Effects of Zataria multiflora Essential Oil Nanoemulsion on Chemical, Microbial and Sensory Properties of Silver Carp Fillets

Background and Objectives: Food industries are searching newer and cheaper ways to safely produce and storage foods. Nanotechnology offers several options for the production, encapsulation and emulsion of foods. The aim of this study was to investigate effects of nanoemulsion of Zataria multiflora essential oil on microbial, chemical and sensory properties of silver carp fillets.  Materials & Methods: In general, effects of four treatments of 1) fillet without nanoemulsion of Z. multiflora essential oil (control), treatment; 2) 0.5% nanoemulsion of Z. multiflora essential oil, treatment; 3) 1% nanoemulsion of Z. multiflora essential oil and treatment; and 4) 1/5% nanoemulsion of Z. multiflora essential oil on microbial and chemical parameters of silver carp fillets were investigated trice on Days 0, 3, 6, 9, 12 and 15 at refrigerator temperature. Results: With increasing Z. multiflora essential oil nanoemulsion, the chemical indices (pH, TVB-N, TBA, PV and FFA) decreased. Microbial count in all treatments, except for 1.5% Z. multiflora essential oil nanoemulsion, crossed the eligible limit (107 Log cfu/g) on Day 15. For sensory evaluation 1.5 and 1% of treatments of Z. multiflora essential oil nanoemulsion included higher qualities. In all four treatments, the color index included bright brown. Results have shown that Z. multiflora essential oil nanoemulsion acts as a natural preservative and increases biochemical parameters (pH, TBA, TVB-N, PV and FFA) while preserving qualitative characteristics of the fillets. Furthermore results demonstrated that the bacterial growth rate was slowed down. Conclusion: Treatment of 1.5% Z. multiflora essential oil nanoemulsion included the highest efficiency and increased shelf life of the silver carp fillets by 12 (4 days longer than the control).