Effect of Essential Oils and Packaging on Hot Smoked Rainbow Trout during Storage

This study investigated the effect of essential oils (EOs) (thyme and rosemary) and packaging (vacuum and modified atmosphere – 50% CO₂/+50% N₂) on hot smoking rainbow trout during storage (4C) for 90 days. Fillets were conducted to microbiological (i.e., total aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, Clostridium perfringens, C. botulinum, yeast and mold) and chemical (i.e., pH, thiobarbituric acid reactive substances, total volatile base nitrogen) analyses and sensory quality on 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 days. In conclusion, EO treatment to smoking showed positive effect on shelf life, especially thyme oil showed more positive effect when compared with rosemary oil. PRACTICAL APPLICATIONS: Smoking is one of the oldest methods used for preserving fresh fish and other seafood products. The use of an essential oil in fresh fish preservation may be considered an alternative “natural” additive, extending the shelf life of the product. Our study has clearly shown that addition of rosemary and thyme extract in smoked fish resulted in longer shelf life, and this method could be commercially used.