1993 Volume 40 Issue 6 Pages 393-399
The synergistic antioxidant effects of organic acids and their derivatives with tocopherol (Toc) on cookies was studied. As a synergist, L-ascorbic acid (AA) and its stearyl ester (AS), erythorbic acid (EA), citric acid (CA) and its isopropyl ester (IPC) were used and one of them was added to cookie dough with or without of α-, δ-Toc and a mixed tocopherols concentrate (m-Toc). Baked cookies were stored at 40°C for 12 months, and periodically analyzed on peroxide value (PV) of extracted oil and residual ratios of Toc and synergists. (1) AS showed a clear antioxidant effect on cookies, strongly suppressed the prooxidant effect of α-Toc, and synergistically enhanced the antioxidant effects of δ-and m-Toc. These effects become stronger with an increase in the added amount of AS. The addition of more than 1000 ppm of AS along with 100ppm of δ-Toc was the most effective, and resulted in the complete inhibition of elevation of PV during the storage for 8 months. On the other hand, AA, EA, CA and IPC hardly showed such antioxidant effect and synergistic effect with Tocs. (2) The residual ratio of Tocs in cookies were improved by the addition of AS. The improvement was remarkable in that of α-Toc. However, no improvement was observed in the addition of AA, EA, CA or IPC. (3) AS in cookies entirely disappeared within the storage for 5 months, but its synergistic antioxidant effect with Toc on cookies was still kept even after its disappearance. In the cookies which had δ-or m-Toc, residual ratio of EA or AA was higher than that of AS, but their effects on the oxidative stability of cookies were small.
