• Journal of agriculture & life science
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• v.44 no.2
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• pp.57-66
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• 2010

The antioxidant and neuronal cell protective effects of water extract from purple sweet potato were investigated. The total phenolics and monomeric anthocyanin contents of purple sweet potato extract were 44.25 mg/g and 2,394 mg/L, respectively. The antioxidant activities of purple sweet potato extract were evaluated using various antioxidant tests, including 1,1-diphenyl- 2-picrylhydrazyl (DPPH), 2,2'-azino- bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing/antioxidant power (FRAP) and reducing power. In these assays, the extract of purple sweet potato presented significant radical scavenging activities, FRAP, and reducing power in a dose-dependent manner. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl- tetrazoliumbromide} reduction assay showed significantly increase in cell viability when PC12 cells were pretreated with purple sweet potato extract. Because oxidative stress is also known to increase neuronal cell membrane breakdown, we further investigated by lactate dehydrogenase (LDH) and neutral red uptake assay. Purple sweet potato extract inhibited oxidative stress-induced membrane damage in neuronal cells. Therefore, these data results demonstrated that water extract of purple sweet potato have antioxidant activity and neuronal cell protective effect thus it has great potential as a natural source for human health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1776-1782
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• 2013

Rhus verniciflua was extracted at different temperatures and times, and the extracts were evaluated for contents of total phenolics and flavonoids, and antioxidant activities using DPPH and ABTS radical scavenging activities. Extraction temperatures and times were 80, 100, 120, 140 and $160^{\circ}C$, and 1, 3 and 5 hr. The total phenolic and flavonoid contents as well as antioxidant activities by DPPH and ABTS increased as the extraction temperature increased. The total phenolic contents did not significantly increase at less than $100^{\circ}C$ with different extraction times. However, they were increased at 3 hr and decreased at more than $120^{\circ}C$. The total flavonoid contents reached a high value of 8.04 mg CE/g at $140^{\circ}C$. The antioxidant activity by DPPH increased as the extraction temperature increased and reached high values of 34.28 mg TE/g at $140^{\circ}C$. The total antioxidant activity by ABTS was similar to DPPH. These results presumed that the optimum extraction temperature and time in the process of Rhus verniciflua extraction are $140^{\circ}C$ for 3 hr.

• Food Science and Preservation
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• v.19 no.5
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• pp.744-750
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• 2012

In this study, the optimal conditions for phenolic-compound extraction from medicinal plants were found to be 24 h and about 50% ethanol. The electron-donating scavenging activities (DPPH), ABTS radical-cation decolorization (ABTS), antioxidant protection factor (PF), and thiobarbituric acid reaction substance (TBAR) were measured to determine the antioxidant activities of the extracts of Sanguisorba officinalis Linn., Citrus unshiu Markovich, Melia azedarach L., Asparagus cochinchinensis Merr., Citrus unshiu S., Polygonum aviculare L., and Leonurus sibiricus L. The total phenolic contents of the extracts of medical plants were determined to be 0.45-3.00 mg/g in the water extracts and 0.33-3.15 mg/g in the 50% ethanol extracts. The electron-donating abilities (EDA) of the water and ethanol extracts were both above 85% at the $50{\mu}g/ml$ concentration. The ABTS radical-cation decolorization was above 80% at the $100{\mu}g/ml$ concentration in all the extracts of various medicinal plants. The antioxidant protection factor (PF) of the Melia azedarach L. extracts was found to be $1.65{\pm}0.40$ PF in the water extracts at the $100{\mu}g/ml$ concentration, and was higher than those of the other medicinal-plant extracts. The TBAR inhibition rates of all the medicinal-plant extracts, except Asparagus cochinchinensis Merr., were above 85% at the $100{\mu}g/ml$ concentration. These results confirmed that the various oriental medicinal plants (Sanguisorba officinalis Linn., Citrus unshiu Markovich, Melia azedarach L., Asparagus cochinchinensis Merr., Citrus unshiu S., Polygonum aviculare L., and Leonurus sibiricus L.) that were included in this study are useful functional-food sources.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.252-259
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• 2021

Barley contains health-beneficial compounds, such as phenolic acids, flavonoids, lignans, and tocopherols. The antioxidant activities of pearled and wholegrain hull-less, premature, and black barley harvested in Jeju were investigated by measuring total phenolic content (TPC), total flavonoid content (TFC), phenolic compounds, tocopherols (T), and tocotrienols (T3), along with their in vitro antioxidant activities. Consequently, TPC and TFC in wholegrain barley groups were higher than those in pearled barley. Gallic acid (1.55-2.98 ㎍/g) and protocatechuic acid (0.67-2.84 ㎍/g) were the predominant phenolic compounds in barley. Total T and T3 concentrations of wholegrain barley groups were significantly higher than those of pearled barley (p<0.05). Except for the metal chelating effect and reducing power, the in vitro antioxidant activities of wholegrain barley were significantly higher than those of pearled barley. These results indicate that wholegrain Jeju barley can be used as a natural antioxidant source in the food industry.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.165-170
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• 2006

The antifungal activity of crude methanolic extract and fractions from Yucca smalliana Fern. leaves, roots and flowers were investigated in vitro against a panel of plant pathogenic fungi. The minimal inhibitory concentration(MIC) was determined by an agar dilution method. Preliminary liquid culture and agar plate assays showed that the growth of Fu sarium oxysporum, Phytophthora capsici, Rhizoctonia solani and Botrytis cinerea were inhibited by Y. smalliana extracts. The extracts from flowers and leaves showed antifungal activity of 64.0% and 34.0% against F. oxysporum, 66.0% and 62.0% against P. capsici, and 27.0% and 41.0% against B. cinerea, respectively. The methanolic extract from Y. smallina leaves in distilled water was fractionated using solvents of increasing polarity: hexane, ethyl acetate and butanol. These fractions had a broad spectrum of antifungal activity, found to reside entirely in the butanol and aqueous fraction. The aqueous fraction showed inhibition rate of 60.0, 67.8, 84.6 and 58.3% against F. oxysporum, R. solani, C. gloeosporioides, and B. cinerea, respectively, and the butganol fracgtion showed 36.0, 46.0, 66.1 and 58.3%, respectively. Phenolics(e.g. flavonoids, steroids and terpenoids) were observed in the thin layer profile of the different fractions. Leave extract showed a prominent antioxidant activity totally scavenging the free radical of DPPH at a concentration of 1 mg/ml.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1133-1138
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• 2006

Smilax china root has been used as traditional medicinal remedy in China and Korea and reported to have various biological activities such as anti-inflammatory, antimutagenic and antimicrobial activities. In this study, the possibility of development as natural antioxidants of Smilax china root extracts was investigated. For the evaluation of antioxidant activity, aqueous- and 25% EtOH extract from Smilax china root were prepared and six different evaluation assay methods, i.e., measurement of total phenolics, radical scavenging effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO) and nitrite $(NO_2)$, reducing power, and inhibitory effect on tyrosinase activity, were used. The total phenolics content of two extracts was high as the level of 36 mg of gallic acid equivalent per 1 g of dried sample tested. The radical scavenging activities of ethanol extract toward DPPH and NO were better than those of aqueous extract (p<0.05). The $NO_2$ scavenging activity of both extracts showed the highest value at pH 1.2 (98%). Especially, the $NO_2$ scavenging activities of EtOH extract were significantly stronger than those of aqueous one at pH 4.2 (51%) and pH 6.0 (32%), respectively. In the reducing power test, both extracts revealed higher ferric ion reducing activity than known antioxidant, vitamin C at the level of $0.05\sim0.1mg/mL$ (p<0.01). The 1 mL of aqueous and 25% EtOH extract showed effective inhibition activity on tyrosinase activity as 45% and 53%, respectively. Therefore, these results suggest that two extracts from Smilax china root may serve as useful natural antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1035-1040
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• 2012

This study was aimed to evaluate and compare the biological activities and total phenolic content of ethanol extracts of white (Superior) and colored potatoes (Red, Rose, Haryoung, Blue, Jaseo, and Jasim). Various ethanol extracts (250, 500, 1,000, and $2,000{\mu}g/mL$) were assessed for antioxidant activities of DPPH free radicals and hydroxyl radical scavenging. The cytotoxic activity of the extracts (0, 30, 60, $100{\mu}g/mL$) was also carried out by a human cancer cell lethality bioassay method. Results showed that the DPPH and hydroxyl radical scavenging activities, of all extracts increase in a concentration-dependant manner. All color-fleshed potato extracts, except for Red and Haryoung, showed higher radical scavenging activities than the general white potato extract. Cytotoxicity of the extracts as determined in THP-1 cells showed that Blue and Jasim was highly toxic at most concentrations tested. In addition, the Blue extract had the highest cytotoxic activity on $HepG_2$ cells at the concentration $100{\mu}g/mL$. The contents of total phenolic (TPC) in the extracts significantly varied from 120.0 mg/100 g powder (Superior) to 151.1 mg/100 g powder (Blue), and TPC of all color-fleshed potato extracts was higher than that of white. The greatest positive correlation was found between phenolic contents and hydroxyl radical scavenging activity (r=0.776, p<0.05), and a strong negative correlation was found between hydroxyl radical scavenging activity and cytotoxic activities on $HepG_2$ cells (r=-0.795, p<0.05). The present study demonstrates that color-fleshed potatoes have higher antioxidant and stronger anticancer activities than general potato. These results provide useful and important information for potato breeders and researchers, in order to increase the antioxidant capacity and functional value of colored potatoes for use in the food and pharmaceutical industries.

• Current Research on Agriculture and Life Sciences
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• v.33 no.2
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• pp.49-56
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• 2015

The aim of this research was to investigate the anti-oxidantive activities of extracts from Chionanthus retusus leaves, fruits and flower. The content of phenolics were 20.8 mg/g in water extracts and 32.2 mg/g in 90% ethanol extracts from flower. The DPPH free radical scavenging activity of extracts from Chionanthus retusus was above 70% at phenolic concentration $100{\mu}g/mL$. The ABTS radical decolorization activities of water and ethanol extracts were both above 80% at $100{\mu}g/mL$ phenolic concentration, respectively. The antioxidant protection factor(PF) of water and 80% ethanol extracts from leaves was the highest as 2.27 PF and 1.70 PF at $50{\mu}g/mL$ phenolic concentration. The TBARs inhibition rate of the Chionanthus retusus extracts, was above 70% at $200{\mu}g/mL$ phenolic concentration. The anti-oxidantive activities of extracts from leaves were shown more active than BHT as a positive control except TBARs. These results confirmed that the extracts from Chionanthus retusus leaves, fruits and flower was shown the high anti-oxidant activity. The results can be expected isolated phenolic compounds from Chionanthus retusus to use as functional beauty food resource.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.641-648
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• 2010

The objective of this study was to evaluate the pre-heating treatment effects on the antioxidant properties of ethanolic garlic and onion extracts. Garlic and onion with or without heating ($100^{\circ}C$, 30 min) were extracted with ethanol, and the total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, iron chelating ability, reducing power, and antioxidant activity in a linoleic acid emulsion system were evaluated. Garlic (41%) had a higher drying yield than onion (11%). Regardless of pre-heating, ethanol extracts of onion resulted in an approximately 25-fold higher yield than those of garlic. Thermal treatment before extraction decreased the levels of ethanol-soluble phenolics for both garlic and onion. Regardless of pre-heating, the radical scavenging abilities of ethanol extracts from garlic were greater than the ethanol extracts from onion. The iron chelating abilities of ethanol extracts from fresh and heated garlic were 85 and 81% at 10 mg/mL, respectively, whereas those of onion extracts were 10 and 9% at the same concentration, respectively. However, no differences in reducing power between garlic and onion extracts were observed. Both garlic and onion inhibited the formation of hydroperoxide in linoleic acid emulsion systems when ethanol was used as a solvent. Overall, garlic extracts had greater antioxidant activity than onion extracts, and the antioxidant activity of garlic and onion extracts were not significantly affected by thermal treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.401-411
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• 2015

Bitter melon (Momordica charantia L.) has various biological functions, including anti-diabetic, anti-cancer, anti-inflammatory, anti-viral, and antioxidant activities. However, the development of foods using bitter melon (BM) is unexplored due to its bitter taste. In this study, BM pickle was prepared, and changes in quality characteristics and antioxidant activity during ageing were determined. After 4 weeks of ageing, pH levels, salinities, soluble solids, and reducing sugars of BM pickle decreased, whereas acidities increased. In addition, total viable, lactic acid bacteria, and yeast viable cell numbers greatly increased until 1 week, after which they slightly decreased. Levels of soluble phenolics increased during ageing, antioxidant activity increased accordingly. Crude protein, K, and P contents of pickles were lower than in raw material of BM, whereas crude fat and Na contents increased. Corn silk extracts were added to BM pickle during ageing in order to improve the bitter taste and flavor. The best sensory quality was obtained by adding 0.25% corn silk extracts.