Effect of Gluten on Pasting Properties of Wheat Starch

The effect of gluten on pasting properties of wheat starch was studied to provide a scientific basis for the application of gluten in food production and quality improvement in wheat breeding. The pasting properties of blends were analyzed using PH 1391 wheat starch mixed with five different additions of three kinds of gluten (strong-, medium-, and weak-gluten)and the structures of network were observed with microscope. The significant downtrends of peak viscosity, trough viscosity, final viscosity, area of viscosity, setback, and peak time were observed with the increase in the addition of gluten. In general, the average value of them decreased respectively by 3.6, 4.8, 3.4, 3.8, 4.0, and 1.18% of those corresponding indexes of pure starch for every 2% increase in gluten. The decreasing rate of the indexes mentioned above exceeded more than 2% except peak time, but there were no significant influence of gluten addition on breakdown, pasting temperature and pasting time. The inter layer composed of gluten was not observed when the addition of gluten was 10%, as the compound formed of gluten inlaid in the paste of starch, but obvious inter layer was detected when the addition of gluten was 18%. There was significant or remarkable difference among the effects of three different kinds of gluten on the peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but it had no significant difference among the effects of different glutens on pasting temperature and pasting time. The descending order of the effect of different glutens on peak viscosity, trough viscosity, and area of viscosity was strong-, medium-, and weak-gluten, but the order of them for setback was opposite. Both addition and types of gluten significantly affected peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but there were no significant effects of it on peak time and peak temperature.