Altered starch composition and improved bread quality in novel wheat mutant reveal key transcriptional regulators.

In order to study the effects of different nitrogen application rates on the quality of waxy and non-waxy wheat and brewing quality, the suitable nitrogen application rate for high yield and high-quality production of wheat for brewing was determined. Mianmai 902 (non-waxy) and Zhongkezinuomai 168 (waxy) were used as the experimental materials in Dayi County, Chengdu City, Sichuan Province, in 2019 and 2020. Six nitrogen application rates (0, 45, 90, 135, 180, and 225 kg hm-2) were set to analyze their effects on the quality of wheat raw grain, brewing quality, and volatile flavor compounds. The results showed that the yield, flour quality rate, and ash content of Mianmai 902 were higher. Zhongkezinuomai 168 had higher hardness, bulk density, protein, and fat content, higher total starch and amylopectin content, lower straight branch ratio, and lower RVA characteristic parameters except that breakdown value was higher than that of Mianmai 902. Increasing nitrogen application rate significantly increased wheat yield, and the yield of both varieties reached the maximum at 225 kg hm-2. Silty rate and bulk density decreased with the increase of nitrogen application rate, while hardness index and protein content increased. Fat and ash content were higher in 135 kg hm-2, the total starch and amylopectin content were higher in 90-135 kg hm-2, peak viscosity and trough viscosity decreased significantly after 135 kg hm-2. The wine yield of the two varieties was higher in the range of 90-135 kg hm-2 nitrogen application, but the inter-annual difference was different. The wine yield of Mianmai 902 was significantly higher than that of Zhongkezinuomai 168 in 2019, and the opposite was true in 2020. We speculated that it was related to the more rain at filling stage in 2020, the decrease of grain hardness index and the increase of silty rate of Zhongkezinuomai 168. The content of total acid and total ester in liquor brewed by Mianmai 902 was not high, and the content of fusel oil was relatively low. Zhongkezinuomai 168 was the opposite, but the fusel content was still in the safe range (≤ 0.2 g 100 mL-1). The total acid content of liquor produced by Mianmai 902 was the highest under the treatment of 90 kg hm-2 in the two years, and the total acid content of Zhongkezinuomai 168 was the highest under the treatment of 135 kg hm-2 in 2020. In terms of total ester and fusel oil, the total ester content of the two varieties was relatively low under 135 kg hm-2 treatment, and the fusel oil content was the lowest under 90 kg hm-2 treatment. Compared with 2019, the contents of total acid and total ester of the two varieties decreased significantly in 2020, which may be related to more precipitation at grain filling stage and the decrease of total starch and amylopectin contents. Zhongkezinuomai 168 had more kinds and quantities of volatile flavor substances, and its overall brewing characteristics were better than that of Mianmai 902. The number of volatile flavor compounds of Mianmai 902 was the highest at 90 kg hm-2, and the comprehensive score was the highest. The number of volatile flavor compounds of Zhongke Zinuomai 168 was the highest at 225 kg hm-2, and the comprehensive score was the highest. Correlation analysis and path analysis showed that total starch content and amylopectin content were significantly positively correlated with the total acid and total ester content. Most starch physicochemical indexes played a positive indirect role in the formation of the total ester through amylose and gelatinization temperature. The results showed that the wine yield of wheat was affected by interannual factors and flour quality rate. Starch content, composition, and gelatinization characteristics had important effects on the formation of total acid and total ester, esters were the main components of volatile flavor substances, greatly affected by variety factors. Under the nitrogen application rate of 90-135 kg hm-2, waxy and non-waxy wheat had better starch content, composition and pasting properties, and more volatile flavor substances in liquor-making, which was suitable for high yield and high quality of liquor-making wheat.

NaCl is an important contributor to the taste and texture of bread; therefore, it is challenging to reduce NaCl in bread without compromising quality. This study investigated sensory properties of bread with sourdough fermented with Lactobacillus reuteri accumulating glutamate or γ‐aminobutyrate (GABA). Sourdough was fermented with the GABA‐producing L. reuteri 100‐23 and LTH5448 as well as the glutamate‐accumulating L. reuteri 100‐23ΔgadB and TMW1.106. A consumer panel detected significant differences in the taste of bread with 6% addition of sourdough fermented with glutamate‐ or GABA‐producing L. reuteri. Remarkably, this difference was also detected when GABA‐producing L. reuteri 100‐23 was compared with its glutamate‐producing isogenic mutant L. reuteri 100‐23ΔgadB. The intensity of the salty taste of sourdough bread produced with 1% (flour basis) salt was equivalent to the intensity of the salty taste of reference bread produced with 1.5% salt. A trained panel found that sourdough breads (1 or 2% NaCl flour base) had a higher sour and umami taste intensity when compared with reference bread with the same salt content. Bread produced with sourdough fermented with L. reuteri 100‐23ΔgadB consistently had a higher umami taste intensity when compared with other sourdough breads. Neither sourdough addition nor NaCl level influenced bread volume or texture. In conclusion, the use of sourdough fermented with glutamate‐accumulating lactobacilli allowed reduction of NaCl without adverse effects on the taste or other quality attributes of bread.

The content and composition of starch in cereal grains are closely related to yield. Few studies have been done on the identification of the genes or loci associated with these traits in barley. This study was conducted to identify the genes or loci controlling starch traits in barley grains, including total starch (TS), amylose (AC) and amylopectin (AP) contents. A large genotypic variation was found in all examined starch traits. GWAS analysis detected 13, 2, 10 QTLs for TS, AC and AP, respectively, and 5 of them were commonly shared by AP and TS content. qTS-3.1, qAC-6.2 and qAP-5.1 may explain the largest variation of TS, AC and AP, respectively. Four putative candidate genes, i.e., HORVU6Hr1G087920, HORVU5Hr1G011230, HORVU5Hr1G011270 and HORVU5Hr1G011280, showed the high expression in the developing barley grains when starch accumulates rapidly. The examined 100 barley accessions could be divided into two groups based on the polymorphism of the marker S5H_29297679, with 93 accessions having allele GG and seven accessions having AA. Moreover, significantly positive correlation was found between the number of favorable alleles of the identified QTLs and TS, AC, AP content. In conclusion, the identified loci or genes in this study could be useful for genetic improvement of grains starch in barley.

Effects of irrigation and nitrogen fertilization on the grain yield, protein composition, protein quality, starch composition and starch pasting properties of a strong-gluten winter wheat were investigated in a high fertility field. Compared with non-irrigation treatment, grain yields under irrigation treatments were significantly increased, but the content of grain protein, monomeric protein and flour wet gluten was reduced. There were no significant differences in the above parameters between the irrigation treatments. Nitrogen application could significantly increase grain yield under low irrigation frequency (W0 and W1), while the neglected effect on yield was observed with high irrigation frequency (W2 and W3). With the increase of irrigation frequency, the glutenin content leveled off, but the changes of glutenin composition were not uniform, in which the soluble glutenin content was increased, while the insoluble glutenin content and polymerization index (the ratio of insoluble glutenin to total glutenin) were reduced. Both dough development time and stability time became shorter with the increased irrigation frequency. Nitrogen application improved the content of all grain protein fractions and grain quality, in which the increased degree in non-gluten protein (albumin and globulin) was higher than gluten protein (gliadin and glutenin), and the increased degree in soluble glutenin was found higher than that of insoluble glutenin. The interactive effects of irrigation and nitrogen on starch composition were significant. Starch content and amylopectin content was increased as irrigation frequency added in non-nitrogen treatment. Compared to non-irrigation treatment, irrigation significantly increased the starch content and the amylopectin content in nitrogen application treatment, but the starch and amylopectin content had no significant difference between irrigation treatments. Amylose content and the ratio of amylose to amylopectin were reduced while RVA indexes (peak viscosity, breakdown, final viscosity and setback) were increased as irrigation frequency was increased. Nitrogen application significantly improved the amylopectin content and decreased the amylose content in lower frequency irrigation, while the amylopectin content was decreased and the amylose content was enhanced by nitrogen application in higher frequency irrigations.

An experiment was conducted to evaluate the effect of addition of mungbean flour and gliceryl monostearat (GMS) on the loaf volume, hardness, porosity, colour, texture, taste and flavour of bread. Corn and mung bean flour and then added with 1, 2 and 3 percents of GMS. Physical analysis showed that corn and mungbean flour can be used to produce a good quality bread. Addition of fifteen percents of mungbean in flour resulted in a good loaf volume and increase in the hardness of bread. Addition of GMS with several concentrations were also not negatively affecting to the taste, flavour, the texture and the colour of bread. The panelist prefered the texture of bread with addition of five percents mungbean flour and Iwo percents GMS. While, the panelist prefer the taste of bread with addition of ten percents mungbean flour and two percents GMS.

Fermentation strains play a key role in the quality of bread. The combination of yeast and lactic acid bacteria (LAB) may effectively improve the function and nutritional properties of bread. In this study, the dough was fermented to make bread by using single strain (Saccharomyces cerevisiae, mode A), the combination of two strains (S. cerevisiae and Lactiplantibacillus plantarum, mode B; S. cerevisiae and Lactobacillus delbrueckii, mode C), or three strains (S. cerevisiae, L. plantarum, and L. delbrueckii, mode D). The specific volume, texture, and aroma substances of bread were evaluated. The possibility of mixed fermentation of selected yeast and LAB to replace natural fermentation dough was evaluated. The results showed that the specific volume of bread in mode B was 15.2% higher than that of mode A. The structure was softer and the taste was more vigorous in mode B bread. The content of volatile compounds was highest in mode B bread among the four mode bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol. The cofermentation in mode B made the bread aroma richer and gave better aroma characteristics to bread. Therefore, the fermentation of S. cerevisiae and L. plantarum can be recommended to replace naturally fermented dough to improve the quality of bread. PRACTICAL APPLICATION: L. plantarum and L. delbrueckii, separately or together, assisted in yeast fermentation to make bread. The specific volume, texture, and aroma substances of bread were evaluated to replace natural fermented dough with mixed fermentation. L. plantarum-assisted yeast fermentation improved the specific volume, texture, and aroma of bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol in bread. Therefore, the fermentation of S. cerevisiae and L. plantarum could replace naturally fermented dough to improve the quality of bread.

It have been significantly demonstrated that Hexokinase (HXK), Granule-bound starch synthase (GBSS) and ADP-glucose pyrophosphorylase (AGPase) are three critical enzymes in the starch biosynthetic pathway and are related to starch (amylose, amylopectin and total starch) content in lotus. It is important to develop functional markers in marker-assisted selection of lotus breeding. So far there have been few reports about lotus functional markers. In this study, based on insertion-deletions (INDELs) and single-nucleotide polymorphisms (SNPs), we developed three functional markers, FMHXK-E1, FMGBSS-I8 and FMAGPL-I1. FMHXK-E1 was developed based on polymorphisms of two haplotypes of NnHXK. 26 lotus cultivars that the 320-bp fragment presented in NnHXK had a lower content of amylose and a higher content of amylopectin. FMGBSS-I8 was developed based on polymorphisms of two haplotypes of NnGBSS. The group containing 32 lotus cultivars with the 210-bp fragment had less amylose content and more amylopectin content. FMAGPL-I1 was developed based on polymorphisms of two haplotypes of NnAGPL (ADP-glucose pyrophosphorylase large subunit gene). The group containing 40 lotus cultivars with the 362-bp fragment had less amylopectin, total starch content and more amylose content. According to the study, FMHXK-E1, FMGBSS-I8 and FMAGPL-I1 are closely related to lotus starch content. It could be provided research basis for molecular assisted selection of lotus starch content improve breeding efficiency.

Starch is synthesized from a series of reactions catalyzed by enzymes. ADP-glucose pyrophosphorylase (AGPase) initiates the synthesis pathway and synthesizes ADP-glucose, the substrate of starch synthase (SS), of which SSIV is an isoform. Mutations of the AGPase subunit and SSIV-coding genes affect starch content and cause variation in the number of granules. Here, we pyramided the functional mutation alleles of the AGPase subunit gene TaAGP.L-B1 and the SSIV-coding gene TaSSIVb-D to elucidate their synergistic effects on other key starch biosynthesis genes and their impact on starch content. Both the TaAGP.L-B1 and TaSSIVb-D genes were expressed in wheat grain development, and the expression level of TaAGP.L-B1 was higher than that of TaSSIVb-D. The TaAGP.L-B1 gene was downregulated in the agp.L-B1 single and agp.L-B1/ssIV-D double mutants at 12 to 18 days after flowering (DAF). TaSSIVb-D expression was significantly reduced at 6 DAF in both ssIV-D single and double mutants. In the agp.L-B1/ssIV-D double mutant, TaGBSSII was upregulated, while TaAGPSS, TaSSI, and TaSBEII were downregulated. Under the interaction of these genes, the total starch and amylopectin contents were significantly decreased in agp.L-B1 and agp.L-B1/ssIV-D mutants. The results suggested that the mutations of TaAGP.L-B1 and TaSSIVb-D genes resulted in variation in the expression patterns of the other four starch synthetic genes and led to a reduction in starch and amylopectin contents. These mutants could be used further as germplasm for resistant starch analysis.

This study investigates the effect of pasting on the starch and sugar composition, estimated glycemic index (eGI), antioxidant properties, and antidiabetic properties of cocoyam (Colocasia esculenta) flour. Cocoyam flour (raw) was processed into paste, and their aqueous extracts were prepared. The sugar, starch, amylase, and amylopectin contents, eGI, antioxidant properties as well as the α-amylase and α-glucosidase inhibitory abilities of the cocoyam flour and paste were determined. The results revealed that there was a significant (p < .05) decrease in eGI and sugar content of the flour with pasting. However, no significant (p > .05) change in starch, amylopectin, and amylose contents with pasting was observed. Both raw and paste exhibited high antioxidant properties. Furthermore, the paste had significantly (p < .05) higher α-amylase and α-glucosidase inhibitory activities when compared to raw. Thus, pasting process may decrease the eGI, sugar content, inhibit carbohydrate hydrolyzing enzymes, and enhance antioxidant activities of cocoyam flour. Practical applications The results suggest that cocoyam (Colocasia esculenta) has potential applications as functional foods and nutraceuticals for both animal and human nutrition. In addition, pasting may represent a good processing method due to the increased release of phenolics as well as melanoidins; that could be harnessed in the management of oxidative stress-mediated diseases such as diabetes and cardiovascular diseases.

Although starch is an importt factor for evaluating apple quity it has received little attention.Especially, the composition of starch in Korean apples has not been reported in detail yet.In this study, a calibration procedure to determine the total starch, amylose and arnylopectin contents by a colorimetric method was developed.By using the colorimetric method, the total starch contents of Fuji apples were found 7.70 to 10.9 mglg-dry wt., which corresponded to 0.1 67 to 0.1 93% based on the average weight of 1 apple.The arnylose contents were 44.0 to 55 .4% of the total starch contents.The starch content had a positive correlation with the moisture content while it had little relationships to soluble solids content and pH.

BackgroundInduction of mutation through chemical mutagenesis is a novel approach for preparing diverse germplasm. Introduction of functional alleles in the starch biosynthetic genes help in the improvement of the quality and yield of cereals.ResultsIn the present study, a set of 350 stable mutant lines were used to evaluate dynamic variation of the total starch contents. A megazyme kits were used for measuring the total starch content, resistant starch, amylose, and amylopectin content. Analysis of variance showed significant variation (p < 0.05) in starch content within the population. Furthermore, two high starch mutants (JE0173 and JE0218) and two low starch mutants (JE0089 and JE0418) were selected for studying different traits. A multiple comparison test showed that significant variation in all physiological and morphological traits, with respect to the parent variety (J411) in 2019–2020 and 2020–2021. The quantitative expression of starch metabolic genes revealed that eleven genes of JE0173 and twelve genes of JE0218 had consistent expression in high starch mutant lines. Similarly, in low starch mutant lines, eleven genes of JE0089 and thirteen genes of JE0418 had consistent expression in all stages of seed development. An additional two candidate genes showed over-expression (PHO1, PUL) in the high starch mutant lines, indicating that other starch metabolic genes may also contribute to the starch biosynthesis. The overexpression of SSII, SSIII and SBEI in JE0173 may be due to presence of missense mutations in these genes and SSI also showed overexpression which may be due to 3-primer_UTR variant. These mutations can affect the other starch related genes and help to increase the starch content in this mutant line (JE0173).ConclusionsThis study screened a large scale of mutant population and identified mutants, could provide useful genetic resources for the study of starch biosynthesis and genetic improvement of wheat in the future. Further study will help to understand new genes which are responsible for the fluctuation of total starch.

With the development of new trends in healthy eating, for consumer satisfaction, with aim to expand the range of bakery products and enrich bread with biologically active compounds of hops, bread production with the addition of cones of this unique plant in terms of bitter and polyphenolic substances, aromatic and essential oils has become widespread. The research conducted to study and substantiate the effective utilization of a complex of technologically valuable substances of Ukrainian fine aromatic hops of the Perlyna variety allowed to establish the possibility and feasibility of its application in baking and its impact on bread quality. The analysis of the results showed that the bittering qualities of hops had a significant impact on the taste of bread. In contrast, polyphenolic substances had a lesser effect on the taste, but in combination with bitter substances, they significantly affect consumer qualities. The results of studies of the application of sourdough starter of Perlyna aromatic hop with different content of alpha acids and polyphenolic substances showed that the bread had high taste qualities when added to the 1 kg of flour: 23.9 to 35.8 mg of bitter substances and 45.2 to 72.1 mg of polyphenolic substances. With lower amounts of bitter substances and higher amounts of polyphenols, the taste of the bread was almost the same as the control sample, although the physicochemical parameters improved. With an increase from 35.8 to 43.4 mg of bitter substances, a subtle bitterness was felt against the background of a pleasant hop aroma. Adding more than 50.8 mg of bitter substances to the 1 kg of flour made the bread noticeably bitter. Based on the example of the Pearl hop variety, the dosage of hop expenses was optimized and the calculation of the rate in baking was proposed, taking into account the content of bitter alpha acids in it. The optimally justified rate of bitter substances of hops to ensure excellent taste and consumer properties of bread is the range of added alpha acids from 23.9 to 43.4 mg per 1 kg of flour. The proposed technology has improved the consumer properties and taste of bakery products by imparting a hop aroma and a stable optimally normalized bread taste with a light, delicate bitterness. At the same time, the volume of bread, porosity, porosity structure and elasticity of the crumb are increased. Reducing the amount of yeast did not affect the fermentation of the dough and the stability of the shape of the final product. This will contribute to the health and preventive effects of the products.

The effect of processing on starch composition, glycemic indices (sugar, starch, amylose and amylopectin contents, and estimated glycemic index [eGI]), phenolic profiles, and α-amylase and glucosidase inhibitory effects of cassava (Manihot esculenta) flours was investigated in vitro. Roasted cassava flours had higher starch, amylopectin, and amylose contents but lower sugar and phenolic contents compared to sun-dried cassava flour. Roasted cassava flour showed higher α-amylase and lower α-glucosidase inhibitory activity than sun-dried flour. Roasted cassava flour possessed higher content of gallic and caffeic acids, catechin, quercetin, and kampferol, while sun-dried cassava flour is rich in chlorogenic and ellagic acids and rutin. This study revealed that different processing confers changes in the starch composition and biological effects cassava flour. However, roasted cassava showed promising dietary intervention in diabetes management than sun-dried cassava flour. Practical applications Different traditional processing methods employed in the processing of cassava tuber reduce toxicity and enhances palatability and durability of fresh cassava root into stable products. Cassava starch is used industrially for the preparation of products such as glucose and as a thickening agent. The findings of this research showed that roasting as well as sun drying causes changes in the starch composition and biological effects of cassava flour. Thus, roasted showed promising dietary intervention in diabetes management than sun-dried flour.

Development of amyloplasts and starch synthesis in seeds of field and garden peas Amyloplast development and changes in starch and amylose content in seeds of field and garden peas (Pisum sativum ssp. sativum and ssp. medullare) was studied from flowering to maturity in view of a possible relationship between amyloplast form and starch composition. Starch and amylose contents increased at different rates in both subspecies. In field peas starch content had reached the maximum (44 % in DM) 26 days after flowering with 45 % amylose in total starch. In garden peas, 25 days after flowering, starch content had only reached half of its maximum (32 % in DM) with an extremely high amylose proportion (88 %). At that growth stage form and size of amyloplasts were similar in both subspecies. There seems to be no tight relationship between form of amyloplasts and proportion of amylose in total starch. But then, when amyloplasts abruptly increased in size those of garden peas disrupted suddenly. This disruption is not due to a high amylose content. Because in a cross-breeding of field and garden peas, which was also investigated, the amyloplasts had remained intact irrespective of a high amylose proportion (63 %). The disruption may be due to differences in arrangement of starch molecule and in structure of plastid envelope.

Starch degradation in rumen fluid as influenced by genotype, climatic conditions and maturity stage of maize, grown under controlled conditions