• Food Science and Biotechnology
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• v.18 no.5
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• pp.1096-1099
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• 2009

This study investigated change in the chemical components and antioxidant activity of ramie (Boehmeria nivea) leaves (RL) for the development of functional foods. Proximate compositions of protein, crude ash, and crude fat were 24.49, 11.41, and 4.89%, respectively. Contents of minerals of calcium (Ca), potassium (K), magnesium (Mg), and iron (Fe) were 1,874, 1,433, 362, and 16 mg/100 g, respectively. ${\alpha},\;{\beta}$, and ${\gamma}$-Tocopherol contents were 9.79, 0.18, and 1.44 mg/100 g, respectively. Linoleic and linolenic acid contents were higher than those of palmatic and stearic acid. Total phenolic and flavonoids contents showed the high level of 149 and 49 mg/g. The $IC_{50}$ values of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radical scavenging of RL extracts were 688, 424, and $596{\mu}g/mL$, respectively, while the radical scavenging values by butylated hydroxylanisole (BHA) were 92, 58, and $98{\mu}g/mL$, respectively. Thus, RL has the potential to be used as a healthy and functional food ingredient.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.356-361
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• 2009

Lipid oxidation and contents of tocopherols and phospholipids (PL) in soy-added fried products during storage in the dark were studied. Flour dough containing soy flour at 0, 10, 20, and 30% on a weight basis was fried in corn oil at $180^{\circ}C$ for 2.5 min. The fried products were stored at $60^{\circ}C$ for 11 days in the dark. Lipid oxidation of the fried products was evaluated by conjugated dienoic acid (CDA) and p-anisidine values (PAV). Tocopherols and PL were determined by high performance liquid chromatography (HPLC). CDA contents and PAV of the fried products were increased during storage, and addition of soy flour improved lipid oxidative stability of the fried products, which was partly related to increased amount of tocopherols and PL in the soy-added fried products. Tocopherols and PL were degraded during the dark storage of the fried products. Soy flour addition to the dough did not affect the rate of tocopherols degradation during storage of the fried products; however, PL degradation was higher in the soy-added fried products. Residual amounts of $\alpha$-tocopherol and phosphatidylinositol showed high correlations with the lipid oxidation of the fried products during storage in the dark.

• YAKHAK HOEJI
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• v.54 no.1
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• pp.32-38
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• 2010

The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

• Toxicological Research
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• v.14 no.4
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• pp.541-545
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• 1998

This experiment carried out to compare the protective effects of some antioxidants to hydroxyl radicals in embryonic mouse whole brain tissue culture. The ICR mouse whole brain (13 embryonic day) was cultured in hydroxyl radical system in which radicals were generated by 20 mU / ml glucose oxidase (GO). In this experiment, to make ferrous iron from ferric iron, iron as an accelerator, and ascorbic acid as a reductant were used. For comparison of the protective effects to hydroxyl radicals, antioxidants such as desferrioxamine (DFX), laccase. water or ethanol extracts from Rhus Vemiciflua Stokes (RVS), and $\alpha$-tocopherol were used, because they relate to metal ion. The results of this experiment showed that all antioxidants protected effectively the cytotoxicity from hydroxyl radicals in the brain cultures. More than 70% of cell viabilities among different antioxidants was at 1 mM DFX, 1.43 $\mu\textrm{m}$ laccase, 12.5 $\mu\textrm{m}$ water extract, 12.5 $\mu\textrm{m}$ ethanol extract and 50 $\mu\textrm{m}$ $\alpha$-tocopherol individually, compared with 20 mU/ml GO alone. In comparison to the antioxidative activities of antioxidants, laccase and extracts from RVS showed strong antioxidative effects even at low concentration.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.213-221
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• 2001

Because the intake of vitamin A had been consistently found to be low among Koreans, there has been a concern that mild vitamin A deficiency might be prevalent in the population. However, the inaccuracy of vitamin A database has long been suspected database for the nutrient. This study was performed to assess the vitamin A and E status in 208 adults over 20 years of age living in a rural area of Korea. Newly modified database for vitamin A and E was used to estimate the dietary intake of the subjects in this study. A cross sectional survey of dietary intake with 24-hour recall method was conducted. Serum retinol and $\alpha$-tocopherol levels of the subjects were analyzed in fasting samples using HPLC. For vitamin A, mean levels of dietary intake and percent of RDA were 620.3$\pm$1087RE/day and 88.6$\pm$155.4%, respectively, which were considerably higher than the levels reported in 1995 Korean national Nutrition survey(470.1RE/day and 67.2%, respectively). For vitamin E, the levels were 9.74$\pm$6.30mg/day and 97.4$\pm$63.0%, respectively. Mean concentration of serum retinol was 83.1$\pm$30.1$\mu\textrm{g}$/dl and none of the subjects was below 10$\mu\textrm{g}$/dl, or deficient level. Mean serum retinol in men, 99.8$\pm$30.4$\mu$g/dl, was significantly higher than in women, 70.7$\pm$23.4$\mu\textrm{g}$/dl (p<0.01). Mean concentration of serum $\alpha$-tocopherol was 1.17$\pm$0.52mg/dl and that of one subject was below 0.5mg/dl, or deficient level. Serum $\alpha$-tocopherol levels of the old subjects were higher than the younger subjects in both sexes(p<0.05). These data suggest that contrary to the previous reports about low intake of vitamin a, intake and serum levels of vitamin A among the subjects are not low. Also, in this study, intake and serum levels of vitamin E are not low, either. (Korean J Nutrition 34(2) : 213~221, 2001)

• The Journal of Korean Medicine
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• v.22 no.2
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• pp.53-63
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• 2001

This study was carried out to investigate the physiological activityof the water extract from EA. The present study was done to investigate the effects of EA on cultured hepatocyte cell system and lipid peroxidation in $A{\beta}$ treatment conditions. Pretreatment of EA attenuated in cell cytotoxicity enhanced by increasing concentrations of $A{\beta}$. MDA level induced by $A{\beta}$ treatment was significantly increased and the level was slightly reduced by pretreatment of EA. The ability of EA to reduce cell death and MDA level induced by $A{\beta}$ suggest that EA may be a protective agent against free radical generating compounds such as $A{\beta}$. EA exhibited anti oxidative activity at all concentration tested.The extract was as good as antioxidative activity of the synthetic antioxidants, butylated hydroxy toluene and ascorbic acid. Furthermore, this was superior to that of natural antioxidant, a-tocopherol. In the presence of heavy metal ions ($Fe^{2+},{\;}Zn^{2+}$), EA showed strong antioxidative activity. The extracts showed about 3075% in the nitrite scavenging effect under pH 1.2 and $37^{\circ}C$ for 1 hr. There was significant difference among concentration of extracts.

• Journal of Nutrition and Health
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• v.20 no.2
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• pp.111-121
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• 1987

Lipie peroxide formation, antiperoxidative s system and body adaptability for handling lipid p peroxide were examined in the first and second g generations of rats fed fish oil. Mackerel oil(MO) was used and four other dietary oils and fat, i.e. soybean oil(SO), perilla oil(PO), rapeseed oil(RO) and beef tallow(BT) were also employed to compare the effect of fish oil. Synthetic diets containing these five dietary fats at the level of 1O%(w/w), were given to the correspond­m ing groups of male and female rats weighing about 70 grams. After 34 days of feeding, male a and female rats were mated and their offsprings were raised throughout suckling (17, 26 days) and weanling (39 days) periods. Liver lipid pero­x xide level was highest in MO group of both first (mother rats after lactation) and second genera­t tions of 17 and 26 days old, but not of 39 days old. During suckling period, liver lipid peroxide level was well matched to total unsaturation of dietary fat. Brain lipid peroxide levels were not different among five groups. Liver $alpha$-tocopherol a and reduced glutathione (GSH) levels were lowest in MO fed first generation. In second generation, $alpha$-tocopherol level was also low in MO group, although the effect was less pronoun­c ced, but GSH level was not different from other groups. Oxidized glutathione (GSSG) level did not consistently vary by change in dietary fat. Glutathione peroxidase activity increased as young rats grew up to 39 days. Superoxide d dismutase activity change was insignificant by a age, but was shown as lowest in MO group. At the age of 26 and 39 days, liver glutatione peroxidase activity was increased as was level of lipid peroxide, suggesting that this is the one of the mechanisms responsible for body adapta­b bility for protection against the accumulation of lipid peroxide.

• Nutrition Research and Practice
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• v.12 no.2
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• pp.160-165
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• 2018

BACKGROUND/OBJECTIVES: Korea is quickly becoming an aged society. Dementia is also becoming a vital public health problem in Korea. Cognitive impairment as a pre-stage of dementia shares most risk factors for dementia. The aim of the present study was to determine associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans. SUBJECTS/METHODS: In this cross-sectional study, a total of 230 participants aged 60-79 years from Yangpyeong cohort were included. Cognitive function was assessed by the Korean version of the Mini-Mental State Examination for Dementia Screening. The logistic multivariable regression model was applied to determine the effect of serum vitamins A, C, and E on the risk of cognitive impairment. RESULTS: There was no significant association between the risk of cognitive impairment and serum levels of vitamin A and vitamin C. There was a significant odd ratio when the second tertile group of beta-gamma tocopherol level was compared to the first tertile group [odds ratio (OR) = 0.37, 95% confidence interval (CI) = 0.14-0.98, P for trend = 0.051]. In subgroup analyses, there were significant negative associations between beta-gamma tocopherol level and the risk of cognitive impairment in men (OR = 0.17, 95% CI = 0.03-0.87, P for trend = 0.028), non-drinkers or former drinkers (OR = 0.13, 95% CI = 0.02-0.66, P for trend = 0.025), and non-smokers or former smokers (OR = 0.27, 95% CI = 0.09-0.82, P for trend = 0.017). CONCLUSION: Serum beta-gamma tocopherol levels tended to be inversely associated with the risk of cognitive impairment. Further prospective large-scaled studies are needed to examine this association.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.174-186
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• 2007

Amphora coffeaeformis and Achnanthes longipes are commonly found as dominant benthic microalgae in Jeju coastal water throughout the year. In order to investigate pharmaceutical uses of these diatoms, each single species was isolated with micropipette under phase contrast microscope and subcultured with synthetic seawater media which was enriched with F/2 media, trace metal solution and $Na_2SiO_3$). Growth characteristics of these species were also determined with different combination of salinity, nutrients concentration and temperature. Thereafter, mass culture of each species was done based on the maximum growth condition. Biomass was collected after two weeks of mass culture and freeze dried for antioxidant study. The antioxidant properties of different fractions (n-hexane, chloroform and ethylacetate) obtained by solvent fractionation of 80% methanolic extract of two microalgae were investigated for free radical, reactive oxygen species scavenging (Super oxide, Hydrogen peroxide, Hydroxyl radical and Nitric oxide), metal chelating and lipid peroxidation inhibition activities. All fractions of A. longipes showed higher $DPPH^{\cdot}$ (free radical) scavenging activities (n-hexane: 89.0%, Chloroform: 76.0%, Ethylacetate: 66.0%, Methanol: 90.6% and aqueous residue: 63.0%). N-hexane fraction of A. longipes showed significantly higher activity (49.0%) on nitric-oxide. Ethylacetate fraction of A. longipes and aqueous residue of A. coffeaeformis exhibited 64.0% and 75.6% metal chelating activity which was higher than commercial antioxidants (${\alpha}$-tocopherol: 18.0% and BHT: 16.0%). The n-hexane fraction of A. coffeaeformis had 67.5% activity on $DPPH^{\cdot}$. Chloroform and n-hexane fractions of A. coffeaeformis exhibited 46.2% and 47.6% $H_2O_2$ scavenging effects which were closely similar to commercial antioxidants (${\alpha}$-tocopherol: 49.2% and BHT: 58.6%). Chloroform and ethylacetate fractions of A. longipes and fraction of n-hexane and chloroform of A. coffeaeformis showed better lipid peroxidation activities than ${\alpha}$-tocopherol. These data suggest that both organic and aqueous fractions have good antioxidative compounds with different antioxidant properties.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.4
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• pp.520-531
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• 2007

In this study, we found that the moisture content of black sesame seeds increased in proportion to steaming time, and it decreased in reverse proportion to the roasting temperature and time. The crude fat and crude ash contents were shown to be in the order of steamed black sesame>raw black sesame and roasted black sesame>raw black sesame, Crude protein decreased in reverse proportion to the steaming time, and more crude protein was found in the raw black sesame samples than in the roasted black sesame samples. The contents of sesamin, sesamolin, and total lignans were shown to be in the order of roasted black sesame>raw black sesame>steamed black sesame. In the steamed black sesame samples, sesamin showed its highest level with 20 minutes of treatment, and sesamolin showed its highest level with 15 minutes of treatment. In the roasted black sesame samples, sesamin, sesamolin, and total lignans showed their highest levels with 15 minutes of treatment at $100^{\circ}C$. The phenolic compound content increased in proportion to steaming time in the steamed samples, and reached a peak after 15 minutes of treatment at $100^{\circ}C$, and then decreased after 20 minutes. SOD-like activity reached a peak after 15 minutes of treatment, and in the roasted sample it reached a peak after 15 minutes of treatment, and then decreased after 20 minutes. SOD-like activity was comparatively lower than tocopherol and higher than sesamol. The intensity of electron donating ability, following 30 minute treatments, was shown to be highest in the steamed black sesame samples after 25 minutes of treatment, and next highest in the roasted black sesame samples after 15 minutes at $100^{\circ}C$. The electron donating ability was comparatively lower than tocopherol and sesamol. With regard to lecithin's antioxidant effects, the steamed samples showed a higher oxidation restriction rate in proportion to time, and the roasted samples showed the highest rate after 15 minutes of treatment, and then decreased after 20 minutes of treatment. for hydroxyl radical scavenging, similar scavenging activity to tocopherol, and comparatively higher scavenging activity than sesamol, was shown in all samples: all samples showed scavenging abilities of 90% or higher. In summary, this study applied three different treatment methods to black sesame to determine the optimum treatment conditions, and also examined the antioxidant effects and functional characteristics. The results showed that roasting can be used for other purposes than producing oil, and also suggested that methods other than roasting can be used in a variety of ways in cooking. Also, the different treatment methods can be applied in cooking in a variety of ways, to enhance functionality and preference.