Physicochemical properties, structural characteristics and protein digestibility of pea protein-wheat gluten composited meat analogues prepared via high-moisture extrusion

Abstract

Recently, plant-based meat analogues (MAs) have received increased attention as a sustainable diet. In this study, MAs were prepared from pea protein isolate (PPI) and wheat gluten (WG) via high-moisture extrusion. The effects of different WG contents (0%, 10%, 30%, 50% and 70%) on the product characteristics of MAs were investigated. Results revealed that the addition of WG significantly reduced the hardness and chewiness of MAs, but significantly improved their springiness, brightness and whiteness. MAs containing 30% WG and 50% WG both exhibited a distinct fibrous structure in terms of microstructure, with MAs containing 30% WG having the highest fibrous degree in terms of texture properties. After the addition of WG, there was a tendency for water molecules in MAs to shift from bound water and free water to immobilized water. In addition, the results of protein solubility analysis indicated that hydrogen bonds and disulfide bonds played a major role in forming and maintaining structures within MAs. With the increase of WG content, the ordered structure content, apparent viscosity, storage modulus, loss modulus and protein molecular weight of MAs increased significantly. Finally, the addition of 30% and 50% content of WG resulted in decreased in vitro protein digestibility and essential amino acid content of MAs, but significantly improved their flavor and sensory scores. This study provides useful information for improving the quality of PPI-based MAs to meet consumer needs.