High moisture extrusion of wheat gluten: Relationship between process parameters, protein polymerization, and final product characteristics

The polymerization of wheat gluten induced by the formation of disulfide bonds can be considered as one of the decisive mechanisms leading to the formation of meat analog products with anisotropic structures. Accordingly, the influence of barrel temperature (100, 125, 155 degrees C), screw speed (180, 400, 800 rpm) and feed rate (10, 20 kg/h) on wheat gluten polymerization and final product characteristics was investigated. Analysis of total SOS-extractable protein (SDS-EP) confirmed that wheat gluten polymerization increased with increasing thermomechanical treatment. The observed increase in polymerization could be correlated with the formation of anisotropic product structures and an increase in hardness and Young's modulus. Altogether, these results demonstrate that defining polymerization reactions of wheat gluten and their relation to extrusion process conditions can provide essential information towards tailoring final product characteristics.