• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.115-120
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• 1998

This Study was performed to investigate the contents of aflatoxin $B_{1}$ in cereal, pulse, nuts and these products of domestic and import. These results were as follows. 1. Average concentration(in ${\mu}g/kg$) of aflatoxin $B_{1}$ in domestic foods were 2.6 in cereal, 3.9 in pulse, 4.2 in nuts and 1.4 grain products. The contents of aflatoxin B$_{1}$ in pulse and nuts were much higher than those of cereal and grain products. But their values were still within $10{\mu}g/kg$ the maximum residual level of aflatoxin $B_{1}$ for food of Korea. 2. Average contents of aflatoxin $B_{1}$ in import foods were 4.8, 5.4, 6.0, $3.8{\mu}g/kg$ for cereal pulse , nuts and popcorn & peanuts butter, respectively. And these values were found to be below the maximum residual level ($10{\mu}g/kg$) of aflatoxin $B_{1}$ for food of Korea. 3. The concentration of aflatoxin $B_{1}$ in 2 samples of domestic and 9 samples of import foods were over the tolerance limit for aflatoxin $B_{1}$ in food of Korea. Therefore, the hygienic managements of the foods should be required during storage and circulation at market.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.7-10
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• 1975

A series of experiment was undertaken to pursue the possibility of aflatoxin accumulation in stored grains which were artificially contaminated with A. flavus var. columnaris isolated from deteriorated rice in Korea. In storage of rice grain, aflatoxin formation needed relative humidity over 80%, once accumulated aflatoxin was degraded by other microbial growth maintaining 50% level and the absence of other microoganisms brought about the remarkable accumulation of aflatoxin. The formation of aflatoxin in grains was increasing in the order of soybean, peanut, corn, wheat, barley, foxtail millet, rice, polished wheat, mung bean and great millet and it appears to be affected by the size and oil content of grains.

• Journal of Environmental Health Sciences
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• v.12 no.1
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• pp.39-45
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• 1986

This study was designed to observe the effect of temperature cycling on the production of aflatoxin by Aspergillus parasiticus R-716 in rice, barley, peanut and soybean. In those media, temperature cycling resulted in more total aflatoxin production by the strain of R-716 than constant incubation at $28{\circ}$C and natural condition did. Especially, high level of total aflatoxin ($1826{\mu}g$/30g) in rice medium at temperature cycling was produced. The intensity of yellow color of chloroform extracts correlated with the concentration of aflatoxin, and the ratio of aflatoxin $B_1$ to aflatoxin $B_2, G_1, G_2$ is lower at temperature cycling condition than at $28{\circ}$C.

• Journal of Food Hygiene and Safety
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• v.11 no.1
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• pp.35-39
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• 1996

The effect of allyisothiocyanate, the mahor compound of radish on the growth of Aspergillus parasiticus R-716 and aflatoxin production, was investigated. An increase in the level of allylisothiocyanate results in a decrease both growth and aflatoxin per myclial weight, and the addition of 125 ppm allylisothocynate completely inhibited the growth of the strain. The addition of allylisothiocyanate to the culture of R-716 strain the production of aflatoxin. The inhibition of aflatoxin was more B-group than G-group and M-group during cultural period. The growth of strain and aflatoxin production were greatly affected by the addition of allylisothiocyanate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.117-126
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• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.721-725
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• 1989

Aflatoxin accumulation by Aspergillus flavus in rice was inhibited by A. kawachii and A. Shirousamii so that the rate of toxin accumulation and the maximum concentration of accumulated aflatoxins were considerablly reduced, although the initiation of aflatoxin accumulation was not affected. The maximal accumulated aflatoxin $B_1$ in rice by A. flavus at $28^{\circ}C$ and 85% RH was $40{\mu}g/50g$ rice after 35 days. Under the same condition but the additional inoculation of A. kawachii, $25{\mu}g\;of\;aflatoxin\;B_1$ was accumulated maximally in 50g rice after 45 days. When A. shirousamii was inoculated simultaneously with A. flavus on rice, however, only trace levels of aflatoxins were detected throughout 60 days of storage. Aflatoxins added to rice were reduced by 97% with A. kawachii and by 98% with A. shirousamii after 7 days during rife koji preparation. They were also reduced after 48 Hours of incubation by 30-67%, with A. kawachii koji and by 16-75% with A. shirousamii koji.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.55-56
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• 2002

Aflatoxin is a secondary fungal metabolite and is a public health hazard because it is a human carcinogenic and has many deleterious effects in men and animals. Rice is one of the better substrates for the fungus which can produce aflatoxins. This study was performed to investigate aflatoxin reduction during the cooking and processing of rice. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on well-milled rice(Japonica type) at the level of 13.2 ppb. Cooked rice, rice cakes (baek-sol-gi, plain steamed rice bread), fermented rice (sik-hye, sweet rice beverage), and popped rice were prepared from the aflatoxin-contaminated rice. Aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level was decreased to 46.9％ in the cooked rice, 85.6％ in the rice cakes, 11.4％ in the fermented rice, and 7.6％ in the popped rice, respectively (p＜0.05). This reduction brought the level of aflatoxins down to below the Standard and Specification of Korea (10 ppb), except for the rice cakes. These results indicate that washing, steaming, fermentation, and popping of rice was helpful in reducing the aflatoxin level in the rice and the most helpful factors were high temperature & high pressure. More research is needed to understand why the preparation of rice cakes did not reduce the level of aflatoxin as much as the other cooking methods.

• Korean Journal of Food Science and Technology
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• v.6 no.3
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• pp.169-176
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• 1974

In order to investigate the producibility of aflatoxins by seven Aspergillus flavus strains isolated from deteriolated rice in Korea, polished rice was artificially inoculated and subjected to isolation and quantitation of the mycotoxin. It was proved that all strains were capable of producing aflatoxins, preferentially $B_1$ but no $G_1$ at all and their producibility was closely related to the color of culture media and chloroform extracts. The strain producing the most aflatoxin was A. flavus var. columnaris, excreting 1 ppm on rice. Aflatoxin $B_1$ was isolated and identified by thin-layer chromatography, ultraviolet absorption spectra and derivative formation of water and acetate adducts.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.385-391
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• 2003

The influences of the extracts from Cinnamomi Cortex, Eucommiae Cortex, Puerariae Radix, Lycii Fructus, Zizyphi Fructus, Schisandrae Fructus, Mume Fructus, Chaenomelis Fructus on mycelial growth and aflatoxin $B_1$ production from Aspergillus parasiticus were analyzed. The pH of the culture media were reduced to below pH 4 by all the herbal extracts after 3 days incubation. However, the pH of the culture media increased above pH 6 after 6 days incubation using the extracts from Cinnamomi Cortex, Eucommiae Cortex, Puerariae Radix and Lycii Fructus. The mycelial growth of A. parasiticus was increased over the amount of the control. Puerariae Radix produced the largest amount of mycelial growth and Chaenomelis Fructus produced the smallest amount of mycelial growth. The productions of aflatoxin $B_1$ from A. parasticus culture were increased by the extracts of Puerariae Radix and Zizyphi Fructus, while inhibited by the extracts of Cinnamomi Cortex, Eucommiae Cortex, Lycii Fructus, Schisandrae Fructus, Mume Fructus and Chaenomelis Fructus. In particular, the extracts of Cinnamomi Cortex, Lycii Fructus and Schisandrae Fructus almost inhibited the production of aflatoxin $B_1$. The production of the total protein from Cinnamomi Cortex, which produced much less aflatoxin $B_1$, and Puerariae Radix, which produced a great deal of aflatoxin $B_1$ from A parasticus were slightly higher than the production of the total protein of the control medium.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.155-162
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• 2010

Aflatoxin $B_1$, a known human carcinogen, is the member of aflatoxin subfamily that is most frequently found in contaminated foods. Epidemiological studies have suggested that aflatoxins may be associated with human liver cancer and acute hepatitis. Recently it was reported that the traditional medical herbs sold in domestic markets are contaminated with aflatoxins. Long-term administration of these contaminated medicines could result in adverse health effects. Therefore, it is important to evaluate the levels of exposure to aflatoxin in people who ingest traditional herbal medicines. Blood samples were collected, before and after the herbal medicine intake, from 151 subjects who visited the hospital. The metabolite of aflatoxin $B_1$ in blood, aflatoxin $B_1$-albumin (aflatoxin $B_1$-lysine), is reportedly an appropriate internal exposure indicator, and its levels in the collected bloods were therefore analyzed using a liquid chromatography-mass spectrometry. The analytical method of aflatoxin $B_1$-lysine in blood was firstly optimized in Korea and the levels were detected below quantification limits (2 pg/mg albumin) in this study population. Consequently, the exposure levels of aflatoxin $B_1$ by ingestion of herbal medicines were low but it is important to monitor routinely due to the possibility of risk on the aflatoxin exposure.