• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.675-682
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• 2011

This study was conducted to monitor the concentrations of 24 anti-impotence drugs and their analogues in various foods and dietary supplements, with the aim of ensuring the safety of the foods and supplements. The measurements were done in 226 samples using high performance liquid chromatography/photodiode array detector (HPLC/PDA) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Five male sexual function enhancing products have been detected as follows: acethylvardenafil (21,476 mg/kg; 15 mg/capsule from one sample), sildenafil (52,778 mg/kg, 29 mg/capsule in one sample; 71,535 mg/kg, 48 mg/capsule in one sample), and tadalafil (9,772-55,545 mg/kg, 6-33 mg/capsule in four samples). A sustainable monitoring of anti-impotence drugs and their analogues in various foods and dietary supplement is recommended.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.13-22
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• 2020

A total of 244 cereal samples (oat, sorghum, adlay, and proso millet) were collected from fields to examine the contamination of Fusarium mycotoxins in cereals during harvest season in 2017 and 2018. The contamination levels of deoxynivalenol (DON), nivalenol (NIV), and zearalenone (ZEA) were analyzed individually by using the immunoaffinity column clean-up method with ultra performance liquid chromatography, and fumonisins (FUM) were analyzed by using the QuEChERS method with liquid chromatography-mass spectrometry. Highest level of NIV contamination (120.0-3277.0 mg/kg) was observed in oat samples among the analyzed cereals. In the adlay samples, DON contamination was the highest (maximum level 730.0 ㎍/kg). The proso millet samples had a high frequency of detection of NIV and ZEA (61.5% and 57.9%, respectively), but the levels were low (average detection level of NIV, 75.6 ㎍/kg, for ZEA, 21.5 ㎍/kg). Among the cereal samples, sorghum had the highest contamination frequency of DON, ZEA, and FUM, and the co-occurrence of Fusarium mycotoxin was 70.0%, which was higher than the average of 29.9%. In order to safely manage Fusarium mycotoxin levels in cereals, continuous research on the development of contamination prevention technologies together with monitoring of mycotoxin contamination is needed.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.558-563
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• 2011

In the course of our investigation for chemical constituents in the ethyl acetate layer of Korean black raspberry wine, five compounds were isolated and purified by silica gel column chromatography and high-performance liquid chromatography. The isolated compounds were identified as ethyl succinate (1), vanillic acid (2), ethyl 3,4-dihydroxybenzoate (3), furan-2-ol (4), and 4-(4-hydroxyphenyl)butan-2(S)-ol (5) based on the spectroscopic data of electrospray ionization tandem mass spectrometry and nuclear magnetic resonance. The presence of 2 in Korean black raspberry has previously reported. However, 1 and 3-5 in Korean black raspberry and its wine were isolated for the first time.

• Analytical Science and Technology
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• v.32 no.2
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• pp.35-47
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• 2019

In this study, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to detect 26 antidiabetic compounds in adulterated dietary supplements using a simple, selective method. The work presented herein may help prevent incidents related to food adulteration and restrict the illegal food market. The best separation was obtained on a Shiseido Capcell Pak(R) C18 MG-II ($2.0mm{\times}100mm$, $3{\mu}m$), which improved the peak shape and MS detection sensitivity of the target compounds. A gradient elution system composed of 0.1 % (v/v) formic acid in distilled water and methanol at a flow rate of 0.3 mL/min for 18 min was utilized. A triple quadrupole mass spectrometer with an electrospray ionization source operated in the positive or negative mode was employed as the detector. The developed method was validated as follows: specificity was confirmed in the multiple reaction monitoring mode using the precursor and product ion pairs. For solid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL, and for liquid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL. Satisfactory linearity was obtained from calibration curves, with $R^2$ > 0.99. Both intra and inter-day precision were less than 13.19 %. Accuracies ranged from 80.69 to 118.81 % (intra/inter-day), with a stability of less than 14.88 %. Mean recovery was found to be 80.6-119.0 % and less than 13.4 % RSD. Using the validated method, glibenclamide and pioglitazone were simultaneously determined in one capsule at concentrations of 1.52 and 0.53 mg (per capsule), respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5167-5170
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• 2012

Chilean red chili peppers contaminated with aflatoxins were reported in a previous study. If the development of gallbladder cancer (GBC) in Chile is associated with a high level of consumption of aflatoxin-contaminated red chili peppers, such peppers from other countries having a high GBC incidence rate may also be contaminated with aflatoxins. We aimed to determine whether this might be the case for red chili peppers from Bolivia and Peru. A total of 7 samples (3 from Bolivia, 4 from Peru) and 3 controls (2 from China, 1 from Japan) were evaluated. Aflatoxins were extracted with acetonitrile:water (9:1, v/v) and eluted through an immuno-affinity column. The concentrations of aflatoxins B1, B2, G1, and G2 were measured using high-performance liquid chromatography (HPLC), and then the detected aflatoxins were identified using HPLC-mass spectrometry. In some but not all of the samples from Bolivia and Peru, aflatoxin B1 or aflatoxins B1 and B2 were detected. In particular, aflatoxin B1 or total aflatoxin concentrations in a Bolivian samples were above the maximum levels for aflatoxins in spices proposed by the European Commission. Red chili peppers from Bolivia and Peru consumed by populations having high GBC incidence rates would appear to be contaminated with aflatoxins. These data suggest the possibility that a high level of consumption of aflatoxin-contaminated red chili peppers is related to the development of GBC, and the association between the two should be confirmed by a case-control study.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.524-528
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• 2020

The aim of this study was to enhance the use of wheat bran in lactic acid bacteria (LAB) fermentation. LAB fermentation of wheat bran and the flavor components and amino acids of fermentation products were analyzed using gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC). The results showed that total flavor components increased by 93% and 73% in the animal-based LAB mixture (T2) and plant-based LAB mixture (T3), respectively, after fermentation. Among these components, 2,3-butanedione (diacetyl), known for its buttery flavor, was detected at concentrations of 18.44 ng/g (T2) and 16.95 ng/g (T3). Levels of hexanal and nonanal, which causes off-flavor components in wheat bran, dramatically decreased after T2 fermentation; similarly, levels of total free amino acids decreased by 37.6% (T2) and 36.7% (T3) after fermentation. This may explain why some components were bound to volatile compounds during LAB fermentation. These results suggest that LAB-fermented wheat bran is a potential value-added food material.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.25-31
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• 2005

A soil bacterium, Bacillus subtilis HJ927, exhibiting strong antagonistic property against pathogenic fungi was isolated from pepper fields infested with Phytophthora capsici. Pepper plants inoculated with P. capsici revealed severe root mortality while plants co-inoculated with B. subtilis HJ927 and P. capsici showed drastically reduced root mortality. Low molecular weight substances released by B. subtilis HJ927 mediated the plant protective effect. The anti-fungal compounds released by B. subtilis HJ927 were identified as 3-methylbutyric acid, 2-methylbutyric acid, and methyl 2-hydroxy, 3-phenylpropanoate by high-performance liquid chromatography and gas chromatography-mass spectrometry. In addition to these compounds, B. subtilis HJ927 also produced ${\beta}$-1,3-glucanase, a hydrolytic enzyme implicated in antifungal activity.

• Food Science and Preservation
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• v.21 no.1
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• pp.69-74
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• 2014

We tested for residual pesticide levels in school foodservice agricultural products in Seoul, Korea from 2010 to 2012. A total of 316 samples of 23 different types of agricultural products were analyzed via gas chromatography-nitrogen phosphate detector (GC-NPD), an electron capture detector (GC-${\mu}ECD$), a mass spectrometry detector (GC-MSD), and a high performance liquid chromatography-ultraviolet detector (HPLC-UV). We used multi-analysis methods to analyze 185 different pesticide types. Among the selected agricultural products, residual pesticides were detected in 26 samples (8.2%), of which 6 samples (1.9%) exceeded the Korea Maximum Residue limits (MRLs). We detected pesticide residue in more than 65% of the Chwinamul, while 6 among 9 analyzed samples contained pesticide residue, and 1 sample exceeded the Korea MRLs. Among the 185 kinds of pesticides that we have tested, 18 were detected, while 7 of them were detected more than twice. Data obtained were then used for estimating the potential health risks associated with the exposures to these pesticides. The most critical commodity is carbofuran in the perilla leaves, which has contributed 3.8% to the hazard index (HI). These results showed that the detected pesticides could not be considered as a serious public health problem. Nevertheless, constant supervision is recommended.

• Journal of Microbiology
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• v.45 no.5
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• pp.460-465
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• 2007

This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1073-1080
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• 2018

There are several types of petroleum products used for the fuel oil, according to their respective quality standards, grades and usage. Depending on the degree of oil tax rate by country, even the same petroleum products will have price gap. The illegal mixing of cheap petroleum products, which are subject to the lower tax rate, with relatively expensive transportation fuel causes problems such as tax evasion, environmental pollution and vehicle breakdown. In order to prevent illicit production and mixing of these different petroleum products, a small amount of markers are legally added to specific petroleum products. In Korea, markers are introduced and used to prevent illegal activity that kerosene used as fuel for house and commercial boiler are mixed with automotive diesel fuels, and marker contents are analyzed to use UV-Vis spectrophotometer and high performance liquid chromatography (HPLC). In this study, we have developed a method to qualitatively and quantitatively determine the marker added to petroleum products by gas chromatography-mass spectrometry (GC-MS) without adding developing reagent or sample pre-treatments.