• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3766-3773
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• 2014

This study examined the antioxidant capacities of apple peel, grape peel, and sweet potato peel. The antioxidant activities were evaluated using total phenolic contents, total flavonoids contents, DPPH radical scavenging activity, ABTS radical cation scavenging activity, FRAP reducing power, and ORAC assay. The total phenolic (7.76 ${\mu}M$ quercetin equivalent/g peel) and total flavonoids (1.03 ${\mu}M$ quercetin equivalent/g peel) contents in apple peel were significantly higher than in grape peel and sweet potato peel (P<0.05). The scavenging activities of DPPH and ABTS radicals of a 70% ethanol extract of apple peel was 3.2-4.6 and 2.8-5.4 times high than those of grape and sweet potato peel, respectively. In addition, the FRAP reducing power and ORAC assay of 70% ethanol extraction from apple peel were significantly higher than those of the other samples. Therefore, apple peel can be used efficiently as a natural antioxidant.

• Journal of Life Science
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• v.26 no.12
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• pp.1400-1408
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• 2016

The black currant (Ribes nigrum L.) is belong to the Grossulariaceae family, and has piquant berries, which can be eaten as raw or as processed foods, such as jams, jelly, juice and syrups. In this study, the fresh juice of black currant (FJBC) from Austria and its subsequent organic solvent fractions, such as hexane fraction, ethylacetate (EA) fraction, butanol fraction and water residue, were prepared and their in-vitro anti-oxidant, anti-coagulation and anti-platelet aggregation activities were evaluated. The FJBC and EA fraction, which has concentrated polyphenol and flavonoid, showed strong radical scavenging activities and reducing power. The $RC_{50}s$ of EA fraction against DPPH anion, ABTS cation, nitrite were 136.3, 66.2 and $115.5{\mu}g/ml$, respectively, those are 1/10, 1/16, and 1/7.7 of $RC_{50}s$ of vitamin C. In anti-coagulation assay, the FJBC, EA and butanol fraction showed significant inhibitory activities against thrombin, prothrombin and coagulation factors. Furthermore, the anti-platelet aggregation activities of EA and butanol fraction were the stronger than that of aspirin. The concentrations required for 50% platelet aggregation inhibition of aspirin, EA and butanol fraction were 0.395, 0.192 and 0.261 mg/ml, respectively. The EA and butanol fraction have no hemolysis activities up to 0.5 mg/ml against human red blood cells. The results suggest that the FJBC and its EA and butanol fraction have high potentials as novel anti-thrombosis agents. This report provides the first evidence of anti-thrombosis activity of black currant.

• Food Science and Preservation
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• v.24 no.7
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• pp.965-974
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• 2017

This study was carried out to investigate the effect of particle size of naked oat flour (NOF) on physicochemical property and antioxidant activity. The NOF was passed through $250{\mu}m$ and $160{\mu}m$ size sieves to obtain three fractions (fraction A: $250{\mu}m$ or more, fraction B: $160-250{\mu}m$, and fraction C: $160{\mu}m$ or less). Moisture, crude protein, crude fat, and crude ash contents of NOF were 8.4, 15.7, 10.0, and 1.8%, respectively, and these contents were increased as the particle size of NOF decreased. The mineral and free amino acid contents of NOF also had a similar tendency. The contents of total starch, amylose, starch damage, total dietary fiber, ${\beta}$-glucan, total phenolics, and flavonoids in NOF were 56.4%, 21.4%, 11.7%, 11.0%, 4.7%, $237.8{\mu}g/g$ and $90.9{\mu}g/g$, respectively. As the particle size of NOF decreased, total starch, amylose, and starch damage contents increased, whereas total dietary fiber, ${\beta}$-glucan, total phenolic and flavonoid contents decreased. Also, three antioxidant activities of NOF were closely correlated with their total phenolics and flavonoids contents, showing high correlation coefficient values ($R^2=0.87$ and 0.81, respectively).

• Journal of Life Science
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• v.25 no.7
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• pp.757-764
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• 2015

The immature fruit of Rubus coreanus Miquel (bokbunja in Korean) is mainly consumed as a fruit wine due to its sour taste and low sugar content. The lees (LBW) remaining after the production of bokbunja wine are discarded as they have no specific usage. The aim of this study was to develop high-value-added biomaterials for functional foods and beauty/health products by investigating the anti-microbial, anti-oxidant, and anti-thrombosis activities of LBW using ethanol and hot water extracts and their subsequent organic solvent fractions. The ethyl acetate (EA) fraction of LBW extracts has a high polyphenol content (413–459 mg/g), and showed strong anti-microbial activity against gram-positive bacteria. The EA fraction also showed excellent radical-scavenging activity against DPPH anion, ABTS cation, and nitrite, with strong reducing power. The polyphenol-enriched EA fraction strongly inhibited thrombin, prothrombin, and blood coagulation factors. The butanol fraction showed a specific inhibition of coagulation factors, as measured in activated partial thromboplastin time assay, which is linked to intrinsic blood coagulation. The butanol fraction also showed strong inhibition of platelet aggregation, at levels comparable to aspirin. The residue of the hot-water extract, which is produced by sequential solvent fractionation of the LBW extract, showed superior inhibition against platelet aggregation when compared to aspirin. Our results suggest that the LBW, which are currently discarded, are a promising source of novel functional foods and beauty/health products.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.259-265
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• 2020

Antioxidative activities of 50% ethanolic extracts from Du-zhong (Eucommia ulmoides Oliver) leaf and bark were investigated. Yields of the leaf and bark extract were 8.1±0.31 and 17.4±0.89%, respectively. Polyphenol contents of the leaf and bark extract were 64.1±3.35 and 42.4±2.38 ㎍ gallic acid equivalents/mg, respectively. Flavonoid contents of the leaf and bark extract were 24.0±3.15 and 36.7±3.18 ㎍ quercetin equivalents/mg, respectively. As concentration of the leaf and bark extract increased, their antioxidative activities proportionally increased. EC₅₀ values of the leaf and bark extract for cation radical scavenging were 560.6±17.65 and 1,357.4±8.45 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for free radical scavenging were 574.2±14.70 and 2,103.1±108.59 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for ferric reducing antioxidant power were 319.9±13.42 and 705.9±26.08 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for nitrite scavenging were 2,329.2±35.11 and 5,467.6±243.92 ㎍/mL, respectively. In the presence of 74.8 ㎍/mL of the leaf extract and 177.2 ㎍/mL of the bark extract, linoleic acid peroxidation was inhibited by 70.0 and 79.1%, respectively. The Du-zhong leaf extract possessed higher antioxidative activities than its bark extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1637-1644
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• 2015

To develop health-functional food ingredients for improvement of diabetes, we examined biological activities, including total contents of polyphenols and flavonoids, antioxidant activity, and inhibition of ${\alpha}$-glucosidase and pancreatic lipase activities of ethanol extracts from unripe fruit of Momordica charantia L. cultivated in Hamyang, Korea. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, and 70%) and temperatures ($50^{\circ}C$ and $70^{\circ}C$). Experimental results showed that total polyphenol and flavonoid contents were achieved concentrations of 7.77 mg/g (tannic acid), 7.66 mg/g (gallic acid), and 10.66 mg/g (rutin). The hydroxyl radical scavenging, ABTS cation radical scavenging, and FRAP activities were 82.19%, 42.82%, and 0.19 under the same conditions, respectively. The highest inhibitory activities of ${\alpha}$-glucosidase and pancreatic lipase were achieved in the 70% ethanol extract at $70^{\circ}C$. These results will be useful for development of health functional foods for anti-diabetes using 70% ethanol extract from unripe fruit of bitter melon.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.572-577
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• 2017

Background: Panax ginseng Meyer is cultivated because of its medicinal effects on the immune system, blood pressure, and cancer. Major ginsenosides in fresh ginseng are converted to minor ginsenosides by structural changes such as hydrolysis and dehydration. The transformed ginsenosides are generally more bioavailable and bioactive than the primary ginsenosides. Therefore, in this study, hydrothermal processing was applied to ginseng preparation to increase the yields of the transformed ginsenosides, such as 20(S)-Rg3, Rk1, and Rg5, and enhance antioxidant activities in an effective way. Methods: Ginseng extract was hydrothermally processed using batch reactors at $100-160^{\circ}C$ with differing reaction times. Quantitative analysis of the ginsenoside yields was performed using HPLC, and the antioxidant activity was qualitatively analyzed by evaluating 2,2'-azino-bis radical cation scavenging, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, and phenolic antioxidants. Red ginseng and sun ginseng were prepared by conventional steaming as the control group. Results: Unlike steaming, the hydrothermal process was performed under homogeneous conditions. Chemical reaction, heat transfer, and mass transfer are generally more efficient in homogeneous reactions. Therefore, maximum yields for the hydrothermal process were 2.5-25 times higher than those for steaming, and the antioxidant activities showed 1.6-4-fold increases for the hydrothermal process. Moreover, the reaction time was decreased from 3 h to 15-35 min using hydrothermal processing. Conclusion: Therefore, hydrothermal processing offers significant improvements over the conventional steaming process. In particular, at temperatures over $140^{\circ}C$, high yields of the transformed ginsenosides and increased antioxidant activities were obtained in tens of minutes.

• Journal of Life Science
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• v.25 no.4
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• pp.425-432
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• 2015

This study was performed to develop high-value-added biomaterials for health and beauty products. Extracts of ethanol and hot water and their subsequent organic solvent fractions were prepared from Lees of Wookukseng (LW), a commercialized Korean traditional rice wine. We investigated their activities on blood coagulation, platelet aggregation, hemolysis against human red blood cells (hRBCs), and anti-oxidation. The water content, pH and brix of the LW were 80.3%, 3.94 and 13.0°, respectively. The yield of ethanol extraction (6.62%) was 3.15 times higher than that of hot-water extraction (2.1%), and the ethyacetate fraction (EAF) of ethanol extract showed the highest content of total polyphenol (128 mg/g) among the various fractions. In anticoagulation activity assay, the EAF of ethanol extract showed a 15-fold extension in TT, PT, and aPTT, indicating that the EAFs contain various inhibitory substances against thrombin, prothrombin and coagulation factors. In anti-platelet aggregation activity assay, the butanol fraction and water residue of ethanol extract showed significant inhibition activity. The activities were comparable to aspirin, a commercial anti-thrombosis agent. The above extracts and fractions did not show hemolysis activity against hRBC up to 5 mg/ml, and had radical scavenging activity against DPPH anion, ABTS cation and nitrite. Our results suggest that the active fractions prepared from LW, which has no specific usage until now, have a high potential as novel resources for anti-thrombosis agents.

• Journal of Life Science
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• v.24 no.6
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• pp.648-654
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• 2014

Grape pruning stems constitute a scarcely investigated class of byproducts with limited reports on their bioactive polyphenol content and/or industrial applications. Herein we present the outcome of our investigation on grape pruning stems extracts, concerning the assessment of their total polyphenolic content and the detailed evaluation of their antioxidant properties. Results obtained indicate that grape pruning stems are particularly rich in flavonoids and trans-resveratrol. The antioxidant activities was analyzed and expressed as electron donating ability, ABTS cation radical decolorization, hydrogen peroxide scavenging activity and superoxide anion radical scavenging activity, the antioxidant activity of Vitis labrusca L. pruning stems extracted (GPSE) was higher than that of BHA and L-ascrobic acid. The whitening and anti-wrinkle activities display an capability. Results herein grape pruning stems used as a valuable resource for the extraction of resveratrol, which would be added to functional cosmetics and food materials.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.445-454
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• 2022

This study aimed to improve the physiological activity of onion juice via lactic acid bacterial fermentation. Seven types of lactic acid bacteria were used for the fermentation of onion juice. The pH and sugar content of the onion juice decreased, while its titratable acidity increased after lactic acid bacteria fermentation, and the cell count of lactic acid bacteria was 7.31-10.40 log CFU/mL. The total free sugar content decreased, while the total organic acid content increased in the fermented onion juice. Quercetin content of the fermented juice was 0.13-0.53 mg/kg. The total polyphenol and flavonoid contents increased after fermentation. Additionally, the 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical cation scavenging activities were increased by fermentation. Overall, lactic acid bacteria fermentation of onion juice enhanced its physiological activity. Based on these findings, Bifidobacterium breve KCTC 3441 was selected as the onion juice fermentation strain.