In order to predict lipid oxidation of the minced irdinary muscle during cold storage, the minced ordinary muscles of fatty and lean fish were stored at -5°C for four weeks and the extent of lipid oxidation was evaluated by TBA number (mg MA/kg muscle). On the other hand, homogenates of the fresh ordinary muscles with water (1:1) were incubated at 37°C for 2 h and at 5°C for 24 h without or with 40 ppm of Cu⁺⁺and then TBA numbers were determined. The susceptibilities were expressed by TBA_37°C-2h, TBA_{cu⁺⁺-37°C-2h}, TBA_5°C-24h and TBA_{cu⁺⁺-5°C-24h}.
During the storage of the minced ordinary muscles, lipid oxidation proceeded in pacific mackerel and sardine, fatty fish, whereas hardly proceeded in plaice and carp, lean fish. Among these four susceptibilities, TBA_37°C-2h bore an approximately linear relationship to lipid oxidation during the storage (r=0.96).
In various minced tissues of pacific mackerel, lipid oxidation proceeded during the storage in the following order of skin>viscera>dark muscle>ordinary muscle. In the round, although the same order was observed, lipid oxidation was markedly depressed and hardly proceeded in the tissues except the skin. Thus preferential lipid oxidation in the skin was demonstrated. These differences of lipid oxidation among the various tissues were not predicted by TBA_37°C-2h of the tissues.