Effects of chitosan and nano-chitosan as coating materials on the quality properties of large scale tongue sole Cynoglossus arel during super-chilling storage

The present study examined the effects of chitosan (Ch) and chitosan combined with sodium tripolyphosphate (Nch) nanoparticles as coating materials for Cynoglossus arel fillets during superchilling storage. Treatments included the following: C (untreated, control samples), AC (treated with 1% glacial acetic acid, acid control), Ch (treated with 2% w/v chitosan solution, Chitosan) and Nch (treated with 2% w/v chitosan and 2% sodium tripolyphosphate, Nanochitosan). Nch and Ch coatings significantly were effective on total mesophilic counts (TMC), psychrotrophilic bacteria (PTC) and Enterobacteriaceae. Production of total volatile bases nitrogen (TVBN) and trimethylamine (TMA) for Nch and Ch samples was significantly lower than in control samples during storage. The thiobarbituric acid (TBA) and free fatty acids (FFA) exhibited an increasing trend (p<0.05), whereas the total sulfhydryl (SH) decreased (p<0.05) with increasing storage time. The results indicated that Nch and Ch can be used for preservation of quality properties of fish samples. The Nch was better than ones Ch in reducing lipid oxidation of fillets and bacterial contamination.