Role of pea protein isolate in modulating pea starch digestibility: insights from physicochemical and microstructural analysis

Abstract

BackgroundUnderstanding the interactions between protein and starch was crucial in revealing the mechanisms by which protein influence starch digestibility. This study investigated the impact of different contents of pea protein isolate (PPI) on the physicochemical properties and digestibility of pea starch (PS).ResultsThe results demonstrated that as the content of PPI increased from 0 to 12%, the digestion of PS decreased by 12.3%. Rheological analysis indicated that PPI primarily interacted with molecular chains of PS through hydrogen bonds. Increasing the content of PPI resulted in a 30.6% decrease in the hardness of the composite gels, accompanied by a 10% reduction in the short‐ordered structure of PS. This hindered the formation of molecular aggregation and resulted in a loose and disordered gel network structure. The microstructure confirmed that the attachment of PPI to PS served as a physical barrier, impeding the starch digestibility.CONCLUSIONIn summary, the primary mechanism by which PPI inhibited PS digestion involved steric hindrance exerted by PPI and its interaction with PS via hydrogen bonds. These findings contribute to a better understanding of the interaction mechanisms between PS and PPI and offer insights for the optimal utilization of pea resources.This article is protected by copyright. All rights reserved.