• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.464-473
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• 2018

The objective of the current study was to evaluate the effects of roasting methods on volatile flavor compounds of boricha using solvent-assisted flavor evaporation-gas chromatography (GC)-mass spectrometry and GC-olfactometry. The barley roasting methods tested were air roasting (AR), drum roasting (DR), and air/drum roasting (ADR). Twenty, twenty-one, and eighteen aroma-active compounds were detected in the products of AR, DR, and ADR, respectively. Guaiacol (smoky), 2-acetylpyrazine (almond-like), and furfuryl alcohol (burnt sugar-like) were detected as high intensity aroma-active compounds. Intensities of most aroma-active compounds produced by the DR method were higher. On the other hand, aroma intensities of phenols produced by the AR method, such as guaiacol and 2-methoxy-4-vinylphenol (curry-like), tended to be stronger. Aroma characteristics of phenols are not considered to be desirable for boricha. Although roasting time for DR was longer than that for AR, DR may be an effective barley roasting method for enhancing desirable aroma characteristics of boricha.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.338-345
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• 2003

Response surface methodology was used for monitoring changes in phenolic compounds properties of Rubi Fructus extract depening on extraction conditons. The three independent variables (extraction conditions) were ratio of solvent to sample content (5, 10, 15 mL/g), ethanol concentration (20, 40, 60%) and extraction time (2, 4, 6 hr). It was anticipated that each of the five dependent Y variables (responses) would be affected by the three independent variables. The dependent responses were total yield, total phenolics content, electron donating ability, antioxidant ability and nitrite-scavenging ability (pH 1.2, 3.0, 4.2, 6.0). Total yield, total phenolics content, electron donating ability and antioxidant ability were affected by ratio of solvent to sample content. Nitrite- scavenging ability at pH 1.2 and pH 6.0 was affected by ethanol concentration, while it was affected by extraction time at pH 3.0 and pH 4.2. The optimum extraction conditions for total yield were 14.16 mL/g ratio of solvent to sample content,39.08% ethanol concentration and 2.99 hr extraction time. The maximum total phenolics content of extracts were shown at 14.06 mL/g ratio of solvent to sample content, 35.51% ethanol concentration and 3.15 hr extraction time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.303-310
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• 2007

Sweetpotato shoot tops (leaves, tips and petioles) are known to be very useful parts as vegetables because of their high nutritive values and great biomass yield. In this study, the phenolic compound contents, antibacterial activity, mutagenic activity, and antimutagenic activity were investigated in sweetpotato tips that were 10-15cm of shoot top including stems, petioles and tender leaves after sprout of storage roots. The study was done by extracting sweetpotato tips with 80% ethanol and the ethanol fraction was re-extracted with hexane, chloroform, ethyl acetate, butanol and water. In ethyl acetate and butanol fractions, total phenolic compounds contained 95. 6mg/g extract and 69.3 mg/g extract, respectively, The antibacterial activity was measured using the paper disk method with concentrations of 1, 2, 5 and 10 mg/disk of butanol and ethyl acetate fractions against L. monocytogenes and S. Typhimurium strains. Higher doses of solvent extracts showed the higher antibacterial activities. In addition, 5, 10 and 20 mg/mL of the extracts were tested to determine the antibacterial activity in liquid culture. The sweetpotato leaf extract by ethyl acetate showed 1 log reduction compared to control after 24 hrs on Listeria monocytogenes, but 20 mg/ml of butanol extract completely inhibited the growth of the pathogen after 12 hrs. The extracts from ethyl acetate or butanol on Salmonella Typhimurium did less than 1 log reduction during cultivation compared to control. The numbers of S. Typhimirium TA98 and TA100 revertant colonies were 29-33 and 159-188 CFU/plate, respectively, indicating that solvent extracts were no mutagenic activity. The antimutagenic test was performed by adding direct mutagen 2-NF and MMS, and butanol and ethyl acetate showed antimutagenic effect. Thus, this study showed that sweetpotato tips had high phenolic contents and both antimicrobiol and antimutagenic properties. Sweetpotato tips would be good nutritive source because of their high nutrient content without any toxicity in consuming.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.273-279
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• 2005

The degradation of o-chlorophenol(o-CP) in the presence of NaOH and the byproducts formed were investigated in a supercritical water(SCW) destruction process. The conversion of o-CP in the absence of NaOH was less than 20%, however it showed 100% conversion in the presence of NaOH(mole ratio[NaOH]/[o-CP] over than 2) with a residence time of less than 1 second. The formation of PAHs and the phenolic compounds formed were decreased in the presence of NaOH. The results revealed that the formation of byproducts during the destruction of o-CP in SCW was effected by the addition of NaOH. Phenol, cresols, chlorinated phenols, PAHs, p,p'-dihydroxybiphenyl and oxygenated polyaromatic compounds such as 1-indanone, dibenzofuran and dibenzo-p-dioxin were detected in both conditions(presence and absence of NaOH). At the same time, in the presence of NaOH, 2-ethylphenol, o-hydroxyacetophenone, hydroquinone, 4-allylphenol, 3-phenoxyphenol and 4,4'-oxybisphenol were also detected. The observed results suggest that the destruction of o-CP in SCW with NaOH occurs through a number of complicated reaction pathways. Dibenzofuran and dibenzo-p-dioxin were also detected during destruction of o-CP by SCW. The above observation suggests that there may be a common relationship between the thermal incineration process and SCW decomposition process.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.55-60
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• 2015

Skin blackening is a serious postharvest disorder occurring in 'Fuyu' persimmon fruits (Diospyros kaki, 'Fuyu'). Phenolic content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and lipid saturation were investigated in skin tissue of 'Fuyu' fruits. The phenolic compounds were accumulated unevenly on fruit skin depending on sunlight exposure, i.e., the most accumulation on sunny side and the least on the opposite, shaded side. The fruits harvested from shaded branches inside the canopy showed relatively even distribution of phenolic compounds in the skin. The activity distribution of PPO and POD were also uneven but only in fruits suffering f rom skin b lackening disorder, w ith the h ighest and the lowest a ctivity of PPO and P OD, respectively, in the blackened area of the fruit. When the sunny, southern sides of fruits were marked at harvesting time and fruits were stored at low temperature, a round black spot, as a symptom of skin blackening disorder, developed during storage exactly on the marked region. In addition, the sunny side of fruit showed higher lipid saturation, thus indicating adaptation to high temperature caused by the sunlight. These results suggest that the skin blackening disorder of 'Fuyu' fruits can be considered as a kind of chilling injury symptom that develops on the high-temperature-acclimated skin tissue of sunlight-exposed fruits when they are later exposed to low temperature.

• Culinary science and hospitality research
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• v.21 no.3
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• pp.259-269
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• 2015

This study was performed to investigate the phenolic compounds content and antioxidative activity of methanol extract from Chinese soybean. The content of total phenolics and total flavonoids of Chinese soybean Heinong 48) extract were $9.91{\pm}0.57GAE\;mg/g$ and $4.15{\pm}0.39QE\;mg/g$, respectively. The antioxidative activities of Chinese soybean extract were significantly increased in a dose dependent manner on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical scavenging($IC_{50}$ values were $2.04{\pm}0.16$ and $3.31{\pm}0.31mg/mL$, respectively). These results suggest that Chinese soybean may have great potential as a natural antioxidant source with health benefits.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.761-769
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• 2013

This study used HPLC to analyze the contents of catechins, alkaloids, theanine, total phenolic compounds and antioxidant activities of commercial Hadong green tea leaves(Uzen, Sezak, Jungzak, Daezak). The content of catechins, alkaloids, theanine, total phenolic compounds were lower by water extracts than by 80% ethanol-water extracts. Total catechin and alkaloid contents in Uzen(172.33 mg/g, 30.80 mg/g) by 80% ethanol extract were the highest. Theanine contents of 80% ethanol-water extracts ranged form 55.36 to 37.48 mg/g of tea leaves. Total phenloic compounds contents of green tea were higher than Uzen. Antioxidative of green tea by DPPH, FTC, TBA method were higher than that Uzen.

• Journal of Plant Biotechnology
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• v.40 no.3
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• pp.178-183
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• 2013

Traditionally, Codonopsis lanceolata root have been used as a source of natural heath food. This study was initiated to investigate the impacts of methyl jasmonate (MeJA) and salicylic acid (SA) on adventitious growth C. lanceolata, the production of secondary metabolites, such as flavonoids, total phenolic compound, antioxidative activity (DPPH). The highest phenolics content was observed in treatment of 20 uM MeJA (74.53 mg/g). The content of total flavonoids followed the similar pattern as that of total phenolics, showing 38.45 mg/g of C. lanceolata treated by 20 uM MeJA. The DPPH scavenging activity was 24.2 ($IC_{50}$) of C. lanceolata treated by 20 uM MeJA. These results provide useful information for enhancing biological properties of cultural roots of C. lanceolata.

• Proceedings of the Korean Nutrition Society Conference
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• 2001.11a
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• pp.45-45
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• 2001

• Bulletin of Food Technology
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• v.18 no.1
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• pp.99-109
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• 2005