ANTIOXIDATIVE ACTIVITY OF TEA POLYPHENOL EXTRACTS IN SOYBEAN OIL

Abstract

      Tea polyphenol extracts (TPE) (94.08% dry mater (DM) total polyphenols, 71.14% DM total catechins) at three concentrations (100 ppm, 200 ppm, and 400 ppm) were examined in soybean oil in accelerated oxidation conditions at 60^oC. A sample without antioxidants and a sample with 100 ppm butylated hydroxyanisole (BHA) + 100 ppm butylated hydroxytoluene (BHT) were used as the negative and positive controls, respectively. The results showed that TPE was more effective than BHA+BHT for the stability of soybean oil at the same concentration (200 ppm). TPE was capable of the maintenance of the sensorial properties, and reductions of diene and peroxide formations as well as the secondary oxidative compounds (p-anisidine). Concerning the TPE concentration, 200 ppm of TPE was suitable to stabilize the soybean oil quality during storage.