ABSTRACT
The postharvest biochemical and microbial changes in fish tissues depend very sigificantly upon the factors which effect the concentration of substrates and metabolites in the tissues of the live fish, the activity of the endogenous enzymes, the microbial contamination, and the conditions after catching. The biochemical post-mortem changes, involving the main chemical constituents of the tissues, bring about various structural alterations in the tissues, including rigor mortis, and different degrees of disintegration of the muscle ultrastructure. The biochemical state of the postrigor muscles is different from that of the prerigor flesh. The time after which the onset of rigor is noticeable, the degree of change in the rheological properties of the fish body, and the duration of the stiff condition depend upon factors influencing the biochemical state of the muscles at the time of death and on the rate of post-mortem processes.
