Surveying the Effect of Rosmarinus officinalis essential oil (free and nanoemulsion) on shelf life of chicken fillet in refrigerated condition

Due to the high amount of pH, moisture and protein content, chicken meat is a sensitive product which could be a good host for pathogen and spoilage microorganisms. In the recent years there has been a remarkable attention to use natural preservative instead of chemical preservative among producers of food products. Different studies has shown rosemary essential oil contain antioxidant and antimicrobial properties. The present study was conducted to evaluate effect of rosemary essential oil (free and nanoemulsion) on chemical, microbial and sensorial quality of chicken fillet during refrigerated storage. Samples were examined in days of 0, 3, 6, 9 and 12. The results showed noticeable effects of both forms of rosemary essential oils in microbial, chemical and sensorial quality improvement. Moreover the results indicated that nanoemultion form of rosemary had significant effects on delaying the increase trend of psychrophilic, ,enterobacteriacea and mesophilic bacterial counts as compared to free form of rosemary (P<0.05). Furthermore The results of TVN, TBA and pH measurements indicated that nanoemulsion form of rosemary improved chemical quality of the samples in comparison with free form of rosemary during storage time (P<0.001).  Also in terms of sensorial characteristics, application of nanoemulsion essential oil lead to improvement of odor and overall acceptance factors compared to control group after twelve days of storage.