Evaluation of Oxidative Stability of Pre-cooked Rainbow Trout (Oncorhynchus mykiss) Fillet Treated with Anethum graveolens L. Essential Oil

Aims: Today, a part of studies on food science has investigated the effect of cooking methods on the oxidation of various types of meat and the use of natural herbal preservatives instead of synthetic preservatives. The aim of the present study was to evaluate the oxidative stability of pre-cooked rainbow trout (Oncorhynchus mykiss) fillet treated with Dill (Anethum graveolens L.) essential oil (EOs).
In the present experimental research, rainbow trout fillet with dill EOs and Butylated hydroxytoluene (BHT) were treated, each at 3 different concentrations, and cooked by 3 methods, including frying, oven baking, and steaming. The cooked samples were stored at -18◦C for 4 months and analyzed at the end of each month. The extracted oil was used to measure the value of free fatty acid (FFA), peroxide value (PV), and thiobarbituric acid (TBARS). The data were analyzed by SPSS 20, using two-way ANOVA, Tukey's post hoc, Kruskal-Wallis, and Mann-Whitney U tests.
Findings: The FFA formation showed increase in all samples, especially oven baked rainbow trout fillets (p In rainbow trout, the lipid oxidation increases with the thermal process, but the essential oil postpones the oxidation during the storage period as frozen. The samples cooked with Dill EOs have lower amount of FFA, PV, and TBARS compared with the control peers.