Tomato seed mucilage-whey protein isolate coating enriched with shallot essential oil: Effect on quality changes of the trout fish fillet during cold storage

Abstract

The current study assessed the effect of tomato seed mucilage (TSM) active coating on rainbow trout's physical, chemical, visual, and microbial characteristics during cold storage. This research also investigated the effect of replacing TSM with whey protein isolate (WPI) and adding shallot essential oil (SEO) at varying concentrations (0%, 1%, and 2%). Ultimately, the correlation between the characteristics and their modeling was examined by applying zero order, first order, and Weibull kinetic models. According to the findings, the application of TSM-WPI coating, particularly when combined with SEO, and substituting 50% of TSM with WPI resulted in a significantly reduction (p˂0.05) in the rate of alterations in weight loss (WL), textural attributes (Hardness, Chewiness, Springiness, Cohesiveness, and Gumminess), pH, TBA, TVB-N, visual characteristics (L*, and ΔE), as well as total viable count (TVC) and psychrotrophic bacteria count (PTC). Furthermore, a significant decrease (p˂0.05) in the rate of changes for all qualitative variables was observed when the ratio of WPI to TSM and SEO concentration were increased. Generally, the coating consisting of 50% TSM and 50% WPI containing 2% SEO exhibited the most effective performance in delaying unfavorable quality changes. Pearson's analysis indicated a notable correlation between the physical, color, chemical, and microbial characteristics. The kinetic models successfully and accurately predicted the physical, chemical, and visual changes in trout fillets during storage with various treatments. The Weibull model performed the best.