• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1637-1642
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• 2007

The objectives of this study were to compare the aroma characteristics and antioxidant activity of raw and heated garlic ($130^{\circ}C$, 2 hr) from different cultivation areas (Danyang, Seosan, Uiseong Namhae, Namdo, Daeseo and China). The volatile compounds were extracted by simultaneous steam distillation extraction and identified with gas chromatography/mass spectrometer. The major volatile compounds of raw garlic were sulfur compounds such as diallyl disulfide, methyl-2-propenyl trisulfide, di-2-propenyl trisulfide etc. After heating, the major volatile compounds were allyl mercaptan, methyl pyrazine, 2,2-dimethyl-1,3-dithiane, 2-propenyl propyl disulfide, allyl methyl sulfide, allyl alcohol, and allyl sulfide etc. The DPPH radical scavenging activity (EDA, %) of volatile compounds from raw garlic and heated garlic was increased in a dose-dependent manner. The antioxidant activities (EDA, %) of volatile compounds from raw garlic cultivated in Danyang, Namhae and China were 20.07, 34.62, and 9.71% respectively. After heating, these values were increased to 79.90, 93.59, and 77.26% respectively. Results showed that heat treatment significantly enhanced the antioxidant activities (EDA, %) of the garlic.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.78-83
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• 2005

Purge & Trap method was applied to perform more simple and rapid detection for analysis of volatile flavor compounds in milk. Maximal sampling of 30 mL milk for glass flask sparger was treated by He gas purging for 2 hours. Reported major volatile compounds were detected by GC-MS after 2 hours absorption and desorbed from Purge & Trap equipped with Tenax trap. Volatile flavor compounds were analyzed by Purge & Trap and GC-MS to investigate the changes of flavor components in milk between raw and deodorized milk. Fourteen volatile compounds including acetaldehyde, ethanol, 2-propanone, dimethyl sulfide, isobutanal, 3-methyl 2-butanone, 2-butanone, 3-methyl butanal, pentanal, 3-hydroxy-2-butanone, methyl disulfide, hexanal, and 2 others were detected. Six compounds such as ethanol, dimethyl sulfide, pentanal, 3-hydroxy-2-butanone, and methyl disulfide were completely eliminated after deodorization treatment. Four compounds such as 3-methyl 2-butanone, 2-butanone, 3-methyl butanal, and an unknown compound 81 (M/sup +/) were also decreased after raw milk was deodorized. The other four compounds such as acetaldehyde, 2-propanone, hexanal, and an unknown compound (M/sup +/) were not decreased.

• Journal of Korean society of Dental Hygiene
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• v.11 no.2
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• pp.263-275
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• 2011

Objectives : This study was performed analysis of Halitosis components following by subjective cognition of halitosis and Oral State in order to provide basic data for halitosis prevention and establish a device to efficiently eliminate halitosis and analyze the factors that affect the halitosis. Methods : 80 adults were participated who visited at the Dental Clinic in Kyoung-gi do, on the period of the March to September in 2010. The obtained results, through the oral examination, halitosis check and interview, Individually, were as followings. Results : According to the ammonia level was a high relationship between sex, CPI, Tongue plaque, DMFT index which were statistically significant (p<0.05). Total oral gas level was a relationship between VAS, tongue plaque, DMFT index(p<0.05). The Correlation coefficient between the Hydrogen sulfide level and Methyl mercaptan was estimated as r=0.534(p<0.01). As for the multiple regression analysis result, there have been selected dimethyl sulfide and Tongue plaque, Gingival index as factors affecting Bridge, Methyl mercaptan level is as factors affecting Hydrogen sulfide level. Conclusions : There was relationship between the periodontal disease and Ammonia gas component, hydrogen sulfide, dimethyl sulfide, methyl mercaptan. Which were statistically significant total oral gas level and oral variables. Such dental caries as the prevention or early treatment of periodontal disease.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1971-1978
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• 2013

The aim was to be utilized as basic data in arranging efficient plan for removing halitosis by surveying correlation with halitosis components by each factor after measuring halitosis and analyzing components by subject of adults on halitosis. It targeted totally 160 people by 80 outpatients of 1 dental hospital, respectively, where is located in Daejeon and Chungnam, for 12 months from February 1, 2011 to January 30, 2012. As a result of analysis, in the halitosis measurement value of Oral chroma, it was shown to be 9.4% in case of being more than 112ppb in the measurement value of hydrogen sulfide, 20.6% in case of being more than 26ppb in the measurement value of methyl mercaptan, and 44.0% in case of being more than 8ppb in the measurement value of dimethyl sulfide, which was indicated to be the highest value among three components. Only the methyl mercaptan component and the dimethyl sulfide component, which were measured with oral chroma, stood at 0.578, thereby having been shown to have high positive correlation. Accordingly, a multilateral research is considered to be likely necessity as for diverse components of causing halitosis.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.313-318
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• 1987

The approximate rate and stoichiometry of the reaction of excess Thexylbromoborane-methyl sulfide, $ThxBHBr{\cdot}SMe_2,$ with selected organic compounds containing representative functional groups under standardized conditions (methylene chloride, $0^{\circ}C)$ were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The selectivity of the reagent was also compared to the selectivity of thexylchloroborane-methyl sulfide. Thexylbromoborane appears to be a much milder and hence more selective reducing agent than thexylchloroborane. The reagent tolerates many organic functionalities. Thus, the reagent shows very little reactivity or no reactivity toward acid chlorides, esters, epoxides, amides, nitro compounds including simple olefins. However, this reagent can reduce aldehydes, ketones, carboxylic acids, nitriles, and sulfoxides. Especially the reagent reduces carboxylic acids including ${\alpha},{\beta}$ -unsaturated ones and nitriles to the corresponding aldehydes. In addition to that, thexylbromoborane shows good stereoselectivity toward cyclic ketones, much better than the chloro-derivative.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1515-1518
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• 2007

A preparative method of Me2SCuX (X = Cl, Br) via one-pot reaction was developed from common chemicals such as benzyl halide, DMSO, and Cu(0). In the reaction mixture small molecules such as methyl halide and dimethyl sulfide etc. were efficiently generated in situ, resulting in the formation of Me2SCuX. Oxidation of Cu(0) in reacting with both benzyl halide (starting material) and methyl halide (in situ generated product) to Cu(I) followed by complexing with dimethyl sulfide (in situ generated product) could explain the formation of Me2SCuX. In particular we found out that heterogeneous reaction of Me2SCuX and arenediazonium tetrafluoroborate in acetonitrile was so effective to afford corresponding bromoaromatics under mild conditions.

• Journal of Life Science
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• v.12 no.1
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• pp.26-31
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• 2002

Choline esters that are used with substrate of BChE-catalyzed hydrolyses were synthesized by two methods. First, 2-chloroethyl thiohexanoate, 2-chloroethyl thioheptanoate, and 2-chloroethyl thiooctanoate were synthesized by the treatment of hexanoyl chloride with ethylene sulfide. Hexanoyl thiocholine and octanoyl thiocholine were synthesized by using 2-chloroethyl thiohexanoate and 2-chloroethyl thiooctanoate with trimethyl amine. Second, after reaction of ethylene sulfide and dimethyl amine, followed by acylation with acid anhydride and then heptanonyl thiocholine, decanoyl thiocholine were synthesized by treatment of methyl iodide.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.230-235
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• 2005

Volatile organic components from fresh and freeze-dried onions were extracted by SDE apparatus and analyzed by GC/MS. Components of 40 and 31 were identified in fresh and freeze-dried onions respectively. These components included esters, aldehydes, ketones, alcohols and S-containing compounds. Major compounds of S-containing compounds such as 1-propanethiol, dipropyl trisulfide, and methyl propyl trisulfide in fresh onions were clearly decreased in freeze-dried onions. Then, S-containing compounds such as methyl allyl sulfide, propyl ally sulfide, dially disulfide and 3,5-diethyl-l,2,4-trithiolane and alcohols such as pentanol, hexanol and propanol were disappeared by freeze-drying. Exceptionally, ethyl acetate, dimethyl disulfide and 2-methyl-2-pentenal were increased as different trend with major S-containing compounds. (Z)-Propenyl methyl disulfide and (E)-propenyl methyl disulfide were also changed by freeze-drying in the similar pattern as mentioned above compounds.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.666-671
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• 1999

In this work, sulfonated poly(phenylene sulfide) (SPPS) was prepared by demethylation with aqueous NaOH solution after poly[methyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate](PPST) was sulfonated with fumic sulfonic acid(10% $SO_{3}-H_{2}SO_{4}$). PPST soluble in organic solvents was synthesiszed by self-condensation polymerization of methyl-(phenylthio)phenyl sulfoxide(MPPSO). SPPS showed IR bands of asymmetric O=S=O stretching at $1200cm^{-1}$ and S-O stretching at $621cm^{-1}$ from $-SO_{3}H$ group. From the result, it could be known that sulfonic acid groups were introduced to poly(phenylene sulfide). when PPST was sulfonated for 12hr at $150^{\circ}C$, 1.48 sulfonic acid groups were introduced per repeat unit. The weight average molecular weight(Mw) of PPST and SPPS determined by high temperature GPC were 118323 and 131204, respectively. The SPPS exhibited adsorption capacity of ammonia gas $9.67mmol\;NH_{3}/g$ and it was much higher than that of active carbon or silica gel.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.301-304
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• 1987

A systematic study of the partial reduction of nitriles to the corresponding aldehydes with thexylbromoborane-methyl sulfide $(ThxBHBr{\cdot}SMe_2)$ under practical conditions has been carried out. The yields of aldehydes are good in the aliphatic series. However, the yields of aromatic series vary with substituents and ring itself.