• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.314-320
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• 2014

Flavor quality of Liriopis tuber tea that was made using a steaming process was studied by measuring changes in headspace volatile compounds. Headspace volatile compounds of the prepared samples were isolated, separated and identified by the combined system of purge & trap, automatic thermal desorber, gas chromatography, and mass selective detector. As steaming frequencies were increased, the area percent of aldehydes decreased from 32.01% to 3.39% at 1 and 9 steaming frequency times, respectively. However, furans and ketones increased from 18.67% to 33.86% and from 9.60% to 17.40% at 1 and 9 times, respectively. The savory flavor of Liriopis tuber tea was due to a decrease in aldehydes contributing a fresh flavor at the 1st steaming process and newly generated furans from nonenzymatic browning with repeated steaming frequencies. These results will provide basic information for quality control of the newly developed Liriopis tuber tea.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.35-41
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• 2014

Trihalomethanes (THMs) are formed as a results of the reaction of residual chlorine, used as a disinfectant in drinking water, with the organic matter in raw water. Although chlorinated and brominated THMs are the most common disinfection byproducts (DBPs) reported, iodinated THMs (I-THMs) can be formed when iodide is present in raw water. I-THMs have been usually associated with several medicinal or pharmaceutical taste and odor problems and is a potential health concern since they have been reported to be more toxic than their brominated and chlorinated analogs. Currently, there is no published standard analytical method for I-THMs in water. An automated headspace-gas chromatography/electron capture detector (GC/ECD) technique was developed for routine analysis of 10 THMs including 6 I-THMs in water samples. The optimization of the method is discussed. The limits of detection (LOD) and limits of quantification (LOQ) range from 12 ng/L to 56 ng/L and from 38 ng/L to 178 ng/L for 10 THMs, respectively. Matrix effects in river water, sea water and wastewater treatment plant (WWTP) final effluent water were investigated and it was shown that the method is suitable for the analysis of trace levels of I-THMs, in a wide range of waters. The method developed in the present study has the advantage of being rapid, simple and sensitive.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.171-176
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• 1992

Volatile flavor components of Codonopsis lanceolata were extracted by gas co-distillation (GCD), solvent extraction/fractionation (SEF), and headspace sampling (HSS) methods. The extracts were analyzed by dual-capillary gas chromatography-retention index (GC-RI) and gas chromatography-mass spectrometry(GC-MS). The two extracts prepared by SEF and HSS gave more similar fragrance to the Codonopsis lanceolata than the GCD extract. The GC profiles of the SEF and HSS extracts were similar to each other except for differences in peak areas. The extract prepared by SEF gave a sweet note while the extract prepared by HSS gave a green note. The GCD extract began to give a burnt note of herb medicine with prolonged distillation. Rapid extraction of flavor components from Codonopsis lanceolata was possible in several short steps by SEF and HSS methods compared to GCD. GC-MS and GC-RI were used for peak identification. GC-RI was more effective for identification of isomers, and polar FFAP column was more suitable for identification of polar compounds. From Codonopsis lanceolata we identified 35 volatile flavor constituents, 24 of which have not been previously reported by simultaneous distillation extraction method $^{(5)}$. trans-2-Hexanal, cis-3-hexen-1-ol, trans-2-hexen-1-ol, and hexanol were considered key components of the green note and 1-octen-3-ol, the component of the fresh note. Esters, including amyl propionate, seem to be responsible for the sweet note particular to Codonopsis lanceolata.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.934-950
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• 2024

This study addresses the prevalent issue of meat species authentication and adulteration through a chemometrics-based approach, crucial for upholding public health and ensuring a fair marketplace. Volatile compounds were extracted and analyzed using headspace-solid-phase-microextraction-gas chromatography-mass spectrometry. Adulterated meat samples were effectively identified through principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Through variable importance in projection scores and a Random Forest test, 11 key compounds, including nonanal, octanal, hexadecanal, benzaldehyde, 1-octanol, hexanoic acid, heptanoic acid, octanoic acid, and 2-acetylpyrrole for beef, and hexanal and 1-octen-3-ol for pork, were robustly identified as biomarkers. These compounds exhibited a discernible trend in adulterated samples based on adulteration ratios, evident in a heatmap. Notably, lipid degradation compounds strongly influenced meat discrimination. PCA and PLS-DA yielded significant sample separation, with the first two components capturing 80% and 72.1% of total variance, respectively. This technique could be a reliable method for detecting meat adulteration in cooked meat.

• 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.

• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.30-37
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• 1981

A simple micro-sampling system is described which facilitates isolation and concentration of complex organic constituents into three fractions of different volatilities. The method involves the headspace trapping of very volatile components from a complex matrix onto a porous polymer, Tenax GC, followed by the solvent elution of the matrix and the subsequent fractions of the eluate into volatile and less-volatile fractions. The headspace and the volatile fractions are then analyzed by high-resolution capillary gas chromatography. The less-volatile fraction is analyzed by high-performance liquid chromatography. Experimental details and the results obtained using tobacco leaves as a complex organic matrix are presented.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.45-51
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• 1986

Equimolar aqueous solutions of D-glucose and glycine were heated at $50^{\circ}C\;and\;95^{\circ}C$ at pH 6.7. The headspace volatiles and the ether extracts from the reaction mixture were analyzed by gas chromatography and gas chromatography-mass spectrometry using a fused silica capillary column. The major components formed were identified as diacetyl, three furfurals, two pyrroles, one furanone, two pyranones and two amides. In order to elucidate the formation mechanisms of the amides formed front amino-carbonyl reaction, two model systems were adopted. N-butylacetamide were formed as major components from diacetyl-butylamine ana glyoxal-butylamine systems, respectively. The results obtained suggest that such ${\alpha}-dicarbonyls$ as 3-deoxy-D-erythro-2,3-hexodiulose and diacetyl generated in the amino-carbonyl reaction react with amino compounds, amides then being formed by cleavage of the C-C bond in the ${\alpha}-dicarbonyls$.

• KSBB Journal
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• v.26 no.2
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• pp.177-181
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• 2011

This study was conducted to investigate the effects of gamma irradiation on the change of volatile flavor compounds of raw oyster and its cooking drips using headspace methods. Major volatile flavor compounds of the raw oyster were identified as methylthiomethane and 1,5-hexadiene. When the raw oyster was irradiated at the dose of 5 kGy, 1-pentane was newly detected. On the other hand, 9 compounds including N-methoxyformaldehyde were identified as the major volatile compounds of cooking drips from oyster. Among them, N-methoxyformaldehyde contents in cooking drip was decreased by the gamma irradiation. By the gamma irradiation above 30 kGy, new heterocyclic compounds was found in oyster cooking drips. Therefore, the amount of volatile flavor compounds in the raw oyster and cooking drips were changed by gamma irradiation, and these results could be potentially used in the seasoning industry.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.125-132
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• 2022

There are many types of spring blossoms on the Daedeok campus of Chungnam National University (CNU) at the area of 1,600,000 square meters. As an assignment for the class of Analytical Chemistry I for second-year undergraduate students, 2021, flower petals collected from various floral groups (Korean azalea, Korean forsythia, Dilatata lilac, Lilytree, Lily magnolia, and Prunus yedoensis) were analyzed using headspace extraction coupled to gas chromatography-mass spectrometry (HS-GC-MS) to study the aromatic profiles and fragrance compounds of each sample group. Various types of compounds associated with the aroma profiles were detected, including saturated alcohols and aldehydes (ethanol, 1-hexanol, and nonanal), terpenes (limonene, pinene, and ocimene), and aromatic compounds (benzyl alcohol, benzaldehyde). The different contribution of these compounds for each floral type was visualized using statistical tools and classification models based on principal component analysis with high reliability (R² = 0.824, Q² = 0.616). These results showed that HS-GC-MS with statistical analysis is a powerful method to characterize the volatile aromatic profile of biological specimens.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.76-79
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• 1994

The concentration of styrne in blood of the occupationally syrene-exposed workers was checked by gas chromatographic headspace analysis. Mandelic acd in urine, that is a major metabolite of styrene, and hippuric acid wre also analyzed by high performance liquid chromatography. For the biological monitoring of styrene-exposed workers, the routine method of the quantitative determination of styrene nad its metabolites in the biolgical samples were studied.