• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.271-276
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• 2008

In this study, volatile compounds were isolated from traditional and commercial fermented soybean pastes according to different heating temperatures (room temperature, $50^{\circ}C$, $100^{\circ}C$) using headspace-solid phase microextraction (HS-SPME). The compounds were then analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 51 volatile components, including 18 esters, 3 alcohols, 6 acids, 8 pyrazines, 5 volatile phenols, 6 aldehydes, and 5 miscellaneous compounds, were identified. Esters and acids such as ethyl hexadecanoate, acetic acid, and 2/3-methyl butanoic acid were the largest groups among the quantified volatiles. By applying principal component analyses to the GCMS data sets, differences were observed in the volatile components of the soybean pastes as to the different heating temperatures. A large variation was shown between the volatile components of the traditional and commercial soybean pastes by increasing the heating temperature. Commercial samples had significantly higher levels of longer chain ethyl esters, aldehydes, and thermal degradation products such as maltol and 2-acetyl pyrrole, while traditional samples showed higher concentrations of acids and pyrazines.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.263-268
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• 2019

Methanol is a toxic alcohol used in various products such as antifreeze, detergent, disinfectant and industrial solvent. In the human body, methanol is oxidized to formaldehyde and formic acid, which can lead to metabolic acidosis, optic nerve impairment, and death. In this study, the methanol levels in detergents (n=191) and rinse aids (n=13) were analyzed by gas chromatography-headspace-mass spectrometry (GC-HS-MS). Limit of detection was 1.09 mg/kg, accuracy and precision were 91.1-97.9% and <10%, and it was suitable for quantitative analysis. This analysis method was simple and fast with a higher recovery rate than the conventional MFDS (Ministry of Food and Drug Safety) method of diluting the sample in water and putting it in a headspace vial.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.165-177
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• 2024

Volatile compounds (VOCs) are an important factor affecting meat quality. However, the characteristic VOCs in different parts of donkey meat remain unknown. Accordingly, this study represents a preliminary investigation of VOCs to differentiate between different cuts of donkey meat by using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with chemometrics analysis. The results showed that the 31 VOCs identified in donkey meat, ketones, alcohols, aldehydes, and esters were the predominant categories. A total of 10 VOCs with relative odor activity values ≥1 were found to be characteristic of donkey meat, including pentanone, hexanal, nonanal, octanal, and 3-methylbutanal. The VOC profiles in different parts of donkey meat were well differentiated using three- and two-dimensional fingerprint maps. Nine differential VOCs that represent potential markers to discriminate different parts of donkey meat were identified by chemometrics analysis. These include 2-butanone, 2-pentanone, and 2-heptanone. Thus, the VOC profiles in donkey meat and specific VOCs in different parts of donkey meat were revealed by HS-GC-IMS combined with chemometrics, whcih provided a basis and method of investigating the characteristic VOCs and quality control of donkey meat.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.700-708
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• 2014

The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaughter), the most abundant compound class was the aldehydes (52.231%), while that was alcohols (26.260%) in group C (veal calves fed starter diet for at least 60 d before slaughter). In both classes the absolute percentages of the volatile compounds in veal were different indicating that the veal diet significantly (p<0.05) affected headspace volatile composition in veal as determined by principal component analysis (PCA). Twenty three volatile compounds showed significance by using a partial least-squared discriminate analysis (PLS-DA) (VIP>1). The establishment of the global volatile signature of veal may be a useful tool to define the beef diet that improves the organoleptic characteristics of the meat and consequently impacts both its taste and economic value.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.140-140
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• 2001

A sensitive analytical method based on gas chromatograpy-mass spectrometry with a selected ion monitoring (GC/MS-SIM) with the purge-and-trap concentration and with headspace method (in limited applications) was developed for determining of epichlorohydrin in canned beverages coated with epoxy resin. The calibration curve in the range of $0.5\sim50ng$ had correlation coefficient greater than 0.998 and a detection limit of $0.l\mug/L$ was obtained using a sample volume of 20ml. The predominant ions of epichlorohydrin produced in MSD using electron ionization(EI) were m/z 57 ([M-CI]+) and 62/64 $([M-CH_2O]+)$. In survey of epichlorohydrin in thirty commercial canned beverage samples, none of them was detected.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3603-3609
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• 2011

A novel sampling method of the headspace poly(dimethylsiloxane) (PDMS) mini-disk extraction (HS-PDE) was developed, optimized, validated and applied for the GC/MS analysis of spices flavors. A prototype PDMS mini-disk (8 mm outer diameter, 0.157 mm thickness, 9.4 mg weight) has been designed and fabricated as a sorption device. The technique uses a small PDMS mini-disk and very small volume of organic solvent and less sample size than the solvent extraction. This new HS-PDE method is very simple to use, inexpensive, rapid, requires less labor. Linearities of calibration curves for ${\alpha}$-pinene, ${\beta}$-pinene, limonene and ${\gamma}$-terpinene by HS-PDE combined with GC/MS were excellent having $r^2$ values greater than 0.99 at the dynamic range of 6.06~3500 ng/mL. The limit of detection (LOD) and the limit of quantitation (LOQ) showed very low values. This method exhibited good precision and accuracy. The overall extraction efficiency of this method was evaluated by using partition coefficients ($K_p$) and concentration factors (CF) for several characteristic components from nutmeg and mace. Partition coefficients were in the range from $2.04{\times}10^4$ to $4.42{\times}10^5$, while CF values were 0.88-15.03. HS-PDE was applied successfully for the analysis of flavors compositions from nutmeg, mace and cumin. The HS-PDE method is a very promising sampling technique for the characterization of volatile flavors.

• 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.

• Korean Journal of Oriental Medicine
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• v.1 no.1
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• pp.541-553
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• 1995

In order to study the stability of herbal oil(Yoo-Je), the Yoo-Je from walnut and safflower measured their rancidity by gas chromatographic analysis. The use of specificity of column for estimating the oxidative deterioration of Yoo-Je was attempted. These results suggested the possible implication of pentanal and hexanal as an stability index for rancidity evaluation of Yoo-Je.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.164.2-165
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• 2003

Structured lipids (SLs) are defined as triacylglycerols to change the fatty acid composition in the glycerol backbone and lipases are known as a powerful tool for the syntheses of SLs. Structured lipid from corn oil, capric acid, and conjugated linoleic acid (CLA) by transesterification reaction and using several amounts of immobilized lipase RM IM (from Rhizomucor miehei) was studied, and 4% of lipase amount was selected for further study as the optimal amount. Comparison the chemical properties (free fatty acid value, iodine value, saponification value, tocopherols, and color analysis), solidification behavior, and volatile fractions (from headspace SPME GC-MS) between com oil and SL com oil was obtained.