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Bread-making quality of wheat flour is largely determined by the accumulation, concentration and composition of the proteins in the grain, which are influenced by genetic (G) and environment (E) variation and their interactions. We have therefore evaluated the importance of G and E factors and their interactions in determining the accumulation and composition of the proteins in the wheat grain. The cultivar determined development time (CDDT), together with the amount and timing of N application, played a significant role in determining the accumulation and final composition of the wheat grain proteins, explaining 21–59% of the variation. At low temperature, N application both at spike formation and at anthesis explained the highest proportion of variation (36%) in the percentage of sodium dodecyl sulphate (SDS) unextractable polymers in the total amount of polymers (% UPP), while at high temperature CDDT contributed most to the variation in % UPP (20%). The largest contributor to variation in the amount of total SDS extractable proteins (TOTE) was N application at anthesis, both at low and high temperatures (12% and 36%, respectively). Thus, the climate should be considered in recommendations for improving the protein quality and thereby the bread-making quality of wheat. 相似文献
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Eva Johansson Ali Hafeez Malik Abrar Hussain Faiza Rasheed William R. Newson Tomas Plivelic Mikael S. Hedenqvist Mikael Gllstedt Ramune Kuktaite 《Cereal Chemistry》2013,90(4):367-376
For a number of applications, gluten protein polymer structures are of the highest importance in determining end‐use properties. The present article focuses on gluten protein structures in the wheat grain, genotype‐ and environment‐related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end‐use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide‐sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide‐sulfhydryl exchange, sulfhydryl oxidation, β‐eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β‐sheet structures of both intermolecular and extended type and a hexagonal close‐packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end‐use quality of wheat‐ and gluten‐based products. 相似文献
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The present study has investigated the individual and combined influence of pre- and post-anthesis temperatures and cultivars on the protein composition in barley grains. Two barley cultivars were grown in soil and hydroponic systems in daylight chambers with different pre- and post-anthesis temperatures. Size exclusion (SE)-HPLC was used to evaluate the protein composition in mature barley grains. The results showed that individual and interactive effects of pre- and post-anthesis temperatures and cultivar variations influenced protein composition in the barley grains. Pre-anthesis temperature greatly affected the amounts of total sodium dodecyl sulphate (SDS) extractable proteins (TOTE) and explained 30% of the variation in TOTE. The barley cultivars accounted for 20% of the variation in TOTE. Variation in malting barley cultivars was found to influence the SDS extractable small monomers (41% of the variation). Percentage of SDS un-extractable polymeric proteins in total amount of polymeric proteins (%UPP) was governed by post-anthesis temperature, accounting for 11% of the variation and cultivar differences accounted for 7% of the variation. Thus, the climatic conditions during the specific growing period and a choice of cultivars played a major role in determining the protein composition and ultimately the malting quality of spring barley. 相似文献
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The effect of mixing time on gluten formation was studied for four commercial flour mixtures. The gluten phase was separated from dough using a nondestructive ultracentrifugation method. Small deformation dynamic rheological measurements and light and scanning electron microscopy were used. The recovered gluten was relatively pure with a small amount of starch granules embedded. The protein matrix observed by microscopy became smoother with prolonged mixing. No effect of overmixing was observed on the storage modulus (G′) of gluten for any of the flours. The amount of water in gluten increased from optimum to over‐mixing for most of the flours. Increased water content during prolonged mixing was not related to an effect on G′. The Standard flour resulted in the highest water content of gluten, which increased considerably with mixing time. The Strong flour had the lowest G′ of dough, a high G′ of gluten, and no increase in gluten water content from optimum to over‐mixing. The Durum flour did not show gluten development and breakdown similar to the other flours. The differences in gluten protein network formation during dough mixing are genetically determined and depend on the flour type. 相似文献
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Abrar Hussain Hans Larsson Ramune Kuktaite Maria Luisa Prieto‐Linde Eva Johansson 《Cereal Chemistry》2013,90(1):80-86
In the present study, we evaluated 444 organically grown wheat genotypes for the amount and size distribution of polymeric proteins by size‐exclusion HPLC. The investigated genotypes were divided into six genotype groups—selection, spelt, old cultivar, primitive, landrace, and cultivar—and these were grown in four different locations, namely, Alnarp, Bohuslän, Gotland, and Uppsala in Sweden. The results showed that the percentage of unextractable polymeric proteins in total polymeric proteins (%UPP) and percentage of large unextractable polymeric proteins in total polymeric proteins were higher in the cultivar group as compared with the rest of the investigated genotype groups. The amounts of total extractable polymeric proteins (TOTE) and total unextractable polymeric proteins were low in cultivars and selections, respectively. Spring wheat grain was found to have a significantly higher amount of all protein fractions as compared with winter wheat. The genotype Kenya was found to belong to both groups of the 20 genotypes with the highest TOTE and %UPP. Thus, the genotype Kenya might be of relevance for consumption and future breeding to improve the breadmaking quality of organically produced wheat. 相似文献
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Achieving high quality of organic bread is a major objective of organic wheat production. The aim of the present study was to understand the mechanisms related to bread-making quality in organically grown wheat genotypes from a diverse background. Fifty one organically grown winter and spring wheat genotypes were evaluated for percentage of unextractable polymeric proteins in total polymeric proteins (%UPP) in flour and dough, mixing behaviour and structural properties. The results showed a large variation in genotypes for %UPP in flour, changes in %UPP at mixing, mixing parameters and structural properties. Genotypes with high %UPP in flour and low change in %UPP at optimum mixing were; Agron, Hjelmqvist 6357 blå and Effrada. The light microscopy (LM) and confocal laser scanning microscopy (CLSM) results confirmed that genotypes with high %UPP in flour and a low change at optimal mixing resulted in a more extended protein network (continuous and interconnected) at mixing as compared to the other genotypes. Genotypes with good mixing properties as to the mixograph analyses were; Diamant ax, Lantvete Gotland 4496 spelt, Erbe brun and Jacoby 59. The present study shows the presence of opportunities to select genotypes suitable for cultivation and breeding of bread wheat for organic production. 相似文献
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