amylopectin and Amylopectin. The highly branched phytoglycogens were more tightly packed molecules exhibiting greater dispersed densities than sugary -Amylopectin and Amylopectin. These results suggest that the levels of DBE in rice endosperm control the biosynthetic pathway of branched α-glucans and produce Amylopectin, sugary -Amylopectin and phytoglycogen.
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differences in Amylopectin structure between two rice varieties in relation to the effects of temperature during grain filling
Starch-starke, 1999Co-Authors: Takayuki Umemoto, Yasunori Nakamura, Kazuo Terashima, Hikaru SatohAbstract:The structure of endosperm Amylopectin was compared between two rice varieties, Kinmaze (subspecies japonica) and IR36 (subspecies indica), as well as their waxy mutants, all grown under controlled temperature. The distinct varietal difference in chain length distribution of Amylopectin was confirmed by high performance anion-exchange chromatography equipped with pulsed amperometric detection. Amylopectin from Kinmaze contains more very short chains with degree of polymerization (DP) between 6 and 10 and less chains with DP from 13 to 22 than Amylopectin from IR36, while there is little difference in the distribution of longer chains with DP > 24 between the two varieties. Waxy mutation had little effect on chain length distribution of endosperm Amylopectin. The temperature during grain-filling affected the chain length distribution of Amylopectin in both varieties in a similar way; grain-filling at lower temperatures lead to an increased proportion of chains of DP 6—13 and decreased the percentage of chains with DP 20—27 and DP 44—54. However, the temperature-dependent changes in chain length distribution of Amylopectin were within the range of varietal difference between Kinmaze and IR36. These results strongly suggest that factors regulating the varietal difference in patterns of chain length of Amylopectin are dissimilar to those causing the temperature effects on Amylopectin fine structure in rice endosperm.