the stabilizing effect of natural and synthetic antioxidant on mutton tallow- evaluation of dsc and its comparison with rancimat

the antioxidant activities of tbhq, bht and tocopherol mixtures at different concentrations (0, 100, 200, 400 mg/kg) have been evaluated by the application of differential scanning calorimetry (dsc) and rancimat apparatus. rancimat apparatus that measures the secondary oxidation products was set at 110 ⁰c with an air flow of 18-20 l/h to measure the induction period (ip) of the samples. the dsc method was concerned with the oxidation of the samples in an oxygen flow dsc cell, while the cell temperature was set at isothermal temperature of 150⁰c. oxidative induction time (t0), and the maximum of the peak (tmax) were improved with increasing antioxidant concentrations. according to the results, tocopherols mixture was the most efficient antioxidant, followed by tbhq and bht. furthermore, it was indicated that there is a good agreement (p<0.0001) between both methods and values obtained. in conclusion, the dsc method is a fast, convenient and reliable method to predict the antioxidant activities.