Quality characteristics of refrigerated mackerel Scomberomorus commerson using gelatin-polycaprolactone composite film incorporated with lysozyme and pomegranate peel extract

The aim of this study was to evaluate the preservation effect of the pomegranate peel extract (PPE)-lysozyme (Lys) combination addition on gelatin (G)–polycaprolactone (PCL) composite film on the quality of mackerel Scomberomorus commerson via physicochemical analysis (pH, total viable bases nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA), weight loss, color), microbiological (total mesophilic count (TMC) and psychrotrophic (PTC) count) and sensorial assessments during refrigerated storage. The results showed that incorporating PPE and Lys into G/PCL solution could significantly (P < .05) improve the quality of fish fillets. Among all treatments, TMC and PTC of mackerel fish with the control treatment increased rapidly and were generally higher than other treatments (P < .05). Thus, G-PCL film containing both of Lys and PPE can remarkably delay the growth of bacteria of mackerel fillets. The results indicated that the Lys in combination with PPE could be effective in the reduction of TBARS and FFA values of mackerel wrapped. In addition, the synergistic effect between Lys and PPE improved the antibacterial activity of the gelatin solution. G/PCL-Lys-PPE had the best effect on reducing the weight loss and color properties of the samples. It was seen that the addition of Lys/PPE improved the sensory quality of mackerel fish and these results were supported by the outcomes of bacterial and physicochemical analysis. The increase (>9 days) in the shelf-life was attributed to the antioxidant and antimicrobial characteristics of G/PCL film containing both of PPE and Lys. These results confirmed that G/PCL-Lys-PPE film was effective for the preservation of mackerel.