Effects of L-Cysteine on some characteristics of wheat starch

In this study the effects of L-Cysteine as a food additive on wheat starch characteristics before and after gelatinization were studied. L-Cysteine (63 mg/kg, starch basis) was added to slurry of wheat starch in water (30%, w/w). One set of samples was prepared by mixing it at 40 °C for 45 min. Another set was gelatinized at 100 °C for 45 min. The scanning electro-micrographs of the samples prepared at 40 °C in the presence of L-Cysteine showed some spots on the granules. However, thermal properties, X-ray patterns and the degree of crystallinity of the samples did not obviously change (P > 0.05); while a reduction in intrinsic viscosity, peak and final viscosities of the samples was observed. After gelatinization, intrinsic, peak and final viscosities of the samples were reduced. Some of these changes may indicate degradation of starch molecules in the presence of L-Cysteine, particularly after gelatinization.