Synergistic Effect of Tocopherol, Citric Acid and Sodium Polyphosphate on the Oxidative Stability of Heated Frying Oil

가열유지(加熱油脂)의 산화안정성(酸化安定性)에 대(對)한 Tocopheol, 구연산 및 인산염(燐酸鹽)의 상승효과(相乘效果)

The oxidative stability of palm oil with moisture addition during heationg was investigated and the antioxidant effects of tocopherol, citric acid and sodium polyphosphate were evaluated. The addition of natural tocopherol up to 200 ppm level did not improve the oxidative stability of palm oil with moisture (1m1 $H_2O$ additive to 200g of oil at $180^{\circ}C$). The maximum antioxidant effect was observed at the Concentration of 400 ppm. Addition of citirc acid did not influence the effective concentration of tocopherol. Whereas addition of sodium polyphosphate and citric acid increased the antioxidant effect of tocopherol. The maximum synergistice effect was observed at the concentrations of 50 ppm citric acid and 50 ppm of sodium polyphosphate. Addition of 50 ppm citric acid and 50 ppm sodium polyphosphate to 100 ppm of tocopherol exceeded the antioxidant effect of 400 ppm tocopherol alone.