Plant-based protein emulsions with soy protein isolate and gluten improve freeze-thaw stability and shelf life of pork meatballs

Abstract

This study investigated the effects of oil-in-water emulsions used as fat substitutes on the physicochemical properties of meatballs during frozen storage. Different formulations of fat replacers were prepared, including pork fat as the control (C), oil and water (OW), oil-in-water emulsion (E), emulsion with soy protein isolate (SE), emulsion with gluten (GE), and emulsion with soy protein isolate and gluten (SG). These fat substitutes were applied to a meatball paste. The samples were stored at −18 °C for 30 and 60 days, and their physicochemical properties were analyzed after thawing at 4 °C for 12 h. The SE formulation had the highest values for both water content and liquid holding capacity during frozen storage (P < 0.05). SE, GE, and SG showed significantly higher hardness, cohesiveness, springiness, gumminess, and chewiness than those of E during storage (P < 0.05). The vegetable protein addition treatments maintained a compact structure throughout storage. SE, GE, and SG prevented lipid and protein oxidation during frozen storage. These results demonstrated that SE, GE, and SG offer significant advantages in improving the freeze-thaw stability, liquid holding capacity, and oxidation stability of pork meatballs during long-term frozen storage. Therefore, our study suggest that plant-based protein emulsions can effectively replace animal fats while maintaining product quality, offering valuable implications for the meat processing industry.