• Journal of Community Nutrition
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• v.5 no.1
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• pp.13-20
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• 2003

This study was done to evaluate the antioxidant status of female college students by determining their intakes and plasma levels of antioxidnt vitamins (vitamin C, A and E) and total antioxidant status (TAS). Subjects were 46 healthy female college students aged 20 - 29 years. Body composition was determined by a multifrequency bioelectrical impedance analysis. Dietary intakes were examined by 24hr record method and nutrients intakes were analyzed by the Computer Aided Nutritional analysis program for professional (CAN-pro). Plasma vitamin C level were measured by spectrophotometric method and retinol, ${\beta}$-carotene, ${\alpha}$-tocopherol were measured by HPLC. Plasma TAS was measured with a Randox kit using the trolox equivalent antioxidant capacity (TEAC) method. Daily energy and protein intakes of the female college students were 1670.5㎉ (83% of RDA) and 63.3g (115.1% of RDA), respectively. However their intakes of Ca and Fe were below 75% of RDA. Their intakes of vitamin A and C were 596.6 ${\mu}$ gRE (85.2% of RDA) and 71.0mg (101.4% of RDA), respectively. Plasma levels of vitamin C, retinol, ${\beta}$-carotene and ${\alpha}$-tocopherol were 14.7mg/L, 0.7mg/L, 0.2mg/L and 9.1mg/L, respectively which were within normal range. There was no subject with deficiency or marginal level in plasma vitamin A and C. However 1.6% of the subjects had below adequate level in vitamin E. Plasma TAS level was 1.2mmol/L. Correlation data showed that all plasma antioxidant vitamins were positively correlated with plasma TAS. Overall data indicate that the antioxidant status of female college students were pretty good. However it might be necessary to educate them to eat more fruits and vegetables for preventing many chronic diseases in a later life. (J Community Nutrition 5(1) : 13∼20, 2003)

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1079-1084
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• 2004

The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.

• Journal of Ginseng Research
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• v.33 no.1
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• pp.40-47
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• 2009

This study evaluates changes in the chemical composition and bioactivities of American ginseng (Panax quinquefolius L.) processed by boiling in water, $75^{\circ}C$ for 10, 20, 30, and 40 min, and autoclaving at high temperatures, $115^{\circ}C$ for 30 and 60 min and $130^{\circ}C$ for 90 and 120 min. Total ginsenoside contents of boiled ginseng remained relatively unchanged, whereas the contents of autoclaved ginseng samples significantly decreased with an increase of both time and temperature. Compared to unheated ginseng (control), the color of both boiled and autoclaved ginseng decreased in lightness and increased in redness. The acidic polysaccharide contents, the total phenolic contents and the antioxidant capacity of boiled and autoclaved ginseng were higher than the untreated ginseng, with the highest values being exhibited by the autoclaved samples. In particular, the antioxidant capacity of unheated ginseng increased about 2.5 times ($285.7{\pm}14.03\;mg$/100g to $777.2{\pm}26.4\;mg$/100g) when ginseng was autoclaved at $130^{\circ}C$ for 120 min as compared to the control. It was concluded that as American ginseng was processed at a high temperature, especially steam-heated in an autoclave, its chemical constituents changed and, in particular, acidic polysaccharides, total phenolics and antioxidant capacity were considerably increased.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.307-312
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• 2003

Antioxidative activities of Methanol and Ethanol extract of branch, bark, leaves, fruits, wood of Hovenia dulcis THUNBER var. koreana Nakai were analyzed for total poly phenol, flavonoid, antioxidant capacity and DPPH free radical scavanging activitiy. The most total polyphenol and flavonoid contents measerd extract from bark and fruits. Extract from fruits and bark show hight on antioxidant capacity and DPPH free radical scavanging activitiy. There was a good correlation between total polyphenol or flavonoid contents and antioxidant activity.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.278-284
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• 2016

Commercial Korean domestic and foreign intermediate food materials (IFMs) of blueberry, Aronia, oat, sweet pumpkin, and ginger were purchased to compare their functional properties, including total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and antioxidant capacity. Each IFM was extracted using 80% (v/v) methanol for the analyses. The TPC (mg gallic acid equivalent/100 g dried sample) and TFC (mg catechin equivalent/100 g dried sample) levels in domestic blueberry (TPC, 2,916 ± 200; TFC, 1,327 ± 31) and sweet pumpkin (TPC, 476 ± 20; TFC, 23 ± 32) IFMs were significantly higher than those in the foreign IFMs. In the case of TAC (mg cyanidin-3-glucoside/100 g dried sample), the level in domestic blueberry IFM (949 ± 57) was significantly higher than that in the foreign product. Among the domestic IFMs, the antioxidant capacities (mg vitamin C equivalent/100 g dried sample) of blueberry, sweet pumpkin, and ginger were 7,057 ± 321, 311 ± 8, and 3,321 ± 109, respectively, being significantly higher than those of their foreign counterparts, based on the ABTS radical scavenging assay. In the DPPH radical scavenging assay, foreign Aronia (12,667 ± 437) and ginger (2,067 ± 99) IFMs showed significantly higher levels of free radical scavenging activity than did the domestic IFMs. These results provide basic information regarding the functional properties of Korean domestic IFMs, compared with their foreign counterparts.

• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.289-293
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• 2003

Antioxidant activity and nicotine degradation activity (NDA) of 21 medicinal herbs were determined by using a 1,1-diphenol-2-picrylhydrazyl (DPPH) method and a PLC/PRF5 human liver cell line method, respectively, to develop an anti-smoking aid. The highest and lowest antioxidant activities represented by $IC_{50}$/ value were 30 $\mu$g/mL of Eugenia caryophyllus and 3,270 $\mu$g/mL of Panax ginseng C. A. Meyer, respectively. Antioxidant activity of Eugenia caryophyllus was equal to 38.0$\pm$1.2 mg VCEAC(vitamin C equivalent antioxidant capacity)/ g herb. The highest and lowest NDA values were 1.81 of Astrgalus membranaceus Bunge and 1.01 of Raphani seed and Lespedeza tomentosa Sieb, respectively. Eleven medicinal herbs with high antioxidant activity and/or NDA were selected to make an herbal tea. The herbal tea had high antioxidant activity (50 $\mu$g/mL $IC_{50}$/ and 22.4$\pm$1.4 mgVCEAC/g) and NDA (1.243). The medicinal herb tea could help smokers quitting smoking by degrading and exhausting nicotine accumulated in body and removing reactive oxygen species.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.359-367
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• 2020

Neurodegenerative disorders in the elderly are characterized by gradual loss of memory and cognitive function. Oxidative stress caused by reactive oxygen species is associated with progressive neuronal cell damage and death in Alzheimer's disease, one of the most common neurodegenerative disorders. An edible brown seaweed, Ecklonia cava, contains a variety of biologically active compounds such as phlorotannins. In this study, we comparatively evaluated the total phenolic content, antioxidant capacity, and neuroprotective effects of the phlorotannin-rich extract from E. cava (PEEC). The total phenolic content of PEEC and dieckol was 810.8 mg gallic acid equivalents (GAE)/g and 996.6 mg GAE/g, respectively. Antioxidant capacity of PEEC was 1,233.8 mg vitamin C equivalents (VCE)/g and 392.1 mg VCE/g determined using ABTS and DPPH assays, respectively, while those of dieckol were 2,238.4 mg VCE/g and 817.7 mg VCE/g. High-performance liquid chromatography results revealed 48.08 ± 0.67 mg dieckol/g of PEEC. PEEC had neuroprotective effects in pheochromocytoma (PC-12) and human neuroblastoma (SH-SY5Y) cells against H₂O₂- and AAPH-induced oxidative damage, partly due to reduced intracellular oxidative stress. PEEC treatment inhibited acetylcholinesterase and butyrylcholinesterase in a dose-dependent manner. Taken together, these findings suggest that PEEC is a good source of antioxidants and neuroprotective materials.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.261-266
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• 2015

To quantitatively evaluate the total phenolics, total flavonoids, and antioxidant capacity in the leaves, bulbs, and roots of fresh Allium hookeri, they were extracted using various solvents including water, aqueous methanol (20, 40, 60, and 80%; v/v), and absolute methanol. The leaves had the highest levels of total phenolics (240.4-276.6 mg gallic acid equivalents/100 g) and total flavonoids (9.7-34.1 mg catechin equivalents/100 g). The highest antioxidant capacities of 78.7- 103.4 mg vitamin C equivalents (VCE)/100 g, 24.4-59.0 mg VCE/100 g, and 1,798.8-2,169.7 mg VCE/100 g in the leaves were also observed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. The total phenolics had a higher linear correlation with antioxidant capacity than the total flavonoids. In general, 60% (v/v) aqueous methanol extract had higher levels of total phenolics and flavonoids, and higher antioxidant capacity than any other solvents used. This study suggested that A. hookeri might be a good source of phenolics and antioxidants.

• Journal of the Korean Society of Food Culture
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• v.35 no.6
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• pp.597-604
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• 2020

This study examined the bioactive compound content and the antioxidant activities of bitter melon (Momordica charantia Linn.) leaves. The content of vitamin C, beta-carotene, and total carotenoids was 69.77, 45.68, and 65.08 mg/100 g, respectively. To investigate the antioxidant capacity, bitter melon leaves were extracted using various concentrations of ethanol (60, 80, or 100%). Highest content of total polyphenols (18.07 mg gallic acid equivalent/g) and flavonoids (4.53 mg cathechin equivalent/g) was found in the 100% ethanolic extract of the leaves (E100). Also, the E100 extract showed the highest levels of 2,2'azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and α-α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging activities. Reducing power was also the highest (39.21 mg Trolox equivalent/g) in E100 extract. The E100 extract effectively inhibited lipid peroxidation by 91.45% compared to the control group. Also, the E100 extract showed a cytoprotective effect against oxidative stress in HepG2 cells and decreased the generation of intracellular reactive oxygen species. These results suggest that bitter melon leaves could be regarded as a potential source of natural antioxidants.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.132-139
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• 2016

The purpose of this study was to investigate the contents of antioxidant compounds and antioxidant activities in teas. A total of 99 teas were tested for their antioxidant activities based on their ability to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. Antioxidant activity was expressed as mg of ascorbic acid equivalents per 100 g tea sample (L-ascorbic acid equivalent antioxidant capacity, AEAC) and was expressed as mg per 1 serving size (free radical scavenging activity, $FSC_{50}$). The total polyphenol contents of the extracts was quantified using the Folin-Ciocalteu method and the total flavonoid contents of the extracts was determined using a modied method of Davis. Vitamin C was analyzed by HPLC method. According to the AEAC value, mate tea, green tea, black tea, oriental raisin tea, chamomile tea and burdock tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of total polyphenol compounds were observed in black tea, green tea and mate tea. The high concentrations of total flavonoid compounds were observed in mate tea, black tea and yam tea and the amount of vitamin C contents were found to be high in citron tea and green tea. As a result, steeping tea was much higher in antioxidant activity than either powdered tea or liquefied tea. According to the study, a high correlation was demonstrated between the total polyphenol contents and antioxidant activities in teas (r = 0.846) and correlations between the total flavonoid contents and antioxidant activities was statistically significant in teas (r = 0.625). It was found that also the proportional relationship established among the total polyphenol content and antioxidant activities. That is, antioxidant activity of teas has been confirmed to have been caused by the total polyphenol.