Effect of protease hydrolysis pretreatment on extruder response and the structural characteristics of high-moisture plant-protein extrudates

Abstract

This study aimed to investigate the effect of protease hydrolysis pretreatment (PHP) on extruder response and the structural characteristics of high-moisture plant-protein extrudates. The results showed that specific mechanical energy of the extruder decreased from 147.06 kJ/kg to 116.14 kJ/kg, which reduced the energy consumption of the extruder and was beneficial for the application of hydrated wheat gluten with strong viscoelasticity during the extrusion process. Texturization degree that characterized the fibrous structure formation of high-moisture plant-protein extrudates reduced from 1.70 to 1.05. The hardness and chewiness decreased, while the springiness of the extrudates increased. Moderate PHP weakened the cross-linking strength and viscoelasticity of the extrudates, which can improve the problem of the excessively dense texture of high-moisture plant-protein extrudates. Meanwhile, PHP improved protein extractability and increased immobilized water and free water content in the extrudates.