Effects of chitosan film and storage time on chemical and microbial properties of perch fillet (Sander lucioperca) by response surface method

This study aimed at evaluating the use of chitosan as a coat to improve the shelf life of perch fillet. For this purpose, low molecular weight chitosan was prepared and three different levels (0.5, 1, and 2 percentage) were used as a food coat in perch fillet. The samples were stored in refrigerator temperature(4 and 7 ºC) for 21 days. Bacterial analysis indicated that coating had significant effects (P<0.05) on reducing the mesophilic and psychrophilic counts with at least a 7-day extension of shelf life. The chitosan-coated products showed lower TBA and pH values than the uncoated samples for up to 21 days of storage at 4°C. The results indicated that the application of chitosan coating significantly improved (P<0.05) the sensory quality of samples. This study thus clearly indicated that the effects of chitosan coating on samples were to retain their good quality characteristics and extend the shelf life during refrigerated storage, which was supported by the results of microbiological, chemical, and sensorial properties.