Heating is a vital step in the gelation of surimi. Conventional water bath heating (WB) has the advantages of easy operation and low equipment requirements. However, the slow heat penetration during WB may lead to poor gel formation or gels prone to deterioration, especially with one-step heating. The two-step WB is time-consuming, and a large amount of water used tends to cause environmental problems. This review focuses on key factors affecting the quality of surimi gels in various heating technologies, such as surimi protein structure, chemical forces, or the activity of endogenous enzymes. In addition, the relationships between these factors and the gel performance of surimi under various heating modes are discussed by analyzing the heating temperature and heating rate. Compared with WB, the gel performance can be improved by controlling the heating conditions of microwave heating and ohmic heating, which are mainly achieved by changing the molecular structure of myofibrillar proteins or the activity of endogenous enzymes in surimi. Nevertheless, the novel thermal technologies still face several limitations and further research is needed to realize large-scale industrial production. This review provides ideas and directions for developing heat-induced surimi products with excellent gel properties.

Plasma is a new technology used to modify myofibrillar proteins (MPs) structure and promote protein aggregation. In order to study the mechanism of plasma modifying MPs thus the effects on qualities of MP gels, MPs were extracted by 0.6 M NaCl solution prepared with plasma-activated water (PAW) at different treatment time (0 s, 30 s, 60 s, 120 s, 240 s). With the prolonged PAW treatment time from 0 to 240 s, the pH values of natural MP solutions decreased significantly from 5.91 to 2.61 (P < 0.05), the H₂O₂ concentration in PAW increased from 0 to 70.82 μg/L (P < 0.05), and the net negative charges of MPs first decreased and then increased (P < 0.05). In addition, PAW caused significantly (P < 0.05) weakened ionic bonds and enhanced hydrophobic interactions, which promoted the aggregation and gelation of MPs thus forming MP gel with higher gel strength and a denser three-dimensional network. Furthermore, Raman spectra and intrinsic fluorescence suggested that PAW promoted the unfolding of MP structures and transformation from α-helixes and random coils to β-sheets and β-turns. Dynamic rheology indicated a gradually increased storage modulus and shortened degradation time of MPs with an increasing treatment time of PAW. Furthermore, PAW modification significantly improved the water holding capacity of MPs gels. These results demonstrated that the declined pH of MP solutions induced by PAW and increased H₂O₂ in PAW altered the ζ-potential of MP solutions and promoted the unfolding and aggregation of MPs during heating via hydrophobic interactions, ultimately enhancing gelling properties of MPs. The present work suggested the potential use of PAW in preparing freshwater MP gels with high quality.