Antibacterial and antioxidant potential of rosemary extract (Rosmarinus officinalis) on shelf life extension of Rainbow trout (Oncorhynchus mykiss)

Antibacterial and antioxidant effect of rosemary extract were investigated on vacuum packed rainbow trout (Oncorhynchus mykiss). Microbial (total viable، psycrotrophic، lactic acid bacteria and enterobacteriacea counts)، chemical (pH، TMA، TBA، FFA، PV) and sensory analysis were done at 2±1°C for 18 days. Rosemary extract significantly (p<0/05) delayed lipid oxidation in treated samples. Psycrotrophic bacteria and total viable count of treated samples with rosemary extract maintained lower than the proposed acceptable limit (7 log cfu/g) as far as microbial spoilage significantly (p<0/05) decreased in rosemary samples in comparison with the control samples. According to sensory and microbial analysis rosemary samples were acceptable for eat to end of storage thus rosemary extract was able to increase shelf life of this samples 4 days in compare with the control samples.