Zataria multiflora Boiss essential oil and sodium acetate: how they affect shelf life of vacuum-packaged trout burgers

The preservative effects of Zataria multiflora Boiss essential oil (ZEO) at 0.025%, 0.05% and 0.1%, sodium acetate (SA) at 2% and their combination on the quality changes of vacuum-packaged trout burgers during 21-day refrigerated storage (4 +/- 1 degrees C) were investigated. Results showed that control and ZEO-treated samples reached undesirable levels of rancidity (P<0.05) at 15th day, whereas samples with the combined effect of SA and ZEOs, especially at higher concentrations, proved to be more stable in sensory, biochemical (PV, TBA, FFA and pH) and microbiological analyses (P<0.05). Therefore, ZEO+SA-treated samples showed good overall acceptability even until 21st day. Regarding the results obtained from ZEO-treated samples, it becomes apparent that combined application of SA and ZEO extended the shelf life of fish burgers during cold storage to 21days, 1.4-fold longer than other treatments, which indicates the potential application of synergistic activity of these agents in vacuum-packaged fishburgers.