Improvement of the shelf life of grey mullet (Mugil cephalus) fish steaks using edible coatings containing chitosan, nanochitosan, and clove oil during refrigerated storage

Abstract

The effects of edible coatings made of chitosan, or chitosan nanoparticles, and their combinations with clove oil on the physical, chemical, microbiological, and sensory properties of grey mullet (Mugil cephalus) steaks during refrigerated storage (4 °C) for 24 days were evaluated. The data indicated that metrics for all of these characteristics were improved significantly (P ≤ 0.05) in coated fish steak samples compared to the control sample. The coated steaks texture values were higher than those of control sample through storage time with nanochitosan coating containing clove oil having best value 2.51 kg/cm2 among tested samples at the end of storage period. However, pH values of coated samples were lower, a good indicator, than corresponding one of the control (6.46) with nanochitosan coatings with or without clove oil showed low mean values (6.11–6.13). Similar trend regarding chemical indices, i.e. total volatile basic-nitrogen, trimethylamine, peroxide, and thiobarbituric acid reactive substances values for samples coated with nanochitosan with or without clove oil giving better lower values than control or other treatments. Also, the coating delayed microbial (aerobic plate count, psychrotrophic bacteria, yeasts and molds, and total coliform bacteria) growth during the refrigeration storage period, and coated samples produced better results compared to the control sample. Sensory evaluations showed that the treatment enhanced the scores of fish steak samples compared to the control. The results showed that a nanochitosan coating with clove oil was the best treatment prolonged the shelf life of mullet steaks and efficiently maintained the quality attributes to an acceptable level during refrigerated storage for 24 days. Thus, these findings can be bases for producer to provide consumers with fresh fish steaks with good shelf life at refrigerated temperature for up to 24 days.Graphical