Summary:
Temperature stress and fluctuations are common problems in frozen storage of fish products. This study investigated how storage temperature variations within an industrial frozen storage facility affected the physicochemical properties of Tra catfish (Pangasius hypophthalmus) fillets. Effects of commercial processing additives (mixture of sodium phosphates, sodium chloride, sodium citrate and citric acid), and vacuum packaging on the physicochemical properties of the fillets during 12 months of industrial storage were also studied and compared to controlled storage conditions (−18.6 ± 0.2 ° C). Temperature in the industrial storage was above −18 ° C, which is the recommended temperature for frozen fish products. This accelerated thawing loss, lipid oxidation and hydrolysis. Additives were effective in inhibiting lipid degradation, and retaining cooking yield, while vacuum packaging protected the fish from lipid oxidation and hydrolysis. Most importantly, temperature must be strictly controlled to ensure the quality of Tra catfish products during frozen storage.