Process Optimization of Textured Soybean Protein for Enhancing Textural Properties of surimi gels

To effectively improve the textural quality of surimi, this study employed Textured Soybean Protein（TSP）as a modifier. Through single-factor experiments combined with response surface methodology（RSM）, we optimized the surimi textural improvement process and investigated the effects of TSP addition level, protease pretreatment, and processing parameters on surimi texture. The results demonstrated that with increasing TSP addition（0%～30%, wet basis）, surimi hardness, springiness, gel strength, and water holding capacity initially increased and then decreased, while whiteness value continuously declined. The optimal TSP addition level was determined to be 10%, at which the textural parameters of surimi gel reached their maximum values. Additionally, pretreatment of TSP with papain（100 U·g⁻¹, 60℃, 30 min）significantly enhanced surimi gel strength. Furthermore, supplementation with 0.12 U·g⁻¹ transglutaminase（TGase）markedly improved water holding capacity. Through response surface analysis, the optimal processing parameters were identified as follows: papain-pretreated TSP addition level of 10.5%, gelation time of 35 min, and cooking time of 35 min. Under these conditions, the predicted gel strength was 4,633.87 g·mm, while the measured value from validation experiments was 4,582.27 g·mm, with a relative error of less than 1.2%, confirming the reliability of the model.