Abstract: This study aimed to improve the functional properties of frozen whole egg (FWE) for the purpose of developing FEW-based food products for special dietary use. The changes in the functional and physicochemical properties of FWE with NaCl added at 0.5%, 1%, 2% and 4% during six months of frozen storage were researched. With this aim, fresh liquid whole egg was added with NaCl, stirred thoroughly and quick-frozen before frozen storage. The results showed that the surface hydrophobicity of FWE was increased with increasing storage time and NaCl content. Total sulfhydryl content and surface sulfhydryl content were decreased with the extension of storage time, but they displayed irregular changes with NaCl content. Solubility was gradually decreased during storage time, and in terms of solubility, FWE with 1% and 2% NaCl added were better than the blank group significantly. The foaming capacity of FWE exhibited an overall decreasing trend, while the foam stability was changed reversely. The foaming capacity of FWE was significantly improved by adding 2% NaCl, and after frozen storage for 60–180 days, it was higher than that of the quick-frozen samples without NaCl addition and without storage and that of the fresh samples. Simultaneously, gel hardness and water holding capacity rose in the early storage period and then continuously declined. Moreover, gelling properties of FWE were obviously improved by adding 1% NaCl, and after 30 days of storage, they were higher than those of fresh egg and FWE without storage or NaCl addition. Therefore, we concluded that the functional properties of FWE could be effectively improved by adding an appropriate amount of NaCl, which can provided a theoretical guidance for the development of FEW-based food products for special dietary use.

Key words: frozen liquid whole egg, NaCl, functional properties, frozen storage