抄録
The synergistic antioxidant effects of d-tocopherol (Toc) and L-ascorbyl stearate (AS) on several solid fats having different physical properties were investigated by storage tests at 30°C or 40°C. The effects were compared to those in the liquid state by AOM tests. The fats were fully hardened beef tallow mixed lard olein or stripped safflower oil, and fully hardened palm kernel oil mixed stripped safflower oil at different ratios.
1) In the storage test at 40°C, AS synergistically enhanced the antioxidant effect of a mixed tocopherols concentrate (m-Toc) on fully hardened beef tallow mixed lard olein in the solid state, as well as that in the liquid state by the AOM test. However, the synergistic effect in the solid state was more pronounced than that in the liquid state. These effects were also observed on the hardened tallow mixed stripped safflower oil.
2) Fully hardened palm kernel oil mixed stripped safflower oil had less SFC and was softer but much more stable against oxidation than fully hardened beef tallow mixed with liquid oil in the same ratio. Thus, the synergistic effect of AS with m-Toc could not be clearly detected in the solid state by the storage test at 30°C. However, the results of the AOM test indicated AS to possibly enhance antioxidant effect of m-Toc on mixed fats in the solid state as well as that in the liquid state.
3) The remnant ratios of Toc and AS following storage at 30°C or 40°C for 100 days indicated Tocs to decompose with the production of hydroperoxides in substrates, and AS to rapidly decompose in all cases.
