Combining ozone and modified atmosphere packaging (MAP) to maximize shelf-life and quality of striped red mullet (Mullus surmuletus)

Abstract

The combined effect of ozone treatment and modified atmosphere packaging (MAP) on microbiological, biochemical, and sensory changes of striped red mullet was studied by monitoring quality during 21 days of storage at 1 °C. Striped red mullet treated with ozonated water (0.3 mg L−1) and packaged under MAP (50% CO2, 50% N2) were compared with samples packaged under MAP conditions alone and samples stored in air. Total viable count (TVC), total volatile basic nitrogen (TVB-N), peroxide value (PV), trimethylamine (TMA-N), appearance and odour were assayed on the raw fish at regular intervals. Microbiological results revealed that ozone significantly delayed the bacterial growth in fish muscle such that the levels remained relatively low until day 10 (<6 log CFU g−1). Chemical indices of both OMAP (ozone combined with MAP) and MAP samples remained significantly lower than the traditional refrigerated samples during the storage period. Pre-washing in ozonated water was also associated with improved chemical quality indicators. Similarly, appearance and odour measurements indicated that MAP and OMAP packaged samples retained desirable characteristics throughout the first 10 days of storage. This experiment showed that ozone treatment combined with MAP represents a promising technique to extend the shelf-life of striped red mullet maintaining high safety and quality.