• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.483-489
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• 2014

This study aimed at a scientific examination of the relationship between NVOCs concentration and the physical environment of red pine forest in spring season. Atmospheric NVOC samples in red pine forest was collected through five trials conducted from March to May 2013, using Tanax-Ta-charged disposable tubes and mini-pumps. At each trial, measurements were taken at three different points in daytime (sunrise, southing and sunset). For maximum accuracy, two tubes were used for each measurement at the same location, and the mean value was used for analysis. Compound analysis on the NVOC samples was done using the HS-SPME method and GC-MS. Analysis of the relationship between NVOC and the physical forest environment found higher concentrations of most substances, including ${\alpha}$-pinene and ${\beta}$-pinene, with higher temperature, dew point, and lower concentrations with higher wind velocity. The findings of this study offer scientific evidence which can inform the creation of 'healing forests' and 'recreational forests' as well as forest environment in general, helping to promote public health and recreational activities.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.152-164
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• 2018

Fermented seasoning pastes were prepared by Aspergillus oryzae and Bacillus subtilis using three edible insects, Tenebrio molitor larvae (TMP), Gryllus bimaculatus (GBP), and Bombyx mori pupa (SPP), with soybean (SBP) as a negative control. Volatile compounds were extracted by the headspace solid-phase microextraction (HS-SPME) method and confirmed by gas chromatograph-mass spectrometry (GC-MS). In total, 121 volatiles from four samples were identified and sub-grouped as 11 esters, 18 alcohols, 23 aldehydes, 5 acids, 10 pyrazines, 2 pyridines, 7 aromatic hydrocarbons, 10 ketones, 19 alkanes, 9 amides, 4 furans and 3 miscellaneous. TMP, GBP, SPP and SBP had 48, 54, 36, and 55 volatile compounds, respectively. Overall, 2,6-dimethylpyrazine and trimethylpyrazine were found by a high proportion in all samples. Tetramethylpyrazine, a main flavor of doenjang, a Korean fermented seasoning soybean paste, was identified as one of the major compounds in TMP, SPP, and SBP. SBP had benzaldehyde, hexanal, n-pentanal, and aldehydes and SPP with pyrazines.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.267-273
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• 2013

We aimed to improve the flavor quality of plain yogurt, which is known to be sour and less desirable in flavor, varying concentrations of a buckwheat saccharification solution (BSS) were added to milk, followed by fermentation with commercially available mixed strains of lactic acid bacteria. Volatile compounds were analyzed using the gas chromatography-headspace-solid phase microextraction (GC-HS-SPME) method. Fermentation properties, including pH, titratable acidity, viable cells, viscosity, and color value were also measured. Eleven volatile compounds were identified with GC-MS. Of which, diacetyl, butanoic acid, and 2-heptanone proportionally increased as the levels of BSS increased. Undesirable compounds such as acetic acid and 2-butanone, decreased as BSS concentration increased. Fermentation properties were significantly altered with the addition of BSS. Our findings indicate that the flavor quality of plain yogurt can be improved by adding BSS for fermentation, with an additional health benefit from buckwheat.

• Analytical Science and Technology
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• v.24 no.2
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• pp.119-126
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• 2011

Abstract: The amount of benzene, toluene, ethylbenzene, and o-xylene (BTEX) in 30 kinds of bottled waters purchased from market and 9 kinds of tap waters from home were determined using headspace solid phase microextraction (HS-SPME). The sample was stirred at 1200 RPM G for 4 min using a magnetic bar with $100\;{\mu}m$ PDMS as adsorbent for BTEX. Then it was desorbed from the fiber for 1 min at room temperature. Quantitation was achieved using standard calibration method. The limit of detection was determined as benzene 0.39 (${\pm}0.04$) ng/mL, toluene 0.08 (${\pm}0.04$) ng/mL, ethylbenzene 0.04 (${\pm}0.01$) ng/mL, and o-xylene 0.05 (${\pm}0.02$) ng/mL. Benzene and o-xylene were not detected in any samples, but toluene was detected in 11 samples, and ethylbenzene was detected just in 3 samples among 30 investigated bottled waters. The concentration range of investigated materials for toluene and o-xylene were $0.24({\pm}0.09)\sim2.95\;({\pm}0.08)\;ng/mL$, $0.08({\pm}0.06)\sim0.93({\pm}0.10)\;ng/mL$, respectively.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2691-2696
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• 2013

The electronic cigarette (E-cigarette) is a battery-powered device that aerosolizes nicotine so that it is readily delivered into the respiratory tract. The analytical data regarding the substances present in E-cigarettes are very limited. The aim of this study was to measure the concentration of aldehydes-formaldehyde (FA), acetaldehyde (AA) and, acrolein (AL)-in 225 replacement liquid brands from 17 E-cigarette shops sold in the Republic of Korea by headspace solid-phase micro extraction and gas chromatography-mass spectrometry (HS-SPME GC-MS). The concentration range of FA and AA was 0.02-10.09 mg/L (mean = 2.16 mg/L, detected in 207 of 225 samples) and 0.10-15.63 mg/L (mean = 4.98 mg/L, detected in all samples), respectively. AL was not detected in any of 225 replacement liquids. FA and AA were originally present in almost all replacement liquids of electronic cigarettes.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1495-1499
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• 2009

The volatiles formed from the reactions of L-ascorbic acid with L-alanine at 5 different pH (5, 6, 7, 8, or 9) and $140{\pm}2^{\circ}C$ for 2 hr was performed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis were identified to be 25 different kinds. The reaction between L-ascorbic acid and L-alanine led mainly to the formation of pyrazines. Many of these were alkylpyrazines, such as 3-ethyl-2,5-dimethylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, 3,5-diethyl-2-methylpyrazine, methylpyrazine, 2-ethyl-6-methylpyrazine, and 2,3-diethyl-5-methylpyrazine, other compounds identified were furans, phenols, benzoquinones, 2,4,6-trimethylpyridine, and 2-methylbenzoxazole. The studies showed that furans, such as furfural and benzofuran were formed mainly at acidic pH. In contrast, higher pH values could promote the production of pyrazines.

• Analytical Science and Technology
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• v.21 no.4
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• pp.259-271
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• 2008

The analytical method of extracting compounds from human blood to examine accumulated organochlorine pesticides (OCPs) has been widely used the traditional liquid-liquid extraction (LLE) method and solid-phase extraction (SPE) method, yet these methods have certain limitations in purification and usafe of a large amount of sample. In order to overcome the se problems reside in these, solid-phase microextraction (SPME), known as a highly efficient extration method with less samples and relatively simple, was employed to collect 18 different kinds of OCPs in blood as extraction method in this study. To optimize extraction method, we examine various experimental SPME-parameters such as adsorption (fiber type, adsorption time, adsorption temperature, salting out effect), and desorption (desorption time, desorption temperature etc.). From the experimental results, the optimal conditions are as follows: fiber was polyacrylate with $85{\mu}m$, adsorption time was for 5 min, adsorption optimum temperature was at $280^{\circ}C$, and salting out effect was NaCl with 0.1 g. MDL, precision and accuracy was in the ranges of 0.05~0.20 ng/mL, 5.59~13.39%, respedively, and accuracy was -0.5% ~24.5% for all OCPs.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.383-389
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• 2012

Green tea leaves grown in Jeju island were harvested at different times in 2010 and 2011. Green teas harvested in 2010 experienced higher effective accumulative temperature than green teas harvested in 2011. The free and bound volatile compounds in green tea were analyzed using headspace-solid phase microextraction gas chromatography (GC) and GC-mass spectrometry. All green teas contained the 6 major volatile compounds ${\alpha}$-methylbutanal, pentanal, (E)-2-hexen-1-ol, ${\beta}$-linalool, geraniol and ${\alpha}$-farnesene. After enzyme treatment, (Z)-3-hexen-1-ol, benzaldehyde, (Z)-3-hexenyl acetate, ${\beta}$-linalool and geraniol were increased in all green teas. (Z)-3-hexen-1-ol increased significantly in green tea harvested in 2010, and benzaldehyde increased widely in green tea harvested in 2011. However, the total volatile compounds in green teas harvested in 2011 were remarkably decreased in comparison to harvested in 2010. It was confirmed that free and bound volatile compounds in green tea are affected by low winter temperatures.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.238-244
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• 2008

The essential oil was obtained from the aerial part of Caryopteris incana Miq. by steam distillation, samples were collected by headspace (HS) and solid-phase microextraction (SPME) methods, and the compositions of the essential oil were analyzed by gas chromatography-mass spectrometry (GCMS). The fragrance of the essential oil was fougere and woody. There were sixty-nine constituents in the essential oil: 28 carbohydrates, 22 alcohols, 7 acetates, 7 ketones, 3 aldehydes, and 2 others. Major constituents were 4,6,6-trimethyl [1S-($1{\alpha},2{\beta},5{\alpha}$)]-bicyclo[3.1.1]hept-3-en-2-ol (11.8%), taucadinol (9.4%), myrtenyl acetate (9.2%), pinocarvone (7.0%), 1-hydroxy-1,7-dimethyl-4-isopropyl-2,7-cyclodecadiene (6.3%), ${\delta}$-3-carene (6.2%). By SPME extraction, forty-nine constituents were identified: 22 hydrocarbons, 16 alcohols, 6 acetates, 3 ketones, and 2 ethers. Major constituents of the SPME-extracted sample were ${\delta}$-3-carene (12.6%), (-)-myrtenyl acetate (11.2%), 6,6-dimethyl-2-methylene-bicycol [3.1.1] heptan-3-o1 (10.9%), pinocarvone (9.3%). By HS extraction, ten constituents were identified: 5 hydrocarbons, 2 amines, 1 alcohol, and 2 others. Major constituents of the HS-extracted sample were (Z)-2-fluoro-2-butene (34.9%), ${\delta}$-3-carene (6.9%), 6-(4-chlorophenul)tetrahydro-2-methyl-2H-1,2-oxazine (5.9%). The $IC_{50}$ value (0.011 ${\mu}g/mg$) in MTT assay using HaCaT keratinocyte cell line was lower than those of commercially-selling rosemary and tea tree, suggesting more toxicological studies are needed for commercial use of the essential oil of Caryopteris incana Miq.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.651-661
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• 2024

Chicken broth has a taste of umami, and the stewing time has an important effect on the quality of chicken broth, but there are fewer studies on the control of the stewing time. Based on this, the study was conducted to analyze the effects of different stewing times on the sensory, small molecular metabolites, free fatty acids, and volatile flavor compounds contents in chicken broths by liquid chromatography-quadrupole/time-of-flight mass spectrometry, gas chromatography-mass spectrometry, headspace solid-phase microextraction, and gas chromatography-mass spectrometry. Eighty-nine small molecular metabolites, 15 free fatty acids, and 86 volatile flavor compounds were detected. Palmitic and stearic acids were the more abundant fatty acids, and aldehydes were the main volatile flavor compounds. The study found that chicken broth had the best sensory evaluation, the highest content of taste components, and the richest content of volatile flavor components when the stewing time was 2.5 h. This study investigated the effect of stewing time on the quality of chicken broth to provide scientific and theoretical guidance for developing and utilizing local chicken.