THAWED COD FILLETS SPOIL LESS RAPIDLY THAN UNFROZEN FILLETS WHEN STORED UNDER MODIFIED ATMOSPHERE AT 2-DEGREES-C

The effect of two months of frozen storage at -20 degrees C on the spo ilage characteristics and shelf life of thawed and modified atmosphere packed (MAP) cod fillets stored at 2 degrees C was studied. Thawed MA P cod fillets were compared with fresh cod fillets stored in CO2-conta ining modified atmospheres with and without added oxygen. The shelf li fe of 11 to 12 days in the fresh MAP cod was extended to more than 20 days in the thawed MAP cod at 2 degrees C. This shelf life extension w as most likely due to the inactivation of the spoilage bacterium Photo bacterium phosphoreum during frozen storage as reflected both in chemi cal analyses and sensory evaluation. In contrast to fresh MAP cod fill ets no significant production of trimethylamine occurred and almost no amine odor and taste were detected during 20 days of chill storage of thawed MAP cod fillets. The use of frozen fillets as raw material not only provides a more stable product in MAP but also allows much great er flexibility for production and distribution. However, a slightly in creased concentration of dimethylamine, a larger drip loss, and detect ion of weak frozen storage flavor were observed in the thawed MAP cod fillets.