In this review, recent findings related to various factors influencing quality properties of fish meat and its products during frozen storage are introduced. Many studies have indicated that protein denaturation is the factor determining the quality of frozen fish meat. Ice crystal size does not necessarily determine the quality of frozen fish meat because the tissue of meat reabsorbs water during the thawing process, unless it has been previously damaged by protein denaturation. However, the effects of ice crystals on the quality of thawed fish meat differ based on the fish species, post-mortem stages, protein denaturation, and processing conditions of the fish meat. In the case of frozen-thawed lightly salted fish meat, salting conditions greatly affect the water holding capacity of muscle and the ice crystal size. Also, in the case of frozen kamaboko, which is denatured protein gel, as the thawed water is not absorbed enough by the protein gel, ice crystal size could be a determining factor of quality. The appropriate freezing and storage conditions required for maintaining quality must be based upon the characteristics of each seafood product.
Several kinds of emulsified surimi gels were prepared from different quality levels of Alaska Pollack surimi, and the relationship between the emulsifying stability (ES) of myofibrillar protein and the properties of the emulsified surimi gels was investigated. Fish oil emulsified into surimi gels enhanced the breaking strength, but this was decreased by denaturation of the surimi protein, and the rate of enhanced gel‐forming ability with emulsification decreased with decreasing ES. Expressible drip also decreased with emulsification; however, increasing amounts of lipid in the expressible drip were separated out from the gel upon protein denaturation of the source surimi. Scanning electron microscopy revealed that the shape of fish oil particles became irregular and some voids caused by oil leakage were observed with increasing storage period of source surimi. The results suggested that improvement in gel properties of the emulsified surimi gels was correlated with ES as well as the level of protein denaturation.