Effect of Wheat Starch Characteristics on the Gelatinization, Retrogradation, and Gelation Properties

The objective of this study was to clarify the relationship between amylose content and the gelatinization, retrogradation, and gelation properties of starch using wheat starches differing in amylose content. Starches were prepared by reciprocal crossing between waxy and non-waxy wheat, and mixing waxy and non-waxy wheat starch. Gelatinization temperature and endothermic enthalpy measured by differential scanning calorimetry correlated negatively with amylose content. Mixed starches showed significantly lower gelatinization onset and peak temperature than F1 starches with the same amylose content. Rapid Visco Analyser measurement showed that F1 starches had a higher peak viscosity than waxy and non-waxy wheat starches, and mixed starches had characteristic profiles with two low peaks. The rheological properties of 30% and 40% starch gels were measured using mixed starches with an amylose content of 5, 10, 18, 20, 23, and 25%. The slight difference in amylose content contributed greatly to the elastic component in starches forming a gel network. For 40% starch gels, mixed starch with lower amylose rapidly developed rigidity and had a higher rate constant of starch retrogradation. The proportion of waxy starch in the mixture played a major role in starch gel properties. Some of the gelatinization and gelation properties differed between mixed starch and simple starch isolated from cultivars, even though they have similar amylose content.