Fabrication of low-digestible potato starch–rice peptide complexes via heat-moisture treatment for low-glycemic-index crispy noodles

The strategic combination of thermal processing and food component interactions is a crucial approach for developing low-glycemic index (GI) foods. This study aimed to develop a low-digestible potato starch–rice peptide (PS–RP) complexes through heat-moisture treatment (HMT) to formulate low-glycemic-index crispy noodles. The dual-action mechanism combines (1) steric hindrance from PS–RP complex and (2) enzyme inhibition by free peptides. The addition of RP promoted multiscale aggregate formation, thereby improving thermal stability, molecular order, and crystallinity, while reducing viscosity. The optimized PS–RP20 complex was incorporated into wheat flour to evaluate its potential application in crispy noodles. Notably, incorporating PS–RP20 significantly increased the content of slowly digestible and resistant starch, reducing the estimated GI of the noodles while maintaining acceptable dough processing suitability. Higher levels adversely affected dough texture. HMT-modified PS–RP complexes show promise as functional ingredients for low-GI starchy foods with improved metabolic benefits.