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Background and Objective: Plant extracts are rich sources of natural antioxidant and antibacterial compounds. In recent decades, the need for using natural antioxidants in foods, pharmaceuticals and cosmetics has promopted extensive scientific research. The purpose of this investigation was to determine the antioxidant and antibacterial activities of shallot extract on shelf-life of vacuum-packaged gutted rainbow trout stored at 4±1˚C. Materials and Methods: Prepared fish were divided into two batches. One batch was treated by dipping in an aqueous solution of shallot extract, vacuum-packaged, and kept at 4±1˚C, serving as the treatment sample, and one batch was vacuum-packaged and served as control. Chemical (TVN, TBA, PV) and microbial (total viable count, psychrotrophic) tests were performed , pH measured, and sensory analysis done on all the samples kept for 20 days. Results: Shallot extract delayed significantly (p<0.05) lipid oxidation in the treated sample, in which the psychotrophic bacteria and total viable counts also remained lower than the proposed acceptable limit (7 log cfu/g). Furtehrmore, microbial spoilage decreased significantly (p<0.05) in the treated, in comparison with the control, sample. According to sensory analysis results, treated samples were acceptable even at the end of the 20-day storage. Conclusion: The findings indicate that shallot extract exerts antioxidant and antibacterial effects on vacuum-packaged rainbow trout during storage and increases its shelf life. Keywords: Rainbow trout, Shallot extract, Vacuum packaging, Shelf life

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Background and Objective: Fish and fish products are highly perishable because of their high contents of unsaturated fatty acids and high-quality protein. Therefore, it is essential to protect them against spoilage and extend their shelf-life by using natural preservatives, e.g., plant extarcts. The objective of this study was to determine the antioxidant and antibacterial effects of combined turmeric and shallot extracts on the shelf-life of silver carp (Hypophthalmichthys molitrix) paste stored at -18°C. Materials and Methods: Two samples of fresh silver carp paste were prepared. One sample was mixed with a mixture of 0.5% shallot extract and 0.25% turmeric extract (treatment group), packed and stored for 70 days at -18 °C. The other sample was packed and stored for the same period of time at the same temperature without mixing with the plant extracts (control group). Microbial counting (total viable count =TVC) and psychorotropic count (PTC)) and chemical analysis (peroxide value =PV, free fatty acids =FFA, total volatile basic nitrogen =TVB-N, and 2-thio- barbituric acid (TBA)) were performed at days 0, 15, 30, 40, 60 and 70 of storage . Results: The data showed that the combined turmeric and shallot extracts could delay the microbial, lipid and protein spoilage in the fish paste and presrve its nutritive value and safety by preventing undesirable changes in lipids. Conclusion: The findings demonstrate that a combination of shallot and turmeric extracts can significantly extend the shelf life of silver carp paste stored at -18 °C. Keyword: Silver carp, Shallot extract, Turmeric extract, Storage, Lipid spoilage, Bacterial spoilnage