Effect of Flaxseed Gum on the Gelling and Structural Properties of Fish Gelatin

Fish gelatin (FG) has garnered significant attention as an alternative to mammalian gelatin, primarily attributed to its distinct advantages. These include the absence of epidemic transmission risks and the lack of religious restrictions, making it a more universally acceptable and safer option. However, its application is limited due to shortcomings such as insufficient gel properties (such as rheological properties, gel strength, etc.). In this study, flaxseed gum (FFG) of 0–1.2% w/v was used to modify FG. The rheological properties, structural characteristics, and chemical bond changes of FG before and after modification were systematically analyzed using instruments such as a rheometer, infrared spectrometer, and Zeta potential analyzer. The results revealed that an appropriate amount of FFG could increase the gel strength of FG, but excessive FFG (>0.4%) reduced its gel strength. Moreover, FFG could increase the gelation transition temperature and apparent viscosity of the composite gel. FTIR confirmed that FFG and FG were bound through hydrogen bonding, β-sheet structure formation, and multi-electrolyte complexation. The ESEM showed that FFG promoted the formation of a denser network structure of FG. This study laid a theoretical foundation for the application and development of FG in the field of high-gel foods.