Bioactive gelatin composites with natural antimicrobial agents for preventing quality deterioration and extending the shelf life of premium quality raw tuna fillets

The novel edible antimicrobial gelatin film was developed with extracts of Garcinia cambogia (GC), Myristica fragrans rind (NM), and Allium sativum peel (GP) to extend the shelf life of Tuna. The strongest inhibition zone for of 20 mm was observed against Staphylococcus aureus and 22 mm against Escherichia coli with the extracts. Gelatin films containing 1%, 2%, and 3% (w/v) extracts were evaluated for physicomechanical properties and preservation efficacy. The 3% antimicrobial film exhibited the lowest oxygen transmission rate (324.76 ± 8.75d cm3/m2.24h.0.1 MPa), water vapor permeability rate (995.40 ± 15.4cg/m2.24h), highest tensile strength (3.36 ± 0.11d MPa) and elongation at break (138.54 ± 1.3d %). Tuna fillets packed with antimicrobial films were stored at −4 °C for 13 days. Tuna preserved with the 3%(w/v) extract film exhibited a slower rise in pH (6.49), higher water-holding capacity, and reduced lipid oxidation. TBARS values were observed as (2.01 mg MDA/100 mg) for 3% film and found to be increased upto 3.53 mg MDA/100 mg on day 13 for tuna without film. Microbial growth was effectively suppressed, with delayed yeast and mold development.