CHANGES IN INTRAMUSCULAR COLLAGEN OF COD (GADUS-MORHUA) DURING POSTMORTEM STORAGE IN ICE

Intramuscular collagen was isolated from the muscle of large and small cod (Gadus morhua L) stored in ice for periods up to 24 days. The solubilities in salt solution (salt soluble collagen), in dilute acetic acid (acid soluble collagen) and on heating (heat soluble collagen) were used as indices of aggregation. The solubility of collagen decreased slightly as rigor mortis developed in the flesh, but as rigor resolved it increased markedly. On storage post-rigor the solubilities on heating and in acid increased steadily and coincided with sharp increases in acidic and alkaline proteolytic activity in the muscle. The results obtained indicate that degradation of collagen takes places initially with the development of rigor mortis and that it continues as the muscle ages. Possible mechanisms are discussed.