Effects of inflation rate on the quality of tilapia fillet with modified atmosphere packaging during controlled freezing-point storage

Packaged fresh tilapia fillets with different inflatable volume(V)- fish weight (m) ratios were stored at freezing-point; indices such as micro-organisms, TVB-N and TBA values were observed to study the effects of different inflatable ratios on the quality of fresh tilapia fillets.Experimental results showed that the ratio≥3 : 1 significantly inhibited the microbial growth of products (P < 0.05);the microbial number was still within the acceptable limit(10⁶ cfu·g^-1) at 25^th day of storage.The gravy leakage rate of the modified atmosphere packaging(MAP) samples were higher than those in the control group, and the higher the inflatable ratio was, the more obvious the influence on the gravy leakage rate of products was.With the extension of storage time, TVB-N value in the control group was significantly higher than that of the packaging samples with the inflatable ratio≥3 : 1 after 4 days, and TVB-N value of samples with the inflatable ratio≥3 : 1 was still within the safety limit at 19^th day, being about 19.30 mg·100 g^-1.Different inflatable ratios had no obvious effects on the products′ pH value, and TBA value increased slowly throughout the storage period; the MAP samples did not differ significantly, but there was significant difference (P < 0.05)between the experimental group and the control group. To summarize, the inflatable ratio between 3 : 1 and 4 : 1, which did not significantly influence the quality of MAP samples during storage, could prolong the shelf life of fresh tilapia fillets significantly.