OXYTETRACYCLINE DEGRADATION IN THERMALLY PROCESSED FARMED SALMON

Oxytetracycline (OTC) thermal degradation time (TDT) studies were performed in both model buffer and salmon muscle samples for the purpose of determining OTC thermal stability. Thermal stability of OTC was pH dependent and different between model buffer (pH 3.0 and pH 6.9) systems. OTC decimal reduction (D) values were higher at pH 3.0 than at pH 6.9 in buffer. Corresponding OTC D values from salmon muscle indicated greater stability than when present in a similar model pH buffer. OTC z values in muscle (30.1-degrees-C) were lower than in the pH 6.9 buffer (42.6-degrees-C). Retention of OTC under normal frying cooking conditions was 30.1 +/- 6.8%, which agreed with results from the TDT studies. It is concluded that OTC is more heat stable in salmon tissue than in simple buffer systems.