This study used sardine oil as the oil phase and beeswax as the gelling agent to establish the spatiotemporal relationship between the structural characteristics of the sol-gel system and its oxidative stability. A comprehensive investigation was conducted into changes in crystal morphology and distribution, textural characteristics, rheological behavior, oil retention capacity, and oxidative stability during the phase transition. The results showed that the formation of beeswax-based fish oil oleogel involved three stages: melting, recrystallization, and gelation. During melting, no gel structure formed. During recrystallization and gelation, beeswax initially formed needle-like crystal chains, which subsequently cross-linked and aggregated into a dense crystalline network, enhancing the stability, viscoelastic properties and apparent viscosity of the gel system. The hardness and gel strength of the beeswax-based fish oil oleogel increased significantly, and the oil-binding capacity reached 100%. Throughout the three stages, peroxide value (POV), thiobarbituric acid reactive substances (TBARS), p-anisidine value (p-AV), and acid value (AV) decreased significantly, indicating a notable improvement in oxidative stability. This study provides a theoretical basis for developing and applying high-quality and stable fish oil oleogels.

Chopping and emulsification treatment can play a decisive role in the texture and oil and water retention of emulsified meat products, but unreasonable chopping or emulsifying process will cause quality defects such as water and oil exudation and loos structure. Thus, how to improve meat product quality is a major technical difficulty in the meat processing industry. The stability of emulsified gels involves myosin aggregation behavior, gelation and interfacial membrane emulsification-adsorption behavior. In this context, this paper reviews the effect of myosin spatial conformation on the stability of emulsified gels in the process of chopping and emulsification from the perspective of protein hydration, focusing on the effects of hydration characteristics during chopping and the spatial conformation of myosin aggregates on the structure of heat-induced gels and the influence of the interfacial protein membrane’s structure on the stability of emulsified gels. The interactions between water, fat and myosin during the emulsification-adsorption process are discussed, and the significant effects of the structure, thickness and viscoelastic properties of interfacial protein membranes on emulsion stability are clarified, which will provide an improved understanding of the stabilization mechanism of emulsified gels. Hydrogels have good gelling and emulsifying properties, so it can be used as an animal fat substitute to reduce the fat content in meat products. Furthermore, hydrogels can improve the rheological and mechanical properties of muscle proteins, thus enhancing the printability of meat products. Therefore, the application of hydrogels to 3D printed meat products will become a new strategy to improve the oil and water retention properties and texture of meat products.

Heat treatment can induce muscle protein denaturation and aggregation and eventually the sol-gel tradition of proteins. The aggregation rate, degree, morphology and pattern can affect the quality of protein gels. Traditional Chinese soy sauce and pot-roast meat products are processed at temperatures above 100 ℃, and secondary heating treatment is commonly used to extend the shelf life of canned foods, both of which can lead to excessive protein aggregation, in turn reducing the fluidity of water as well as protein digestibility, destroying the quality of meat products and reducing the nutritional value. In this paper, the mechanisms of protein aggregation are analyzed by using the Lumry-Eyring nucleated polymerization (LENP) model. Three protein aggregation modes are described including fibril aggregation, hydrogel aggregation and amorphous aggregation. Four strategies for inhibiting excessive thermal aggregation are reviewed from the perspective of the spatial conformation of proteins. pH, amino acids and polyphenol compounds along with hydrophobic and reducing small molecules can effectively inhibit excessive aggregation of myofibrillar proteins and improve the gel properties of heat-induced proteins. As a molecular chaperone, casein can obviously enhance the thermal stability and reduce the degree of aggregation of proteins. Therefore, these strategies for inhibiting excessive aggregation can enhance the gel and texture quality of meat products.