• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.567-575
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• 2022

This study was carried out to elucidate bioacive effects of three domestic cherry tomato cultivars. Total polyphenol and flavonoid of Summerking, Qutiquti, and Minichal cultivar were 12.56±1.88, 12.50±1.92, 11.65±1.85 mg/g and 4.58±1.03, 4.19±0.40, 4.30±0.49 mg/g(dry weight) respectively. Domestic cherry tomatoes showed antioxidative activity(DPPH and ABTS radical scavenging activities). All of the cherry tomatoes had no cytotoxicity for normal liver cell, but showed strong inhibitory effect against cervical cancer cell(HeLa) growth. These results revealed that domestic cherry tomatoes can be used as a bioactive food material.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.21-24
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• 2015

Antioxidant activities of ethanol extracts from three types of sweet potatoes with distinctive flesh color (white, orange, and purple) were investigated. Total phenolic content of purple-fleshed sweet potato (PF) was always 2- to 5-fold higher than those of white-fleshed (WF) and orange-fleshed sweet potato (OF). 2,2-diphenyl-1-picryl-hydrazyl free radical scavenging activity of 70% ethanol extracts was highest ($EC_{50}$ = 0.179 mg/mL) for PF and lowest ($EC_{50}$ = 2.127 mg/mL) for OF. And then, reducing power was also highest ($EC_{50}$ = 0.236 mg/mL) for PF and lowest ($EC_{50}$ = 1.587 mg/mL) for WF. Antioxidant activities of 70% ethanol extracts were closely related to the amount of total phenolics. These results imply that antioxidant activity of PF is 6.7 to 11.9 times higher than those of WF and OF.

• Polymer(Korea)
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• v.36 no.4
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• pp.470-477
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• 2012

A tyrosinase-immobilized biosensor was developed based on various amine-modified multi-walled carbon nanotube (MWNT) supports for the detection of phenolic compounds. MWNTs with various amine groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto MWNT supports and the subsequent amination of poly(GMA) graft chains. The physical and chemical properties of the poly(GMA)-grafted MWNT supports and the aminated MWNT supports were investigated by SEM, XPS, and TGA. Furthermore, the electrochemical properties of the prepared tyrosinase-modified biosensor based on MWNT supports with amine groups were also investigated. The response of the enzymatic biosensor was in the range of 0.1-0.9 mM for the concentration of phenol in a phosphate buffer solution. Various parameters influencing biosensor performance have been optimized: binder effects, pH, temperature, and the response to various phenolic compounds. The biosensor was tested on phenolic compounds contained in two different commercial red wines.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.540-544
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• 2012

The aim of this study was to evaluate the antioxidant activity, total phenolics, flavonoids, and vitamin C contents in peels of 11 commercial fruits commonly consumed in the Republic of Korea. The antioxidant activities were evaluated by ABTS, DPPH radical scavenging methods and reducing power. The peels of plum (Prunus spp.) and golden kiwifruit (Actinidia chinensis) exhibited the highest values of antioxidant activity and total phenolics, while the highest level of ascorbic acid was recorded in the peel of citrus fruit (p<0.05). There were positive correlations between the antioxidant activity assessed by both reducing power and ABTS methods and total polyphenol content ($R^2$=0.6356), suggesting that phenolic compounds are the major contributors to these activities. The results indicate that plum and golden kiwifruit peels can be used as natural antioxidant ingredients and in production of functional foods in the Korean diet.

• Korean Journal of Plant Resources
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• v.27 no.2
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• pp.111-118
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• 2014

Contents of phenolics, flavonoids, and catechins, and antioxidant activity were investigated in the ethanol extracts of three different flower species, Magnolia denudata, Prunus mume, Carthamus tinctorius. Total phenolics were more present in M. denudata than P. mume or C. tinctorius, ranging from 72.6 to 118.0 mg/kg (p < 0.05). Total flavonoids level had same tendency to total phenolics content, showing highest amount (25.1 mg/kg) in M. denudata. The antioxidant activity of the methanol extracts from all the flowers dose-dependently increased. DPPH free radical scavenging activity at 250 mg/kgwas higher in M. denudata and P. mume by 93.0 and 92.6%, respectively, than C. tinctorius by 23.0% (p < 0.05). Total catechins content including 6 compounds was higher in M. denudate (9,425.5 mg/kg) than that in P. mume or C. tinctorius (3,407.8 or 190.6 mg/kg). However, P. mume extracts showed highest amount in caffeine as well as vitamine C. DPPH radical scavenging activity in three different flowers was highly correlated with contents of total phenolics ($r^2=0.7994$), total flavonoids ($r^2=0.9131$), and total catechins ($r^2=0.5929$), and their content and activities were different depending on species.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.04a
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• pp.29-40
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• 2002

감잎으로부터 통풍치료, 미백효과, 고혈압 억제효과의 개발목적으로 9종의 flavan-3-ol 화합물을 분리하였고 기기분석에 의해 화학구조를 자혔다. 각 화합물은 (+)-catechin (+)-gallocatechin procyanidinB-l, pyrocyanidin C-1, prodelphinidin B-3, gallocatechin-(4$\alpha$$\longrightarrow$8)-catechin과 감나무 잎에서 새로운물질인pocyanidin B-7-3-0-gallate, procyanidin C-1-3'-3" -3.'S _0-trigallate, (-)-epigallocatechin-(4 $\beta$ -18)-epigallocatechin-(4$\beta$-'8)-catechin 3종류를 발견하였다. 감잎으로부터 순수 분리한 polyphenol류의ACE 저해활성측정을 실험한 결과 pocyanidin B-7-3-0-gallate는 100rM농도에서 94%의 저해효과를 나타내었으며 epigallocatechin-(4$\beta$$\longrightarrow$8)-epigallo-catechin-(4$\beta$$\longrightarrow$8)-catechia procyanidin C-1-3'-3" -3f'.-0-trigallate는 각각 90.69, 80.90% 저해를 하였다. Xanthine oxidase 저해활성측정을 조사한 결과pocyanidin B-7-3-0-galtate와 pocyanidin C-1-3'-3" -3/'S _0-trigallate 즉, gallate가 붙은 호합물에서100rM의 농도에서 66%와 63%의 강한 저해효과를 나타났다. Tyrosinase 저해활성을 측정한 결과는pocyanidin C-1-3'-3" -3.'S _0-trigallate는 100rM에서 70%의 강한 저해효과를 나타냈으며,epigallocatechin-(4$\beta$$\longrightarrow$8)-epigallo-catechin-(4$\beta$$\longrightarrow$8)-catechin는 51%의 저해효과를 나타내었다. 산업적응용을 위해 분획한 폴리페놀군은 미백효과 검증실험인 tyrosinase 저해율 측정평가에서 폴리페놀 함량이 가장 높은 Fraction 111의 경우 Sooppm에서 74.2%의 높은 저해율을 나타내었다. 항산화력 실험에서는500pw1이상에서 강한 활성능을 보인 SOD 유사활성능을 제외한 나머지 DPPH와 xanthine oxidase 저해효과에서는 Fraction II와III 모두가50ppm이상에서 80% 이상의 높은 유리라디칼 소거능력을 나타내었다. 그리고 각 Fraction별 항균력 측정 결과 Fraction 르와 111이 우수하게 나타났고 항균활성은 그람음성균보다 그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달리하여 미생물의 생육도를 측정한 결과, fraction II磎꼭\ulcorner경우 그람양성균에 대해 500 ppm 이상에서 뚜렷한 증식억제효과를 나타내었다.서 뚜렷한 증식억제효과를 나타내었다.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.127-134
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• 2014

This study was performed to evaluate the effects of sesame oil addition to a tuna oil-enriched emulsion during chlorophyll-photosensitized oxidation. The emulsion principally consisted of tocopherol-stripped canola and tuna oil with or without sesame oil, acetic acid, phospholipids, and xanthan gum. Chlorophyll b was added to promote the production of singlet oxygen upon exposure to light. The oxidation of oil in the emulsion was evaluated by determining the peroxide value (POV) and conjugated dienoic acid (CDA) contents. Concentrations of minor compounds in the emulsion were monitored. Increasing POV and CDA contents in the emulsion were paralleled with decreased docosahexaenoic acid during oxidation, and oxidation was inhibited by the addition of sesame oil. Chlorophyll, polyphenols, tocopherol, and phospholipids were degraded during oxidation of the emulsion; however, their degradation was slowed down by the addition of sesame oil. Lignans in the emulsions containing added sesame oil were barely changed, suggesting that they quenched singlet oxygen physically. Polyphenols were the most effective in improving the stability of tuna oil-enriched emulsions during chlorophyll-photosensitized oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.

• Journal of Life Science
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• v.21 no.5
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• pp.746-752
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• 2011

The contents of bioactive materials (e.g. polyphenolics compounds, flavonoids, minerals, and fatty acids) and antioxidative activities (DPPH (${\alpha}$,${\alpha}$'-diphenyl-${\beta}$-picrylhydrazyl) free radical scavenging activity, peroxidation of linoleic acid and rat hepatocyte microsome, and Fe/Cu reducing power) were tested by in vitro experimental models using water, ethanol and methanol extracts of leaves (TOL) and fruits (TOF) from Thuja orientalis. Methanol extract from TOL showed the highest extraction yield (12.90%) as well as contents of polyphenolic compounds (16.02%) and flavonoids (0.25%). Major minerals were Ca, K, and Mg. Major fatty acids were palmitic and lauric acids in TOL and palmitic and decanoic acids in TOF. In oxidation of in vitro models using DPPH free radical scavenging activity, Fe/Cu reducing power, $Fe^{2+}$/ascorbate-induced linolenic acid peroxidation by ferric thiocyanate and thiobarbituric acid (TBA) methods, and autooxidation of rat hepatic microsomes membrane, anti-oxidative activities were stronger in all extracts of TOL than in those of TOF in a dose-dependent manner. From these results, methanol extract of TOL was shown to have the most potent anti-oxidative properties and the highes content of antioxidative compounds such as polyphenolic compounds and flavonoids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.1-8
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• 2009

This study was investigated to analyze the contents of flavonoid and polyphenol compounds, and inhibitory activities of tyrosinase and antioxidation to measure physiological effect of reflux water extraction (WE), reflux ethanol extraction (EE) and hot water extract under high pressure (HWE) of Torreya nucifera seed. HWE yields the highest contents of flavonoid compounds (176.34 mg/g) and polyphenol compounds (112.95 mg/g). The tyrosinase inhibitory rates were $5.62{\sim}28.71%$ at 2.0 mg/mL and HWE showed the highest inhibition rate. The nitrite scavenging abilities of all extracts were over 90% at pH 1.2 and 3.0 at the concentration of 2.0 mg/mL. The superoxide dismutase (SOD)-like activities of HWE was the highest value of 33.58%. The electron donating abilities (EDA) were $66.46{\sim}89.72%$ and HWE was the highest when the extracts were tested at 0.1 mg/mL. The EDA of all extracts were decreased with an increment of the extracts concentrations. The xanthine oxidase inhibitory rate of HWE was the highest value of 89.29% at the concentration of 2.0 mg/mL and the WE and HWE were over 75% rate of xanthine oxidase inhibition at 0.5 mg/mL.