Protein changes during frozen storage

Farouk, M.M. and Swan, J.E. 1998. Effect of muscle condition before freezing and simulated chemical changes during frozen storage on protein functionality in beef, Meat Sci., 50, 235. 

Information on the molecular changes occurring during frozen storage of whole muscle or of isolated protein preparations will be reviewed here. 

The water-activity relations, effects of displacements of water or effects of changes in the state of water must be the most important factors to trigger and to promote the denaturation of muscle proteins during frozen storage. 

Actomyosin. Solubility. Studies have dealt with changes in the solubility of proteins during frozen storage of fish muscle or solutions of isolated actomyosin (33,51,52). Analysis by gel filtration of the salt extracts has shown that the actomyosin fraction decreases in solubility during frozen storage whereas the sarcoplasmic proteins remain essentially unchanged (53). 

Electron Microscopy. Examination of fish proteins by electron microscopy conclusively shows that actomyosin aggregates during frozen storage (59,63,69). The change in structures of the extracted myofibrillar proteins and of the myofibril residues of frozen-stored cod muscle was studied by electron microscopy. The decrease in the number of actomyosin filaments and an increase in the number and size of large aggregate were found (69). Unfrozen carp actomyosin, either dissolved in 0.6M KC1 or suspended in 0.05M KC1, exists in a typical arrowhead... 

Benjakul, S., Visessanguan, W., Thongkaew, C., and Tanaka, M. 2003a. Comparative study on physicochemical changes of muscle proteins from some tropical fish during frozen storage. Food Research International 36 787-795. 

Kjnrsgard JVH, Nprrelykke MR, Jessen F (2006). Changes in cod muscle proteins during frozen storage hy proteome analysis and multivariate data analysis. Proteomics, 6 1606-1618. 

Jiang, S.T. Hwang, B.O. Tsao, CT. Protein denaturation and changes in nucleotides of fish muscle during frozen storage. J. Agric. Food Chem. 1987a, 35, 22-27. 

---