Morphology and Physicochemical Properties of Starch in Wheat Superior and Inferior Grains

Wheat inferior grains severely restrict yield and quality because of their poor grain-filling and low grain weight, which have impacts on the morphology and physicochemical properties of starch. However, little is known about differences in morphological structures and physicochemical properties of starch between types of wheat grains. Compared with superior grains, inferior grains showed lower 1000-grain weight and total starch content but higher apparent amylose content. Both grains contained A- and B-type starch granules, but superior grains had more B-type starch granules. Superior grains showed lower peak temperature, enthalpy, and gelatinization temperature but higher setback viscosity, solubility, and hydrolysis degree than inferior grains. Moreover, superior grains had lower relative crystallinity and proportion of single helices and amorphous structure, and higher proportion of double helices. Therefore, the morphology and physicochemical properties of starch between superior and inferior grains were notably different. This study provides an important theoretical basis for application of wheat starch in food and non-food industries.