-
Effect of Amylose and Crystallinity Pattern on the Gelatinization Behavior of Cross-Linked Starches.Polymers Jul 2022Starches from normal maize (NM), normal potato (NP), waxy maize (WM), and waxy potato (WP) were cross-linked with seven different concentrations (0.01, 0.05, 0.1, 0.5,...
Starches from normal maize (NM), normal potato (NP), waxy maize (WM), and waxy potato (WP) were cross-linked with seven different concentrations (0.01, 0.05, 0.1, 0.5, 1, 5, 10%) of sodium trimetaphosphate and sodium tripolyphosphate. The use of low-amylose WM and WP as well as A-crystalline maize and B-crystalline potato starches can determine the influence of the amylose content and crystallinity pattern on the cross-linking of starches. The results showed that the viscosity of the cross-linked starch (CLs) first increased and then deceased, and finally no viscosity was detected; WM showed no viscosity at 5% and NP at 1%. In addition, the viscosity of NM first increased and then became undetectable at 0.5%. Strikingly, the WP developed viscosity even at a 10% reagent level (RL), and it developed the highest viscosity of all samples at 1%. The starch-iodine method was a facile and high-performance method for the characterization of the cross-linking degree (CL%), having been applied to normal starches, because the increase in the CL% resulted in a decrease of iodine-complexed amylose and blue intensity. In this study, the starch-iodine method was extended to waxy starches, which stained brown with iodine, and the brown intensity decreased with the increase of the CL%. Moreover, the CL% and RL showed a linear-log relationship.
PubMed: 35890646
DOI: 10.3390/polym14142870 -
International Journal of Molecular... May 2021The () gene, encoding the granule-bound starch synthase (GBSS), is responsible for amylose biosynthesis and plays a crucial role in defining eating and cooking quality.... (Review)
Review
The () gene, encoding the granule-bound starch synthase (GBSS), is responsible for amylose biosynthesis and plays a crucial role in defining eating and cooking quality. The waxy locus controls both the non-waxy and waxy rice phenotypes. Rice starch can be altered into various forms by either reducing or increasing the amylose content, depending on consumer preference and region. Low-amylose rice is preferred by consumers because of its softness and sticky appearance. A better way of improving crops other than downregulation and overexpression of a gene or genes may be achieved through the posttranslational modification of sites or regulatory enzymes that regulate them because of their significance. The impact of posttranslational GBSSI modifications on extra-long unit chains (ELCs) remains largely unknown. Numerous studies have been reported on different crops, such as wheat, maize, and barley, but the rice starch granule proteome remains largely unknown. There is a need to improve the yield of low-amylose rice by employing posttranslational modification of , since the market demand is increasing every day in order to meet the market demand for low-amylose rice in the regional area that prefers low-amylose rice, particularly in China. In this review, we have conducted an in-depth review of waxy rice, starch properties, starch biosynthesis, and posttranslational modification of waxy protein to genetically improve starch quality in rice grains.
Topics: Amylose; Edible Grain; Gene Expression Regulation, Plant; Oryza; Plant Proteins; Plants, Genetically Modified; Protein Processing, Post-Translational; Starch; Starch Synthase
PubMed: 34063649
DOI: 10.3390/ijms22094845 -
Biochemical Society Transactions Aug 2017Starch is the most widespread and abundant storage carbohydrate in plants and the main source of carbohydrate in the human diet. Owing to its remarkable properties and... (Review)
Review
Starch is the most widespread and abundant storage carbohydrate in plants and the main source of carbohydrate in the human diet. Owing to its remarkable properties and commercial applications, starch is still of growing interest. Its unique granular structure made of intercalated layers of amylopectin and amylose has been unraveled thanks to recent progress in microscopic imaging, but the origin of such periodicity is still under debate. Both amylose and amylopectin are made of linear chains of α-1,4-bound glucose residues, with branch points formed by α-1,6 linkages. The net difference in the distribution of chain lengths and the branching pattern of amylose (mainly linear), compared with amylopectin (racemose structure), leads to different physico-chemical properties. Amylose is an amorphous and soluble polysaccharide, whereas amylopectin is insoluble and exhibits a highly organized structure of densely packed double helices formed between neighboring linear chains. Contrarily to starch degradation that has been investigated since the early 20th century, starch production is still poorly understood. Most enzymes involved in starch growth (elongation, branching, debranching, and partial hydrolysis) are now identified. However, their specific action, their interplay (cooperative or competitive), and their kinetic properties are still largely unknown. After reviewing recent results on starch structure and starch growth and degradation enzymatic activity, we discuss recent results and current challenges for growing polysaccharides on granular surface. Finally, we highlight the importance of novel stochastic models to support the analysis of recent and complex experimental results, and to address how macroscopic properties emerge from enzymatic activity and structural rearrangements.
Topics: Amylopectin; Amylose; Carbohydrate Conformation; Cytoplasmic Granules; Glucans; Hydrolysis; Models, Molecular; Plant Proteins; Plants; Solid-Phase Synthesis Techniques; Solubility; Starch; Stochastic Processes
PubMed: 28673938
DOI: 10.1042/BST20160407 -
The Journal of Nutrition Jan 2023High amylose starchy foods modulate the postprandial metabolic response in humans. However, the mechanisms of their metabolic benefits and their impact on the subsequent... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
High amylose starchy foods modulate the postprandial metabolic response in humans. However, the mechanisms of their metabolic benefits and their impact on the subsequent meal have not been fully elucidated.
OBJECTIVE
We aimed to evaluate whether glucose and insulin responses to a standard lunch are influenced by the consumption of amylose-rich bread at breakfast in overweight adults and whether changes in plasma short chain fatty acids (SCFAs) concentrations contribute to their metabolic effects.
METHODS
Using a randomized crossover design, 11 men and 9 women, BMI 30 ± 3 kg/m, 48 ± 19 y, consumed at breakfast 2 breads made with high amylose flour (HAF): 85%-HAF (180 g) and 75%-HAF (170 g), and control bread (120 g) containing 100% conventional flour. Plasma samples were collected at fasting, 4 h after breakfast, and 2 h after a standard lunch to measure glucose, insulin, and SCFA concentrations. ANOVA posthoc analyses were used for comparisons.
RESULTS
Postprandial plasma glucose responses were 27% and 39% lower after breakfasts with 85%- and 70%-HAF breads than control bread (P = 0.026 and P = 0.003, respectively), with no difference after lunch. Insulin responses were not different between the 3 breakfasts, whereas there was a 28% lower response after the lunch following breakfast with 85%-HAF bread than the control (P = 0.049). Propionate concentrations increased from fasting by 9% and 12% 6 h after breakfasts with 85%- and 70%-HAF breads and decreased by 11% with control bread (P < 0.05). At 6 h after breakfast with 70%-HAF bread, plasma propionate and insulin were inversely correlated (r = -0.566; P = 0.044).
CONCLUSIONS
Amylose-rich bread reduces the postprandial glucose response after breakfast and insulin concentrations after the subsequent lunch in overweight adults. This second meal effect may be mediated by the elevation of plasma propionate due to intestinal fermentation of resistant starch. High amylose products could be a promising tool in a dietary prevention strategy for type 2 diabetes.
THIS TRIAL WAS REGISTERED AT CLINICAL TRIAL REGISTRY AS
NCT03899974 (https://www.
CLINICALTRIALS
gov/ct2/show/NCT03899974).
Topics: Adult; Female; Humans; Male; Amylose; Blood Glucose; Bread; Breakfast; Cross-Over Studies; Glucose; Insulin; Insulin, Regular, Human; Overweight; Postprandial Period; Propionates; Triticum
PubMed: 36913446
DOI: 10.1016/j.tjnut.2022.10.007 -
BioMed Research International 2018Occurrence of chalkiness in rice is attributed to genetic and environmental factors, especially high temperature (HT). The HT induces heat stress, which in turn... (Review)
Review
Occurrence of chalkiness in rice is attributed to genetic and environmental factors, especially high temperature (HT). The HT induces heat stress, which in turn compromises many grain qualities, especially transparency. Chalkiness in rice is commonly studied together with other quality traits such as amylose content, gel consistency, and protein storage. In addition to the fundamental QTLs, some other QTLs have been identified which accelerate chalkiness occurrence under HT condition. In this review, some of the relatively stable chalkiness, amylose content, and gel consistency related QTLs have been presented well. Genetically, HT effect on chalkiness is explained by the location of certain chalkiness gene in the vicinity of high-temperature-responsive genes. With regard to stable QTL distribution and availability of potential material resources, there is still feasibility to find out novel stable QTLs related to chalkiness under HT condition. A better understanding of those achievements is essential to develop new rice varieties with a reduced chalky grain percentage. Therefore, we propose the pyramiding of relatively stable and nonallelic QTLs controlling low chalkiness endosperm into adaptable rice varieties as pragmatic approach to mitigate HT effect.
Topics: Amylose; Hot Temperature; Oryza; Quantitative Trait Loci; Temperature
PubMed: 30065932
DOI: 10.1155/2018/1653721 -
Breeding Science Mar 2020Common buckwheat ( Moench, CB) and Tartary buckwheat ( (L.) Gaertn., TB) are used in human nutrition. The idea to screen in the haploid phase for genes affecting low...
Common buckwheat ( Moench, CB) and Tartary buckwheat ( (L.) Gaertn., TB) are used in human nutrition. The idea to screen in the haploid phase for genes affecting low amylose concentration opens the possibility for the effective search of low amylose (waxy) genotypes in CB populations. Self-pollinated homozygous plants of TB might allow us to use a part of endosperm for screening of amylose content. Phenolic substances have a significant inhibitory effect on the digestion of CB and TB proteins, thus metabolites may have impact on protein digestibility. Digestion-resistant peptides are largely responsible for the bile acid elimination. Breeding to diminish polyphenols and anti-nutritional substances might have negative effects on the resistance of plants against pests, diseases and UV-radiation. Bread and pasta are popular CB and TB dishes. During dough making most of CB or TB rutin is degraded to quercetin by rutin-degrading enzymes. The new trace-rutinosidase TB variety makes possible making TB bread with considerable amount of rutin, preserving the initial rutin from flour. Breeding CB and TB for larger embryos would make it possible to increase protein, rutin, and essential minerals concentration in CB and TB grain.
PubMed: 32351305
DOI: 10.1270/jsbbs.19016 -
Journal of Animal Science and... Aug 2023Starch is a major component of carbohydrates and a major energy source for monogastric animals. Starch is composed of amylose and amylopectin and has different...
BACKGROUND
Starch is a major component of carbohydrates and a major energy source for monogastric animals. Starch is composed of amylose and amylopectin and has different physiological functions due to its different structure. It has been shown that the energy supply efficiency of amylose is lower than that of amylopectin. However, there are few studies on the effect of starch structure on the available energy of pigs. The purpose of this study was to measure the effect of different structures of starch in the diet on the net energy (NE) of pigs using a comparative slaughter method and to establish a prediction equation to estimate the NE of starch with different structures. Fifty-six barrows (initial BW 10.18 ± 0.11 kg) were used, and they were housed and fed individually. Pigs were divided into 7 treatments, with 8 replicates for each treatment and 1 pig for each replicate. One of the treatments was randomly selected as the initial slaughter group (ISG). Pigs in the remaining treatments were assigned to 6 diets, fed with basic diet and semi-pure diets with amylose/amylopectin ratio (AR) of 3.09, 1.47, 0.25, 0.15 and 0.12, respectively. The experiment lasted for 28 d.
RESULTS
Results showed that compared with the high amylose (AM) groups (AR 3.09 and 1.47), the high amylopectin (AP) group (AR 0.15) significantly increased the final BW, average daily weight gain and average daily feed intake of pigs (P < 0.05), but the F:G of the AM group was lower (P < 0.01). In addition, AR 0.15 and 0.12 groups have higher (P < 0.01) nutrient digestibility of dry matter, crude protein, gross energy and crude ash. Meanwhile, compared with other groups, AR 0.15 group has a higher (P < 0.05) NE intake and energy retention (RE). The regressive equation for predicting with starch structures was established as RE = 1,235.243 - 48.298AM/AP (R = 0.657, P = 0.05).
CONCLUSIONS
In conclusion, NE intake and RE of pigs augmented with the increase of dietary amylopectin content, indicating that diets high in amylopectin were more conducive to promoting the growth of pigs in the late conservation period.
PubMed: 37553706
DOI: 10.1186/s40104-023-00908-2 -
Frontiers in Nutrition 2021Increasing the ratio of amylose in the diet can increase the quantity of starch that flows to the large intestine for microbial fermentation. This leads to the...
Increasing the ratio of amylose in the diet can increase the quantity of starch that flows to the large intestine for microbial fermentation. This leads to the alteration of microbiota and metabolite of the hindgut, where the underlying mechanism is not clearly understood. The present study used a combination of 16S amplicon sequencing technology and metabolomics technique to reveal the effects of increasing ratios of amylose/amylopectin on cecal mucosa- and digesta-associated microbiota and their metabolites in young goats. Twenty-seven Xiangdong black female goats with average body weights (9.00 ± 1.12 kg) were used in this study. The goats were randomly allocated to one of the three diets containing starch with 0% amylose corn (T1), 50% high amylose corn (T2), and 100% high amylose corn (T3) for 35 days. Results showed that cecal valerate concentration was higher ( < 0.05) in the T2 group than those in the T1 and T3 groups. The levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were decreased ( < 0.05) in cecal tissue while IL-10 was increased ( < 0.05) in the T2 group when compared with T1 or T3 groups. At the phylum level, the proportion of mucosa-associated Spirochaetes was increased ( < 0.05), while Proteobacteria was deceased by feeding high amylose ratios ( < 0.05). The abundance of Verrucomicrobia was decreased ( < 0.05) in the T3 group compared with the T1 and T2 groups. The abundance of digesta-associated Firmicutes was increased ( < 0.05) while Verrucomicrobia and Tenericutes were deceased ( < 0.05) with the increment of amylose/amylopectin ratios. The LEfSe analysis showed that a diet with 50% high amylose enriched the abundance of beneficial bacteria such as and in the digesta and in the mucosa compared with the T1 diet. The metabolomics results revealed that feeding a diet containing 50% high amylose decreased the concentration of fatty acyls-related metabolites, including dodecanedioic acid, heptadecanoic acid, and stearidonic acid ethyl ester compared with the T1 diet. The results suggested that a diet consisting of 50% high amylose could maintain a better cecal microbiota composition and host immune function.
PubMed: 34957184
DOI: 10.3389/fnut.2021.774766 -
Foods (Basel, Switzerland) Mar 2023In this study, Glutinous rice (GR), Japonica rice (JR), and Indica rice (IR), with amylose contents at 1.57 ± 0.18%, 15.88 ± 1.16%, and 26.14 ± 0.25%, respectively,...
In this study, Glutinous rice (GR), Japonica rice (JR), and Indica rice (IR), with amylose contents at 1.57 ± 0.18%, 15.88 ± 1.16%, and 26.14 ± 0.25%, respectively, were selected to reveal the role of amylose in the gel forming of rice flours. The strength and elasticity of the associated gels were found in an ascendant order with the increase in amylose content. For the retrograded gels (at 4 °C for 7 days), the peak temperature (Tp) was positively related to the amylose content. In general, Tp of IR increased to 63.21 ± 0.13 °C, and the relative crystallinities of IR were in the top ranking at 10.67 ± 0.16%, followed by those of JR and GR. The relative amounts of short-range ordered structures to amorphous regions in JR and IR were also higher than that of GR, and the number of compact network structure were positively related to the amylose content. These results indicated that amylose can enhance the strength and elasticity of gels by facilitating the formation of crystalline, short-range ordered, and compact network structures. These results can provide a reference for the development of rice products.
PubMed: 36981139
DOI: 10.3390/foods12061210 -
BMC Plant Biology May 2023Heat stress threatens rice yield and quality at flowering stage. In this study, average relative seed setting rate under heat stress (RHSR) and genotypes of 284...
BACKGROUND
Heat stress threatens rice yield and quality at flowering stage. In this study, average relative seed setting rate under heat stress (RHSR) and genotypes of 284 varieties were used for a genome-wide association study.
RESULTS
We identified eight and six QTLs distributed on chromosomes 1, 3, 4, 5, 7 and 12 in the full population and indica, respectively. qHTT4.2 was detected in both the full population and indica as an overlapping QTL. RHSR was positively correlated with the accumulation of heat-tolerant superior alleles (SA), and indica accession contained at least two heat-tolerant SA with average RHSR greater than 43%, meeting the needs of stable production and heat-tolerant QTLs were offer yield basic for chalkiness degree, amylose content, gel consistency and gelatinization temperature. Chalkiness degree, amylose content, and gelatinization temperature under heat stress increased with accumulation of heat-tolerant SA. Gel consistency under heat stress decreased with polymerization of heat-tolerant SA. The study revealed qHTT4.2 as a stable heat-tolerant QTL that can be used for breeding that was detected in the full population and indica. And the grain quality of qHTT4.2-haplotype1 (Hap1) with chalk5, wx, and alk was better than that of qHTT4.2-Hap1 with CHALK5, WX, and ALK. Twelve putative candidate genes were identified for qHTT4.2 that enhance RHSR based on gene expression data and these genes were validated in two groups. Candidate genes LOC_Os04g52830 and LOC_Os04g52870 were induced by high temperature.
CONCLUSIONS
Our findings identify strong heat-tolerant cultivars and heat-tolerant QTLs with great potential value to improve rice tolerance to heat stress, and suggest a strategy for the breeding of yield-balance-quality heat-tolerant crop varieties.
Topics: Oryza; Genome-Wide Association Study; Alleles; Amylose; Plant Breeding; Receptor Protein-Tyrosine Kinases
PubMed: 37189032
DOI: 10.1186/s12870-023-04260-5