The effects of chitosan coatings enriched with thyme oil on the quality of rainbow trout

Abstract

The purpose of the present study is to investigate the effects of chitosan coatings, enriched with thyme oil, on the quality of rainbow trout (Oncorhynchus mykiss) during storage at 4 °C. Samples were analyzed at 0, 3, 6, 9, 12, 15 and 18 days for microbiological (i.e. total aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, Pseudomonas), chemical (i.e. pH, thiobarbituric acid reactive substances—TBARS, total volatile base nitrogen—TVB-N, peroxide value—PV) and sensory quality (texture, color, odor, general acceptability). Significant differences were determined among the groups in terms of total number of aerobic mesophilic bacteria, psychrotrophic bacteria and lactic acid bacteria (p < 0.05) during the storage. TVB-N, TBARS and peroxide values in the treated groups were lower than those in the untreated group. The best sensory quality was attained at the highest thyme oil concentration (2%) compared with control samples.