Evaluation Of The Effect Of Icing With Pullulan and Bay Leaf Extract On The Shelf Life of Rainbow Trout During Storage In The Freezer

In this study, the effect of icing covered with pullulan with bay leaf extract on the shelf life of rainbow trout under freezer conditions was investigated. For this purpose, first the bay laef extract was extracted using ultrasound waves and the constituents of the extract were determined. The most common components of the extract were 1,8-Cineole (56.45), Sabinene (13.55) and α-terpinyl acetate (9.35). Then 4 studied treatments including 1: control, 2: icing with pullulan, 3: pullulan+ extract at 750 ppm and 4: pullulan+ extract at 1500 ppm were produced and profile of fatty acid, index texture, peroxide value, thiobarbiotic acid, total amounts of bacteria and psychrotrophic counts bacteria during the 4 month storage period in the freezer were evaluated. The highest levels of saturated fatty acid were palmitic acid (12.29%), monounsaturated fatty acid oleic acid (60.98%) and polyunsaturated linoleic acid (9.55%). In general, coating of pullulan with the extract slowed down the increasing trend of oxidative and microbial spoilage indices compared to the control treatment and with increasing concentration, better results were observed. Also, texture changes and fatty acids were less in these treatments. According to the obtained results, it can be concluded that in general, icing with edible coating of pullulan along with bay leaf extract maintains the quality of fish fillets during storage in the freezer.