• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.643-647
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• 2012

The antioxidant capacity of aloe vera gel (AG), aloe vera exudates (AE), and a low molecular filtrate of aloe vera gel (ALMF) prepared from aloe vera grown on Jeju Island, Korea was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), and oxygen radical absorbance capacity (ORAC) assays, and total phenolic content (TPC), and total flavonoid content (TFC) were determined. The phenolic compounds in aloe samples were analyzed. Antioxidant capacities in oil-in-water emulsions following riboflavin photosensitization were analyzed using lipid hydroperoxide. AE had significantly higher antioxidant capacity than that of the other samples based on the DPPH, ABTS, and ORAC assays (p<0.05). Lipid hydroperoxide values of 5 mg/mL for AG, AE, and ALMF were 521.78, 272.32, and 699.89 mmol/kg oil, respectively, whereas that of samples without aloe vera was 893.07 mmol/kg oil over 48 h. AE had higher TPC and TFC values. Aloesin and aloin were found in AE, whereas those compounds were only found in trace amounts in AG and ALMF.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.445-450
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• 2010

This study was carried out to investigate the antioxidative capacity of Ampelopsis brevipedunculata 95% ethanol extracts. The concentration of A. brevipedunculata extract at which DPPH radical scavenging activity was inhibited by 50% was 0.42 mg/mL as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against ABTS radical reactions. Total antioxidant capacities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 0.65 and 3.71 mM Trolox equivalents, respectively. Oxygen radical absorbance capacities of A. brevipedunculata extract at the concentrations of 5 and $100\;{\mu}g/mL$ were 22.75 and $131.25\;{\mu}M$ gallic acid equivalents, respectively. Superoxide scavenging activities of A. brevipedunculata extract at the concentrations of 0.1 and 1 mg/mL were 27.7 and 56.0%, respectively. Total phenolic contents of A. brevipedunculata extract at the concentrations of 0.5 and 2.0 mg/mL were 0.55 and 2.06 mM gallic acid equivalents, respectively. A. brevipedunculata extract at the concentration of 0.1 mg/mL inhibited 0.2 mM and 0.5 mM tert-butyl hydroperoxide induced cyototoxicity by 36.2 and 23.3%, respectively, in HepG2 cell culture system. Thus strong antioxidant and cytotoxicity-inhibiting effects of A. brevipedunculata extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in total phenolic contents.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.425-430
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• 2009

The objective of this study was to investigate the antioxidative capacity of oregano extracts. Amount of oregano extract at which DPPH radical scavenging activity was inhibited by 50% was $21.8{\mu}g$ as compared to 100% by pyrogallol as a reference. Total antioxidant status was examined by total antioxidant capacity against potent free radical reactions. Total antioxidant capacities of oregano extract at the amounts of 7.5 and $15{\mu}g$ were 15.1 and 31.4 nmol Trolox equivalents, respectively. Oxygen radical absorbance capacities of oregano extract at the amounts of 0.2 and $0.4{\mu}g$ were 1.4 and 2.4 nmol gallic acid equivalents, respectively. Total phenolic contents of oregano extract at the amounts of 30 and $75{\mu}g$ were 40.5 and 83.9 nmol gallic acid equivalents, respectively. The inhibitory effect of oregano extract on lipid peroxidation was examined using rat liver mitochondria induced by $FeSO_4$/ascorbic acid. Oregano extracts at the amounts of 20 and $50{\mu}g$ decreased TBARS level by 20 and 64%, respectively. Thus strong antioxidant effects of oregano extract seem to be due to, at least in part, the prevention against free radicals-induced oxidation, followed by inhibition of lipid peroxidation.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.1-9
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• 2017

Purpose: Fruit and vegetable juices are known to be rich sources of antioxidants, which have beneficial effects on diseases caused by oxidative stress. The purpose of this study was to directly compare the antioxidant activities of fruit and vegetable juices marketed in Korea. Methods: We analyzed four fruit juices, two vegetable juices, two yellow-green juices, and six mixed vegetable juices. Antioxidant activities were analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) test, and oxygen radical absorbance capacity (ORAC) assay. Protective effects against DNA damage were determined using an ex vivo comet assay with human lymphocytes. Results: DPPH radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > kale juice > mixed vegetable P juice > grape juice. ABTS radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > grape juice > mixed vegetable P juice > kale juice. Peroxyl radical scavenging activities as assessed by ORAC assay were in the following order: blueberry juice > kale juice > mixed vegetable C juice > grape juice. Grape or blueberry juice showed strong abilities to prevent DNA damage in lymphocytes, and the difference between them was not significant according to the GSTM1/GSTT1 genotype. Conclusion: Antioxidant activities of fruit and vegetable juices and ex vivo DNA protective activity increased in the order of blueberry juice, grape juice, and kale juice, although the rankings were slightly different. Therefore, these juices rich in polyphenols and flavonoids deserve more attention for their high antioxidant capacity.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.8-14
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• 2015

Many studies on broccoli have analyzed the functional components and their functionality in terms of antioxidant and anticancer activities; however, these studies have focused on the florets of different varieties. Investigation of the functionality of broccoli by-products such as leaves, stems, and leaf stems from different cultivars and harvest dates might be valuable for utilizing waste materials as useful food components. Total phenolics and sulforaphane contents, and antioxidant and anticancer activities were measured in the leaves, leaf stems, and stems of early-maturing (Kyoyoshi), middle-maturing (Myeongil 96), and late-maturing broccoli (SK3-085) at different harvest dates. Total phenolics in the leaves of Kyoyoshi were about 1.8-fold to 12.1-fold higher than those in all of the other cultivars and parts. The sulforaphane content of Kyoyoshi was 2.8-fold higher in the stems than in the florets. Antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorbance capacity were highest in Kyoyoshi, followed by Myeongil 96 and SK3-085, most notably in the leaves harvested at the immature stage. Inhibition activity of cell growth against the NCI-H1299 cell lines was highest in the leaves of all cultivars in decreasing order of florets, leaf stems, and stems. The leaves harvested in October (nonflowering stage) had the highest inhibition activity, while those harvested in January (mature broccoli) showed the lowest. The results of this study demonstrate that broccoli leaves and stems contain high levels of total phenolics, and high antioxidant and anticancer activities and can provide opportunities for early-maturing broccoli as functional fresh raw vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1206-1211
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• 2015

Grape juice is consumed worldwide and studied due to the high antioxidant activities and contents. The color of grape juice is due to the presence of phenolic compounds such as anthocyanins. Therefore, color values can be an indicator of antioxidant capacities of grape juice. However, the correlation between color values and antioxidant activities in grape juice has not been well studied. In this study, the physicochemical characteristics and correlation between color values and antioxidant capacities of Korean red grape juices (five commercial juices from market and two juices prepared in the laboratory) were investigated to estimate antioxidant capacities. Antioxidant capacities were determined by 1,1-diphenlyl-2-picrylhydrazyl radical scavenging assay, ferric ion reducing antioxidant power assay, and oxygen radical absorbance capacity assay. Total phenolic contents, total flavonoid contents, and total anthocyanin contents, including five kinds of polyphenolic compounds, were examined by high performance liquid chromatography (HPLC). The results for physicochemical properties showed similar values, except titratable acidity. The color hue values of the prepared juices were higher than those of commercial juices, which was in contrast to the lower color intensity values (P<0.05). The Hunter L, a, and b values showed almost no difference between commercial and prepared juices. The antioxidant activities and total phenolic contents of commercial juices were higher than those of prepared ones. Gallic acid, catechin, and quercetin were confirmed by HPLC in all samples. The total phenolic and total flavonoid contents showed positive correlation with antioxidant activities. In addition, antioxidant activities and contents correlated with color values. Thus, estimation of antioxidant capacity could be feasible through the spectrophotometric measurement of color values.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.178-186
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• 2014

Many recent studies have focused on maintaining a healthy life by preventing and/or postponing the aging process. Numerous studies have reported that continuous exposure to reactive oxygen species can stimulate skin aging and that excessive accumulation of fat can cause an impaired skin barrier and tissue structure alterations. Thus, the maintenance of antioxidant homeostasis and the suppression of adipose accumulation are important strategies for skin anti-aging. Here, we prepared three types of extracts [whole juice, acetone-perchloric acid (PCA), and ethanol] from 20 fruits and medicinal herbs native to the Gyeongnam area of Korea. The total phenolic content of each extract was analyzed, and we observed higher total phenolic contents in the medicinal herbs. Consistent with this, the results of the oxygen radical absorbance activity capacity assay indicated that the in vitro antioxidant activities of the medicinal herb extracts were stronger than those of the fruit extracts. The fruits and medicinal herbs had strong effects on cell-based systems, including $H_2O_2$-induced oxidative stress in human keratinocytes and 3T3-L1 lipid accumulation. Nishimura Wase persimmon, Taishu persimmon, wrinkled giant hyssop, sweet wormwood, Chinese cedar, red perilla, tan shen, hiyodori-jogo, and cramp bark may be natural anti-aging materials with effective antioxidant and anti-adipogenic activities. Taken together, our findings may provide scientific evidence supporting the development of functional foods and nutraceuticals from fruits and medicinal herbs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1709-1715
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• 2014

The objective of this study was to examine the antioxidant activities of extracts from Mori ramulus using different extraction methods (HE, hot water extraction; EE, 50% ethanol extraction; UE, ultrasonic extraction; PE, pressured extraction). The extraction yield of PE (3.07%) was higher than that of UE (1.43%), EE (1.18%), and HE (1.07%). The total phenolic and flavonoid contents of EE were 334.66 mg/g, and 35.64 mg/g, respectively. The oxygen radical absorbance capacity (ORAC) of EE ($3,483.37{\mu}M/g$ FW) was higher than those of HE ($2,687.52{\mu}M/g$ FW), UE ($2,300.45{\mu}M/g$ FW), and PE ($2,117.62{\mu}M/g$ FW). The DPPH and ABTS radical scavenging activities of EE at $1,000{\mu}g/mL$ were 65.84%, and 97.52%, respectively. The superoxide radical scavenging activity of EE was 67.77~98.74% ($100{\sim}500{\mu}g/mL$) higher than those of other extracts. The ferric reducing antioxidant power and reducing power of EE were $189.00{\sim}974.80{\mu}M$, and 0.12~0.82, respectively. The tyrosinase inhibitory activity of EE (23.25~67.20%) improved with an increase treatment concentration. The antioxidant and tyrosinase inhibitory activities of EE were significantly higher than those of other extracts. In conclusion, we provided experimental evidence that extracts from Mori ramulus have potential as functional materials.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.293-298
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• 2013

We aimed to provide the basic data for the development of a beverage using the juices from bioresources from Jeju. Our results show that pH and $^{\circ}Bx$ of the bioresources ranged 2.0-6.5 and 3.3-16.8, respectively. Rubus coreanus Miquel juice had the highest total phenol content (47.3 mg gallic acid equivalent (GAE)/100 mL). Citrus sphaerocarpa juice showed higher rates of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging (86.8%) than those of other juices. However, the oxygen radical absorbance capacity (ORAC) value ($2,409.5{\mu}M$ TE/mL) of Citrus sudachi Hort. ex Shirai juice was higher than those of other juices. A high correlation (R=0.7343) was observed between the pH and ORAC values for the 20 bioresources. Furthermore, a high correlation (R=0.8752) was found between the phenolic contents and DPPH radical scavenging for the 5 citrus fruits. These results suggest that the bioresources in Jeju could be used as natural antioxidants for the development of functional foods, including healthy beverages.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.60-66
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• 2014

The aim of this study was to evaluate the antioxidant activity and protective effect of extracts from the stems and leaves of Chrysanthemum boreale (CBSL) on t-BHP induced oxidative stress in human liver cells (Chang cells). Antioxidant activities in the extracts were determined for various radical scavenging activities including ferric reducing antioxidant power, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, and oxygen radical absorbance capacity (ORAC). CBSL showed a very good scavenging effect of DPPH radical ($IC_{50}$ $0.009{\pm}0.002$ mg/mL), alkyl radical ($IC_{50}$ $0.004{\pm}0.001$ mg/mL), and hydroxyl radical ($IC_{50}$ $6.742{\pm}0.152$ mg/mL). CBSL also showed a strong antioxidant effect in the ORAC assay. In the MTT assay on human liver cells (Chang cells), the extracts showed protective effects by increasing cell viability, decreasing ROS, and restoring mitochondria membrane potential upon t-BHP induced oxidative stress. Our findings suggest that CBSL extracts are a potential therapeutic with protective antioxidant effects upon oxidative stress.