Does vacuum packaging retain the quality of hilsa fish (Tenualosa ilisha) during long-term frozen storage?

The long-term frozen storage deteriorates the quality of hilsa fish (Tenualosa ilisha), which is famous for its delicious taste and flavors. Vacuum packaging may retain the flavor and quality of hilsa fish. To this end, biochemical and microbiological analyses were used to assess the quality of hilsa fishes under whole & not sealed pack, whole & vacuum pack, dressed & not sealed pack, and dressed & vacuum pack at a monthly interval during nine months of storage at -18°C. There were no significant differences (p> 0.05) in the values of pH, free fatty acids (FFA), total volatile base nitrogen (TVB-N), and aerobic plate count (APC) among the treatments, and the values remained within the acceptable limit in the storage period. However, thiobarbituric acid reactive substances (TBARS) were significantly (p< 0.05) lower in samples under vacuum (whole & dressed) compared to unsealed pack. TBARS values did not cross the acceptable limit for vacuum pack samples in nearly the entire storage period but exceeded for unsealed pack samples within the first month. It is assumed that the vacuum packaging reduced the secondary oxidation of fatty fish like hilsa during the frozen storage, which can ensure a year-round supply of quality hilsa fish without altering the distinctive taste and flavor.