SHELF-LIFE OF FRESH TILAPIA FILLETS PACKAGED IN HIGH BARRIER FILM WITH MODIFIED ATMOSPHERES

The effect of modified atmospheres (MAs) (75% CO2:25% N-2; 50% CO2: 50 % N-2; and 25% CO2: 75% N-2) and 100% air on shelf life of fresh tilap ia fillets packaged in high barrier film bags was evaluated at refrige ration temperature (4.0 degrees C). Fillets packaged in 100% air spoil ed after 9 days, as indicated by sensory characteristics, and had incr eased surface pH, TMA content, K-value and high microbial counts. When levels of CO2 were increased from 25 to 75% in the package atmosphere , the shelf life of MA-packaged tilapia fillets was extended 4-21 days more than that of fillets packaged under 100% air. Although fillets p ackaged under 75% CO2:25% N-2 were judged by sensory characteristics t o be acceptable for more than 25 days, their K-value was high (93.1%). K-values were independent of spoilage and correlated only with length of storage of the MA-packaged fillets.