Wheat gluten elasticity

Another requirement for proper leavening is the presence of a protein matrix sufftciendy elastic to trap small carbon dioxide bubbles. Wheat gluten fulfills this requirement. Rye protein is less suitable and the proteins of other cereals, eg, rice, oats, or com, are practically useless. 

In this paper, we will explore the measurement of and the basis for the cohesive and elastic properties of a commonly used component of foods that excels in these characteristics, wheat gluten. Gluten constitutes from 10 to 16% of wheat flour, from which it may be separated by Martin, batter, or Raisio processes (2, 3). The separated wheat gluten is 70 to 80% protein, of which 85% is insoluble in saline solution. We shall also seek to correlate some of the basic concepts developed in studies of gluten to other protein systems, such as those of soybean protein isolates and concentrates. 

In case of bread wheat, increases in gluten elasticity could be obtained by inserting additional genes for HMW-GS to increase the total amount of HMW subunit protein. In addition, these genes could possibly be mutated to give more subtle differences, due to effects on the cross-linking or other properties of the glutenin polymers. 

The balance between viscosity and elasticity is close to optimum for wheat gluten protein at the water content used in dough-making. We have seen that the first requirement for a protein in dough to have viscoelastic properties is that its Tg be below the processing (usually ambient) temperature for the water content used. A second requirement for dough in an aerated product is that the molecular weight distribution (MWD) of the protein be optimal. 

Wheat gluten — the plastic and elastic mass which is obtained by washing out wheat flour with water — has for a lor time been considered as a mixture of two proteins containing water or better of two groups of protein components which to distinguish them are denoted by the terms gliadin and glutenin,... 

Wheat gluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye. WG gives elasticity to dough, helping it rise and keep its shape and often gives the final product a chewy texture. WG may also... 

The mechanical properties of protein-based materials are substantially lower than those of standard synthetic materials, such as polyvinylidene chloride (PVDC) or polyester (Table 11.11). The mechanical properties of protein-based materials were measured and modelled as a function of film characteristics [74, 131, 132]. For stronger materials (e.g., based on wheat gluten, corn gluten and myofibrillar proteins, critical deformation (DC) = 0.7 mm) and elastic modulus (K = 510 N/m) values are slightly lower than those of reference materials such as LDPE (DC = 2.3 mm, K = 135 N/m), cellulose (DC = 3.3 mm, K = 350 N/m) or even PVC films. The mechanical properties of corn gluten-based material are close to those of PVC. 

Gluten Tough, elastic protein which remains when fkiur is washed to remove the starch. Wheat Imparts elasticity to doughs, thereby enabling them io be leavened with yeast. 

Devitalized w. (sweet gluten powder) consist of wheat gluten proteins that have irreversibly lost their native properties. During - wiieat starch production, w. is obtained as a highly hydrated (70% water), cohesive, elastic dough after separation of the wheat starches by starch extractors and decanter centrifuges. 

In both technologies, fresh gluten remains a highly hydrated, coherent elastic dough of about 30% d.s., which is washed and dewatered by conical screw presses to 35% d.b. (- wheat gluten). 

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