Effects of Formulation and Extrusion Conditions for Isolated Pea Protein-Based High-Moisture Meat Analogs: Insights into Gelation and Structural Development.

Abstract

This study examines how varying the isolated pea protein (IPP) levels (0, 10, 20, 30, 40, 50%) together with key extrusion conditions, including moisture level, barrel heating profile, and screw rotation speed, affect the physicochemical attributes and textural characteristics of high-moisture meat analogs (HMMAs). Results indicated that increased IPP content reduced the fiber structure, springiness, cohesiveness, chewiness, cutting strength, and integrity index of HMMAs. Processing conditions resulted in pronounced changes in both the physicochemical attributes and texture of HMMAs. The increase in moisture content resulted in a decrease in HMMA fiber structure and textural properties. In contrast, increases in barrel temperature and screw speed were associated with higher TPA values, greater cutting strength in both vertical and parallel orientations, and an improved integrity index in HMMAs. Furthermore, the gelation behavior of IPP played a critical role in the formation of the fibrous structure, with optimal gel strength and water retention achieved under specific extrusion conditions. These findings underscore the importance of protein gelation in structuring IPP-based meat analogs and provide insights into the gel-based mechanisms underlying their textural properties. Overall, the optimum IPP content to produce HMMAs in this experiment was 30%, and the process variables were 55% moisture content, barrel temperature of 160 °C, and screw speed of 250 rpm.