• Korean Journal of Medicinal Crop Science
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• v.18 no.5
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• pp.338-344
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• 2010

Our paper shows the results of 302 samples of herb medicines about fungal contamination at Yakyeang markets in Seoul. The sample medicines were treated VICAM pretreatment and analysed by post column derivatisation procedure(PHRED-HPLC) with a fluorescence detector. Aflatoxin B1 was founded from 50.3% of samples, aflatoxin B2 was 39.7%, aflatoxin G1 was 21.2% and aflatoxin G2 was 23.5%. The detected ranges of aflatoxin B1, B2, G1 and G2 were from 0.1 to $57.2\;{\mu}g/kg$, 0.1 to $42.6\;{\mu}g/kg$, 0.1 to $23.5\;{\mu}g/kg$ and 0.1 to $9.5\;{\mu}g/kg$ respectively. Among total samples, 26 samples contained aflatoxin B1 violated the regulation (less than 10 ug/kg) for aflatoxin B1 of KFDA. From the result, we could presumed that more than a half of samples were contaminated by aflatoxins. Therefore, it seems to be necessary that the new safety giudeline will be established aflatoxin B2, G1 and G2 from herb medicines as aflatoxin B1.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.702-710
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• 2011

The occurrence of aflatoxins $B_1$, $B_2$, $G_1$ and $G_2$ in nuts, their products and dried fruits was investigated. Samples were collected from local markets in Seoul and analyzed by rapid resolution liquid chromatography coupled with tandem mass spectrometry using an immunoaffinity column. The chromatography method was validated for assay of aflatoxins using linearity, accuracy, precision and limit of detection and quantification. The linearity in the concentration ranged from 0.10 to $20{\mu}g/kg$ with $R^2$ > 0.9999. Sample recoveries ranged from 71.1 to 97.2% with relative standard deviations below 4.5% for spiking levels from 1 to $10{\mu}g/kg$. The limits of detection ranged between 0.02 and $0.05{\mu}g/kg$ and the limits of quantification ranged between 0.05 and $0.10{\mu}g/kg$. The levels of aflatoxin $B_1$, $B_2$, $G_1$ and $G_2$ in nuts, their products and dried fruits were $B_1$ 0.10 to $9.94{\mu}g/kg$, $B_2$ 0.08 to $1.54{\mu}g/kg$, $G_1$ 0.04 to $3.21{\mu}g/kg$ and $G_2$ 0.06 to $0.14{\mu}g/kg$.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.111-119
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• 2013

Eleven mycotoxins, including aflatoxins, ochratoxin A, fumonisins, zearalenone, T-2 toxin, deoxynivalenol, and HT-2 toxin, were analyzed simultaneously in rice, barley, and maize produced in 2011 by liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Limits of detection (LOD) are 0.2 ${\mu}g/kg$ for aflatoxin $B_1$, and $G_1$, 0.3 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.1 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 3.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Limits of quantification (LOQ) were 0.6 ${\mu}g/kg$ for aflatoxins $B_1$, and $G_1$, 0.9 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.3 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 10.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Recoveries for 11 mycotoxins ranged from 70.45 to 111.11%. Fumonisins, deoxynivalenol, and zaeralenone were detected from 0.9 to 334.0 ${\mu}g/kg$ in the polished rice, barley and raw corn cultivated in Korea. Other mycotoxins were not detected. Deoxynivalenol contamination was mainly found in barley (24 out of 43 samples) and the average value in positive samples was 113.30 ${\mu}g/kg$.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.12
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• pp.1757-1762
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• 2011

Aflatoxins are natural contaminants of poultry feeds and feed ingredients and cause liver damage, immunosuppression, reduction in performance and mortality in broilers. A number of studies have been carried out to study the effects of aflatoxin on feed conversion ratio in broilers. The results on feed conversion ratio of 10 research articles in broilers fed with aflatoxin from first day of age to six weeks of age were compiled and were subjected to meta-analysis. Chi-square test and $Tau^2$ (heterogeneity co-efficient) were applied to test for significance of heterogeneity of studies. To integrate results, fixed effect model by Inverse Variance method (IV method) was used when heterogeneity was insignificant and otherwise random effect model by DerSimonian and Laird Method (DL method) was used. The results of meta-analysis showed that the adverse effect of aflatoxin on feed conversion ratio at the end of first week was negligible, second week was medium and third to six weeks was very large.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1038-1041
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• 2009

Aflatoxins are secondary metabolites produced by the aflatoxigenic fungi in suitable conditions. Saffron, Crocus sativus, is the most expensive spice in the world. Saffron is normally contaminated with soil and hand microflora during harvest and post-harvest operations. In this study, rapid assessment of aflatoxigenic fungi in saffron was accomplished using polymerase chain reaction. In total, 37 market samples were assayed in order to isolate aflatoxin-producing fungi. The 18.9% of the total samples were contaminated with aflatoxigenic fungi. Our results also show that most of the isolated fungi were saprophytes which are normally originated from soil during harvest and postharvest process.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.154-160
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• 2000

Aflatoxin B1 is known as the most potent mycotoxin produced by several fungi. It has been demonstrated to be not only carcinogenic but teratogenic and mutagenic as well in humans. To prevent or inactivate aflatoxins, several chemical of physical methods were tested for ammoniation, using insecticides as an wxample, but they were unsuitable for food products. On the contrary, biological control by antagonistic microorgani는 is and ideal method. In order to control aflatoxin B1 biologically, the antagonists #07, #63, #75, #74, and #61 were separated from various samples by using the antagonistic activity test. Among them, culture filtrate part A (non heat-treated) of #63 and #74 on aflatoxin B1 produced by Aspergillus fkavus were shown to be 95% and 75%, respectively. Based on the morphological characteristics, #63 was deduced as an Azospirillum sp.

• Journal of Life Science
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• v.12 no.5
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• pp.632-648
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• 2002

The term polyketide defines a class of natural products synthesized through the successive condensation of small arboxylic acids, which results in products containing multiple carbonyl or hydroxyl groups, each separated by one arbon atom, as in the structural element CH$_2$C(=0)CH$_2$CH(OE)CH$_2$C(=0)-. Plant flavonoids, fungal aflatoxins, as well as undreds of compounds of different structures that can inhibit the growth of bacteria, viruses, fungi, parasites or human umor cells are included in this diverse group. Some of antifungal polyketides also have immunosuppresive activity. olyketides can vary widely in structure, and the diversity of polyketide structures reflects the wide variety of their iological properties. This review focuses on the biosynthesis of polyketides and recent progress in combinatorial iosynthesis of new hybrid polyketide compounds.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.571-575
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• 1995

A total of 455 food samples representing 22 different food types were collected from several localities at Alexandria province in Egypt. Aflatoxin B1 and aflatoxin M1 were detected in 5 out of 455 (1.1%) of these food samples. From the same samples 206 fungal isolates were obtained. Thirty two of these isolates (15.5%) were found to be aflatoxin producers. Aspergillus flavus was the dominant isolate, while Aspergillus parasaticus was also isolated from a few other food samples. Among locally consumed foodstuffs. Peanut (7.5%) and Milk powder (6.6%) were found to be a suitable substrates for aflatoxin production. The hygienic and public health significance of the isolated aflatoxigenic strains were discussed.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.515-521
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• 2006

아플라톡신(aflatoxin)은 곰팡이의 2차 대사산물이며 인간발암원으로 보건상 위해를 준다. 쌀은 아플라톡신을 생성하는 곰팡이인 Aspergillus flavus와 A. parasitidcus에 좋은 기질이다. 이 연구에서는 쌀과 쌀제품 및 쌀부산물에서 전세계적으로 나타나고 있는 아플라톡신 오염 정도와 오염 수준에 대하여 고찰하였다. 아플라톡신 오염 정도와 오염 수준은 시료의 유형과 시료채취 지역에 따라 다르게 나타나는 것으로 보인다. 쌀과 쌀제품 2,511 시료 중 36.6%에서, 그리고 쌀부산물 374 시료 중 57.8%에서 아플라톡신이 검출되었다. 이들 시료에서 aflatoxin $B_{1}$ 및 total aflatoxin오염도는 $0-185{\mu}g/kg$였다. 일부 백미 시료에서는 $20{\mu}g/kg$을 초과하는 시료가 있었다. 쌀의 아플라톡신 관련 위생관리지표를 고안할 수 있는 기초자료를 제공하기 위하여 쌀의 아플라톡신 오염에 대한 모니터링이 필요하다. 또 쌀과 쌀제품 생산의 모든 단계와 저장에서 아플라톡신 관리를 위한 통합적 접근법이 필요하다. 가축을 아플라톡신으로부터 보호하는 전략은 인간집단을 보호할 수 있는 효과적인 접근법이 될 수 있다.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.