Effects of nanoemulsion based on essential oil rosmery (Rosmarinus officinalis) and thymus (Thymus vulgaris) on sensory, chemical and microbiological quality of trout (Oncorhynchus mykiss walbaum, 1792) stored in iced

The effects of nanoemülsions based on rosemary and thyme essential oils for chemical, sensory and microbiological quality of rainbow trout in ice were investigated. According to sensory analyses, nanoemulsions extended the shelf life of fish approximately 3 days. Lower pH, total volite basic nitrogen (TVB-N), thiobarbituric acid (TBA), peroxide value (PV), free fatty acids (FFA) compared to the control were obtained from the sample treated with rosemary and thymus nanoemulsions during storage period. TVB-N content of fish exceed the acceptability limit at day 21 for the control (38.07 mg/100g), at day 23 for the tymus and rosemary groups (35.26 mg/100g ve 40.62 mg/100 g, respectively). The highest TBA was obtained from the control (2.26 mg MA/kg). PV did not exceed 20 meq O2/kg recommended value for all groups during storage period. There were fluctuations in FFA contents of all groups during storage period. Total mesophilic aerobic bacteria (TAMB), total aerobic psychrotrophic bacteria (TAPB) and total Enterobacteriaceae counts were found lower in the treatment groups than those of the control. E.coli, Staphylococcus aureus, Salmonella, Listeria monocytogenes were not detected during storage period for all groups. The results of this study suggested that nanoemülsiyons based on thyme end rosemary essential oils extended the shelf life and improved the quality of trout fillets in ice during storage period.