Effects of drying temperature on the qualities of tilapia

The influences of different drying temperatures (i.e.drying at 30, 40, 55, 70℃) on the lipolysis oxidation, proximate composition, proteolysis and sensory characteristics of tilapia fillets were investigated.There was great significant influence of the drying temperatures on the Non-protein nitrogen, Amino nitrogen, TVB-N, Acid value, Peroxide value and TBA of tilapia fillets (p<0.05) .The order of NPN and the protein hydro-lysis index was as follows:30℃>40℃>70℃>55℃, and low temperature was conductive to the hydrolysis of the protein to form the amino nitrogenous compound.The results showed higher lipolysis oxidation was found at low temperatures (i.e.30 and 40℃) rather than at high temperatures (i.e.55 and 70℃) .The maxi-mum content of acid value and peroxide value of products were achieved at 30℃ without excessing the national standards.It was noteworthy that the products drying at 30℃ had a better quality in texture, color, taste and chewiness with a good acceptability.Drying at low temperature was contributed to forming full flavor.The moderate lipolysisoxidation and proteolysis would promote the formation of the flavor, which were affected by drying temperature.