The effect of some essential oils on the shelf life of smoked and vacummed rainbow trout (Oncorhynchus mykiss) fillets

In this study, it was aimed to investigate the chemical, microbiological and sensory attributes of smoked trout with application of rosemary, thyme, sage and clove oils.Five different experimental groups together with control group, containing rosemary, thyme, sage and clove oils at 600 ppm concentration were prepared and were stored at +4±1 °C Samples were analyzed as microbiological (total mesophilic anaerobe, psychrophile, lactic Streptococcus spp., Lactobacillus spp., lipoytic, yeast and mold), chemical properties (pH, moisture, dry matter, fat, salt, TBA, PV and FFA) and sensory attributes on days 0, 7, 14, 28, 42, 56, 70, 84, 98 and 112 during the storage period. Three replicates for each group were made.The results indicated that there was no significant differences among the groups in terms of total mesophilic anaerobe, psychrophile, lactic Streptococcus spp., Lactobacillus spp., lipoytic microorganism during the storage period (p>0.05).Significant differences between pH values, moisture, dry matter, fat levels of control and other groups have not been observed (p>0.05). However, significant differences were found both among groups and during the storage period of groups in term of TBA and PV, FFA values (p<0.05).As the results of sensory attributes analyses, changes were observed in appearance, flavor, and color among groups during storage period (p<0.05).In conclusion, essential oils treatment to smoking were showed positive effect on shelf life, especially clove oil showed more positive effect when compared with others. In the present study, usage of these essential oils in smoked fish were showed that, they have got a positive effect on the product?s chemical and sensory attributes.