• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.1
• /
• pp.23-28
• /
• 1992

Starch solid model system was employed to investigate the effect of lipoxygenase, ${\beta}-carotene$, ${\alpha}-tocopherol$ and water activity on the oxidation of linoleic acid. The rate of oxidation of linoleic acid by lipoxygenase was increased with the increase in water activity, Addition of ${\beta}-carotene$ and ${\alpha}-tocopherol$ to this system has been shown to inhibit the oxidation of linoleic acid and ${\alpha}-tocopherol$ was more effective antioxidant than ${\beta}-carotene$. However, an increase in the concentration of ${\beta}-carotene$ was found to have a strong antioxidant effect in the solid model system. And also the antioxidative action of ${\beta}-carotene$ was increased with increasing water activity in this system.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.1
• /
• pp.67-73
• /
• 1995

Effects of tocopherols and $\beta$-carotene on the oxidation of the solid model system of a free fatty acid mixture (64.5% of linolic acid ; 26.4% of oleic acid ; 5.0% of palmitic acid) with tocopherols and $\beta$-carotene were studied. $\alpha$-tocopherol revealed an antioxidant activity at the concentration below 0.05%, however, it showed a prooxidant activity when the concentration was higher than 0.05%. The antioxidant activity of ${\gamma}$ -tocopherol was not affected by the concentrations in the range of 0.01~0.10% in the model and ${\gamma}$-tocopherol showed higher antioxidant activity than that of $\alpha$-tocopherol. It seemed that $\alpha$-tocopherol was unstable compared to ${\gamma}$-tocopherol during oxidation. $\beta$-carotene showed a weak antioxidative activity at the initial stage of this system while $\beta$-carotene showed a prooxidant activity in the presence of tocopherol. $\beta$ -carotene was highly susceptible to autoxidative degradation during oxidation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.5
• /
• pp.943-947
• /
• 2000

The purpose of this study was to investigate the extraction method of phenolic compounds from Rubus coreanum and antioxidative activity. antioxidative activities of Rubus coreanum were tested with ability of donating hydrogen to DPPH, and HPLC, fluorometry which measure the amount of MDA after reacting linoleic acid with $H_2O$$_2$, and LDL with $H_2O$$_2$ and FeCl$_2$. The most suitable extraction conditions of the phenolic compounds from Rubus coreanum was 3 times with 60% ethanol, and the yield of extract containing 35% moisture was 15.28%. In extraction efficacy of phenolic compounds, 60% ethanol was superior to water as extraction solvent, and extraction efficacy with 60% ethanol did not differ from disolving by water after evaporation of 60% ethanol extract. 60% ethanol extract of Rubus coreanum had an ability of hydrogen donating to DPPH, MDA determination showed the antioxidative effect with inhibition ratio of 77.91% on linoleic acid oxidation by addition of Rubus coreanum extract with the concentration of 1.500 ppm. and about 65.74% of LDL oxidation was inhibited by addition of 1,000 ppm.

• Preventive Nutrition and Food Science
• /
• v.9 no.2
• /
• pp.167-173
• /
• 2004

The aim of this study was to investigate the antioxidant effect of medicinal plants used by diabetic patients. Fourteen medicinal plants were selected and antioxidant activity such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, inhibition effect of linoleic acid autoxidation and low density lipoprotein (LDL) oxidation, thiobarbituric acid (TBA) value were measured. The Cornus officinalis had DPPH radical scavenging activity of 84.79%, which was higher than the 78.79% for $\alpha$-tocopherol. Rosa rugosa Thunberg, Pueraria thundergiana Bentham, Artemisia princeps var. orientalis and Sasamorpha purpurascens Nakai also had high values. Extracts with higher DPPH radical scavenging activities had higher total phenol concentrations, and positive correlations between these parameters were found. Inhibitory activities of linoleic acid autoxidation, LDL oxidation and TBA value, used as indices of oxidative stress, were observed in most of the selected medicinal plants. The highest inhibitory activity for TBA value was observed in the extract of Pueraria thundergiana Bentham. Rosa rugosa Thunberg (75.50 %), Sasamorpha purpurascens Nakai (74.00 %), and Cornus officinalis (73.00 %) all had high antioxidant activity against linoleic acid autoxidation, similar to that of $\alpha$-tocopherol. The same 3 plants also had high in inhibitory activity against LDL oxidation. Therefore, we demonstrated that medicinal plants used as folk remedy by diabetic patients had antioxidant activity. Especially, Rosa rugosa Thunberg, Cornus officinalis, Pueraria thundergiana Bentham, Arlemisia princeps var. orientalis, and Sasamorpha purpurascens Nakai had high phenol concentrations which resulted in high values for DPPH radical scavenging. These same plants exhibited high values for inhibitory activities for TBA value, linoleic acid autoxidation and LDL oxidation, indices associated with lipid peroxidation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.2
• /
• pp.238-243
• /
• 1994

Changes of lipid components in modified oleoresin during cooking at high temperature were investigated. In preparation of the modified oleoresin, dried red pepper was milled to 100 mesh of size particle and extracted oily compounds by reduced pressure steam distillation . The rest part was reextracted and concentrated and concentrated. The extracts were combined. The same volume of water and 4% of polyglycerol condensed ricinoleate (PGDR) were added to the combined extract, and emulsified to make oleresin red pepper. Non-polar lipid components were quantified 3 times higher in the oleoresin than polar lipid components . The components of non-polar lipd was mainly triglyceride comprising 75.8%. The level of phosphatidyl choline and phosphatidyl ethanolamine were 38.6and 26.1%, respectively. linoleic acid was distinctively abundant (63.1%) and followed by palmitic acid, oleic acid, linolenic acid and stearic acid in the oleoresin. Oxidation of lipid at high temperature was principally affected by temperature rather than oxygen existence . With the result of oxidation , palmitic acid and myristic acid increased, however, oleic acid, linoleic acid, and linolenic acid decreased.

• Korean journal of food and cookery science
• /
• v.11 no.5
• /
• pp.536-541
• /
• 1995

The antioxidative effect of Aloe extracts on 0.1 M-linoleic acid was compared with some commercial antioxidants during storage at 50${\pm}$2$^{\circ}C$ for 20 hours, and on soybean oils at 60${\pm}$2$^{\circ}C$ for 30 days. In the oxidation of linoleic acid, antioxidative effects of various Aloe extracts and other antioxidants were shown as following orders: 3％ Aloe methanol extract > 1％ Aloe methanol extract > 0.02% BHT > 3％ Aloe ethyl acetate extract > 0.5％ Aloe methanol extract > 0.02%-Tocopherol>Aloe methanol extract, 0.1, 0.02％ > Aloe ethylacetate extract, 1, 0.5, 0.1, 0.02％ > control, while in the oxidation of soybean oil, l％ Aloe methanol extract > 0.02％ BHT > 3％ Aloe methanol extract > 0.02%-Tocopherol>control.

• Journal of Animal Science and Technology
• /
• v.48 no.1
• /
• pp.107-114
• /
• 2006

A total of 180 Arbor Acre broilers (35 days of age) were fed a diet containing 0%, 0.6%, 1.2%, 1.8%, 2.4% or 4.8% conjugated linoleic acid (CLA) for 3 weeks then slaughtered at week 1, 2 and 3. Thigh and breast muscles were seamed out, vaccum-packed prior to storage in a chill for days 7 to analyse thiobarbituric acid reactive substances (TBARS). The accumulation of CLA in breast and thigh muscles was increased significantly (P<0.05) as the CLA level was increased, but no significant difference amongst the treatments. The contents of saturated fatty acids were significantly increased(P<0.05) with an increase of dietary CLA level, but those of unsaturated fatty acids were significantly decreased (P<0.05). The content of mono unsaturated fatty acid (MUFA) was decreased as dietary CLA level increased, even though that of poly unsaturated fatty acid (PUFA) had a little difference between dietary CLA level. Dietary CLA reduced the degree of lipid oxidation in raw chicken meat during storage.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.6
• /
• pp.954-958
• /
• 1994

The bleaching effect of chlorophyll a by two lipoxygenase isoenzymes (LOX-1, LOX-2) isolated from potato tuber(variety DEinma ) was studied. In the presence of LOX-1 or LOX0-2 with linoleic acid chlorophyll a bleaching occurred during two isoenzymes-mediated oxidation of linoleic acid. Chlorophyll a bleaching porceeded with decreasing in the formation of conjugated dienes form linoleic acidyb LOX-1 and LOX-2 . In the presence of chlorophyll a, LOX-2 showed a markable decrease inproduction of conjugated dienes from linoleic acid and a higher chlorophyll a bleaching activity. compared with LOX-1. These results suggest chlorophyll-bleaching reaction required intermediates formed during the peroxidation of linoleic acid by lipoxygenase isoenzymes, thus preventing formation of conjugated dienes.

• Korean Journal of Pharmacognosy
• /
• v.35 no.4 s.139
• /
• pp.338-345
• /
• 2004

Scavenging effects of DPPH radical and hydroxyl radical, inhibition of linoleic acid oxidation, inhibition of NO synthesis and iNOS expression were tested with extracts and chromatographic subfractions of Canavalia lineata obtained at Jeju island. Chloroform extract and its subfractions gave moderate effects on scavenging DPPH radical and hydroxyl radical, They also inhibited linoleic acid oxidation, and NO synthesis. Inhibition of NO synthesis resulted from the repression of iNOS gene expression. Ethyl acetate extract and its subfractions showed excellent effects on scavenging DPPH radical and hydroxyl radical, while they were cytotoxic.

• Food Science and Preservation
• /
• v.9 no.1
• /
• pp.67-73
• /
• 2002

In order to obtain the basal data far quality and sanitary stability of sesame oil extracted from imported sesame flours oil of whole sesame and flour sesame were investigated the proximate composition, chemical properties, fatty acid composition, sesamol, sesamolin, sesamin contents and oxidation induction period by AOM test. Moisture contents of sesame flours were less remarkably than whole sesame. There were no differences in proteins. Acid value and saponiflcation value were higher sesame flour oil than whole sesame oil. iodine value of sesame flour oil were lower than whole sesame oils. In fatty acid composition of sesame oil, contents of linolenic acid and linoleic acid were 222.44 ∼144.14 and 2713.00 ∼ 1776.46 mg/mL, respectively. And the contents of linoleic acid and γ-linoleic acid were lower sesame flour oil than whole sesame oil. The sesamol contents of sesame oil were higher whole sesame oil than sesame flour oil, sesamol content of India whole sesame oil was highest of them. The sesaminl sesamolin contents of Korean whole sesame oil were the Highest Oxidation induction periods of sesame oil by AOM were 6.76 and 13.35 In on north Korea and Chinese sesame flour oil, respectively. Therefore, it appears that oxidative stability was lower in north Korea and China sesame flour oil than in whole sesame oil group.