Effects of Gelatin Edible Films Containing Onion Peel Extract on the Quality of Rainbow Trout Fillets

Abstract

In this study, quality changes of rainbow trout fillets covered with gelatin films prepared by adding onion peel extract (OPE) in different concentrations (2.5%, 5% and 10%) were examined during storage at 4±1oC. For this purpose, trout fillets are divided into five groups: the group covered with gelatin film (GF), the groups covered with gelatin film containing different concentrations of OPE (O2.5, O5, O10), and the group without coating (control, C). According to the results obtained, peroxide values increased until end the of storage, but the highest values were found to be in the C and GF groups. The lowest TBARS values were observed in the groups covered with gelatin films enriched with OPE. Results of the study showed that lipid oxidation was delayed in the groups covered with gelatin films prepared by adding OPE. Microbial growth increased in all groups by the end of storage, and the highest values were observed in the C and GF groups at the end of storage. As a result, it can be concluded that the addition of OPE increased the effectiveness of gelatin films and delayed microbiological spoilage and lipid oxidation in rainbow trout fillets during refrigerated storage.