• Food Science and Biotechnology
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• v.17 no.5
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• pp.1032-1037
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• 2008

Lowly volatile heterocyclic sulfur compounds generated in autoclaved garlic extract were isolated and identified, and their antimicrobial activity was determined. Two kinds of unusual volatile sulfur compounds were separated from heated garlic by preparative recycling high performance liquid chromatography (HPLC), and identified by gas chromatography (GC)-mass spectrometry (MS) and $^1H$-nuclear magnetic resonance (NMR). They had heterocyclic structures with 4 to 5 sulfur atoms in the molecules. 4-Methyl-1,2,3-trithiolane (MTTT) is highly volatile and was not able to be concentrated, and was identified by GCMS only. MTTT and 6-methyl-1,2,3,4,5-pentathiepane (MPTP) are lowly volatile and were obtained in pure states to be positively identified for the first time. All 3 heterocyclic sulfur compounds began to appear by the time when the early-formed diallyl sulfides started to disappear. The minimum inhibitory concentration range of MTTT and MPTP was determined to be between 1 and 6 ppm against all yeasts tested. MTTT and MPTP were lowly volatile and sparingly soluble in water.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.579-589
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• 2009

This study was conducted to investigate the effects of heating, fiber type used in solid-phase microextraction (SPME, two phase vs three phase) and storage time on the volatile compounds of porcine M. longissimus dorsi (LD). Volatile compounds were measured using a gas chromatography and mass spectrometry (GC/MS) with a quadrupole mass analyzer. Among the volatile compounds identified, aldehydes (49.33%), alcohols (24.63%) and ketones (9.85%) were higher in pre-heated loins ($100^{\circ}C$/30 min), whereas, alcohols (34.33%), hydrocarbons (22.84%) and ketones (16.88%) were higher in non-heated loins. Heating of loins induced the formation of various volatile compounds such as aldehydes (hexanal) and alcohols. The total contents of hydrocarbons, alcohols, and carboxylic acids were higher in two phase fibers, whereas those of esters tended to be higher in three-phase fibers (p<0.05). Most volatile compounds increased (p<0.05) with increased storage time. Thus, the analysis of volatile compounds were affected by the fiber type, while heating and refrigerated storage of pork M. longissimus dorsi increased the volatile compounds derived from lipid oxidation and amino acid catabolism, respectively.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.24-29
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• 2015

Objectives: The objective of this study was to identify determine factors for blood VOCs levels in college students. Methods: Venous blood samples were collected from healthy 29 male and 25 female volunteers. The samples were analyzed with solid-phase microextraction gas chromatography and mass spectrometry. Results: Blood concentrations of benzene, toluene, ethylbenzene, m-,p-xylene, o-xylene were higher in smoking group than in non-smoking group. Geometric means of smoking group and non-smoking group were 0.45 and $0.36{\mu}g/L$ in benzene, 0.82 and $0.47{\mu}g/L$ in toluene, 0.44 and $0.41{\mu}g/L$ in ethylbenzene, 0.49 and $0.39{\mu}g/L$ in m-,p-xylene and 0.47 and $0.43{\mu}g/L$ in o-xylene, respectively. Gender, alcohol drinking, coffee, commuting time (30 minutes) by a car and adjacency between home and road were not associated with increasing blood VOCs concentrations of college students. Conclusion: Smoking habit was significantly associated with blood concentrations of benzene, toluene, ethylbenzene, o-,m-,p-xylene in college students.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.76-85
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• 2009

This study determined the effect of refrigerated and thermal storage on the volatile profile of commercial aseptic soymilk. Volatile components in commercial aseptic soymilk stored either under refrigerated ($4^{\circ}C$) or thermal ($55^{\circ}C$) conditions for 30 days were periodically analyzed by combined solvent-assisted flavor evaporation-gas chromatography-mass spectrometry (SAFE-GC-MS). The concentrations of most of the volatile components, including aldehydes, ketones, alcohols, acids, nitrogen- and sulfur-containing compounds, alkylfurans, furan derivatives and phenolic compounds, were affected to a greater extent by thermal storage compared with refrigerated storage. Profound increases in some volatile compounds with low odor detection thresholds, such as hexanal, octanal, (E)-2-octenal, (E,E)-2,4-decadienal, 1-octen-3-ol, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 2-pentylfuran, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, dimethyl trisulfide, guaiacol, 4-vinylguaiacol and 4-vinylphenol, were observed in thermal stored soymilk. The volatile profile changes caused by thermal storage may influence the aroma quality of thermal-stored aseptic soymilk.

• Toxicological Research
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• v.31 no.3
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• pp.273-278
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• 2015

The aim of this study was to develop an efficient quantitative method for the determination of acetaldehyde (AA) and formaldehyde (FA) contents in solid and liquid food matrices. The determination of those compounds was validated and performed using gas chromatography-mass spectrometry combined by solid phase micro-extraction after derivatization with O-(2,3,4,5,6-pentafluoro-benzyl)-hydroxylamine hydrochloride. Validation was carried out in terms of limit of detection, limit of quantitation, linearity, precision, and recovery. Then their contents were analyzed in various food samples including 15 fruits, 22 milk products, 31 alcohol-free beverages, and 13 alcoholic beverages. The highest contents of AA and FA were determined in a white wine (40,607.02 ng/g) and an instant coffee (1,522.46 ng/g), respectively.

• Journal of Life Science
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• v.11 no.1
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• pp.35-42
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• 2001

Irradiation-induced volatile flavor compounds in irradiated (0, 1, 3, 5, 10 kGy) pork meats were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred nine volatile compounds were detected in irradiated pork meats. These compounds were mainly composed of hydrocarbons (42 compounds), aromatic compounds (39), aldehydes(9), ketones(5) and miscellaneous compounds (14). Among these, three volatile compounds, such as decene, 1,2,3,4,-tetrahydro-6-methylnaphthalene and 1,2,3,4-tetrahydro-dimethylnaphthalene were selected as irradiation-induced compounds comparing with irradiation dosages in irradiated pork meats. By the high correlation coefficient with the increment of irradiation dose, however, decene (r=0.93) was considered as marker compound for detecting irradiation dosage in fresh pork meats.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.946-951
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• 2005

Biodegradation of the endocrine-disrupting chemical di-n-butyl phthalate (DBP) was investigated using a bacterium, Pseudomonas fluorescens B-1, isolated from mangrove sediment. The effects of temperature, pH, salinity, and oxygen availability on DBP degradation were studied. Degradation of DBP was monitored by solid-phase extraction using reversed-phase HPLC and UV detection. The major metabolites of DBP degradation were identified as mono-n-butyl phthalate and phthalic acid by gas chromatography-mass spectrometry (GC-MS) and a pathway of degradation was proposed. Degradation by P. fluorescens B-1 conformed to first-order kinetics. Degradation of DBP was also tested in seawater by inoculating P. fluorescens B-1, and complete degradation of an initial concentration of $100{\mu}g/l$ was achieved in 144 h. These results suggest that DBP is readily degraded by bacteria in natural environments.

• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.14-20
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• 2018

Purpose: The purpose of this study was to investigate the performance of a vacuum pyrolysis system, to analyze bio-oil characteristics, and to examine the applicability for farm-scale capacity. Methods: The biomass was pyrolyzed at 450, 480, and $490^{\circ}C$ on an electric heat plate in a vacuum reactor. The waste heat from the heat exchanger of the reactor was recycled to evaporate water from the bio-oil. The chemical composition of the bio-oil was analyzed by gas chromatography-mass spectrometry (GC-MS). Results: According to the analysis, the moisture content (MC) in the bio-oil was approximately 9%, the high heating value (HHV) was approximately 26 MJ/kg, and 29 compounds were identified. These 29 compounds consisted of six series of carbohydrates, 17 series of lignins, and six series of resins. Conclusions: Owing to low water content and the oxygen content, the HHV of the bio-oil produced from the vacuum reactor was higher by about 6 MJ/kg than that of the bio-oil produced from a fluidized bed reactor.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.180-185
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• 2006

Two different extraction procedures, SDE and SPME, were employed to determine a comprehensive and efficient fragrance profile of Korean Rosa hybrida. Both extraction methods could compensate for each other, covering compounds with diverse boiling point, polarities, and chemical properties. A total of 46 compounds were identified in Mi-hyang. The identified compounds were composed of 17 alcohols, 14 carbonyls, 7 aliphatic hydrocarbons, 2 terpene hydrocarbons, 4 benzenes, 1 ester, and 1 miscellaneous compound. Quantitatively, carbonyls($12.96{\sim}21.79%$ in essential oils of SDE and $2.89{\sim}8.44%$ in SPME headspace) and alcohols($7.98{\sim}11.73%$ in essential oils of SDE and $3.39{\sim}17.35%$ in SPME headspace) were dominant in Mi-hyang's volatiles.

• Journal of Aquaculture
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• v.18 no.3
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• pp.200-206
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• 2005

We previously pointed out that the polluted sediment elutriate manifestly affected the early events of reproductive outputs in the Pacific oysters, Crassostrea gigas. A serial dilution of priority xenobiotic sediment elutriates determined by gas chromatography/mass spectrometry (GC/MS) were exposed to gametes of the oyster with different stress burdens to detail the maternal stress transfer to its reproductive outputs. There was an apparent critical concentration over which survival and morphogenesis were significantly affected with more profound damage in morphogenesis. The critical concentration which drives mortality and abnormal morphogenesis of the larvae corresponded to a dilution between 10 and 20% of our elutriate. The adverse effects of the early lives by the xenobiotic exposure over the critical concentration were magnified by the maternal stress from the exposed benzo(a)pyrene (BaP), one of the priority polyaromatic hydrocarbons (PAHs) during the maturation condition. These results indicate that maternal transfer of the xenobiotic compounds from oysters living in the contaminated location might represent a significant adverse effect to their larval population of wild seeds.