Effect of high molecular weight chitosan coating on quality and shelf life of refrigerated channel catfish fillets

This study investigated effects of the high molecular-weight (800 kDa) chitosan coating on quality and shelf life of channel catfish (Ictalurus punctatus) fillets stored at 4 degrees C. Distilled water (control), CHAC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and CHAS3% (3% w/v chitosan in 3% w/v aspartic acid) were used as coating solutions. Microbial (total aerobic mesophilic bacteria-TAMB; total aerobic psychrophilic bacteria-TAPB), physicochemical, and consumer perception parameters of chitosan-coated catfish fillets were analyzed at 0, 3, 6, 8, and 10 days. Chitosan coating treatments, especially CHAS3%, effectively inhibited microbial growth, delayed lipid oxidation, reduced cooking loss, and retained water holding capacity, color, and texture. Overall acceptance and purchase intent of CHAS3% fillets drastically decreased from 6.16 to 84% on the 8th day to 4.31 and 44.67% on the 10th day of storage. Shelf life of catfish fillets was extended by CHAS3% from 6 days to 8 (based on consumer acceptance) and/or 10 (based on TAMB and TAPB) days compared to the control. This study demonstrated that CHAS3% coating showed promise as a natural preservative to extend shelf life by delaying chemical and microbial deterioration of refrigerated catfish fillets, and potentially for other fish fillets.