Effect of Packaging Method and Use of Acetic Acid on the Shelf Life of Fish During Refrigeration Storage

This experiment was conducted to evaluate the efficacy of application of acetic acid 1%, non-vacuum packaging and vacuum packaging on the shelf-life of tilapia fish filets at refrigerated temperature (2±1 o C) during 21 days of storage period. In this regard, the current study investigated the quality attributes including sensory, TBA, TVB-N, pH and microbial loads of examined fish. Vacuum packing and acetic acid were found to possess potent antibacterial effects on a variety of microorganisms. The fish were divided into four groups after being gutted and filleted: Group A (GA): fish fillets were vacuum packaged in Polyamide/ Polyethylene (PA/PE) bags. Group B (GB): the fillets were stored in non-vacuum containers. Group C (GC): the fillets underwent chemical treatment by immersion in 1% acetic acid for 2 minutes at room temperature, drained for two minutes then vacuum packaged in Polyamide/ Polyethylene (PA/PE) bags. Group D (GD): the fillets treated as in GC stored in non-vacuum containers. All groups were stored at 2±1 o C, 80% CO 2 and 20% N 2 for 21 days. The experiment was repeated in triplicate. The sensory analysis of fish fillets revealed that samples in group C which were treated with acetic acid 1% in combination with vacuum packaging during storage for 21 days at 2±1 o C had the best sensory properties and the best shelf life, and a low pH value reduced or even limited microbial levels, and ensured the safety of different microbial counts as well as reduction of TBA and TVB-N in acetic acid-treated groups compared with other groups. Together with the sensory characteristics, the low or limited microbial counts (total viable count, total psychrotrophic count, and total coliform counts) suggested that autolysis or other causes other than microbial activity may be to blame for the deterioration. Meanwhile, the shelf-life of fish treated with vacuum packaging had a longer shelf-life than that treated with non-vacuum packaging. Overall, the research underscores the need for more research and development to produce seafood that is stable and safe against microbes and has a long shelf life in order to meet customer demand.