Improving the oxidation stability of high-oleic sunflower oil with composite antioxidants
This study aimed to search for the optimum antioxidant mixture for improvement of the stability of high-oleic sunflower oil. Seven antioxidants including vitamin E, phytic acid, antioxidant of bamboo leaves, rosemary extract, tea polyphenols, ascorbyl palmitate (AP) as well as tea polyphenol palmitate (TPP) were used. Peroxide value, free radicals and Rancimat induction time results all proved that TPP was the best single antioxidant. Therefore, TPP was selected to mix with other antioxidants to form composite antioxidants. The combination of TPP and AP revealed the best antioxidant efficiency among the composite antioxidants comprised of two and three constituents in the oil. By optimizing the mixture proportions, the best antioxidant activity could be achieved when combining 480 mg/kg TPP with 40 mg/kg AP. The high-oleic sunflower oil sample (containing 480 mg/kg TPP and 40 mg/kg AP) had 1.96-fold longer shelf life (prediction by Rancimat method) compared with the blank sample.