| Summary: | 碩士 === 國立中興大學 === 獸醫學系暨研究所 === 98 === Heat stability of veterinary drug is an important issue to food safety due to its potential harmful consequences to consumers. Ractopamine (RAC) is a beta-adrenergic agonists which residue in food can cause tachycardia, hypotension, skeletal muscle trembling and disturbance in human. Since most food are cooked before eating, it is important to understand the effect of cooking on RAC to give more accurate estimatation of consumer exposure to RAC. The purposes of this study were to evaluate the heat stability of RAC in different heating processes (water bath, microwaving and autoclave), different heating length (100 ℃ in water bath for 15, 30, 60 and 120 min) and different matrices (including water, soy sauce, beef, pork, swine liver, swine kidney, swine lung and beef/ pork in soy sauce). High performance liquid chromatrography with UV detection was used for drug analysis. Results showed that the degradation of RAC in water was highest after autoclaving (13.1%) and lowest after microwaving. In general, RAC concentration reduced as heating time increased, and showed linear relationship (R2 >0.9). Differential degradation in different matrices was evident. In liquid matrices, RAC decreased minimally in water, but decreased up to 35.5 % when heating in soy sauce. In meat matrices (beef and pork), degradation were higher in pork (40.9 %) than in beef (24.4 %), but after heating with soy sauce, the degradation were similar in pork and beef both at 28.7 %. Degradation of RAC in swine tissues (muscle, liver, kidney and lung) ranged from 34.1 to 46.4 % and was highest in lung with significant difference (p＜0.05) to liver and kidney, suggesting that degradation of RAC were different in different matrices. In conclusion, RAC is considered heat stable in water, but degradation varies in different matrices. Overall, heating can not be relied on to completely degraded RAC.
|
|---|
