Impact of chitosan application technique on refrigerated catfish fillet quality

The aim of this study was to evaluate the effect of chitosan application method on refrigerated catfish fillet quality. Chitosan solution was prepared by dissolving a medium molecular weight chitosan (0.5%) in 1% acetic acid solution. Chitosan solution was applied to the fillets using three techniques: (1) spraying (15 mL of chitosan solution per 100 g catfish fillets), (2) dipping for 10 min at a 1:1 ratio (w/v), and (3) vacuum tumbling for 10 min at a 1:1 ratio (w/v). After application of chitosan, the fresh catfish fillets were kept under refrigerated storage (4 °C) for 16 days. The fillets were analyzed for solution pick up, pH, aerobic plate counts (APC), lipid oxidation, total volatile nitrogen (TVB-N), color, and texture. Based on aerobic plate counts and total volatile basic nitrogen analysis, catfish fillets that were vacuum tumbled with chitosan solution had an eight-day shelf life increase and sprayed or dipped fillets had four day increases compared to untreated fillets. This study suggests that vacuum tumbling with chitosan solution can deter the proliferation of aerobic bacteria in catfish fillets under refrigerated storage.