Effects of extrusion types, screw speed and addition of wheat gluten on physicochemical characteristics and cooking stability of meat analogues

BACKGROUND Plant protein-based products such as meat analogues have been receiving attention over the years. However, comparisons of product properties and mechanisms applied in the production of low- and high-moisture meat analogues have not been reported. In this study, the effects of extrusion types (low- and high-moisture extrusion cooking), absence or presence of added wheat gluten, as well as screw speed (150 and 200 rpm) on the physicochemical properties of meat analogues were evaluated. The mechanism of protein texturization of low- and high-moisture meat analogues was studied. RESULTS Extrusion types and addition of wheat gluten had a major influence on physicochemical characteristics which were critical in controlling the fibrous texture of the final product, while screw speed had a minor impact on springiness only (P < 0.001). All high-moisture meat analogues (HMMAs) were associated with a higher integrity index and greater stability of springiness and cutting strength than low-moisture meat analogues (LMMAs) using the same formula and screw speed, while the nitrogen solubility index of HMMAs was lower. Based on the physicochemical properties determined, the higher cross-link formation in HMMAs is proposed to occur in the cooling die section. CONCLUSION Our findings show that the utilization of high-moisture extrusion cooking and the incorporation of wheat gluten into the formula at 400 g kg(-1) could impart a fibrous and compact structure to extrudates similar to that of actual muscle meat, with a greater integrity index and texture stability. (c) 2019 Society of Chemical Industry