• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.511-517
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• 1988

Kimchi, a traditional vegitable fermented food in Korea, was prepared and fermented at $5^{\circ}C$ in order to analyze the taste and flavor compounds. Major flavor components were identified as dimethyl-disulfide, dimethyl-trisulfide, dipropyl-disulfide, 1-butane 1-isothiocyanate, diallyl-disulfide by GC and GC/MS. Some organic acids such as lactic acid and citric acid increased from 1.2mg/100g and 5.4mg/100g in the initial stage to 33.3mg/100g and 44.4mg/100g at the end of fermentation, respectively. Free amino acids in kimchi were found to play an important role for the taste. The contents of total free amino acid increased from 316.3mg/100g to 600mg/100g in the fermented kimchi and glutamic acid, alanine, valine, leucine, lysine and arginine were abundant in kimchi. The results of sensory evaluation showed that the taste of kimchi was closely related to the contents of non-volatile organic acid, free amino acid and pH.

• Food Science and Preservation
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• v.18 no.5
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• pp.803-810
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• 2011

This study was performed to evaluate the quality of the commercial brown-rice vinegars of South Korean and Japanese origins, which were prepared via static acetic-acid fermentation. The major free amino acids of Korean brown-rice vinegars were proline, glutamic acid and phenylalanine, while those of the Japanese were proline, valine, phenylalanine, lysine, ${\gamma}$-aminobutyric acid, alanine and isoleucine. The ${\gamma}$-aminobutyric acid (GABA) and total amino acids (3686.37~4212.27 mg%) contents were found to be significantly higher in the Japanese than in the Korean brown-rice vinegars. The key volatile compounds of the Korean brown-rice vinegars, analyzed with GC-MS, were acetic acid, benzaldehyde, phenethyl alcohol and phenethyl acetate while those of the Japanese brown-rice vinegars were acetic acid, ethyl acetate, ethyl alcohol, isoamyl acetate, phenethyl acetate and benzaldehyde. The volatile patterns of the Korean and Japanese commercial brown-rice vinegars were effectively distinguished from each other using an electronic nose, through which it was also elucidated that the volatiles profiles were similar among the Japanese vinegars but were different among the Korean vinegars.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.539-547
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• 2013

This study investigates the change of chemical components, antioxidant and antimutagenic activity in Glycyrrhiza uralensis Fischer stems and leaves (GU) by the various processing methods, as follows: fresh (GU-1), dried under the shade (GU-2), blanched (GU-3), roasted 3 times (GU-4), roasted 4 times (GU-5). The components have been identified and quantified through the use of gas chromatograph-mass spectrometry (GC-MS). At results, cis-1,3-dimethyl-2-methylenecyclohexaneat at 19.7 min and n-hexadecanoic acid at 21.5 min were detected in five kinds of extract. 3-O-Methyl-D-fructose at 17.8 min was observed in four extracts except in GU-1 and aminopyrazine at 19.8min was observed in four extracts except in GU-4. The total phenolics contents was high in GU-4(3.38 g/100 g). ABTS radical scavenging was high in GU-5($EC_{50}$, 0.57 ug) and DPPH radical scavenging was high in GU-4($EC_{50}$, 2.66 ug). The extracts of GU-3, GU-4, and GU-2 were most potent in anti-mutagenicity activity against 1-NP, Trip-P-1, and Trip-P-2, respectively. GU-3 and GU-4 also showed most potent effect of anti-mutagenicity on 2-AA and AFB1, respectively.

• Food Science and Preservation
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• v.11 no.4
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• pp.544-549
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• 2004

Major components and antioxidant activity of fermented tea were investigated. Contents of total flavonoid and total phenol showed the highest score in ethanol extract ($481.4\;{\mu}g/g$ and 33.5 g/100g), respectively. Their contents in hot water extract ($405.7\;{\mu}g/g$ and 23.6 g/100g) were lower than those of the others extracts. However, their contents of ethyl acetate extract($495.2\;{\mu}g/g$, 39.5 g/100g) from fermented tea stored for 1 year had the highest amount among all tested samples. Catechins of fermented tea were found to be EGC, GC, catechin, catechol and EGCG. However, they were not detected in hot water extract. Scavenging activities of DPPH free radical of all extracts from fermented tea were increased in proportion to their concentration and were $72.4\%$ for fermented tea and $80.9\%$ for fermented tea stored for 1 year. Reducing power of ethanol extract at $500\;{\mu}g/mL$ were 0.78 as OD value of 700 nm for fermented tea and 0.88 for fermented tea stored for 1 year, respectively. Antioxidant activities of ethyl acetate extracts at $3000\;{\mu}g/mL$ were $86.6\%$ for fermented tea and $73.7\%$ for fermented tea stored for 1 year, respectively.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.120-124
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• 2007

Fusarium proliferatum KGL0401 was previously isolated from Physalis alkekengi var. francheti plant roots and exhibited higher GA productivity than wild type Gibberella fujikuroi. The :tim of this work was to find out an optimal culture condition for GA production. Various carbon(fructose, glucose, lactose, maltose, sucrose) and nitrogen($KNO_3$, urea, glycine, $NaNO_3,\;NH_4Cl$) sources were used for this study. GAs activities were analysed by gas chromatography and mass spectrometry(GC-MS). The highest yield of $GA_3$ was found in the growth medium supplemented with sucrose as carbon source and $NH_4Cl$ as nitrogen source. The optimum carbon-nitrogen concentration for $GA_3$ production was found to be 0.5 M:0.17 M. Supernatant was prepared from the culture fluid of F. proliferatum KGL0401 cultured for 7 days at 3 0'E and the 10 ul supernatant was treated with 2 leaf-rice seedling.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1050-1056
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• 2000

To identify the irradiation-induced volatile flavor compounds, which were not detected in unirradiated sample and had positive correlation with the increment of irradiation dose, the volatile flavor compounds of irradiated (0, 1, 3, 5, 10 kGy) chicken were analyzed by liquid liquid continuous extraction (LLCE) and gas ehromatographyimass spectrometry (GC/MS) methods. One hundred twenty nine compounds were detected in irradiated chicken, and these compounds were composed mainly of hydrocarbons (62 compounds), aromatic compounds (44), aldehydes (9), ketones (5) and miscellaneous compounds (10). Among these, only 3 volatile compounds including 2-methylpentanal (r=0.24), 4-methylcyclohexene (r=0.08) and cyclotetradecene (r=0.92), were detected as irradiation-induced volatile flavor compounds in irradiated chicken. However, only cyclotetradecene was selected as a marker compound for detecting irradiation dosages with high correlation coefficient in irradiated chicken.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.905-910
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• 2002

4-Hydroxyalkenals are cytotoxic aldehydes generated by the oxidation of n-6 and n-3 polyunsaturated fatty acids. To evaluate the potential risk of 4-hydroxyalkenals on Koreans, quantitative data of various oils are necessary. Simultaneous monitoring of 4-hydroxyhexenal and 4-hydroxynoneal in 39 samples including new and used ones through single ion monitoring mode of GC/MS detected both aldehydes in all samples tested, ranging from 0.21 to 26.9 nmol/g for 4-hydroxy-2-hexenal and 0.06 to 56.6 nmol/g for 4-hydroxy-2-nonenal. Frying oils collected from local markets showed 2.28-7.90 and 8.31-30.5 nmol/g of 4-hydroxyhexenal and 4-hydroxynoneal, respectively. National health and nutrition survey data were employed to determine the exposure effect to these 4-hydroxyalkenals from the four most consumed oils in Korea. Daily exposures to hydroxyalkenals excluding possible exposure from fried food were $1.9\;{\mu}g$ from soybean oil, $0.5\;{\mu}g$ from sesame oil, $0.2\;{\mu}g$ from corn oil, and $0.1\;{\mu}g$ from perilla oil. Due to the increasing consumption of polyunsaturated fatty acids in Korea, these data may provide valuable information for evaluating possible physiological effects of 4-hydroxyalkenals from vegetable oils.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.596-602
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• 1991

The comopositon of lipids extracted from corn embryo with various solvents were analyzed. The solvents for the extraction were benzene(BZ), n-hexane(HX), pet. ether(PE), trichlorethylene (TE), chloroform-methoanol(2:1, v/v) (CM), dichlormethane - methanol(2:1, v/v)(DM) and hexanediethyl ether(5:1, v/v)(HD). The lipids were than fractinated by silicis acid column chromatography(SACC) into three lipid fractions. The Neutral lipid fractons were further separated by thin layer chromatography(TLC) and the individual lipid spots were quantitatived by TLC scanner. And then the fatty acid compositions of total lipids and neutral lipids were determined by gas chromatography(GC). Crude oil contents of corn embryo were most efficient by using DM, CM and neutral lipid was extracted much HX, BZ, HD systems than did PE, DM, DM an CM were most efficient solvent systems for extracting glycolipid and phospholipid. The major component of the neutral lipid fractions was found to be triglyceride, and it was superior DM to PE. Linoleic acid was the predominant fatty acid in the total lipids, and it was most efficient with BZ and TE. The major fatty acid in neutral lipids was also linoleic acid and it was superior BZ to PE, CM, HD and oleic acid was similar to seven solvents and palmitic acid was found much superior in using CM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.236-242
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• 2005

To develop a new detection method using irradiation-induced volatile marker compounds of red pepper powder (RP), the volatile compounds of irradiated RP (0, 1, 3, 5, and 10 kGy) were analyzed by purge and trap (P&T)/solid phase microextraction (SPME)/gas chromatography/mass spectrometry (GC/MS) methods. A total of 51 and 31 compounds were detected in IRP by SPME and P&T methods, respectively. Among these, 25 compounds, which were composed of 4 hydrocarbons, 7 aldehydes, 1 ketone, 3 alcohols, 4 aromatic compounds, 2 esters and 4 miscellaneous compounds, showed irradiation dependent manner with significant positive correlation (p<0.01 or p<0.05) between irradiation dose and relative concentration. However, all compounds except 1,3-bis(1,1-dimethylethyl)benzene were not suitable as marker compounds because of their low determination coefficients ($R^2$<0.80) between irradiation dose and their concentrations, and detectablilty in nonirradiated sample. Therefore, only one compound, 1,3-bis(1,1-dimethylethyl)benzene, was tentatively identified as a volatile marker compound to detect irradiated RP.

• Journal of Adhesion and Interface
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• v.16 no.4
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• pp.146-151
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• 2015

Raw sap of essential oil in Korean Dendropanax lacquer was extracted with ethanol, and which was cured by using ROMP (ring opening metathesis polymerization, one of olefin metathesis). Curing behavior with subsequent film properties were studied and compared with conventional curing (under ambient conditions) and UV photo curing. The compositional changes of major ingredients in the lacquer before and after curing were studied by using GC-MS (gas chromatography mass spectrometry). ROMP-cured coating film showed higher gel contents (40%) as compared to those of conventional (8%) and UV curing (25%). ROMP curing with 2 wt% Grubbs' catalyst at $100^{\circ}C$ completed curing reaction within 2 h, which was much faster than that of conventional curing. The quality of coating film prepared with ROMP was more homogeneous and wrinkle-free as compared with that with UV curing. It was found that major ingredients of sesquiterpenes, such as ${\alpha}$-selinene, ${\beta}$-selinene, and ${\delta}$-cadinene were reacted in ROMP, as well as polyacetylenes.