Shelf-life extension of refrigerated rainbow trout fillets using total Farsi gum-based coatings containing clove and thyme essential oils emulsions

In this study, total (non-fractionated) Farsi gumbased coatings (FGC) incorporated with clove (CEO) and Shirazi thyme (SEO) essential oils emulsions were utilized to extend the shelf-life of refrigerated rainbow trout fillets. Sonication decreased the amount of water insoluble fraction of FGC. Physicochemical, microbial and sensory characteristics of coated fillets were evaluated during 16 days. The results showed that incorporating CEO and SEO into FGC could significantly (p < 0.05) improve the quality of fish fillets. During storage, the increase in the amounts of peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and total volatile basic-nitrogen (TVB-N) followed this order: CEO-SEO loaded FGC < FGC < uncoated (control). Regarding color parameters including L* and b* increased; whereas, a* decreased. Texture, odor, color and overall acceptability of coated fillets were significantly (p < 0.05) better than those of uncoated ones. A significant (p < 0.05) improvement in the microbial quality (total viable count (TVC), psychrophilic and lactic acid bacteria counts) was observed in the presence of essential oil-loaded coatings. Interestingly, an obvious synergistic effect was observed between CEO and SEO. The increase (> 6 days) in the shelf-life was attributed to the antioxidant and antimicrobial characteristics of CEO and SEO. (C) 2017 Elsevier Ltd. All rights reserved.