The synergistic antioxidant effects of tocopherol (Toc) and L-ascorbic or erythorbic acid on lard and palm oil were investigated by the oven test and AOM test. Both tests were carried out by the method previously described [Yukagaku, 32, 695 (1983)]. The antioxidant effects of those acids were also studied in the same manner.
1) In the oven test, L-ascorbic acid showed clear antioxidant effects on lard and palm oil. The same was observed for the AOM test. But, considering that the periods to attain POV 100 were almost equal between the system with L-ascorbic acid and that without it, no effects were observed on palm oil.
2) In the oven test, L-ascorbic acid contributed to a synergistic enhancement of antioxidant effects of a mixture of Tocs (m-Toc) and dl-α-Toc on lard, and remarkably controlled the increase in POV, particularly at the initial stage. Notably, when 50ppm of L-ascorbic acid were used in combination with dl-α-Toc (0.0050.01%), the effects were more marked than those due to m-Toc (0.02%) when used alone. However, no synergistic effects with Toc on palm oil were found.
3) In the AOM test, L-ascorbic acid showed synergistic effects with Toc on lard, Slight effects were observed by adding the acid together with m-Toc on the palm oil.
4) The synergistic and antioxidant effects of erythorbic acid on lard and palm oil were essentially the same as those of L-ascorbic acid,
