• Food Science and Biotechnology
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• v.18 no.6
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• pp.1476-1480
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• 2009

Antioxidant activities of mulberry leaf extracted with different concentrations of EtOH were investigated. Total phenolic content and electron donating abilities of extract from 70% EtOH were the highest. Extracts obtained from EtOH-water mixture were shown to be significantly higher superoxide dismutase (SOD)-like activities than other treatment (p<0.05). Angiotensin-converting enzyme (ACE) inhibition was the greatest at 50% EtOH concentration (p<0.05). The extracts from 30-70% EtOH exhibited higher ferric reducing ability of plasma (FRAP) value than rest of the concentration (p<0.05). In case of nitrite scavenging activity, much higher scavenging activities were observed when the extraction was performed with EtOH or EtOH-water mixture (p<0.05). The results indicate that concentration of EtOH as extraction solvents can affect the antioxidant activity of mulberry leaf, which may provide useful information on the optimal solvent conditions for the extraction.

• Preventive Nutrition and Food Science
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• v.19 no.2
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• pp.108-114
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• 2014

Four Korean kernel fruit (apple, pear, persimmon, and mandarin orange) juices were obtained by household processing techniques (i.e., blending, juicing). Whole and flesh fractions of each fruit were extracted by a blender or a juicer and then examined for phytochemical content (i.e., organic acids, polyphenol compounds). The antioxidant capacity of each juice was determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Results revealed that juices that had been prepared by blending whole fruits had stronger antioxidant activities and contained larger amounts of phenolic compounds than juices that had been prepared by juicing the flesh fraction of the fruit. However, the concentration of ascorbic acid in apple, pear, and mandarin orange juices was significantly (P<0.05) higher in juice that had been processed by juicing, rather than blending. The juices with the highest ascorbic acid (233.9 mg/serving), total polyphenols (862.3 mg gallic acid equivalents/serving), and flavonoids (295.1 mg quercetin equivalents/serving) concentrations were blended persimmon juice, blended mandarin orange juice, and juiced apple juice, respectively. These results indicate that juice extraction techniques significantly (P<0.05) influences the phytochemical levels and antioxidant capacity of fruit juices.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1160-1167
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• 2018

The objective of this study was to evaluate the composition, pH, titratable activity, microbial properties, and antioxidant effect of yogurt using ginseng extract powder (GEP), Lactobacillus plantarum NK181, and Streptococcus thermophilus as the starter culture. Different concentration of GEP (0%, 0.5%, 1%, 1.5%, and 2% (w/v)) were used in the yogurt. During yogurt fermentation, pH was decreased; however, titratable acidity and viable cell counts were increased. The addition of GEP to yogurt led to a decrease in moisture content and an increase in the fat, ash, and total solids content. The antioxidant effect using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ${\beta}$-carotene bleaching, and ferric reducing antioxidant power (FRAP) assay gradually increased with added GEP. Overall, yogurt fermented with 1% GEP was acceptable in terms of cell viability and antioxidant effect. These results might provide information regarding development of ginseng dairy products with enhanced antioxidant activities and probiotic properties.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.143-150
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• 2011

Lactic fermented dongchimi naengmyeun broth which has enhanced antioxidative activity was developed. During lactic fermentation of dongchimi naengmyeun broth at $25^{\circ}C$, changes of total lactic acid bacteria, pH, acidity, soluble phenolics, and anthocyanins were investigated. After 72 h of fermentation, the stronger antioxidant activities were observed in dongchimi naengmyeun broth supplemented with purple sweet potato than those of control dongchimi naengmyeun broth which showing 96.80% in DPPH radical scavenging activity, 100.82% in $ABTs^{+{\cdot}}$ scavenging activity, 7.77 in reducing power, and 6.89 in ferric reducing/antioxidant power, respectively. These high antioxidant activities related with higher contents of soluble phenolics and anthocyanins in dongchimi naengmyeun broth supplemented with purple sweet potato. The results suggest that the making of functional dongchimi naengmyeun broth by using high soluble phenolics and anthocyanins supplements such as purple sweet potato powder was possible.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.555-561
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• 2017

This study was conducted to investigate the several physicochemical extraction characteristics and the antioxidant activities of ethanol extract from Rhus javanica bark. The contents of soluble solid and sugar in extract was measured to 73.5 mg/100g dry basis and $17.8^{\circ}Brix$, respectively. The contents of total aromatics, total flavonoids and total phenolic compounds was measured to 0.508 in absorbance, 49.88 mg/100g and 296.6 mg/100g, respectively. The reducing power of extract was about 27.5 % of ascorbic acid with the same soluble solid contents of the extract. But the ferric reducing antioxidant power and the DPPH radical scavenging ability of extract were measured to equivalent to those of ascorbic acid. The metal ion chelating ability of the extract was 81.58 % whereas that of ascorbic acid was 74.73 %. The nitrite scavenging ability of the extract was measured to 51.76 % at pH 2. And the antioxidative effect of the extract on soybean oil was observed with Rancimat test.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.710-714
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• 2007

Ligularia fischeri (LF) has been used to treat jaundice, scarlet-fever, rheumatoidal arthritis, and hepatic diseases. This study was carried out to determine the antioxidant activity of the extract from the leaves of LF by using various established in vitro systems with ${\alpha}$-tocopherol as positive control. The results showed that the ethanol extract of LF (0.05-0.5 mg/mL) displayed a strong free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, ${O_2}^{{\cdot}-}$, and $H_2O_2$ radicals. It was observed that LF extract (1 mg/mL) significantly decreased the levels of malondialdehyde (MDA) to 69 and 89% of control, measured by ferric thiocyanate (FTC) and thiobarbituric acid (TBA) test, respectively. LF extract (0.5-2 mg/mL) was also found to inhibit significantly the amount of malondialdehyde formed from liver homogenate to 69-56% of control. Similarly, in the high $Fe^{2+}/ascorbate$ induction system LF extract (1-2 mg/mL) inhibited carbonyl formation measured by 2,4-dinitrophenylhydrazine reaction to 89-79% of control. Like antioxidant activity, the reducing power of LF extract was excellent at concentration of 0.5-2 mg/mL. These results indicate that LF could be used as a potential source of natural antioxidant.

• Animal cells and systems
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• v.11 no.2
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• pp.161-164
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• 2007

Oxidative stress is prerequisite for the development of atherosclerosis. Apart from the traditional risk factors that contribute to this devastating condition, in the past few decades, much attention has been focused on plasma total homocysteine mainly because of its strong association with coronary artery disease. It has been suggested that homocysteine induces oxidative stress and hence the present work was undertaken to assess the total homocysteine status and plasma total antioxidant capacity in the acute myocardial infarction (AMI) patients among Tamil population. The study subjects included only the Tamil population. Blood samples were collected from 100 AMI patients and 100 controls. Plasma was separated and the total antioxidant status was assessed as a measure of ferric reducing power of antioxidants using spectrophotometric method. Plasma total homocysteine concentrations were assessed by automated chemiluminescence method. While Total antioxidant status was significantly decreased, the plasma homocysteine concentrations were elevated in AMI patients compared to the controls. However, there was no correlation between the homocysteine levels and total antioxidant status. The findings of this study may have therapeutic implications, including food sources rich in antioxidants for all AMI patients to minimize the effect of free radicals formed during oxidative stress among Tamil population.

• KSBB Journal
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• v.31 no.2
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• pp.100-104
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• 2016

Dolsan leaf mustard has various biological functions, including those in the immune system and cancer prevention. It contains high amounts of nutritional and medicinal compounds, which are important for maintaining optimum health. The objective of this study was to determine the total phenolics contents and antioxidant activity in Dolsan leaf mustard pickle (DLMP) during storage. DLMP methanol extracts had the highest total polyphenol and flavonoid contents of $35.56{\pm}0.01GAEmg/g$ and $4.54{\pm}0.03QEmg/g$, respectively. The DPPH and ABTS radical scavenging activities in the DLMP methanol extracts showed the highest activities of 79.4 and 85.36%, respectively. The ferric reducing antioxidant power (FRAP) assay showed 2.24-3.82 mM $FeSO_4$ eq. (p<0.05) in DLMP extracts. Overall, storage at day 14 showed the highest antioxidant activity.

• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.86-94
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• 2018

This study was designed to evaluate the antioxidant activities and protective effects on PC12 cells of the extract of Epimedium koreanum and its main constituents icariin and icariside I. After screening the seven identified flavonoid glycosides from E. koreanum through DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay, E. koreanum, Icariin and Icariside I exhibited significant effect on radical scavenging activity. E. koreanum, icariin and icariside I were examined using DPPH, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (ferric reducing ability power) assay. In all antioxidant assays, E. koreanum, icariin and icariside I showed high radical scavenging activities in a dose-dependent manner. Protective effects against $H_2O_2-induced$ PC12 cells were assessed with MTT assay. The results indicated that cell viability and protection on PC12 cells of icariside I and icariin increased dose dependently. These study results suggest that E. koreanum, icariin and icariside showed high antioxidant capacities and cell protective effects. Icariside I, one of the metabolites of icariin, may be a new and effective flavonoid compound as a functional component.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.388-394
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• 2018

This study was conducted to investigate the antioxidant activity of Kochujang following the addition of Omija (Schizandra chinensis Baillon) by-product extract powder. This study specifically investigated the total levels of phenolics and flavonoids, the activities of DPPH and ABTS radical scavenging, and FRAP (ferric reducing antioxidant power). Our results showed that the total phenolic and flavonoid contents of unmodified Kochujang were 4.06 mg TAE/g and 2.87 mg TAE/g, respectively, and that the total phenolic and flavonoid contents of Kochujang with added Omija by-product extract powder were 3.89~5.19 mg TAE/g and 3.11~5.35 mg TAE/g, respectively. As more Omija by-product extract powder was added, the more the total levels of phenolic compounds and flavonoids increased. This study found that DPPH radical scavenging activity in unmodified Kochujang was 25.8% and that in Kochujang with added Omija by-product extract powder was 27.1~39.7% each. These results indicate that Omija by-product extract powder has possibility not only in Kochujang products but also as a functional food with antioxidant activity characteristics. These results also indicate that adding Omija by-product extract powder to Kochujang had significant effects on overall acceptability. Thus, the addition of 5 or 10% of Omija by-product extract powder is desirable for making Kochujang.