• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.115-122
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• 1989

The mechanisms of aflatoxin $B_1(AFB_1)$ degradation by ammonia and alkaline pH during the storage of Korean soy sauces were studied. In the 0.05%, 0.1% and 0.5% of ammonia solutions, almost all of $AFB_1$(96-100%) was degraded after 2 to 24 hrs of incubation at $30^{\circ}C$. Increased levels of ammonia in both home made soy sauce(HMSS) and commercial soy sauce(CSS) caused slow increases in pH. The pH change was higher in CSS than in HMSS. The degradations of $AFB_1$ were not observed in the samples of HMSS, CSS, distilled water and 20 % of NaCl solution during the storage, however, when the pHs of the samples were adjusted to 10, the toxin was completely removed in all samples. $AFB_1$ was stable at pH 5 and 7 in bath buffer solutions and buffer solutions+0.2% ammonia, however, $AFB_1$ was degraded completely at pHs more than 9. $AFB_1$ was not degraded even at high concentrations of ammonia(0.2-1.0%) when the pH was maintained at 7 in the buffer solution. It indicated that ammonia content in the system was not important but the higher pH was the reason to degrade $AFB_1$. When the pHs of HMSS, CSS, buffersolution and buffer solution + 0.2% ammonia were adjusted to 5 and then reacted with $AFB_1$ for 5 days, the toxin was stable in all samples. However, when the pHs of the samples were adjusted to 7, about 60-70 % of $AFB_1$ was degraded in HMSS and CSS after 5 days of incubation during which the pH was not changed, but $AFB_1$ in the buffer solution and buffer solution + 0.2% ammonia was not degraded at all in the same conditions.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.188-188
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• 2001

Human cytochrome B5 (CYB5) was coexpressed with cytochrome P450 1A2 (CYP1A2), NADPH-CYP450 reductase (CYPR) and Ν-acetyltransferase 2 (NAT2) in Chinese hamster ovary (CHO) cells. The expression of four proteins was determined by Western blot analyses. The introduction of cDNAs to CHO cells were transduced via retroviral vectors. The cytotoxicity assay of 2-aminoanthracene (2-AA) and aflatoxin B$_1$were approximately 4-fold more sensitive than CYB5 free cells.(omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.302-307
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• 1992

The methanol extract of perilla leaves contained compounds to reduce the mutagenicity of aflatoxin B$_1$(AFB$_1$) in Salmonella typhimurium TA98 and 100. They were separated by solvent extractions and identified by GC and GC-MS as 2-ethoxy acetate, 1, 2, 3, 4-tetramethyl-cis-cyclobutene, two isomers of methyl 11, 14, 17-eicosatrienoate, 12-acetyl-9-octadecanoic acid, and phytol. The antimutagenicities of phytol and methyl 11, 14, 17-eicosatrienoate were dependent on the mutagens tested. Phytol reduced the mutagenicity of Trp-p-2 but not of AFB$_1$and methyl 11, 14, 17-eicosatrienoate reduced the activities both of the mutagens.

• Journal of Environmental Health Sciences
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• v.36 no.1
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• pp.52-60
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• 2010

High performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS) have been widely used to quantify aflatoxins in food, but these methods are expensive, time-consuming, unsuitable for analysis of the routine screening of large sample numbers and require derivatization and high level techniques to perform. The objective of this study is to detect aflatoxins in a large number of foods by a high efficient analytical system of combined enzyme linked immunosorbent assay (ELISA) for screening and LC/MS/MS for confirmation. The samples spiked individually with aflatoxin $B_1$ (0.5 and 1.0 ng/g) and total aflatoxins (10 ng/g) were analyzed by ELISA and LC/MS/ MS, and the recoveries for ELISA and LC/MS/MS were 71.8~119.2% and 70.8~135.3%, respectively. A total of 378 samples (grains, nuts, soybean and fermented soybean foods, pepper and fermented pepper foods) were purchased from the six major cities in Korea and analyzed by ELISA-LC/MS/MS system. Twenty two (5.8%; peanut: 11, pistachio: 2, walnut: 6, almond: 1, pepper powder: 1, pepper paste: 1) out of 378 samples were screened as aflatoxin B1 positive by ELISA, but, 4 (1.1%; peanut: 2, pistachio:1, pepper powder: 1) out of the 22 samples screened were confirmed as aflatoxins positive at levels of 1.02~52.79 ng/g by LC/MS/MS. ELISA-LC/MS/MS system provides a more rapid, accurate and cost-effective method for the detection of aflatoxins in large number of samples.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.131-138
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• 2020

The aim of this study was to evaluate the effect of aflatoxin B₁ (AFB₁) on in vitro rumen fermentation at various dose levels of 0 (T₁), 100 (T₂), 200 (T₃), and 300 (T₄) ppb in a wheat straw-based buffalo diet. The results show that the truly degradable dry matter, truly degradable organic matter, gas production, microbial biomass production and partitioning factor values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The total volatile fatty acids, acetate, propionate, and butyrate values in the control group (T₁) were higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor value in the control group (T₁) was higher (p < 0.05) than those of the T₂, T₃, and T₄ groups. The partitioning factor values of the T₂ and T₃ groups were higher (p < 0.05) than that of the T₄ group. There was no significant variation in the partitioning factor value between the T₂ and T₃ group. The acetate : propionate (A : P) ratio in the control group (T₁) was lower (p < 0.05) than those of the T₂, T₃, and T₄ groups. The A : P ratio in the T₂ group was lower (p < 0.05) than those of the T₃ and T₄ groups. It was concluded that different levels of AFB₁ contamination in feed significantly affect the in vitro rumen fermentation characteristics. Thus, these findings could help to determine the influences of AFB₁ in a wheat straw-based buffalo diet. Additionally, it is necessary to manage AFB₁ contamination in ruminants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.308-313
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• 1992

Volatile aromatic compounds collected from raw and roasted mugwort (Artemisia asictica nakai) leaves by the Tenax trap and some major volatile compounds were separated and identified by GC-MS. The identified compounds were tested for the antimutagenic and mutagenic activities against aflatoxin B$_1$(AFB$_1$) using their authentic compounds. Six compounds (myrcene, cineole, camphor, caryophyllen, coumarin, and farnesol) showed antimutagenic activities, but 2-pyrrolidine and thujone showed mutagenic activities. 1-Acetylpiperidine formed during roasting mugwort leaves exhibited mutagenic activities. When the mutagens and antimutagens were mixed, the mixture reduced the mutagenicity of AFB$_1$. These results suggested that the extract of mugwort leaves is not mutagenic and so the mugwort leaves might be used as a food and as medicinal sources without mutagenicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1164-1170
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• 2001

Antimutagenic and antimicrobial effects of cucumber extracts were investigated. Antimutagenic effects of cucumber extract against aflatoxin (AFB$_1$) as indirect mutagen and N-methyl-N'-nitro-N-nitrcsoguanidine (MNNG) as direct mutagen using the Ames assay system with Salmonella typhimurium TA100 were studied. 1.25~5.0% of methanol extract exhibited 11 ~ 17% of antimutagenity against AFB$_1$ and 46~85% of antimutagenity against MNNG. Among fractions of methanol extract, hexane fraction exhibited the highest antimutagenic effect against AFB$_1$ (89%) and butanol fraction exhibited the highest antimutagenic effect against MNNG (95%). Antimicrobial effects of cucumber extract were investigated on the eleven microorganisms. Methanol extract showed anitimicrobial effect on eight microorganisms. Among these tested microorganisms, Klebsiella pnemonia KCTC 2208, pseudomonas aeruginosa KCTC 2004 were the most sensitively inhibited with 13 mm clear zone on holo test. Hexane fraction showed anitimicrobial effect only on Vibrio parahaemolyticus KCTC 2471. Chloroform and ethyl acetate fractions showed a weak effect. V. parahaemolyticus showed the lowest minium inhibitory concentration (MIC) (500 ppm) among eleven tested microorganisms by methanol extract. Sterilization effect of 1% methanol extract on P. aeruginosa incubation is 10 times stronger than 0.5% methanol extract. It estimated to need 26 min for the sterilization of 90% P. aeruginosa cell counts by 1% methanol extract but 250 min by 0.5% methanol extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.880-886
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• 1995

Antimutagenic effects of boiled water extract and tannin from persimmon leaves were studied by using Ames test, spore rec assay and SOS chromotest. Strong antimutagenic activities toward aflatoxin B1(AFB1), dimethyl-aminobiphenyl(DMAB), N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitroquinoline-1-oxide(4-NQO) were observed when boiled water extract and tannin from the persimmon leaves were added in the Salmonella typhimurium TA 100. In spore rec assay using Bacillus subtilis H17($rec^{+}$) and M45($rec^{-}$), boiled water extract and tannin from the persimmon leaves considerably inhibited the mutagenesis induce by MNNG. In SOS chromotest using Escherichia coli PQ37, these samples also exhibited strong antimutagenic activity toward 4-NQO. The tannin was more effective than boiled water extract of persimmon leaves in the antimutagenicity tests.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.439-445
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• 1998

The antimutagenic activity of the water extract of Rehmannia glutinosa Liboschitz (RG) on the mutagenicity induced by 4-nitroquinoline 1-oxide (4-NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), mitomycin C (MMC), $aflatoxin\;B_1\;(AFB_1)$ and benzo(a)pyrene [B(a)P] were studied using the SOS Chromotest with Escherichia coli PQ37. The water extract of RG was separated into methanol soluble and methanol insoluble parts. The methanol soluble part exhibited higher inhibition effects than the methanol insoluble part against the mutagenic activities of five mutagens. Step-wise fractionation of methanol soluble part was done using methanol, ethyl acetate and water. Among these fractions, water fraction had the strongest inhibitory effects against the mutagenenicity of five model mutagens, showing $4.5{\sim}29.5%$ inhibition, but the $AFB_1$ mutagenic potency was increased slightly by ethyl acetate fraction. The water fraction was further partitioned by sephadex LH-20 column chromtography, and 9 subfractions were obtained. The fraction III showed the strongest inhibitory effects with dose response against the mutagenic activities induced by all the tested chemical mutagens. The inhibition rates of fraction III at concentration of $400\;{\mu}g/assay$ were 29%, 35%, 38%, 25% and 24% against 4-NQO, MNNG, MMC, AFBl and B(a)P, respectively. The fraction III also exhibited a strong bio-an-timutagenicity against 4-NQO and $AFB_1$ by showing more than 40% inhibition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.588-592
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• 1996

The flavonoids isolated from Oenanthe javanica were investigated on the antimutagenic effect againt aflatoxin $B_1(AEB_1).$ The 0.5 and 1.0mg/plate of isorhamnetin reduced the mutagenicity of $AFB_1about$ 33 and 59%, respectively. Persicarin showed the 40 and 47% inhibition rate at Previous concentration, respectively.