• Food Science and Preservation
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• v.16 no.2
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• pp.230-237
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• 2009

The phenolic contents, antioxidant effects, and acetylcholinesterase inhibitory activities of hot water extracts prepared from various Korean commercial teas(green tea, puer tea, oolong tea, and black tea) were investigated. Total phenolic contents were in the range 72.03-85.62 mg/g. Flavonol contents of hot water extracts from green tea, puer tea, oolong tea, and black tea were 350.96, 254.17, 334.48, and 240.23 mg/100 g, respectively. Catechin contents were 2,920.35 mg/100 g in green tea, 1,016.23 mg/100 g in puer tea, 2,824.22 mg/100 g in oolong tea, and 1,006.51 mg/100 g in black tea. The highest caffeine content was in the green tea extract. All four extracts scavenged $ABTS^{{\cdot}+}$ radicals in a concentration-dependent manner, and the green tea extract was the most potent in this regard. The highest reducing power was observed in the green tea extract. All four extracts exhibited considerable antioxidative activities in linoleic acid autoxidation, $\beta$-carotene bleaching, and acetylcholinesterase inhibition assays; the effects were concentration-dependent and decreased in the order green tea > oolong tea > puer tea > black tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1369-1379
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• 2014

The physicochemical characteristics and antioxidant activities of leaf, stem, and root of ginger (Zingiber officinale R.) were determined. Nutrient composition, reducing sugar, saponin, mineral, heavy metal, total phenolic and total flavonoid contents, and antioxidant activities based on DPPH radical scavenging and FRAP assay were measured. Catechins, gingerols, shogaols, and capsaicin compositions were also determined by HPLC. The contents of water, proteins, fats, carbohydrates, fiber, and ash from ginger root were 6.4, 6.8, 3.2, 65.4, 7.3, and 18.2%, respectively. Crude fiber contents of leaf and stem were 4~5 times higher than those of root (P<0.05), and reducing sugar content of stem was about 3 times higher than those of root. Crude saponin contents were in the order of stem

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.938-947
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• 2016

Antioxidant activities and neuroprotective effects of ethyl acetate fraction from Dendropanax morbifera (EFDM) against high glucose-induced oxidative stress and neurotoxicity were investigated to confirm their physiological activities. An 80% ethanolic extract of D. morbifera showed the highest contents of total phenolic compounds as well as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. The extract was fractionated using several solvents, and the ethyl acetate fraction showed the highest activities in ferric reducing/antioxidant power and malondialdehyde inhibitory assays. To evaluate the neuroprotective effect based on antioxidant activities, cell viability was assessed using PC12 and MC-IXC cells in $H_2O_2$- and high glucose-induced cytotoxic assays, respectively. EFDM evidently showed neuroprotective effects in all cells (neuron-like PC12 cells and human brain-originated neuroblastoma MC-IXC cells). Inhibitory effect of the extract on acetylcholinesterase (AChE) as an acetylcholine-hydrolyzing enzyme was performed to examine the effect on cognitive function. EFDM presented an AChE inhibitory effect. Finally, high-performance liquid chromatography analysis showed that the major phenolic compound of EFDM is probably a rutin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.35-43
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• 2016

To evaluate processing suitability of lipoxygenase (LOX)-free genotype soybeans (Jinyang, 05C4 and LS), quality characteristics and antioxidant activities of their Doenjang products were compared to those of Doenjang made from Taekwang soybean (LOX-present) as the control. Moisture and crude protein contents of Doenjang were significantly higher in LS than the control. Crude lipid content was not significantly different and was in the range of 7.92~8.22% in all samples. Carbohydrate content was significantly lower in LS than Taekwang. Content of reducing sugar in Doenjang was significantly higher in Jinyang than Taekwang. Contents of amino-type nitrogen were significantly higher in LOX-free cultivars than Taekwang. Colors of 05C4 and LS Doenjang were not different compared to that of Taekwang, whereas Jinyang Doenjang showed a noticeable color difference. Taekwang Doenjang had a slightly stronger savory taste than another sample. LOX-free cultivars had a strong salty taste. Flavor was the strongest in LS, whereas overall acceptability showed little difference among all samples. The total amino acid content was slightly higher in Jinyang and 05C4 than Taekwang, and content of essential amino acids was higher in Doenjang from LOX-free cultivars than Taekwang. Isoflavon content was significantly higher in Doenjang ($522.16{\sim}684.46{\mu}g/g$) made from LOX-free cultivars than in Taekwang ($374.79{\mu}g/g$). Total phenol content was significantly higher in 05C4 and LS, and flavonoid content was significantly higher in LS than Taekwang. Antioxidant activities were highest in Jinyang based on DPPH radical scavenging and reducing power. ABTS radical scavenging activity was significantly higher in Doenjang made from LOX-free cultivars than Taekwang. These results suggest that Doenjang from LOX-free cultivars could have a suitable genotype for Doenjang processing since it is more effective in terms of amino acids, isoflavone contents, and antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1402-1408
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• 2012

Mulberry pomace, a by-product obtained from mulberry juice, has not been utilized as food. In this study, antioxidant activities, proximate composition and physiochemical characteristics of mulberry pomace were evaluated and compared with those of mulberry fruit or mulberry concentrate. Mulberry fruit was pressed and filtered. The filtrate and residue were used as mulberry juice and mulberry pomace, respectively. Mulberry juice was evaporated, after which a concentrate ($24.7^{\circ}Brix$) was obtained. Moisture contents of mulberry concentrate, freeze-dried mulberry, and pomace were 68.7%, 6.03%, and 7.32%, respectively. Reducing sugar contents were 45.7% in freeze-dried mulberry, 24.5% in pomace, and 30.9% in mulberry concentrate. The pH and acidity of the three samples ranged from 5.80~5.92 and, 0.035~0.080%, respectively. Carbohydrate and crude ash contents were the highest in mulberry fruit, whereas crude protein, fat, and fiber contents were the highest in pomace. Redness of the Hunter color system was 4.7 in mulberry and 4.3 in pomace. Total phenolic content was the highest in mulberry fruit, whereas total flavonoid content was the highest in pomace. Antioxidant activities (DPPH, hydroxyl, and ABTS radical scavenging activities) were enhanced in the order of mulberry fruit> pomace> mulberry concentrate. Especially, antioxidant activities, such as DPPH and hydroxyl radical scavenging activities, of mulberry pomace were similar with those of mulberry fruit. Based on these results, freeze-dried mulberry pomace may be considered as a functional as well as an additive material for food processing.

• Journal of Life Science
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• v.28 no.4
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• pp.454-464
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• 2018

Black soybeans are used as food sources as well as for traditional medicines because they contain an abundance of natural phenolic compounds. In this study, total phenolic contents (TPCs) of Korean black seed coat soybean varieties Socheongja (SCJ), Socheong 2 (SC2) and Cheongja 2 (CJ2) as well as their antioxidant capacities were investigated. Among them, TPCs were abundantly present in the order of CJ2$H_2O_2$-stimulated HaCaT human keratinocytes. Our results revealed that treatment with SCJ and SC2 prior to $H_2O_2$ exposure significantly increases the viability of HaCaT cells, indicating that the exposure of HaCaT cells to SCJ and SC2 conferred a protective effect against oxidative stress. SCJ and SC2 also effectively inhibited $H_2O_2$-induced apoptotic cell death through the blocking of mitochondrial dysfunction. SCJ and SC2 also attenuated the phosphorylation of Histone H2AX. Furthermore, they effectively induced the levels of thioredoxin reductase (TrxR) 1, a potent antioxidant enzyme, which is associated with the induction of nuclear transcription factor erythroid-2-like factor 2 (Nrf2); however, the protective effects of SCJ and SC2 were significantly reversed by Auranofin, a TrxR inhibitor. These results indicate that they have protective activity through the blocking of cellular damage related to oxidative stress via the Nrf2 signaling pathway. In conclusion, our study indicated that SCJ and SC2 might potentially serve as novel agents for the treatment and prevention of skin disorders caused by oxidative stress.

• Journal of Life Science
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• v.28 no.1
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• pp.26-36
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• 2018

This study was performed to identify the antioxidant and ${\alpha}$-glucosidase inhibitory activities of water and 70% ethanol extracts of the three following herbs: G. procumbens, M. charantia, and C. longa. In addition, the antioxidant and antidiabetic activities of five types of Jerusalem artichoke composites (JA1 - 5), which were prepared by adding ethanol extracts of several herbs to Jerusalem artichoke concentrate, were studied and compared. The results showed that the total phenol and flavonoid contents of the ethanol extracts were higher than those of the water extracts. The DPPH and ABTS radical scavenging activities and reducing power depended on the total phenol and flavonoid contents. The antioxidant activities of ethanol extracts from G. procumbens and C. longa were comparable. Moreover, the ${\alpha}$-glucosidase inhibitory activity of the ethanol extracts ($2,000{\mu}g/ml$) from each herb was found to be over 50%. In contrast, the five types of JA composites showed higher total phenol and flavonoid contents than those of JA concentrate. In addition, increased antioxidant and ${\alpha}$-glucosidase inhibitory activities were observed, with that of JA1 being the highest. However, all concentrations ($1{\sim}100{\mu}g/ml$) of JA tested did not affect the cell viability of Chang cells. In addition, JA induced the activation of AMP-activated protein kinase (AMPK) in Chang cells and significantly increased the glucose uptake in C2C12 cells. Therefore, it could be concluded that the JA composites (JA1 - 5) mixed with G. procumbens, M. charantia, and C. longa extracts were effective in increasing the extracts' antioxidant and antidiabetic activities.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.481-487
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• 2010

The nutritional components, antioxidant, and neuroprotective effects of water and a 50% methanol extract from litchi fruit pericarp were investigated. The most abundant mineral, amino acid, and fatty acid were K, proline, and palmitic acid, respectively. In addition, the total water phenolics and 50% methanol extracts were 8.02 and 12.28 mg/g, respectively. The DPPH, ABTS radical scavenging activities and ferric reducing antioxidant power of the water and 50% methanol extracts showed dose-dependent antioxidant activity. In a cell viability assay using MTT, almost all extracts showed a protective effect against $H_2O_2$-induced neurotoxicity, and lactate dehydrogenase leakage was also inhibited by the pericarp extracts. In particular, the 50% methanol extract showed a higher cell membrane protective effect than the water extract at the highest concentration. Consequently, these data suggest that litchi fruit pericarp can be utilized as an effective and safe functional food substances for natural antioxidants and may reduce the risk of neurodegenerative disorders.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.226-236
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• 2020

This study was designed to evaluate the biological activities and main constituents of different parts (fruit, leaf, and stem) of aronia (Aronia melanocarpa). The total phenolic and flavonoidcontents, DPPH and ABTS⁺ radical-scavenging activity, reducing power, and ferric reducing/antioxidant power were observed to follow the order of: leaves > stems > fruits, regardless of extraction solvents. The inhibitory activity against lipopolysaccharide-induced NO production in Raw 264.7 cells was significantly higher in the aronialeaf extract-treated group than in the groups treated with stem and fruit extracts. The ultra-performance liquid chromatography (UPLC) analysis was mainly composed of routine. In addition, the highest content level was measured in the case of the catechinmemberepigallocatechin witha higher value than that found in green tea. Theresults of this studyprovide useful information for understanding the chemical constituents and biological activities of aroniafruits and byproducts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.784-791
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• 2013

Four different yeasts (Fermivin (FM), Saf-instant yeast red (SI), Angest wine active dry yeast (AW) and Angest instant yeast high sugar (AI)) were used for the fermentation of black raspberry wine. The amount of reducing sugars in FM (2.7%) and AI (2.8%) were higher than those in SI (2.4%) and AW (2.5%). The amount of glucose (the major free sugar) was higher in AW (2.57 mg/mL) and AI (2.50 mg/mL) than FM (2.03 mg/mL) and SI (1.75 mg/mL). AW (11.95%) had the highest alcohol content, while SI (11.75%) had the lowest. The pH of FM (pH 3.73) was the lowest, and there were no significant differences in total acidity among the samples. The major organic acid in the wines was citric acid (6.71~8.18 mg/mL) and the amount of organic acids depended on the type of yeasts. The amount of malic acid was highest in SI (2.92 mg/mL), and lowest in AI (1.83 mg/mL). The Hunter color test showed that SI was highest in lightness, redness and yellowness, whereas AI was lowest. There were no differences in turbidity between the samples. There were no significant differences in total phenolic contents (TPC) and total anthocyanin contents (TAC). However, the TPC and TAC of black raspberry wines were higher than those in commercial red wines. The antioxidant activities of wines (determined by ABTS and FRAP) increased in the order of FM, AI, AW and SI. It could not be concluded which yeast is adequate for the fermentation of black raspberry wine because any of the tested yeasts showed the best in all the quality characteristics of the wines.