Process Optimization of Textured Soybean Protein for Enhancing the Textural Properties of Surimi Gels

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