In the 1940s, research by Baker established fundamental aspects of the breadmaking process while Finney showed that differences of quality resided in the gluten proteins of flour. Different lipid components have been found to affect loaf volume and texture but variation in lipid composition of current wheat varieties does not account for significant quality differences. Fundamental studies by Tipples and Kilborn showed that optimum dough development had two requirements – a critical mixing intensity and a critical amount of imparted energy. Expansion of a fermenting dough depends on two stabilizing mechanisms resulting from the gluten/starch matrix and the liquid lamellae surrounding the gas bubbles. In the 1970s, wheat cultivars were developed with poor baking properties, related to a dearth of insoluble protein, shown to comprise glutenins of large molecular size. Research by Payne and co-workers revealed that dough strength could be related to glutenin subunits and the genes controlling their synthesis. This has opened up new directions for determining composition-quality relationships and, in turn, has enabled strategies to be devised for improving quality based on wheat genetic composition.

High ratio cakes made from ozonated flour attained volumes and other quality characteristics comparable to those from chlorinated flours at 36 min ozonation time. Ozone thus appears to be a viable and more environmentally acceptable alternative to chlorine. Extraction of lipids from flour caused deterioration of cake quality which was not restored by ozonation, indicating that lipids were involved in the improving effects of ozonation. Oxidation by ozone led to higher molecular weights of polymeric proteins. (C) 2014 Elsevier Ltd. All rights reserved.

In order to clarify the effects of extrusion treatment on the processing properties of extrudates, providing a theoretical basis for the production of gluten-based extrudates with favorable sensory quality. This study examined the effects of various extrusion temperatures on the rheological properties of wheat gluten-peanut oil complexes (WPE) and wheat gluten (WG). At the extrusion temperature conditions of this study, the dynamic moduli of gluten in WG and WPE reached the maximum, and the creep strain reached a minimum at 160 °C. Extrusion treatment resulted in the decrease in β-sheet and α-helix content and an increase in the amount of β-turns and random coils. The secondary structural changes and increase in the number of disulfide bonds led to gluten aggregation, thus affecting their rheological properties. These results enhance our understanding of the variations in the rheological properties of extrudates and promote the potential application of gluten-based complexes in extrusion.

Wheat kernel development can be divided into three phases i.e. cell division, cell enlargement and dehydration. Accumulation of gluten proteins continues till the end of the cell enlargement phase. During the dehydration phase, post-translational polymerization of the glutenin subunits occurs to form very large glutenin polymers. Assembly of the glutenin polymers has been monitored by increase in the unextractable polymeric protein. Lines possessing HMW-GS related to dough strength (e.g. 5 + 10) started accumulating large polymers several days earlier than lines with HMW-GS related to dough weakness (e.g. 2 + 12) and maintained their higher amounts till maturity. This may be explained by faster polymerization resulting from a higher concentration of cysteine residues in the x-type HMW-GS.Sulphur deficiency leads to an increase in the ratio of HMW- to LMW-GS, causing a shift in the MWD to higher MWs, resulting in bucky dough properties. High temperature during grain development appears to shift the MWD to lower MWs with corresponding lowering of dough strength but the presence of strength-associated HMW-GS appears to confer greater tolerance to heat stress. Since sulphur deficiency and higher global temperatures may be expected to increase in the future, some suggestions how breeders may use strategies to counter these effects are put forward. (c) 2012 Elsevier Ltd. All rights reserved.

The present study was designed to determine total phenolic acid contents (TPC) and compositions of bran from newly developed near-isogenic waxy wheat and triticale translocation lines. Two waxy wheat sets, Svevo (durum) and N11 (bread wheat), consisting of partial and waxy null lines and four sets of triticales (GDS7, Trim, Rhino and Rigel) having translocations at 1A.1D and 1R.1D with high molecular weight glutenin subunits (HMW-GS) 5 + 10 and 2 + 12 were investigated. Similar to non-waxy wheat, ferulic acid was the predominant phenolic acid found in waxy wheats analyzed. Two other major phenolics include p-coumaric and vanillic acids followed by lesser quantities of syringic acid. Waxy lines had higher TPC than the parent line in the N11 set, whereas the Svevo set showed the opposite trend. TPC of waxy bread wheats were correlated with amylose fractions in which the order was complete waxy < double waxy nulls < single waxy nulls. Lines with HMW-GS 2 + 12 have lower TPC than other lines in each group of triticales, except the Trim set. TPC was negatively correlated (r = −0.41; p > 0.1) with bran yields in triticale lines studied, indicating that variation in phenolics was not only due to bran yields but also to genotypic differences.

Defatted flours of wheat varieties Karl and Jagger, after removing lipids by chloroform, were used to investigate the contribution of lipid to physicochemical properties and Mantou-making quality by comparing microstructure and thermal properties. The results indicated that defatted flours tend to have more single starch granules, higher gelatinization enthalpy, more water absorption, longer pasting peak time, higher peak and hold viscosity, lower setback and breakdown than those of the control. Meanwhile, the defatted flours had improved cooking stability and better ability to withstand mechanical shear stress. The Mantou-making test showed that the volume of Mantou made from defatted flour did not change significantly. C-Cell analyses on the internal crumb grains of Mantou revealed a deterioration in crumb grain characteristics upon removal of lipids from the flours. The grain cells of Mantou became bigger with thicker cell walls upon removal of lipids.