Innovative insights into the interaction dynamics and gel properties of myofibrillar protein with structurally diverse pectin

Abstract

This study investigated the interactions between three structurally distinct apple pectin fractions and myofibrillar protein at varying ratios, focusing on their effects on gelation behavior. The optimal ratio of pectin to myofibrillar protein (1:7) facilitated the structural transition of myofibrillar protein from α-helix to β-sheet, improving its thermal stability by 1.2 times. This ratio also enhanced the exposure of sulfhydryl groups, hydrophobic groups, and tryptophan residues, promoting intermolecular chain entanglement. Our results indicate that the molecular weight and degree of esterification of pectin were key determinants of gelation properties. Specifically, the pectin with the highest molecular weight (201.6 kDa) and degree of esterification (75 %) exhibited a 97.3 % higher affinity for myofibrillar protein, as well as the highest cross-linking density with myofibrillar protein, compared to the pectin with the lowest molecular weight (131.6 kDa) and esterification degree (34.9 %). These molecular interactions significantly enhanced water-holding capacity (33.8 % increase) and textural attributes (1044 % increase in hardness and 31.5 % increase in elasticity) relative to the control group. These findings highlight the role of pectin structure in food protein applications, offering potential strategies for designing functional protein-based food systems.