Structural and physicochemical properties of pea starch dual-treated with dry heating and galactomannans

The research on the combination of starch and galactomannans (GM) with dry heat treatment (DHT) is currently insufficient, which hinders the starch application. In this study, the impacts of dry heat treatment and GM complex on the structural, gelatinization properties, and digestibility of pea starch (PS) were investigated. The gelatinization viscosity and gel hardness of dry heated-PS were decreased. Moreover, the relative crystallinity of PS was improved when individually treated by dry heating and GM complex, resulting in the decline of digestibility. Besides, the long molecular chains (DP >= 37) proportion and the semi-crystalline lamellae thickness of the PS-GM-DHT complex were increased, which was relevant to the ratio of galactose/mannose residues in galactomannan. In particular, PS was more prone to complex with locust bean gum following dry heat treatment, which has the highest mannose ratio. The present study provided the fundamental information to promote the starch application further.