Influence of high-molecular-weight glutenin subunit deletions at the Glu-A1 and Glu-D1 loci on protein body development, protein components and dough properties of wheat(Triticum aestivum L.)

High-molecular-weight glutenin subunits(HMW-GSs) play a critical role in determining the viscoelastic properties of wheat. As the organelle where proteins are stored, the development of protein bodies(PBs) reflects the status of protein synthesis and also affects grain quality to a great extent. In this study, with special materials of four near-isogenic lines in a Yangmai 18 background we created, the effects of Glu-A1 and Glu-D1 loci deletions on the development and morphological properties of the protein body, protein components and dough properties were investigated. The results showed that the deletion of the HMW-GS subunit delayed the development process of the PBs, and slowed the increases of volume and area of PBs from 10 days after anthesis(DAA) onwards. In contrast, the areas of PBs at 25 DAA, the middle or late stage of endosperm development, showed no distinguishable differences among the four lines. Compared to the wild type and single null type in Glu-A1, the ratios of HMW-GSs to low-molecular-weight glutenin subunits(LMW-GSs), glutenin macropolymer(GMP) content, mixograph parameters as well as extension parameters decreased in the single null type in Glu-D1 and double null type in Glu-A1 and Glu-D1, while the ratios of gliadins(Gli)/glutenins(Glu) in those types increased. The absence of Glu-D1 subunits decreased both dough strength and extensibility significantly compared to the Glu-A1 deletion type. These results provide a detailed description of the effect of HMW-GS deletion on PBs, protein traits and dough properties, and contribute to the utilization of Glu-D1 deletion germplasm in weak gluten wheat improvement for use in cookies, cakes and southern steamed bread in China and liquor processing.

Extraction of Dietary Fiber from Wheat Bran and Effects of Its Additives on Viscosity-elasticity of Noodle Dough

[ Objective] The aim was to study the optimum extraction condition of dietary fiber of wheat bran and to discuss its influence on viscosity-elasticity of noodle dough with added extracts. [ Methed] Influences of a-amylase, alkaline concentration, alkaline hydrolysis time and temperature on water holding capability and swelling capacity of dietary fiber were evaluated using single-factor test and orthogonal test. Effects of added dietary fiber from wheat bran on dough absorption ratio, rupture stress of dough and creep resistance were studied. [ Result] When the hydrolysis condi-tions of wheat bran were 0.4% a-amylase at 75 ℃ for 60 rain, further alkaline conditions were 5% sodium hydroxide for 60 min at 65 ℃, dietary fi-ber exhibited fine water holding capability and swelling capacity. The addition of 3%-5% dietary fiber from wheat bran into dough had little influence on the water absorption ratio of noodle, rupture stress of dough, creep resistance and can make functional noodle with rich dietary fiber from wheat bran. [Coonclusion] The study provided reference for the comprehensive utilization of wheat bran and development of functional product.

The efficacy of sorghum flour addition on dough rheological properties and bread quality: A short review

The baking quality of sorghum-wheat bread is equally reliant on the quantity and the quality of protein existent in the composite flours. A lot of procedures have been proposed for expanding the use of sorghum either as a composite flour blended with wheat or potentially as a straight flour. In any case,the amount of flour that can be subbed is up to a specific degree of sorghum flour to deliver sensory attractive products. The manipulation of the chemical composition, textural properties of the sorghum kernel, and selection of a proper hybrid could proffer desirable value addition results in bread making.The quality of the flour and the adherence to acceptable flour size standards is the key to producing good quality bread. In this paper, the effects of adding sorghum flour on dough rheological properties and the quality of bread were discussed in detail.

Effect of Glutathione and Storage Time on Rheological Properties of Per-proofed Frozen Dough

The effect of reduced glutathione (GSH) on fresh and pre-proofed frozen dough rheological properties were investigated using dynamic stress rheometry and small scale extensibility with the addition of three levels (80×10-6, 160× 10-6 and 240×10-6 GSH) and six storage times (0 and 1 day, 2, 4, 6 and 8 weeks). Three relaxation times (1, 13 and 26min) after loading the dough in the rheometer were used to determine storage (G’) and loss (G”) moduli. Correlations for G’ (r=0.678 and 0.622 at 0.05, and 10Hz, respectively) and G” (r=0.699, and 0.690 at 0.05, and 10Hz, respectively) were observed with the area under the extension curve at 26 min relaxation time. The addition of GSH to fresh dough reduced G’ (16.4% to 55.9%) and G” (13.7% to 52.2%). Freezing and frozen storage caused increase in G’ and G”. The addition of GSH reduced dough strength indicated by the reduction in maximum resistance to extension (Rmax) and the ratio of maximum resistance to extensibility (Rmax/E). The reduction in Rmax across all relaxation times ranged from 16.2% to 59.4%. An increase in dough extension (E) was observed with 240×10-6 GSH at all frozen storage and rest period times. Addition of GSH caused an increase of liquid phase (30.6% to 35.3%) in fresh dough and frozen dough (10.3% to 20.7%) after one day frozen storage. Negative correlations of water content in the solid phase with dough extensibility and area under the extensibility curve were found (r=-0.594 and-0.563, respectively, p<0.001). This suggests a loss of dough extensibility and strength as the water holding capacity of the dough components changes during frozen storage.