Target release rate of antioxidants to extend induction period of lipid oxidation

Evidence from literature has shown that compared with instant addition, slow release of antioxidants has some advantages to inhibit lipid oxidation and extend shelf life of food products. In this paper, the hypothesis that there is a range of release rates of antioxidants which could provide the maximum extension of induction period for lipid oxidation was tested in a model system using a syringe pump to deliver tocopherol into linoleic acid. Conjugated dienes, the first products appearing in lipid oxidation, were measured to determine the length of induction period for onset of lipid oxidation during incubation at 30 and 40 degrees C. Maximum inhibition of oxidation occurred at the release rates of 3.3 x 10(-4) and 7.7 x 10(-4)g/day at 30 and 40 degrees C, respectively, supporting the hypothesis. Based on the results, a term target release rate was defined and its application in controlled release packaging was discussed. (C) 2012 Elsevier Ltd. All rights reserved.