• Korean Journal of Food Science and Technology
• /
• v.25 no.4
• /
• pp.379-385
• /
• 1993

Antioxidative effectiveness and oxidized products in mixture of methyl linoleate(ML) and phenolic compounds were investigated under oxygen blowing at $37^{\circ}C$ for 9 days. Caffeic acid (3,4-dihydroxy cinnamate ; CML) and phloroglucinol(1,3,5-trihydroxy benzene ; PML) showed higher antioxidative effectiveness for methyl linoleate than 0.05% ${\alpha}-tocopherol$ (TML). Oxidized products in ML group were methyl 8-(2-furyl)-octanoate, 9,13-trans, cis hydroperoxide isomer, 9,13-trans, trans hydroperoxide isomer, and 9-TMSO-12,13-epoxy-10-octadecenoate. In CML group the oxidized products were methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer and 9-trans, trans hydroperoxide isomer, but 13-hydroxy isomer was not identified. It was shown that CML were oxidized more slowly than ML group and at 6th day of oxidation, caffeic quinone was found to be major oxidized product of caffeic acid. Oxidixed Products in PML group were methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer, and 9-trans, trans hydroperoxide isomer but phloroglucinol was not oxidized even at the 9th day of reaction.

• Korean Journal of Food Science and Technology
• /
• v.23 no.2
• /
• pp.224-228
• /
• 1991

The effect of linoleate hydroperoxides(LAHPO) on pepsin activity was investigated. The activity of pepsin was largely decreased by LAHPO at various temperatures and pH. The inactivation of pepsin seems to be the radicals in the system because ascorbate and metal ions enhanced the inactivation of enzyme by LAHPO. It was shown by SDS-PAGE that LAHPO caused scission of the enzyme in the model system.

• Journal of the Korean Applied Science and Technology
• /
• v.9 no.2
• /
• pp.175-179
• /
• 1992

In order to investigate the effect of tannic acid and ${\alpha}$-tocopherol on methyl linoleate autoxidation and on inhibition activity of lipoxygenase in phospholipid, the rate of formation of methyl linoleate hydroperoxide was measured by HPLC. The reaction mixture contained methyl linoleate 70mM, radical initiator AMVN 0.7mM, tannic acid and ${\alpha}$-tocopherol 0.7mM, each, in a mixture of hexane/isopropanol(1 : 1, v/v). Under this reaction condition, tannic acid was good enough antioxidant. The tannic acid and ${\alpha}$-tocopherol for the inhibition activivity of lipoxygenase were measured at the reaction conditions: phospholipid $1{\mu}M$. tannic acid and ${\alpha}$-tocopherol were reacted as an inhibitor of lipoxygenase in phospholipid, especialy in phosphatidy lcholine.

• Korean Journal of Food Science and Technology
• /
• v.25 no.6
• /
• pp.614-619
• /
• 1993

Oxidation mechanisms of methyl linoleate with ${\alpha}-Tocopherol$(TML) were investigated by determining oxidized products using GC-MS during oxidation at $37^{\circ}C$ for 9 days. Oxidized products of TML were found to be methyl octanoate, methyl-8-(2-furyl)-octanoate, 9,13-trans, cis isomer and 9,13-trans, trans isomer. In previous report, oxidation products of methyl linoleate(ML) were methyl-8-(2-furyl)octanoate, 9,13-trans, cis hydroperoxide isomer, 9,13-trans, trans hydroperoxide isomer, and 9-TMSO-12,13-epoxy-10-octadecenoate. In the case of ML, 9-TMSO-12,13-epoxy-l0-octadecenoate was produced instead of methyl octanoate in TML. ${\alpha}-Tocopherol$ quinone, as a major oxidized product of ${\alpha}-Tocopherol$ was formed at the 6th day of oxidation. ${\alpha}-Tocopherol$ quinone was produced rather quickly in lipid media than aqueous media. In oxidation of methyl linoleate, it was shown that the first oxidized product was methyl-9,13-hydroxy-octadecadienoate. As second products, methyl-8-(2-furyl)-octanoate, 9-TMSO-12,13-epoxy-10-octadenoate, and methyl octanoate were oxidized from methyl-9-hydroxy-10-trans, 12-trans-octadecadienoate.

• Journal of Nutrition and Health
• /
• v.19 no.3
• /
• pp.169-176
• /
• 1986

The effect of riboflavin feeding on lipid emtabolism in rat were studied. 70 male Sprague-Dawley rats were divided into 7 diet group ; control, riboflavin, cholesterol, MLHP (methyl linoleate hydroperoxide) cholesterol plus MLHP, cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin. After 4 weeks formular feeding sera of animals were collected, then checked cholesterol, triglyceride, phospholipid levels and lipoprotein by use of cellulose acetate papter. The results were as follows ; 1) Marked increase of triglyceride and phospholipid levels were found in the group feeding with cholesterol, cholesterol plus MLHP. 2) Combined riboflavin feeding prevented the increase of triglyceride and phospholipid levels in the group of cholesterol, cholesterol plus MLPH. 3) Also combined riboflavin feeding prevented the increase of $\beta$-lipoprotein fraction in cholesterol feeding group. Our results demonstrate that riboflavin has an inhibitory effects on the derangements of lipid metabolism due to administration of cholesterol, cholesterol plus MLHP.

• Journal of Nutrition and Health
• /
• v.19 no.3
• /
• pp.161-168
• /
• 1986

In order to investigate the effect of riboflavin on cholesterol and MLHP (methyl linoleate hydroperoxide) -induced fatty liver electron microscopically, riboflavin was given to rate receiving high cholestero and MLHP diet for 4 weeks, 8 week old male Sprague-Dawley rats were administrated diets daily, as following group ; usual diet (control ), riboflavin 910 ug/20gm BW), cholesterol (50mg/gm BW), MLHP(0.1ml/20gm BW), cholesterol plus MLHP, cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin, by means of intubation into the stomach for 4 weeks. Each group consisted of 10 rats, The liver of the animals were examined ultrstructurally by transmission electronmicroscope. The results wee as follows ; 1) The three group including cholesterol, MLHP, cholesterol plus MLHP feeding resulted in fatty liver. 2) The main finding of the fatty liver were swelling and vacuolation of mitochondria, a lot of lipid droplets, disarrangements and loss of rough endoplamic reticulums. 3) the most striking features in the group of cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin feeding were decrease of size and number of lipid droplets, mitochondrial swelling and vesiculation, with restortion of rough endoplasmic retriculums. It is postulated with above findings that riboflavin was effective in prevention of cholesterol and MLHP -induced fatty liver.