不同CO_2比例气调包装对冰温贮藏鲜罗非鱼片品质的影响

采用不同的气体组成A(50%CO2/10%O2/40%N2)、B(60%CO2/10%O2/30%N2)、C(70%CO2/10%O2/20%N2)和空气(对照)分别包装鲜罗非鱼片,在-0.5±0.2℃贮藏,研究不同CO2比例气调包装在冰温贮藏条件下对鲜罗非鱼片品质的影响。实验结果表明,罗非鱼的冰点在-0.8～-0.9℃之间,贮藏7d以后,与对照相比,气调包装能显著抑制产品细菌菌落总数和嗜冷菌数的增长(p<0.05)。在冰温贮藏期间,气调包装样品的肉汁渗出率要高于对照产品,随着贮藏时间的延长,四组样品的TVB-N值均有不同程度的上升,但是贮藏10d以后,对照的TVB-N值开始高于三种气调包装样品;包装方式对产品pH的影响并不明显,但是对照的pH随着贮藏时间的延长基本呈上升趋势,四种处理的罗非鱼片在整个贮藏期间TBA值几乎都没有变化。三组CO2比例气调包装样品在贮藏期间的品质差异并不明显,但是在冰温条件下,气调包装处理能明显延长鲜罗非鱼片的货架期。

Effects of different concentrations of carbon dioxide on quality of fresh tilapia fillets packaged in modified atmosphere during super chilling storage

Fresh tilapia fillets packaged under modified atmosphere (MA) (A:50% CO_2/10% O_2/40% N_2 ; B:60% CO_2/10% O_2/30% N_2 ;C:70% CO_2/10% O_2/20% N_2) and air stored at super chilling (-0.5±0.2℃). Quality changes of samples were monitored during 19d of storage. Freezing point for fresh tilapia was-0.8～-0.9℃.A obviously reduced bacterial growth (p < 0.05), measured as total viable counts (TV_C) and psychrotrophic bacteria, was observed in modified atmosphere packaged(MAP) fresh tilapia fillets after 7d of storage.The drip loss of samples in MAP was higher than that in air during storage.The TVB-N values of all samples were increased during storage,but the TVB-N values of samples in MAP were lower than those in air after 10d of storage. There were no differences in pH as a function of storage time or packaging method.There was a general trend of increased pH for samples in air during storage. The TBA values of all samples were no obviously differences during storage. The effects of different gas mixtures were evaluated on the quality of fresh tilapia fillets. MAP combined with super chilling was effective in extending shelf life of fresh tilapia fillets.