• Culinary science and hospitality research
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• v.24 no.2
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• pp.103-111
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• 2018

The objectives of the present study were to examine the antioxidant activity of autofocusing fractions from egg white protein hydrolysates and obtain higher antioxidant peptide fraction, which could be applied to the food model system. Alkaline protease hydrolysate of egg white protein exerted higher antioxidant activities than other protein hydrolysates and were fractionated on the basis of the amphoteric nature of sample peptides by preparative isoelectric focusing without toxic solvents and reagents, which is termed autofocusing. Neutral and basic fractions showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the acidic fractions. The acidic and neutral fractions showed higher hydroxyl (OH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) values than the basic fractions. The acidic fractions showed higher metal chelating activity than basic fractions. Antioxidant activities of some autofocusing fractions except for ORAC showed higher compared to the crude hydrolysate. These results suggest that peptides fractions from egg white protein are effective antioxidant, and that autofocusing could be useful to increase antioxidant activity for application to food system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.305-311
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• 1999

The volatile compounds of soybean pastes(home made soondoenjang, commercial doenjang) were classified into basic, acidic and neutral fractions by dynamic headspace method. The fractionated flavor isolates were analyzed and identified by gas chromatography mass spectrometry. Each peak area of the flavor components was quantified at its ratio to the peak area of internal standard. Sixty one compounds from home made soondoenjang, and forty three compounds from commercial doenjang were identified. The different distribution of volatile compounds between the two soybean paste samples was observed. Ten pyrazines and benzothiazole were identified in the basic fraction of home made soondoenjang. On the other hand, trimethylpyrazine was the only one of nitrogen containing compounds in the commercial doenjang, which was made from soybean(28.3%), wheat(22.2%) and alcohols. The factors which influenced the levels of these identified compounds were considered to be the starting materials of soybean paste. Alcohols, esters and aldehydes in the neutral fraction of both samples were seemed to be characterisitic soybean paste flavor and showed much higher quantities than those of the basic or acidic fractions. Furfural in the commercial doenjang was the highest content (45.28ppm) among all of the compounds identified in the samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.761-769
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• 1995

About 2.1g of pale yellow flavor concentrate was obtained from 10kg of chopped fresh ascidians through a Likens-Nickerson steam distilllation/solvent extraction. These concentrates could be fractionated to neutral $(91.5\%),\;basic\;(1.0\%),\;phenolic\;(3.2\%),\;and\;acidic\;(4.3\%)$ fractions. Total 65 volatile compounds were identified from those concentrates. The neutral fraction was representative flavor fraction which showed a similar flavor of total steam distillates of ascidian. The major compounds $(38.2\%\;of\;neutral\;fraction)$ were identified as carbon atoms 8 to 10 of alcohols. Among these volatile alcohols, 1-octanol, 2,7-decadien-1-o1, 3-octen-l-01, 7-decen-l-ol, and l-decanol were the dominent compounds found in neutral fraction. But the basic, phenolic, and acidic fractions differs from ascidian steam distillates flavor.

• YAKHAK HOEJI
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• v.33 no.1
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• pp.46-53
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• 1989

The extractable organic matter was extraced from airborne particulates collected in Seoul during 1986. It was fractionated to several fracrtions and mutagenicities of them were tested in Salmonella thyphimurium TA98 by Ames method. The neutral fraction showed the highest indirect acting mutagenicity while the highest direct acting mutagenicity was observed in the acidic fraction. Indirect acting mutagenicity of airborne particulate was attributed to its neutral fraction about 88% in average, to acidic about 10% in average and to basic fraction about 2% in average. Direct acting mutagenicity of airborne particulate was attributed to its neutral fraction about 70%, to acidic fraction about 29% and to basic fraction about 1%. Among five subfractions of neutral fraction, the proportion of mutagenicity of polynuclear aromatic hydrocarbon subfraction was 13.2% in indirect acting mutagenicity and 5.0% in direct acting mutagenicity.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.173-182
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• 1992

Regardless of the test species, germination was adversely affected by the different concentrations of the acidic and neutral fractions of sunflower root exudates while the basic and aqueous fractions had no effect on germination. In both test species, root lengths were inhibited slightly more than shoot lengths. Significant reduction in fresh weights of the test species was observed when the test species were treated with the acidic and neutral fractions but not with the basic and aqueous fractions. Six compounds, hydroquinone, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, salicylic acid, and quercetin, were characterized from the acidic fraction. Seven compounds, hydroquinone, gentisic acid, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, ferulic acid, and quercetin, were elucidated from the neutral fraction.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.2
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• pp.67-73
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• 1982

Essential oil components from tobacco powder were investigated as flavouring agent. The essential oil was isolated from tobacco powder by a simple distillation /extraction method The extracted essential oil was fractionated into basic, acidic and neutral groups. And the neutral group of essential oil was separated by column chromatography into 10 fractions. Above groups and fractions were tested for tobacco aroma and smoke aroma. The neutral group except most nonpolar fraction displays good flavouring properties which make them highly suitable for improving the flavour and aroma of tobacco and tobacco smoke. The most nonpolar fraction from neutral group was carefully investigated using preparative column, thin layer and gas chromatography ailed by GC/MS coupling. The major subfraction was identified as hydrocarbons on the basis of the IR spectrum. The 58 hydrocarbon components were identified by their mass spectra and was chromatographic retention times.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.269-278
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• 1996

Airborne suspended particulates were collected by an Andersen high volume air sampler in a traffic area of Seoul from September 1990 to August 1991. Origanic matter extracted from particulates, their fractions, namely acidic, basic, neutral and carcinogenic subfractions (PAHs, nitroarenes) in neutral fractions were assayed for mutagenicity on TA98, TA100 and TA98NR deficient Salmonella strains, use of the pre-incubation method. The relative contribution to total mutanenicity of organic matters was highest in neutral fraction and was lowest in basic fraction. Among subfractions, that of neutral fraction was higher nitroarenes subfraction compared to PAHs subfraction. While the carcinogenic effect of benzo[a]pyrene was calculated as 0.96 persons/million persons based on unit risk estimates by extrapolation method, life time excess cancer risk estimate of EOM, neutral, PAH fraction based on their mutagenicity was calculated as 52, 42, 3.8 persons/million persons, respectively. These findings indicate that the mutagenic hazard of the partciculate, air organic complex mixture, may be dependent upon the mutagen composition in the particulate and interactions each of them. Therfore, health risk from air organic complex mixtures based on mutagenicity might be useful indicator for evaluation of actual risk.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.95-102
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• 1981

From various sources of natural habitat yeasts, which coo 14 transform the constituents of tobacco Powder into flavors, were isolated and three isolates. YOII, M4-1, and M 19-1, were selected These were identified, by their biological characteristics, as Hansenuia ciferri, Pichia acaciae and Candida tropicalis, respectively. Their ferments were extracted with petroleum ether and fractionated into basic, neutral and acidic fractions. The major organoleptic properties of the fermented flavors were detected in the neutral fractions by the sensory test and the yields and threshold values of those fractions were determined and the organoleptic characteristics were described as well.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.289-292
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• 1995

Fig leaves were extracted with methanol and then fractionated with ethyl acetate and various buffers to get active fractions, and their antimicrobial activities in each fraction were determined. Acidic fraction and phenolic fraction of fig leaves showed strong antimicrobial activities, but the basic fraction and neutral fraction did not show any activities. The degree of antimicrobial activities in phenolic fraction against tested bacteria were higher than those in acidic fraction, but these against yeasts and mold were almost equivalent to those in acidic fraction. Especially, phenolic fraction showed the strongest activities against Staphylococcuns aureus and Pseudomonas aeruginosa. Although there were some differences among microorganisms, minimum inhibition concentrations(MIC) in acidic and phenolic fractions against tested microorganisms were 0.05 to 0.1 g eq./ml and 0.01 to 0.25 g eq./ml, on the basis of fresh sample weight, respectively. Minimum lethal concentrations(MLC) in acidic and phenolic fractions were 0.25 to 2.00 g eq./ml and 0.05 to 1.50 g eq./ml, respectively. These supposed the antimicrobial activities in phenolic fraction were generally higher than those in acidic fraction and also phenolic fraction had lower MIC and MLC values than acidic fraction.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.400-406
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• 1997

Chemical composition and antimicrobial activity of Houttuynia cordata Thunb. were investigated to develop a natural food preservative from it. Aspartic acid, glutamic acid, glycine and arginine were major amino acids of Houttuynia cordata Thunb., but were present in a trace amount. Free sugars were composed of glucose, fructose, sucrose and maltose and major fatty acids were linolenic acid, linoleic acid, oleic acid, and palmitic acid. Mineral elements were potassium, calcium, magnesium, iron, zinc, and copper. Antimicrobial activities were shown in acidic, neutral and phenolic fraction of Houttuynia cordata Thunb., but not in basic fraction. Among the four fractions, neutral fraction showed the strongest antimicrobial activities against microorganisms tested, such as Pseudomnas aeruginosa, Micrococcus luteus, Bacillus subtilis, Aspergillus parasiticus and Aspergillus flavus. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the neutral fraction varied according to microoganisms tested. The lowest values of MIC (0.0075 g eq./mL) and MLC (0.10 g eq./mL) were obtained from Pseudomonas aeruginosa.