LIPID-PEROXIDATION AND CHEMICAL-CHANGES IN CATFISH (ICTALURUS-PUNCTATUS) MUSCLE MICROSOMES DURING FROZEN STORAGE

An NADH-dependent lipid peroxidation system previously identified in channel catfish muscle microsomes functioned at -10 degrees C in isolated microsomes. Below that, activity was inhibited. The amount of peroxidase activity remaining after thawing previously frozen isolated microsomes or intact catfish fillets was inversely related to storage temperature. Microsome yield and lipid content were lower in the fillets stored at -10 degrees C than -40 degrees C. Most microsomal fatty acids, especially PUFAs, gradually decreased in the fish fillets stored at -10 degrees C. Prolonged storage of catfish fillets would require storage below -20 degrees C. Any thawing would result in reactivation of the peroxidase system.