Molecular interactions of gallic acid, epigallocatechin gallate, and tannic acid with pea protein during high-moisture extrusion: Impact on meat analogue quality.

Abstract

To provide a deep insight into the regulatory mechanism of polyphenols on the quality of plant-based meat analogues, molecular interactions between pea protein isolate and different phenolic compounds (gallic acid (GA), epigallocatechin gallate (EGCG), and tannic acid (TA)) during high-moisture extrusion were investigated. TA led to the greatest reductions in surface hydrophobicity and highest increases in β-sheet structures, promoting the formation of the extrudate with highest chewiness (477.63 mJ) and anisotropy index (1.56). EGCG enhanced the disulfide bonding, leading to the highest springiness (3.46 mm) and cooking yield (174.47%). GA showed limited effects on protein structural changes and product qualities. Molecular docking revealed that these polyphenols mainly bound to PPI via hydrogen bonding and hydrophobic interactions, with the binding affinity following the order of TA > EGCG > GA. These findings provide a scientific basis for the targeted selection of phenolic compounds as natural functional modifiers for meat analogues.