| Summary: | 碩士 === 國立臺灣大學 === 農業化學研究所 === 76 === In previous study, it was shown that rat''s hepatic lipid peroxidation vas increased in rats fed deteriorated used frying oil diet ( DUFO ). The purpose of this study was to determine the vitamin E of rats fed DUFO containing high or low protein diet, and to evaluate the antioxidative activity of vitaain E and pauchong tea in these animals.
Most of the vitamin E in fresh soybean oil was destroyed during the deep frying process ( dough sheets were fried under 205 ±5℃ for 6 hours/day and repeated for 4 consecutive days.
In experiment I, Long-Evans male rats were divided into ten groups. Three of them were fed 27% lactalbumin containing 15% fresh soybean oil diet(HF) which provided 11.6(HFO), 16(HFA) or 45mg d-α-tocopherol equivalents / Kg ( d-α-T.E./Kg )( HF45 ). Five groups of rats were fed 2796 lactalbumin containing 15% DUFO diet ( HU ) which provided 0(HUO), 16(HUA), 30(HU30), 45(HU45) or 134 mg d-α-T.E./Ka (HUE). Remaining two groups of rats were fed 8% lactalbumin containing 15% DUFO diet ( LU ) which provided 45 (LU45) or 134mg d-α-T.E./Kg (LUE).
In vitro RBC hemolysis, plasma and liver vitamin E content, thiobarbituric acid reactive substances (TBA-RS) of various tissue, superoxide dismutase and glutathione peroxidase activity of liver, and hepatic nicrosomal cytochrome P-450 were analyzed. The dietary vitamin E requirement of rats fed HF diet is 16mg d-α-T.E./Kg(HFA) judged by RBC hemolysis and plasma vitamin E level; however the vitamin E requirement is raised to 45mg d-α-T.E./Kg in rats fed HU diet. On the other hand, the RBC hemolysis of rats fed LU diet could not be prevented by high dietary vitamin E level.
Thp increase in tissue TBA-RS in rats fed frying oil diet could be slightly lowered by the suppleaentation of dietary vitamin E. Nevertheless, the tissue TBA-RS of these rats could never be lowered to the level comparable to the control rats.
In experiaent Ⅱ, to determine the antioxidative effect of pauchong tea on the tissue lipid peroxidation of rats fed DUFO diet, five groups of rats were fed the following diets respectly: HUO, high protein DUFO diet; HUOT, HUO diet supplemented with pauchong instant tea: HFO, high protein fresh oil diet; HFOT, HFO diet supple-mented with pauchong instant tea; HFA, HFO diet supple-mented with 50 IU tocopheryl acetate /Kg. There are no significant differences between the RBC henolysis and tissue TBA reactive substances of HUO and HUOT groups. It appears that the antioxidative activity of vitamin E could not be replaced by pauchong tea.
In experiment Ⅲ, 1 or 5 μg pauchong instant tea were included in the microsomal in vitro lipid peroxidation. The production of malondialdehyde was inhibited for 48% by 5μs pauchong instant tea in aicrosoae system of control group. However, only 14% inhibition was seen in the aicrosome system of rats fed frying oil diet.
It is concluded that the vitamin E requirement of rats fed high protein DUFO diet was raised to three fold of the requirement of control rats. On the other hand, the antioxidative property of tea might act antioxidant as an synergist for vitamin E.
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