Antioxidant and antimicrobial characteristics of chitosan and galbanum gum composite coating incorporated with cumin essential oil on the shelf life of chicken fillets

In this study, an edible composite coating of chitosan and galbanum gum containing cumin essential oil (CEO) was used to increase the shelf life of chicken fillets during a 12-day refrigeration period (4 +/- 1 degrees C). In order to achieve the optimal concentration of essential oil, antioxidant (free radical scavenging DPPH) and antimicrobial properties (MIC and MBC values) were determined. Then, chicken fillet coated with chitosan and galbanum gum (individually and in combination), and different concentrations of CEO (0.75 and 1.5%) was periodically evaluated chemically, microbiologically and sensory. IC50 values of DPPH free radical was to 45.32 mu g/ml for CEO, and MIC and MBC values for different bacteria were 37.15-5.25 and 50-25 mu g/ml, respectively. As results of coated chicken fillets showed that the composite coating with CEO effectively inhibited microbial load (total bacterial counts, psychrotrophic bacteria, lactic acid bacteria, Pseudomonas spp., Enterobacteriaceae, Staphylococcus aureus, yeast and mold) in chicken fillet (P < 0.05). The results of the chemical analysis showed that the coated samples had less peroxide value, thiobarbituric acid, and total volatile basic nitrogen than the control (P < 0.05). At the end of the storage period, the best results were observed in the composite coating containing CEO at 1.5% and were approved by sensory evaluators, thus this study suggests that utilization of this treatment (composite coating containing CEO at 1.5%) can maintain the quality and enhance the shelf life of chicken fillets during refrigeration.