Effects of Prunella vulgaris polysaccharide-based O/W emulsions on water retention, protein conformation, and antioxidant properties of ultrasonically treated reduced-fat pork batter

Abstract

This study examined how Prunella vulgaris polysaccharides (PVP, 0, 2% and 4% w/w in the O/W emulsion) and ultrasonic treatment (0 and 30 min) affect key quality attributes of reduced-fat pork batter. Combined PVP and ultrasound significantly improved (P < 0.05) emulsifying stability and water-holding capacity, cutting cooking loss from 11.75% to 5.88%. PVP alone enhanced water–protein–polysaccharide interactions: it shortened T21 and T22 relaxation times, raised immobilized water from 86.18% to 93.95%, and lowered overall water mobility. It also altered myofibrillar protein structure, reducing α-helix and increasing β-sheet, β-turn, and random coil content, which correlated with significant improvements (P < 0.05) in L* value, hardness, springiness, cohesiveness, chewiness, and sensory scores for color, texture, and overall acceptability. PVP suppressed lipid oxidation during 7-day refrigerated storage (lower TBARS, P < 0.05), though ultrasound partially weakened this effect. Overall, using PVP-based O/W emulsions as pork back-fat replacers, and applying ultrasound, is a promising strategy to simultaneously improve water retention, gel network formation, and oxidative stability in reduced-fat emulsified pork products.