• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.202-210
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• 2022

Aflatoxin contamination in rice has been documented in a number of studies, and has a high incidence in Asian countries, and as such, there has been a growing interest in alternative biocontrol strategies to address this issue. In this study, 147 strains of yeasts and yeast-like fungi were screened for their potential to produce volatile organic compounds (VOCs) active against Aspergillus flavus strains that produce aflatoxin B₁ (AFB₁). Five strains within four different genera showed greater than 50% growth inhibition of some strains of A. flavus. These were Anthracocystis sp. DMKU-PAL124, Aureobasidium sp. DMKU-PAL120, Aureobasidium sp. DMKU-PAL144, Rhodotorula sp. DMKU-PAL99, and Solicococcus keelungensis DMKU-PAL84. VOCs produced by these microorganisms ranged from 4 to 14 compounds and included alcohols, alkenes, aromatics, esters and furans. The major VOCs produced by the closely related Aureobasidium strains were found to bedistinct. Moreover, 2-phenylethanol was the most abundant compound generated by Aureobasidium sp. DMKU-PAL120, while methyl benzeneacetate was the major compound emitted from Aureobasidium sp. DMKU-PAL144. On the other hand, 2-methyl-1-butanol and 3-methyl-1-butanol were significant compounds produced by the other three genera. These antagonists apparently inhibited A. flavus sporulation and mycelial development. Additionally, the reduction of the AFB1 in the fungal-contaminated rice grains was observed after co-incubation with these VOC-producing strains and ranged from 37.7 ± 8.3% to 60.3 ± 3.4%. Our findings suggest that these same microorganisms are promising biological control agents for use against aflatoxin-producing fungi in rice and other agricultural products.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.500-505
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• 2007

The objective of this study was to investigate the effects of cooking methods (cooking apparatus and reaction level of oxygen) on the rancidity, reactive oxygen species (ROS), and furans produced while cooking deep-fired instant noodles. The sample rancidities showed a decreasing trend regardless of the cooking apparatus, as the available oxygen content in the cooking pot was reduced. In particular, soaking and then cooking using a microwave oven was found to be the most effective method to retard rancidity development. The ROS concentration after cooking had a similar trend to the rancidity. The furan concentrations of the samples significantly decreased under all cooking conditions as compared to the control, and the lowest value was 10.69 ppb for the sample cooked in a microwave oven without a cooking pot lid after soaking. The results indicate that cooking in a microwave oven with soaking was the most effective method for the oxidative stability of deep-fried instant noodles.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.839-846
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• 1997

Addition of three natural flavoring materials, hydrolyzed vegetable protein (HVP), hydrolyzed animal protein (HAP) and yeast extract (YE), into 0.2 M cystine-0.1 M lactose-0.1 M maltose solution (control) was studied for development of meat-like flavor by Maillard reaction. The HVP, HAP and YE were added individually at various concentrations and were mixed at selected concentration in order to compare their effects. The absorbance, color, sensory characteristics and volatile compounds of the solutions after the reaction at $100^{\circ}C$ for 8 hr were measured. The results showed that the absorbances of reaction solution at 420 nm and 278 nm were increased as reaction time and the concentration of the natural flavoring material increased. Also ‘L’ values of reaction solutions added with HVP, HAP or YE decreased while the ‘b’ value increased slightly. From the results of sensory evaluation 1.16% HVP, 0.94% HAP, 1.48% YE or 1.16% HVP + 0.94% HAP were selected as the appropriate substrates for the meat-like flavor development. The volatile compounds identified by GC/MS for the control and those added with 1.16% HVP or 1.16% HVP+0.94% HAP were 1 hydrocarbons, 9 aldehydes, 5 ketones, 1 ester, 5 alcohols, 2 aromatics(benzene), 2 furans, 1 sulfur compound.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.256-261
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• 1999

This study was conducted to investigate the effect of barley tea with roasted grains and barley tea with a tea bag on the reduction of chlorination by-product(CBP) levels in chlorinated drinking water. Since the concentrations of six volatile compounds of eight CBPs were blow their respective detection limits after 10 minute heating, two nonvolatile CBPs dichloroacetic acid and trichloroacetic acid, and total chlorine were compared between tap water and two kinds of barley tea. No significant differences were observed in the relative changes of the amounts of the above three items, and new peaks which were not found in the original water appeared in the chromatograms of gas chromatograph/electron capture detector(GC/ECD). Thirty three organic compounds were identified in the extracts of barley tea with roasted grains, barley tea with a tea bag, corn tea, and Cassia tora seed tea which were prepared with distilled/deionized water, using gas chromatography/mass selective detection(GC/MSD). Exclusive of fatty acids, most of the compounds were aromatic compounds such as phenols, furans, and pyrroles.

• Analytical Science and Technology
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• v.15 no.1
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• pp.43-53
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• 2002

The analysis of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzo furans(PCDFs) was performed by using four different gas chromatographic columns (SP-2331, DB-5, DB-17 and DB-DIOXIN). The data reported is pertaining to flue gas, fly ash, ambient air, soil and fish. The difference in quantification of samples according to four columns was observed, it was noted that major difference was observed in the flue gas when compared with soil, fly ash, ambient air and fish. The quantification of the same samples according to four columns it was also found that DB-5 column have the highest concentration whereas SP-2331 column showed the lowest concentration. The quantification of DB-17 column for 1,2,3,6,7,8-HxCDF was found to be twice and three times higher when compared with other columns, whereas the quantification of DB-DIOXIN column for 1,2,3,7,8-PeCDD was also found to be over estimated twice when compared with other columns.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.4
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• pp.169-176
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• 1989

Volatile flavor components in powdered Katsuobushi were simultaneous trapped by steam distillation-extraction method, and these were fractionated into the neutral, the phenolic, the acidic and the basic fraction. Volatile flavor components in these fraction were analyzed by the high-resolution GC and GC-MS equipped with a fused silica capillary column. The whole steam volatile concentrate consisted of $48\%$ neutral fraction(NF), $35\%$ phenolic fraction(PF), $12\%$ acidic fraction(AF) and $5\%$ basic fraction(BF). Thirty components such as 8 hydrocarbons, 8 aldehydes, 6 furans, 5 alcohols and 3 ketones were identified from NF. And sixteen components such as phenol, guaiacol, dimethoxy phenol, eugenol in PF, twelve components such as propionic, butanoic, isopentanoic, n-hexanoic, heptanoic, octanoic acid in AF, ten components such as 2,6-dimethylpyrazine, 2-nethylpyridine, 2,4-dimethylthiaBole in BF were identified. NF and PF gave a much higher yield than others and were assumed to be indispensable for the reproduction of aroma of powdered Katsuobushi. It was also identified eight components of volatile carbonyl compounds such as ethanal, propanal, butanal, pentanal by 2,4-DNPH method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.136-146
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• 1987

Flavor components were trapped by stimultaneous steam distillation-extraction method for investigating it in the bellflower roots and fractionated into four groups such as a neutral, a basic, a phenolic and an acidic fraction. An acidic fraction methylated with diazomethane solution and three others were analysed by GC and GC-MS equipping a fused silica capillary column, and S-containing compounds in these were detected with a flame photometric detector (FPD). The total of one hundred and three compounds from the bellflower roots were identified: they were 6 aliphatic hydrocarbons, 10 aromatic hydrocarbons, 2 terpene hydrocarbons, 12 alcohols, 8 terpene alcohols, 17 aldehydes, 3 terpene aldehydes, 5 ketones, 5 esters, 3 furans, 2 thiazoles, 2 lactones, 2 sulfides, 9 phenols, l2 carboxylic acids and 5 others. The greater part of the others except carboxylic acids were identified from a neutral fraction of which was assumed to be indispensable for the reproduction of bellflower root odor in a sensory evaluation. As a result of a sensory evaluation, 1-hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, trans-2-hexenol, 1-octen-3-ol and so forth identified in a neutral fraction were considered to be the key compounds of grass-like odor in the bellflower roots.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.332-341
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• 2007

The purpose of this study was to investigate the change of flavor compounds of freeze-dried garlic and garlic roasted with soybean oil and sesame oil. Freeze-dried garlic and ground raw garlic roasted with oils was prepared at $180^{\circ}C$ for 5 minutes. Volatile compounds of garlic samples were obtained by Likens-Nickerson distillation/solvent extraction and identified by GC and GC/MS. Sulfur compounds, methyl allyl sulfide, diallyl sulfide, methyl allyl disulfide, dimethyl trisulfide, diallyl disulfide, methyl allyl trisulfide and diallyl trisulfide were the major volatile in garlic flavor which was more than 98% of the total volatile compounds. The total amount of sulfur compounds in freeze-dried garlic roasted with soybean oil was decreased to 20% compare to that of garlic flavor; however, 10 pyrazines such as 2-methyl pyrazine, 2,6-dimethyl pyrazine, 2-ethyl-5-methyl pyrazin and 3-ethyl-2,5-dimethyl pyrazine which were not originated from both freeze-dried garlic and soybean oil were identified. They might be generated from thermal interactions of sugars and nonvolatile flavor precursors of garlic. In freeze-dried garlic roasted with sesame oil, the amount of diallyl sulfide, methyl allyl disulfide, dimethyl trisulfide increased whereas diallyl disulfide completely disappeared. The amount of two cyclic compounds 3,4-dihydro-3-vinyl-1,2-dithiin and 2-vinyl-4H-1,3-dithiin, which were artifacts from allicin, increased in roasted garlic with sesame oil.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.87-100
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• 2003

It is important to understand the potential human health implications of exposure to environmental chemicals that may act as hormonally active agents. It is necessary to have an understanding of how pharmaceutical and personal care products and other chemicals affect the ecosystem of our planet as well as human health. Endocrine disruption is defined as the ability of a chemical contaminating the workplace or the environment to interfere with homeostasis, development, reproduction, and/or behavior in a living organism or it's offspring. Certain classes of environmentally persistent chemicals such as polychlorinated biphenyls (PCBs), dioxins, furans, and some pesticides can adversely effect the endocrine systems of aquatic life and terrestrial wildlife. Research continues to support the theory of endocrine disruption. However, endocrine disruption researches have been applied to proteomics poorly. Proteomics can be defined as the systematic analysis of proteins for their identity, quantity and function. It could increase the predictability of early drug development and identify non-invasive biomarkers of tonicity or efficacy. Proteome analysis is most commonly accomplished by the combination of two-dimensional gel electrophoresis (2D/E) and MALDI-TOF mass spectrometry (MS) sr protein chip array and SELDI-TOF MS. Proteomics have an opportunity to play an important role in resolving the question of what role endocrine disruptors play in initiating human disease. Proteomics can also play an imfortant role in the evaluation of the risk assessment and use of risk management and risk communication tools required to address public health concerns related to notions of endocrine disruptors. Understanding the need for the proteomics and possessing knowledge of the developing biomakers used to abbess endocrine activity potential will he essential components relevant to the topic of endocrine disruptors.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.758-766
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• 2008

To evaluate homologue patterns and removal efficiency before and after water treatment, the concentrations of dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were determined in 122 samples from 42 drinking water treatment plants throughout Japan over a two year period. The mean concentrations and toxic equivalent (TEQ) values of dioxins in raw and treated waters were 60.24 pg/L (0.14 pg-WHO-TEQ/L) and 4.15 pg/L (0.016 pg-WHO-TEQ/L), respectively. The dioxins contribution ratio of drinking water in relation to dioxins tolerable daily intake (TDI, 4 pg-TEQ/kg/day) was 0.016%. The mean TEQ removal rate of dioxins by drinking water treatment was over 88%. However, the mean removal rate of 2, 3, 7, 8-TeCDF (tetrachlorodibenzofuran) by water treatment in the 122 samples was minus 17%. Therefore, to identify which process affected the level of 2, 3, 7, 8-TeCDF, the removal efficiencies at both the advanced and conventional water treatment plants were investigated. For the TEQ removal rate across the processes, the dioxin congeners, TeCDF and non-ortho-PCBs remarkably indicated minus values after chlorination in both the advanced and conventional water treatments plant. From this study, the level of 2, 3, 7, 8-TeCDF was found to be increased as a result of chlorination.