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Wheats affected by late-maturity α-amylase (LMA) contain abnormal amounts of α-amylase with a high isoelectric point (pI), causing their flours to have low falling number (FN), a standard industry test. LMA-affected wheats are often rejected at grain receival points, as low FN is perceived as sign of poor quality. To improve LMA detection and increase screening throughput, an LMA-ELISA has been developed. The present study evaluated the analytical performance of LMA-ELISA and confirmed the correlation between LMA content and enzymatic activity. The LMA-ELISA test demonstrated good discrimination and high precision for intra- and inter-assay measurements. However, results were not reproducible when using three different LMA-ELISA batches acquired in two consecutive years, indicating that LMA-ELISA suffered from batch-to-batch variation. Consistent with previous studies, LMA-ELISA was highly correlated to total α-amylase activity (R = 0.95). LMA-affected flours also had enzymatic activity similar to enzyme-supplemented flours that have been shown to produce some end-products such as bread and noodles that are of satisfactory quality. These results highlight the need to address LMA-ELISA batch-to-batch variation.
Galex K.S. Neoh; Keyu Tao; Mark J. Dieters; Glen P. Fox; Robert G. Gilbert. Late-maturity α-amylase (LMA) testing and its methodological challenges. LWT 2021, 151, 112232 .
AMA StyleGalex K.S. Neoh, Keyu Tao, Mark J. Dieters, Glen P. Fox, Robert G. Gilbert. Late-maturity α-amylase (LMA) testing and its methodological challenges. LWT. 2021; 151 ():112232.
Chicago/Turabian StyleGalex K.S. Neoh; Keyu Tao; Mark J. Dieters; Glen P. Fox; Robert G. Gilbert. 2021. "Late-maturity α-amylase (LMA) testing and its methodological challenges." LWT 151, no. : 112232.
Chickpea (Cicer arietinum L.) seed is a nutritional food high in starch and protein. This study aims to find the relationships between the molecular fine structure of starch and the composition of storage proteins and metabolic enzymes, using different chickpea varieties. It is found that storage proteins and starch biosynthetic enzymes influence each other. The initial formation of amylopectin molecules is affected by storage proteins, as suggested by the positive correlation (p < 0.01) between the average molecular size of amylopectin and total protein content. In addition, a higher amount of seed globulin could be an indication of higher amylose content and more short – medium amylose chains (degree of polymerization, DP, 118–2000). This study might assist selection of chickpea varieties with desirable qualities, such as low starch digestibility.
Xiaoyan Tan; Xinle Tan; Enpeng Li; Yeming Bai; Thoa T.L. Nguyen; Robert G. Gilbert. Starch molecular fine structure is associated with protein composition in chickpea seed. Carbohydrate Polymers 2021, 272, 118489 .
AMA StyleXiaoyan Tan, Xinle Tan, Enpeng Li, Yeming Bai, Thoa T.L. Nguyen, Robert G. Gilbert. Starch molecular fine structure is associated with protein composition in chickpea seed. Carbohydrate Polymers. 2021; 272 ():118489.
Chicago/Turabian StyleXiaoyan Tan; Xinle Tan; Enpeng Li; Yeming Bai; Thoa T.L. Nguyen; Robert G. Gilbert. 2021. "Starch molecular fine structure is associated with protein composition in chickpea seed." Carbohydrate Polymers 272, no. : 118489.
There are many genetic differences between Australian wild rices (AWRs) and domesticated rices (DRs), causing differences in starch molecular structure and starch-related functional properties; these are examined here for polished AWRs and polished DRs. Starch structural parameters for amylopectin and amylose were obtained using size-exclusion chromatography, with and without enzymatic debranching. Thermal properties of starch, in-vitro digestibility and texture of three AWRs were measured and compared to those of typical DRs. The results showed that AWR starches had (a) higher amylose content than most DRs, resulting in a higher gelatinization temperature, (b) fewer amylopectin short chains, causing a higher gelatinization enthalpy, and (c) more amylose shorter chains and more amylopectin longer chains, both causing a slower in-vitro digestion rate. The textural characteristics of AWRs are not significantly different from those of DRs. These findings suggest that AWRs are a potential source of nutritionally-desirable but palatable slowly-digestible starch.
Yingting Zhao; Robert J. Henry; Robert G. Gilbert. Starch structure-property relations in Australian wild rices compared to domesticated rices. Carbohydrate Polymers 2021, 271, 118412 .
AMA StyleYingting Zhao, Robert J. Henry, Robert G. Gilbert. Starch structure-property relations in Australian wild rices compared to domesticated rices. Carbohydrate Polymers. 2021; 271 ():118412.
Chicago/Turabian StyleYingting Zhao; Robert J. Henry; Robert G. Gilbert. 2021. "Starch structure-property relations in Australian wild rices compared to domesticated rices." Carbohydrate Polymers 271, no. : 118412.
Global fisheries production has increased up to ~200 MT, which has resulted in the intensive generation of waste or byproducts (~20 MT), which is creating serious problems for environmental management with zero income. This study proposes an idea of using whole fish (red and white meat, skin, bones, and fins but not scales) for human food (snack food) with the aim of zero waste generation. Whole fish powder (WFP) was prepared by a novel method (using freeze-drying as well as stone ball milling) and fortified in baked snacks at four levels (0, 5, 10, and 15% w/w of 100 g of formulation). The results revealed that the addition of WFP decreased expansion and color parameters compared to control. Hardness was significantly (p< 0.05) increased with the addition of WFP, which was attributed to the mineral content of WFP. Pasting properties determined by rapid visco analyzer (RVA) were dramatically decreased with the addition of 10–15% WFP, suggesting the weak interaction of starch and protein, which was also evidenced by scanning electron microscopy (SEM). Low field nuclear magnetic resonance (LF-NMR) analysis revealed that the amount of free water was increased when 10–15% WFP was added in snacks while bound water was highest in control and 5% WFP samples, respectively. The microstructural analysis by SEM showed that the protein network was increased in those samples incorporated with WFP compared to control that had more starch granules. The results suggest the feasibility of adding 5% WFP for proper structure, texture, pasting properties, and water distribution in order to reduce fish waste.
Asad Nawaz; Ibrahim Khalifa; Noman Walayat; Jose Lorenzo; Sana Irshad; Abdullah; Shakeel Ahmed; Mario Simirgiotis; Madad Ali; Enpeng Li. Whole Fish Powder Snacks: Evaluation of Structural, Textural, Pasting, and Water Distribution Properties. Sustainability 2021, 13, 6010 .
AMA StyleAsad Nawaz, Ibrahim Khalifa, Noman Walayat, Jose Lorenzo, Sana Irshad, Abdullah, Shakeel Ahmed, Mario Simirgiotis, Madad Ali, Enpeng Li. Whole Fish Powder Snacks: Evaluation of Structural, Textural, Pasting, and Water Distribution Properties. Sustainability. 2021; 13 (11):6010.
Chicago/Turabian StyleAsad Nawaz; Ibrahim Khalifa; Noman Walayat; Jose Lorenzo; Sana Irshad; Abdullah; Shakeel Ahmed; Mario Simirgiotis; Madad Ali; Enpeng Li. 2021. "Whole Fish Powder Snacks: Evaluation of Structural, Textural, Pasting, and Water Distribution Properties." Sustainability 13, no. 11: 6010.
The main enzymes controlling the chain-length distributions (CLDs) of starches are starch synthases (SSs), starch branching enzymes (SBEs), and debranching enzymes (DBEs), which have various isoforms, denoted as SSI, SSII-1, etc. Different isozymes dominate the CLD in different ranges of degrees of polymerization (DPs). Models have been developed for the CLDs in terms of the activities of isoforms of these enzymes, in terms of two parameters: βi, which is the ratio of the activity of SBE to that of SS in set i, and hi, which is the relative activity of SS in that set. These provide good fits to data but without specifying which isozymes are in set i. Here, CLDs for amylopectin and amylose synthesis in rice endosperm are explored. Molecular weight distributions of the different chains formed in 87 rice varieties were obtained using size-exclusion chromatography following enzymatic debranching (converting a complex branched macromolecule to linear polymers), and fitted by the biosynthesis-based models. The mutants of each isoform among tested rice varieties were identified by amino-acid mutations in coding sequences based on the extraction and analysis of whole gene sequences. The significant differences between mutant groups of different isoforms indicate that SSI, SSII-3, SSIII-1, SSIII-2, and SBEI as well as GBSSI (an isozyme of granule-bound starch synthase) belong to the enzymes sets that control amylose biosynthesis. Further, GBSSI is in the enzyme sets that control amylopectin chains. This enables specification of all isozymes and the DP range, which they dominate, over the entire DP range. As the CLD controls many functional properties of rice, this can help breeders target and develop improved rice species.
Jihui Zhu; Chang-Quan Zhang; Jianlong Xu; Robert G. Gilbert; Qiaoquan Liu. Identification of Structure-Controlling Rice Biosynthesis Enzymes. Biomacromolecules 2021, 22, 2148 -2159.
AMA StyleJihui Zhu, Chang-Quan Zhang, Jianlong Xu, Robert G. Gilbert, Qiaoquan Liu. Identification of Structure-Controlling Rice Biosynthesis Enzymes. Biomacromolecules. 2021; 22 (5):2148-2159.
Chicago/Turabian StyleJihui Zhu; Chang-Quan Zhang; Jianlong Xu; Robert G. Gilbert; Qiaoquan Liu. 2021. "Identification of Structure-Controlling Rice Biosynthesis Enzymes." Biomacromolecules 22, no. 5: 2148-2159.
Liver glycogen is a branched glucose polymer that functions as a blood-sugar buffer in animals. Previous studies have shown that glycogen’s molecular structure affects its properties. This makes it important to develop a technique that extracts and purifies a representative sample of glycogen. Here we aim to optimize the sucrose density gradient centrifugation method for preserving glycogen’s molecular structure by varying the density of the sucrose solution. The preservation of glycogen’s structure involves: 1) minimizing molecular damage and 2) obtaining a structurally representative sample of glycogen. The addition of a 10-minute boiling step was also tested as a means for denaturing any glycogen degrading enzymes. Lower sucrose concentrations and the introduction of the boiling step were shown to be beneficial in obtaining a more structurally representative sample, with the preservation of smaller glycogen particles and decreased glycogen chain degradation.
Ziyi Wang; Qinghua Liu; Liang Wang; Robert G. Gilbert; Mitchell A. Sullivan. Optimization of liver glycogen extraction when considering the fine molecular structure. Carbohydrate Polymers 2021, 261, 117887 .
AMA StyleZiyi Wang, Qinghua Liu, Liang Wang, Robert G. Gilbert, Mitchell A. Sullivan. Optimization of liver glycogen extraction when considering the fine molecular structure. Carbohydrate Polymers. 2021; 261 ():117887.
Chicago/Turabian StyleZiyi Wang; Qinghua Liu; Liang Wang; Robert G. Gilbert; Mitchell A. Sullivan. 2021. "Optimization of liver glycogen extraction when considering the fine molecular structure." Carbohydrate Polymers 261, no. : 117887.
Diurnal alteration of glycogen molecular structure has been identified in healthy mice. Recently, both fragile (disintegration in dimethyl sulfoxide) and stable (not disintegrating in DMSO) glycogen particles were found in Escherichia coli. However, how glycogen structure changes dynamically in E. coli is not clear. The question examined here is whether fragile, stable glycogen α particles occur in bacteria, following a similar pattern as in mice. In this study, we examine the dynamic changes of glycogen molecular structure over 24-h in E. coli BL21(DE3), using transmission electron microscopy, size exclusion chromatography and fluorophore-assisted carbohydrate electrophoresis at representative time points. It was found that glycogen structure was mainly fragile at the synthesis stage and largely stable during the degradation stage. qRT-PCR results indicated that balance of anabolic and catabolic gene expression levels in glycogen metabolism could be a key factor affecting the fragility of glycogen α particles in bacteria.
Mengmeng Wang; Qinghua Liu; Fen Li; Jiawei Tang; Xuesong Xiong; Yingying Yang; Pei Ju; Ziyi Wang; Robert G. Gilbert; Liang Wang. The dynamic changes of glycogen molecular structure in Escherichia coli BL21(DE3). Carbohydrate Polymers 2021, 259, 117773 .
AMA StyleMengmeng Wang, Qinghua Liu, Fen Li, Jiawei Tang, Xuesong Xiong, Yingying Yang, Pei Ju, Ziyi Wang, Robert G. Gilbert, Liang Wang. The dynamic changes of glycogen molecular structure in Escherichia coli BL21(DE3). Carbohydrate Polymers. 2021; 259 ():117773.
Chicago/Turabian StyleMengmeng Wang; Qinghua Liu; Fen Li; Jiawei Tang; Xuesong Xiong; Yingying Yang; Pei Ju; Ziyi Wang; Robert G. Gilbert; Liang Wang. 2021. "The dynamic changes of glycogen molecular structure in Escherichia coli BL21(DE3)." Carbohydrate Polymers 259, no. : 117773.
When wheat experiences a cold-temperature ‘shock’ during the late stage of grain filling, it triggers the abnormal synthesis of late-maturity α-amylase (LMA). This increases the enzyme content in affected grain, which can lead to a drastic reduction in falling number (FN). By commercial standards, a low FN is taken as an indication of inferior quality, deemed unsuitable for end-product usage. Hence, LMA-affected grains are either rejected or downgraded to feed grade at the grain receiving point. However, previous studies have found no substantial correlation between low FN-LMA and bread quality. The present study extends previous investigations to semi-solid food, evaluating the physical quality of fresh white sauce processed from LMA-affected flour. Results show that high-LMA flours had low FNs and exhibited poor pasting characteristics. However, gelation occurred in the presence of other components during fresh white sauce processing. This demonstrates that LMA-affected flours may have new applications in low-viscosity products.
Galex Neoh; Mark Dieters; Keyu Tao; Glen Fox; Phuong Nguyen; Robert Gilbert. Late-Maturity Alpha-Amylase in Wheat (Triticum aestivum) and Its Impact on Fresh White Sauce Qualities. Foods 2021, 10, 201 .
AMA StyleGalex Neoh, Mark Dieters, Keyu Tao, Glen Fox, Phuong Nguyen, Robert Gilbert. Late-Maturity Alpha-Amylase in Wheat (Triticum aestivum) and Its Impact on Fresh White Sauce Qualities. Foods. 2021; 10 (2):201.
Chicago/Turabian StyleGalex Neoh; Mark Dieters; Keyu Tao; Glen Fox; Phuong Nguyen; Robert Gilbert. 2021. "Late-Maturity Alpha-Amylase in Wheat (Triticum aestivum) and Its Impact on Fresh White Sauce Qualities." Foods 10, no. 2: 201.
Excessively rapid postprandial blood glucose increase from digestion of starchy food can lead to health problems, including obesity and type II diabetes. Pectin, a plant polysaccharide dietary fibre, can beneficially affect starch digestion, but the underlying mechanism is not fully understood. Six pectin samples with different molecular structures were used here to study structure-property relationships for the in vitro digestion of starch in the presence of pectin. Three pectin structural features, namely monosaccharide composition, molecular size distribution and degree of esterification, were characterized by high performance liquid chromatography, size-exclusion chromatography and nuclear magnetic resonance, respectively. The effects of pectins on porcine pancreatic α-amylase activity and rheological changes in solutions were also studied, as were the in vitro digestibility of maize starch with and without pectins. The digestibility kinetics were fitted to two models and correlated to other parameters. It was found that (1) all pectin samples comprised mainly homogalacturonan with different degrees of esterification and different molecular sizes, (2) one pectin sample, denoted PGA, with no detectable degree of esterification and small hydrodynamic size, showed a strong amylase inhibitory effect, (3) the viscosity of solutions with pectins were significantly different, and (4) the presence of pectins in digesta did not change the digestion rate of starch, except for PGA, which markedly lowered the extent of starch amylolysis. Finally, the correlation data showed that pectin's degree of esterification plays a key role in pectin's effects on pancreatic amylase activity and on the in vitro digestion of starch.
Yeming Bai; Sharat Atluri; Zhongwei Zhang; Michael J. Gidley; Enpeng Li; Robert G. Gilbert. Structural reasons for inhibitory effects of pectin on α-amylase enzyme activity and in-vitro digestibility of starch. Food Hydrocolloids 2021, 114, 106581 .
AMA StyleYeming Bai, Sharat Atluri, Zhongwei Zhang, Michael J. Gidley, Enpeng Li, Robert G. Gilbert. Structural reasons for inhibitory effects of pectin on α-amylase enzyme activity and in-vitro digestibility of starch. Food Hydrocolloids. 2021; 114 ():106581.
Chicago/Turabian StyleYeming Bai; Sharat Atluri; Zhongwei Zhang; Michael J. Gidley; Enpeng Li; Robert G. Gilbert. 2021. "Structural reasons for inhibitory effects of pectin on α-amylase enzyme activity and in-vitro digestibility of starch." Food Hydrocolloids 114, no. : 106581.
This study aims to understand the starch molecular structural changes from baking sugar-snap cookies. Changes in the whole-molecule size distribution and chain-length distribution of the parent wheat flour and from final cookie products were measured by size-exclusion chromatography with and without enzymatic debranching, and the results fitted by two biosynthesis-based models. Fraction crystallinity was also analyzed. After cooking, there was a significant decrease in average molecular sizes of amylopectin and in the average lengths of amylose chains, and some starch granules lost birefringence. However, the chain-length distributions of amylopectin showed no noticeable difference, resulting in little change in relative crystallinity and gelatinization temperatures. Both the short-range ordered structure and the periodic lamellar structure were disrupted. This study provides new insight into starch structural changes in sugar-snap cookies after baking, which play an important role in determining final cookie quality. For example, a decrease in size of amylose chains influences cookie sensory properties, and thus can be used as an additional tool for choice of grains.
Zhongwei Zhang; Xiangyun Fan; Hongxiang Ma; Cheng Li; Enpeng Li; Robert G. Gilbert. Characterization of the baking-induced changes in starch molecular and crystalline structures in sugar-snap cookies. Carbohydrate Polymers 2020, 256, 117518 .
AMA StyleZhongwei Zhang, Xiangyun Fan, Hongxiang Ma, Cheng Li, Enpeng Li, Robert G. Gilbert. Characterization of the baking-induced changes in starch molecular and crystalline structures in sugar-snap cookies. Carbohydrate Polymers. 2020; 256 ():117518.
Chicago/Turabian StyleZhongwei Zhang; Xiangyun Fan; Hongxiang Ma; Cheng Li; Enpeng Li; Robert G. Gilbert. 2020. "Characterization of the baking-induced changes in starch molecular and crystalline structures in sugar-snap cookies." Carbohydrate Polymers 256, no. : 117518.
Summary Type 2 diabetes incidence continues to increase rapidly. This disease is characterized by a breakdown in blood glucose homeostasis. The impairment of glycemic control is linked to the structure of glycogen, a highly branched glucose polymer. Liver glycogen, a major controller of blood sugar, comprises small β particles which can link together to form larger α particles. These degrade to glucose more slowly than β particles, enabling a controlled release of blood glucose. The α particles in diabetic mice are however easily broken down into β particles, which degrade more quickly. Because this may lead to higher blood glucose, understanding this diabetes-associated breakdown of α-particle molecular structure may help in the development of diabetes therapeutics. We review the extraction of liver glycogen, its molecular structure, and how this structure is affected by diabetes and then use this knowledge to make postulates to guide the development of strategies to help mitigate type 2 diabetes.
Asad Nawaz; Peng Zhang; Enpeng Li; Robert G. Gilbert; Mitchell A. Sullivan. The importance of glycogen molecular structure for blood glucose control. iScience 2020, 24, 101953 .
AMA StyleAsad Nawaz, Peng Zhang, Enpeng Li, Robert G. Gilbert, Mitchell A. Sullivan. The importance of glycogen molecular structure for blood glucose control. iScience. 2020; 24 (1):101953.
Chicago/Turabian StyleAsad Nawaz; Peng Zhang; Enpeng Li; Robert G. Gilbert; Mitchell A. Sullivan. 2020. "The importance of glycogen molecular structure for blood glucose control." iScience 24, no. 1: 101953.
Rices with higher protein contents are nutritionally desirable. This study investigates the effects of endosperm proteins on starch in vitro digestibility in cooked and uncooked rice, and the mechanisms underlying any changes. The composition of rice endosperm proteins and the morphologies of proteins and starch granules were determined by SDS-PAGE and confocal microscopy. Starch molecular fine structure was examined using size-exclusion chromatography. In vitro digestion showed that the digestion rate coefficients (k) of cooked rice flour were significantly lower than those of isolated starch or of a starch-protein mixture. (e.g for samples from SWR4, k is 9.6, 12.9 and 11.6 × 10-2 min−1 for cooked rice flour, isolated starch and starch-protein mixture, respectively). For uncooked samples, digestion rate coefficients were 1.4, 1.5 and 1.8 × 10-2 min−1 for flour, starch-protein mixture and starch, respectively. The digestion rates in cooked samples were higher than those in uncooked samples. This suggests that, in cooked samples, starch digestion rates are more affected by the protein physical barrier than by some chemical effect (e.g. hydrogen bonding between protein and starch), while in uncooked samples, a chemical effect from protein is more pronounced than a physical barrier from protein.
Changfeng Li; Panpan Cao; Peng Wu; Wenwen Yu; Robert G Gilbert; Enpeng Li. Effects of endogenous proteins on rice digestion during small intestine (in vitro) digestion. Food Chemistry 2020, 344, 128687 .
AMA StyleChangfeng Li, Panpan Cao, Peng Wu, Wenwen Yu, Robert G Gilbert, Enpeng Li. Effects of endogenous proteins on rice digestion during small intestine (in vitro) digestion. Food Chemistry. 2020; 344 ():128687.
Chicago/Turabian StyleChangfeng Li; Panpan Cao; Peng Wu; Wenwen Yu; Robert G Gilbert; Enpeng Li. 2020. "Effects of endogenous proteins on rice digestion during small intestine (in vitro) digestion." Food Chemistry 344, no. : 128687.
Previous studies have suggested that water-soluble polysaccharides from fermented carrot pulp (WSP-p) have stronger anti-diabetic effects than those from un-fermented carrot pulp (WSP-n). This study aimed to improve understanding of these functional differences by comparing their molecular structures. Weight-average molecular weights of WSP-p fractions were lower than those of the corresponding WSP-n fractions. While both WSPs had similar functional groups, more fragmented particles were observed on the surface of large particles of WSP-n than WSP-p. Monosaccharide composition and methylation analysis confirmed that both WSP-p and WSP-n were pectic polysaccharides, containing rhamnogalacturonan-I-type polysaccharides with 1,4-linked α-d-galacturonic acid residues and homogalacturonan regions with 1,4-GalpA linkages. 1H and 13C NMR showed that they had similar linkage patterns. These findings suggested that probiotic fermentation of WSP mainly cleaved the linkages between repeating units, and resulted in less polydisperse molecular size distributions.
Yu-Jun Wan; Tao Hong; Hui-Fang Shi; Jun-Yi Yin; Todor Koev; Shao-Ping Nie; Robert G. Gilbert; Ming-Yong Xie. Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp. Carbohydrate Polymers 2020, 251, 117116 .
AMA StyleYu-Jun Wan, Tao Hong, Hui-Fang Shi, Jun-Yi Yin, Todor Koev, Shao-Ping Nie, Robert G. Gilbert, Ming-Yong Xie. Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp. Carbohydrate Polymers. 2020; 251 ():117116.
Chicago/Turabian StyleYu-Jun Wan; Tao Hong; Hui-Fang Shi; Jun-Yi Yin; Todor Koev; Shao-Ping Nie; Robert G. Gilbert; Ming-Yong Xie. 2020. "Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp." Carbohydrate Polymers 251, no. : 117116.
High-amylose wheat starch (HAWS) and flour (HAWF) have the potential to deliver food products with enhanced nutritional functionality, but structure/function relationships are not well understood. We report the structural bases for differences in water absorption and pasting properties for HAWS and HAWF (amylose contents 71–84 %) compared with wild-type (WTWS/WTWF). With higher amylose content, the proportion of longer amylopectin chains with DP > 25 increased. Both the degree of branching and the branch lengths of amylose were lower for HAWS than WTWS. Compared with WTWF, HAWF contained less total starch, more protein, had lower peak viscosity by high-temperature RVA, lower dough development time and stability time and higher water absorption by Farinograph. Water absorption by HAWS was ∼1.5 times greater than for WTWS, suggesting loose packing of polymers within HAWS granules. Consistent with this, crystallinity and birefringence of starch granules were lower in HAWS.
Caili Li; Sushil Dhital; Robert G. Gilbert; Michael J. Gidley. High-amylose wheat starch: Structural basis for water absorption and pasting properties. Carbohydrate Polymers 2020, 245, 116557 .
AMA StyleCaili Li, Sushil Dhital, Robert G. Gilbert, Michael J. Gidley. High-amylose wheat starch: Structural basis for water absorption and pasting properties. Carbohydrate Polymers. 2020; 245 ():116557.
Chicago/Turabian StyleCaili Li; Sushil Dhital; Robert G. Gilbert; Michael J. Gidley. 2020. "High-amylose wheat starch: Structural basis for water absorption and pasting properties." Carbohydrate Polymers 245, no. : 116557.
Glycogen, a glucose homopolymer with many glucose chains, is the primary blood-sugar reservoir in many organisms. It comprises β particles (∼20 nm) which can bind together to form large α particles with a rosette morphology. When dimethyl sulfoxide (DMSO) is added to glycogen from diabetic livers, α particles break apart to β particles ('fragility'), possibly due to H-bond disruption; this is not seen in healthy livers. Glycogen α and β particles, and α-particle fragility, are observed in mammals and bacteria, and are examined here in the worm Caenorhabditis elegans, with glycogen from two C. elegans strains, cultured in normal and high-glucose conditions. There were mainly β particles, with some large α particles. Most particles were fragile in DMSO. Growing in a high-glucose medium results in more long chains and more fragility, consistent with previous observations in diabetic animal models. Why high glucose levels facilitate fragility is worthy of further investigation.
Qinghua Liu; Zuobin Zhu; Mengmeng Wang; Yuechen Wang; Peng Zhang; Hao Wang; Mengyu Liang; Ying Li; Bin Deng; Daoquan Tang; Robert G. Gilbert; Liang Wang. Characterization of glycogen molecular structure in the worm Caenorhabditis elegans. Carbohydrate Polymers 2020, 237, 116181 .
AMA StyleQinghua Liu, Zuobin Zhu, Mengmeng Wang, Yuechen Wang, Peng Zhang, Hao Wang, Mengyu Liang, Ying Li, Bin Deng, Daoquan Tang, Robert G. Gilbert, Liang Wang. Characterization of glycogen molecular structure in the worm Caenorhabditis elegans. Carbohydrate Polymers. 2020; 237 ():116181.
Chicago/Turabian StyleQinghua Liu; Zuobin Zhu; Mengmeng Wang; Yuechen Wang; Peng Zhang; Hao Wang; Mengyu Liang; Ying Li; Bin Deng; Daoquan Tang; Robert G. Gilbert; Liang Wang. 2020. "Characterization of glycogen molecular structure in the worm Caenorhabditis elegans." Carbohydrate Polymers 237, no. : 116181.
Resistant starch type 3 (RS3) benefits colon health, but the molecular structural reasons for this effect are unclear. Five rice starches with varied amylose content (19.1 %–40.6 %) were used to investigate their effect on gut microbiota. Size-exclusion chromatography and fluorophore-assisted carbohydrate electrophoresis were used to characterize whole starch molecular size distributions and chain length distributions. It was found that RS3 with more chains of degree of polymerization (DP) 36–100 and smaller molecular size can promote the relative abundance of some classes of gut bacteria, while other classes were promoted by RS3 with fewer chains of DP 36–100 and larger molecular size. X-ray diffraction and scanning electron microscopy showed that crystallinity types B or C and differences in physical surface affected the microbiota. This study shows that RS3s with different fine structures are utilized differently by gut microbiota, which may be applied to develop functional foods for gut health.
Fangting Gu; Cheng Li; Bruce R. Hamaker; Robert G. Gilbert; Xiaowei Zhang. Fecal microbiota responses to rice RS3 are specific to amylose molecular structure. Carbohydrate Polymers 2020, 243, 116475 .
AMA StyleFangting Gu, Cheng Li, Bruce R. Hamaker, Robert G. Gilbert, Xiaowei Zhang. Fecal microbiota responses to rice RS3 are specific to amylose molecular structure. Carbohydrate Polymers. 2020; 243 ():116475.
Chicago/Turabian StyleFangting Gu; Cheng Li; Bruce R. Hamaker; Robert G. Gilbert; Xiaowei Zhang. 2020. "Fecal microbiota responses to rice RS3 are specific to amylose molecular structure." Carbohydrate Polymers 243, no. : 116475.
The relationship between wheat-starch molecular structures (obtained by size-exclusion chromatography), physicochemical properties (swelling power (SP), pasting and thermal properties) and noodle eating qualities were examined. SP was negatively correlated with amylose content and positively correlated with the amounts of amylose long chains and short amylopectin chains. Peak viscosity (PV) was negatively correlated with amylose content and the amount of long amylopectin chains, but positively correlated with the lengths of long amylopectin chains and the amount of short amylopectin chains. Noodles adhesiveness was negatively correlated with the amount of short amylose chains, short amylopectin chains, PV and final viscosity (FV). Noodles hardness was positively correlated with amylose content and long amylopectin chains, but negatively correlated with short amylopectin chains, SP, PV, and FV. All these observations are explained in terms of molecular mechanisms. This provides the first associations between starch molecular fine structures (instead of only amylose content) responsible for starch properties of importance in making noodles.
Qingqing Li; Cheng Li; Enpeng Li; Robert G. Gilbert; Bin Xu. A molecular explanation of wheat starch physicochemical properties related to noodle eating quality. Food Hydrocolloids 2020, 108, 106035 .
AMA StyleQingqing Li, Cheng Li, Enpeng Li, Robert G. Gilbert, Bin Xu. A molecular explanation of wheat starch physicochemical properties related to noodle eating quality. Food Hydrocolloids. 2020; 108 ():106035.
Chicago/Turabian StyleQingqing Li; Cheng Li; Enpeng Li; Robert G. Gilbert; Bin Xu. 2020. "A molecular explanation of wheat starch physicochemical properties related to noodle eating quality." Food Hydrocolloids 108, no. : 106035.
Starch, the most abundant component of wheat flour, has a significant influence on sugar-snap cookie quality, but the underlying mechanisms are not well understood. In this study, the solvent retention capacity and rheological properties of sugar-snap cookie dough, and cookie physical characteristics and textural properties, were analyzed. Starch molecular structures were measured by size-exclusion chromatography (SEC) and the results parameterized using two biosynthesis-based mathematical models to obtain structure-property correlations. The results show that the viscoelasticity of sugar-snap cookie dough is positively correlated with the length of amylopectin short chains. In addition, the length of amylose short chains is positively correlated with cookie thickness and negatively correlated with its spread ratio. Starch molecular structure shows no influence on cookie hardness and fracturability. Mechanisms are proposed for these results, which could lead to new ways to improve sugar-snap cookie quality by choosing starches with appropriate structural features.
Zhongwei Zhang; Xiangyun Fan; Xiaoyan Yang; Cheng Li; Robert G. Gilbert; Enpeng Li. Effects of amylose and amylopectin fine structure on sugar-snap cookie dough rheology and cookie quality. Carbohydrate Polymers 2020, 241, 116371 .
AMA StyleZhongwei Zhang, Xiangyun Fan, Xiaoyan Yang, Cheng Li, Robert G. Gilbert, Enpeng Li. Effects of amylose and amylopectin fine structure on sugar-snap cookie dough rheology and cookie quality. Carbohydrate Polymers. 2020; 241 ():116371.
Chicago/Turabian StyleZhongwei Zhang; Xiangyun Fan; Xiaoyan Yang; Cheng Li; Robert G. Gilbert; Enpeng Li. 2020. "Effects of amylose and amylopectin fine structure on sugar-snap cookie dough rheology and cookie quality." Carbohydrate Polymers 241, no. : 116371.
Wheat flour noodles are sometimes fortified with β-glucan for nutritional value, but this can decrease eating quality. The contributions of β-glucan and starch molecular fine structure to physicochemical properties of wholemeal oat flour and to the texture of oat-fortified white salted noodles were investigated here. Hardness of oat-fortified noodles was controlled by the longer amylopectin chains (DP ≥ 26) and amount of longer amylose chains (DP ≥ 1000). Higher levels of β-glucan, in the range from 3.1 to 5.2%, result in increased noodle hardness. Pasting viscosities of wholemeal oat flour positively correlate with the hardness of oat-fortified noodles. The swelling power of oat flour is not correlated with either pasting viscosities of oat flour or noodle hardness. Longer amylopectin chains and the amount of longer amylose chains both control the pasting viscosities of oat flour, which in turn affect noodle texture. This provides new means, based on starch and β-glucan molecular structure, to choose oats with optimal starch structure and β-glucan content for targeted oat-fortified noodle quality.
Thoa T.L. Nguyen; Robert G. Gilbert; Michael J. Gidley; Glen P. Fox. The contribution of β-glucan and starch fine structure to texture of oat-fortified wheat noodles. Food Chemistry 2020, 324, 126858 .
AMA StyleThoa T.L. Nguyen, Robert G. Gilbert, Michael J. Gidley, Glen P. Fox. The contribution of β-glucan and starch fine structure to texture of oat-fortified wheat noodles. Food Chemistry. 2020; 324 ():126858.
Chicago/Turabian StyleThoa T.L. Nguyen; Robert G. Gilbert; Michael J. Gidley; Glen P. Fox. 2020. "The contribution of β-glucan and starch fine structure to texture of oat-fortified wheat noodles." Food Chemistry 324, no. : 126858.
Nitrogen fertilizer is an essential nutrient for rice (Oryza sativa L.), especially, for newly bred ‘super’ rice cultivars with great yield potential. The effects of nitrogen fertilizer (0, 100, 200, 300, 400 kg N ha−1) on the physicochemical properties of two high yielding ‘super’ rice Yongyou 2640 and Lianjing 7 were investigated in this study. The application of nitrogen fertilizer affects the structure of rice starch, thus changing its functional properties, which ultimately leads to a change in the quality of both rice cultivars. There were dose effects of nitrogen fertilizer on grain quality. Grain quality was improved under moderate nitrogen inputs (100 & 200 kg N ha−1), but deteriorated at excessive nitrogen levels (300 & 400 kg N ha−1). With moderate N application, starch granule size increased and the surface of starch granule became smoother; there were higher proportion of short branch-chain of amylopectin and lower proportion of long branch-chain of amylopectin with low relative crystallinity, lower degree of order of structure and higher content of amorphous structure at the outer region of the starch granules; peak viscosity, hot viscosity, breakdown value were increased while setback and pasting temperature were decreased; gelatinization temperature, gelatinization enthalpy, retrogradation enthalpy, retrogradation percentage, hardness were decreased while viscosity were increased. At excessive nitrogen inputs, the grain quality was deteriorated and the opposite results of structure and physicochemical properties of rice starch were observed. These results indicate that nitrogen fertilizer significantly affected the structure and physicochemical properties of rice starch, and appropriate fertilization would improve rice grain quality.
Tianyang Zhou; Qun Zhou; Enpeng Li; Limin Yuan; Weilu Wang; Hao Zhang; Lijun Liu; Zhiqin Wang; Jianchang Yang; Junfei Gu. Effects of nitrogen fertilizer on structure and physicochemical properties of ‘super’ rice starch. Carbohydrate Polymers 2020, 239, 116237 .
AMA StyleTianyang Zhou, Qun Zhou, Enpeng Li, Limin Yuan, Weilu Wang, Hao Zhang, Lijun Liu, Zhiqin Wang, Jianchang Yang, Junfei Gu. Effects of nitrogen fertilizer on structure and physicochemical properties of ‘super’ rice starch. Carbohydrate Polymers. 2020; 239 ():116237.
Chicago/Turabian StyleTianyang Zhou; Qun Zhou; Enpeng Li; Limin Yuan; Weilu Wang; Hao Zhang; Lijun Liu; Zhiqin Wang; Jianchang Yang; Junfei Gu. 2020. "Effects of nitrogen fertilizer on structure and physicochemical properties of ‘super’ rice starch." Carbohydrate Polymers 239, no. : 116237.