• Korean Journal of Food Science and Technology
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• v.1 no.1
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• pp.78-84
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• 1969

An attempt has been made to investigate the possible occurrence of aflatoxins, a group of micotoxin which are toxic metabolites produced by Aspergillus flavus, and aflatoxin like substances in fungal fermented soybean products such as meju and soybean paste. Chloroform extracts from 15 samples which has been defated with petroleum ether are subjected to separations with thin-layer chromatography on silica gel washed with methanol prior to film coating, improves the chromatographic separation and ultraviolet absorption spectral identification. In addition to fluorescencing spot having an Rf value which is same as aflatoxin $B_1$, many of the fluorescencing spots have been occurred in every sample examined. Each fluorescencing spot is scratched and the ethanol extracts are subjected to further separation with thin-layer chromatography. Each fluorescence substance is eluted with ultra violet transparent absolute ethanol and the ultraviolet absorption spectra are checked. None of the absorption curve of eluates shsow accordance with the curve of aflatoxin. 2, 4-Dinitrophenyl hydrazine reagent, Tollen's reagent and ninhydrin reagent are applied on the chromatogram- The data show that aflatoxin is not present in any of the fungal preparations examined.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.376-378
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• 2012

Aflatoxin M1, ingested as aflatoxin B1 via contaminated feedstuff and later converted into, is a major problematic target for milk safety control among the aflatoxin class. Korean government has controlled level of AFM1 in milk at 500 ppt as maximum residue level (MRL), and more recently, government also publicized the proposal for more strict control on fungal toxins about infant and baby foods. In this study the levels of Aflatoxin M1 (AFM1) of 42 marketed milk samples were determined with Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate the status on the contamination of Aflatoxin M1. The evaluated ELISA performances of limit of detection (LOD) and the half maximal inhibitory concentration ($IC_{50}$) were 5 pg/mL (ppt) and 49 ppt, respectively. In all 42 samples, AFM1 appeared above the 5 ppt, with the average of 21 ppt and the range of up to 90 ppt. Only 3 (7%) of samples showed the level of contamination above the EU MRL (50 ppt). Although there was incidence of higher level of contamination compared with previous reports, the result of this study requires more intensive study to control of AFM1 in milk and infant foods.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.182-186
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• 1988

The maximal production of aflatoxin $B_1$, and $G_1$ by A. flavus ATCC 15517 was reduced by 98% and 99% respectively, in the mixed culture with A. awamori var. fumeus in comparison with that in the monoculture of A. flavus. An important cause for the reduction in aflatoxin formation was found that A. awamori var. fumeus excreted aflatoxin degrading factor(s) into the medium during the growth which precipitated by the addition of ammonium sulfate $(0{\sim}80%)$.

• Journal of Food Hygiene and Safety
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• v.3 no.2
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• pp.89-97
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• 1988

The possible effeets of some oriental herbs, whleh have been used to treat eaneerllke dllleue In Korea, on growth and afIatonn production by Aspergillus parasiticus R-716 were investigated. Zedoaria rhizoma, Curcuma longa, Cyperus rotundus, Angelica gigas, Paeonia albiflora, Paeonia mountan, Atractylis ovata, and Pulsatilla koreana were extracted with chloroform. Among them the extract of paeonia mountan was remarkably effective on the growth inhibition, and Curcuma longa, Zedoaria rhizoma, Cyperus rotundus, Paeonia albiflora, Atractylis ovata also inhibited the growth. The ertraet of Atractylis ovata and Curcuma longa, also Inhibited the afIatoxin production but the others showed no effect at all or sometimes stimulated effect. With the addition of O.2ml extract of Atractylis ovata in 30ml SLS medium, the growth was delayed for about 2 days, and after 9 days, mycellum weight was 0.953g, and total afatoxin was reduced 5O%($792\mu\textrm{g}$)of that produced in the control($1547\mu\textrm{g}$). Aflatoxin per mycelium weight was decreased 32%($992\mu\textrm{g}$) of that produced in the control($1467\mu\textrm{g}$), but NADPH oxidase was higher as compared to the control. The extract of Atractylis ovata appeared to have a inhibitory effect on the growth and the aflatoxin production of Aspergillus parasiticus R-716.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.164-170
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• 1998

In this study a commercial fermented milk produced in Korea and a Lactobacillus strain used for the product (L. casei) were found to affect mold growth and inhibit aflatoxin production by Aspergillus parasiticus ATCC 15517. Aflatoxins were determined using an HPLC system that consisted of a $C_{18}$ column and a fluorescence detector. When the fermented milk was added to the yeast-extract broth the levels of aflatoxin $B_{1}\;and\;G_{1}$ significantly decreased by 48.6~58.1% and 29.8~34.2%, respectively (p$B_{1}\;and\;G_{1}$ were found in comparison with the control (monoculture). L. casei was found to be very inhibitory to the growth of A. parasiticus for 5 days, but no significant difference of mycelial weight was observed between the mixed culture and control at the end of incubation. The pH values of the culture broth in mixed culture were observed to be significantly lower than those in monoculture (p

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.177-181
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• 1985

Aflatoxin production by Aspergillus parasiticus NRRL 2999 with two different levels of inoculum sizes ($10^2$ and $10^6$ spores) was studied on such varieties of soybeans produced in Korea as Bongeui, Hwang Keum, Jangbaek, Danyeop, Jangyeop and Namcheon. With the inoculum size of $10^2$ spores/10 g of soybeans, there were statistically difference (p<0.05) on the production of aflatoxins in the varieties of soybeans. The variety of Namcheon produced 7 times higher amount of aflatoxin $B_1$ than that of Bongeui. The variety of Jangyeop produced the highest level of aflatoxin $G_1$ among the varieties employed. Namcheon and Jangyeop were the varieties which supported high amounts of aflatoxins. Much higher levels of aflatoxins were obtained on the soybeans than on rice in general with the inoculum size of $10^2$ spores. With the inoculum size of $10^6$ spores/10 g of soybeans, significantly lower levels of aflatoxins were synthesized by the mold than those with $10^2$ spores. The variety of Namcheon resulted in the lowest production of aflatoxin $B_1$ while Hwangkeum was the variety that produced highest amount of aflatoxin $B_1$. There were no significant differences within the varieties on the production of aflatoxin $G_1$ by the mold except the variety of Hwangkeum. Lower quantities of aflatoxin $B_1$ were produced by the mold en the soybeans than on rice with the inoculum size of $10^6$ spores.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.390-394
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• 1992

Some enzymatic characteristics of the aflatoxin degrading factor produced extraceIlularly by Aspergillus awamori var. fumeus were investigated. When aflatoxin B1 was incubated with the culture filtrate of A. awamori var. fumeus. 60% of it was degraded within an hour. The degradation rate decreased with time and there was virtually no degradation after one hour. The apparent Michaelis constant ($K_m$) determined by Lineweaver-Burk plot was $10.2{\mu}M$. The optimum degradation was observed at $30^{\circ}C$ and pH 5. For the degradation, molecular oxygen seemed to be required. The degradation was enhanced by the $Co^{2+}$. but was inhibited by many other ions like $Fe^{2+}$, $Ca^{2+}$. $Mg^{2+}$, $Zn^{2+}$,$Cu^{2+}$, and $Ba^{2+}$, The presence of either KeN or metyrapone inhibited the reaction while that of $NaI0_4$ cytochrome C or NADPH showed no effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.502-508
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• 1986

Extracts of six seaweeds obtained from solvents such as water, methanol, hexane and ethyl ether have been tested for desmutagenic activities in the Salmonella typhimurium/microsome systems. Water extracts obtained from tangle, sea-tangle, and gompi were moderately effective on the mutagenicity of Trp-P-2 and aflatoxin $B_1$. Methanol extracts of sea-tangle and gompi were effective against Trp-p-2, and all samples of methanol extracts were very effective from 1.0mg to 2.0mg per plate on the mutagenicity of MeIQ and aflatoxin $B_1$. Hexane extracts of tangle, ses-tangle, gompi and sea-straghorn were very effective on the mutagenicity of Trp-p-2, MeIQ and aflatoxin $B_1$ except laver and green laver. Ethyl ether extracts of gompi and sea-straghorn were most effective from 1.0mg to 2.0mg per plate on the mutagenicity of Trp-P-2. Especially, ethyl ether extracts of all samples were great effective on the mutagenicity of MeIQ and aflatoxin $B_1$.

• Food Science and Preservation
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• v.30 no.1
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• pp.28-41
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• 2023

Non-aflatoxigenic Aspergillus oryzae and aflatoxigenic A. flavus cannot be clearly identified by partial sequencing of the internal transcribed spacer (ITS) and 18S ribosomal ribonucleic acid (18S rRNA) regions. This study aimed to compare the accuracy among three aflatoxin detection methods using ultra-performance liquid chromatography (UPLC), high-performance liquid chromatography (HPLC), and an enzyme-linked immunosorbent assay (ELISA) kit and to select the non-aflatoxigenic Aspergillus sp. isolated from soybean paste. All analytical methods were suitable according to the international standards of Codex Alimentarius FAO-WHO (CODEX) or the Ministry of Food and Drug Safety (MFDS). UPLC exhibited the best of limit of detection (LOD) and limit of quantification (LOQ). Based on UPLC, HPLC, and the ELISA kit assay, the P5 and P7 strains isolated from soybean paste had 1,663.49, 1,468.12, and >20 ㎍/kg and 1,470.08, 1,056.73, and >20 ㎍/kg, respectively, detected and re-identified as A. flavus. In contrast, the P3 and P4 strains (A. oryzae), which were detected below the MFDS standards in all assays, were confirmed as non-aflatoxigenic fungi. Among the methods evaluated for quantitative analysis of aflatoxin, UPLC and HPLC are superior in terms of accuracy, and the ELISA kit rapidly detects low concentrations of aflatoxin. Furthermore, this study demonstrates that any Aspergillus sp. isolated for use as a fermentation starter should be analyzed for potential aflatoxin production using UPLC and HPLC for accurate quantitative analysis or ELISA for the rapid detection of low-level concentrations of aflatoxin.

• Journal of Life Science
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• v.26 no.2
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• pp.190-197
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• 2016

Aflatoxin M₁ can be produced in cow’s milk when cows eat contaminated produce. Milk is a major source of food for infants and for children who have a weak level of immunity, and the detection of Aflatoxin M₁ for risk assessment is necessary in order to reduce the amount of it in milk. In this study, the Aflatoxin M₁ level was monitored for one year in raw milk samples obtained from Chungnam Province, Korea. The milk samples were divided into three categories: 1. milk samples from a standard general farm, 2. milk samples from a HACCP controlled farm, and 3. milk samples from the supply of Aflatoxin M₁ reduced fodder. The average concentrations of Aflatoxin M₁ in milk were 0.023±0.005 ug/l for the standard general farm, 0.017±0.004 ug/l for the HACCP controlled farm, and 0.013±0.003 ug/l for the supply of Aflatoxin M₁ reduction fodder. Milk collected from the supply of Aflatoxin M₁ reduction fodder had the lowest level of Aflatoxin M₁. However, when efficiency and economic aspects are considered the most effective way of reducting Aflatoxin M₁, could be taking milk from the HACCP controlled farm and implementing good feed management. Institutional support from the government, careful management of dairy farming, and a strict farm sanitation program are required in order to lower the level of Aflatoxin M₁ in milk.