Does Vacuum Packaging Retain the Quality of Hilsa Fish (Tenualosa ilisha) during Long-Term Frozen Storage?

Long-term frozen storage deteriorates the quality of hilsa fish (Tenualosa ilisha), 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 without pack, whole with vacuum pack, dressed without pack, and dressed with vacuum pack, at a monthly interval during a year of frozen 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 during the storage period. However, thiobarbituric acid reactive substances (TBARS) were significantly (p < 0.05) lower in samples under vacuum (whole and dressed) compared to samples without pack. TBARS values did not cross the acceptable limit for vacuum pack samples in nearly the entire storage period but were exceeded for samples without pack 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 its distinctive taste and flavor.