Gelatinization kinetics and starch particle structure of formula feed in limited water system employing homogeneous thermal treatments

Abstract

AbstractBackground and objectivesDuring conditioning, one of the most important feed thermal processing techniques, the gelatinization of starch in feedstuffs is applied extensively. In this study, the gelatinization kinetics and transformations of starch particle structure of formula feed subjected to thermal treatments in limited water system were investigated.FindingsGelatinization process of feed in limited water system followed the first‐order kinetics model. The relatively low Ea obtained from the linear regressions of kinetics parameters could only be called “incomplete gelatinization activation energy.” The decrease in birefringence was higher in the center of starch granules in heat‐treated feed samples. The crystalline phases of all samples changed to V‐type attributed to the formation of the amylose–lipid complexes, and the relative crystallinity of samples increased with the heating duration within certain temperature.ConclusionGelatinization process of feed samples suffering thermal treatments started from the destruction of amorphous regions in the center of starch granules. Destruction and re‐formation of the crystalline structure occurred simultaneously during the heat–moisture treatments of samples.Significance and noveltyThe results help to understand the mechanisms of starch gelatinization in practical feed conditioning and to find new ways to improve the effects of feed conditioning.