Abstract:

Fresh tilapia fillets packaged under modified atmosphere packaging (MAP, CO2:N2 = 70:30) were stored at temperature of controlled freezing-point (CF, －0.7 ℃). Changes in odor, elasticity, chromatic aberration, total bacterial counts, psychrotrophic counts, pH, TVB-N and drip loss of tilapia fillets were monitored during storage of 24 days. Results showed that MAP and CF storage exhibited a significant fresh-keeping effect on tilapia fillets. After storage for 21 days, the tilapia fillets still remained intact odor, elasticity and color; total bacterial counts and TVB-N were 3.09×105 CFU/g and 17.74 mg/100 g, respectively, which were still in the acceptable range. In contrast, samples in other preservation groups were spoiled. Therefore, a synergistic effect of MAP and CF storage on tilapia fillets preservation was achieved. Compared to individual MAP or CF storage method, the shelf life of tilapia fillets using the combinatorial MAP and CF storage was extended by 3 days and 6 days, respectively. Moreover, the combinatorial MAP and CF storage can provide 4-fold shelf life for tilapia fillets treated with ordinary preservation methods.

Key words: freezing-point storage, modified atmosphere packaging, tilapia fillet, quality