Shelf-Life Extension of Fish Samples by Using Enriched Chitosan Coating with Thyme Essential Oil

Abstract

Abstract The present study examined the effect of chitosan (Ch) and combination of chitosan and Thymus vulgaris essential oil (Ch+T) on the quality and shelf life of butterfly-shaped rainbow trout stored under refrigerated condition (5 ± 1°C) for 15 days. The treatments in the present study were Ch (chitosan: 2% w/v) and Ch+T (chitosan: 2% w/v and Thymus vulgaris essential oil: 1% w/v). The shelf life of the samples were determined using microbiological (total psychrotrophic count), chemical—pH, thiobarbituric acid (TBA), and total volatile basic nitrogen (TVB-N)—and textural analyses. Results showed that total psychrotrophic count decreased significantly (p < 0.05) using Ch+T coating during the entire period of storage. The treatment Ch+T resulted in lower pH, TBA, and TVB-N values in comparison with the other samples. Based mainly on our data, Ch+T treatment extended the product's shelf life by approximately 6 days in comparison with the uncoated control samples. Keywords: chitosanshelf life Thymus vulgaris rainbow trout (Oncorhynchus mykiss)