Improving gel properties of low-salt silver carp surimi through single-mode microwave-assisted processing

Surimi, a product derived from low-value fish, is widely used to produce high-value items such as imitation crabsticks and fish balls. However, surimi from freshwater fish like silver carp generally exhibits inferior gel properties compared to marine fish. This study investigated the effects of 915 MHz single-mode microwave-assisted processing on the gel properties of low-salt silver carp surimi. Traditional water bath processing served as the control for comparison. Gel strength, texture, water-holding capacity (WHC), whiteness, protein secondary structure, and microstructure, along with thermal processing efficiency for microbial inactivation were evaluated. The results demonstrated that single-mode microwave processing significantly improved gel properties compared to water bath processing. Compared with the optimal water bath treatment, the gel strength of microwave processed samples increased significantly from 479.32 g·cm to 821.74 g·cm, while WHC increased from 0.77 to 0.87. The microwave processed surimi exhibited a more uniform microstructure. Because it enhanced the dissolution and cross-linking of myofibrillar proteins, leading to superior gel formation characterized by a lower α-helix content (10.31%) and higher β-sheet content (61.70%). Furthermore, microwave processing achieved faster heating rates, reducing the time spent in the critical gel deterioration temperature range, thereby improving overall gel quality. Single-mode microwave-assisted gelation also provided better thermal processing uniformity and efficiency, achieving pasteurization standards. The study highlights the potential of 915 MHz single-mode microwave processing to produce high-quality, low-salt surimi products, meeting contemporary health and convenience demands. These findings offer valuable insights for the industrial application of single-mode microwave technology in surimi production, promoting the development of innovative processing techniques to enhance the quality of surimi-based food products.