• Journal of Food Hygiene and Safety
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• v.13 no.1
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• pp.47-52
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• 1998

A rice cultivar (Japonica type), Cheong-cheong, was used to examine the ability as a substrate for aflatoxin production. Brown rice samples were inoculated with Aspergillus parasiticus, stored at various conditions, and observed the production of aflatoxin $B_1$ during storage. Enzyme-linked immunosorbent assay (ELISA) was performed to detect aflatoxin $B_1$ in the samples. A temperature of $28^{\circ}C$ favored the aflatoxin production in the samples. Remoisturizing brown rice to 15.8% encouraged the fungus to produce the aflatoxin significantly (p$B_1$ production in rice, and also indicated that other factors such as husking and storage periods were also risk determinants. This study provided evidence that rice could be an efficient medium for aflatoxin production.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.87-93
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• 2003

This study was performed to investigate aflatoxin reduction resulting from the pre-treatment and the cooking and processing of corn. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on a type of corn imported from the United States. The aflatoxin-produced com (AC) was pre-treated in three ways in order to reduce aflatoxin: exposure to sun light for 7 days (SC); ultraviolet irradiation for 56 hours (UC); and washing with water three times (WC). Four kinds of cooking and processing methods (boiling, steaming, baking, and popping) were used to reduce aflatoxin in the AC control, SC, UC, and WC. These treatments produced com gruel, com cakes, com bread and popcorn. The aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level of the AC was significantly decreased by sun light and UV (p<0.05), and decreased by washing. After cooking and processing the AC, SC, UC, and WC, and averaging the total aflatoxin levels in the final products, the greatest reduction was found in the com gruel, then the popcorn, then the corn cakes, and the least reduction in the com bread. These results indicate that sunlight and ultraviolet energy could be effective factors in aflatokin degradation in corn before cooking and processing. This study also indicates that boiling, steaming, baking and popping were helpful in reducing the aflatoxin level in the com and that the most helpful factors were exposure time to heat. More research is needed to reduce the aflatoxin level down to below the maximum tolerable level of aflatoxin in foods.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.79-86
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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 far 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 (sikhye, 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.24 no.4
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• pp.367-370
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• 1992

Aflatoxins are highly carcinogenic agents consistantly found as contaminants in human food supplies in many areas of the world and epidemiologically linked to incidence of human liver cancer. To examine the carcinogenic action of aflatoxin $B_1$, aflatoxin $B_1-DNA$ adducts were chemically synhtesized with the reaction of 20 mg calf thymus DNA, and 8 mg standard aflatoxin $B_1$. Since DNA molecule was too large for analysis, it was fragmented by acid hydrolysis and heat. The fragmented aflatoxin $B_1-DNA$ adducts were selectively concentrated by immunoaffinity column procedure and confirmed by HPLC method. The main component was aflatoxin $B_1-guanine$ adduct, which was quantatively measured as 5.2 mg aflatoxin $B_1$.

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.133-145
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• 1975

한국산 aflatoxin의 독성을 비교 규명하기 위하여 결정 aflatoxin, 사료배합 aflatoxin 및 표준 aflatoxin을 오리병아리에 각 1회씩 경구투며 또는 급식시켜 얻은 결과는 다음과 같다. 1. 각종 aflatoxin의 독성으로 인하여 유발된 공통된 주요 병리조직학적 병변은 출혈(出血), 간세포(肝細胞)의 괴사(壞死), 지방변성(脂肪變性) 및 담관세포(膽管細胞)의 증식(增殖) 등이였다. 2. 병변(病變)의 정도(程度)는 독소의 투여량과 경과시간에 따라 다양(多樣)하게 나타났다. 3. 한국산 aflatoxin의 독성은 표준 aflatoxin에 비해 약간 더 심한 병변(病變)을 나타냈으며, 한국산 aflatoxin에서도 결정 aflatoxin을 투여한 경우보다 사료에 배합하여 급식시킨 경우가 약간 더 심한 병변(病變)을 나타냈다. 4. 닭병아리의 간장에서 aflatoxin이 유발시킨 병리조직학적 소견보다 오리병아리의 간장에서의 경우가 그 정도에 있어 더욱 심하고 뚜렷하였다.

• Food Science and Preservation
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• v.9 no.1
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• pp.78-84
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• 2002

While rice and corn were stored at room temperature for 90 days the degree of aflatoxin production was measured without humidity and temperature control. The amount of aflatoxin production of rice and corn after 30 days was 01.1 and 0.3 ppb, respectively. The degree of aflatoxin production increased rapidly with increasing storage temperature and humidity. The optimum conditions of aflatoxin production were 25 ∼30$\^{C}$ and 80% humidity. The degree of aflatoxin production in corn was higher than in rice under the same conditions. Rice and corn were treated with 0∼0.05%(w/w) of methyl alcohol (MeOH) extract and polyphenol (PP) group materials individually respectively under the optimum conditions. As the result, the inhibition effect of aflatoxin production increased with increasing the amount of treatment. It appeared as follows: catechin (CT)

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.143-147
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• 1988

The effect of ginseng saponin on aflatoxin(AF) production by Aspergillus parasiticus NRRL2999 and the mutagenicity of produced aflatoxin. The production of aflatoxin were decreased by the addition of ginseng saponin and the most effective concentration was 0.05%. The ratio of aflatoxin $B_{1}$ and aflatoxin $G_{1}$ were not changed by the addition of ginseng saponin. For the nutagenicity test, Ames method were adopted. Mutagenicity of mycelial aflatoxin was decreased by the addition of ginseng saponin on TA98, but not changed on TA100. Mutagenicity of excreted aflatoxin to broth was slightly increased by the saponin on TA98, but decreased on TA100.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.263-269
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• 1975

한국산(韓國産) aflatoxin $G_1$의 독성(毒性)을 비교구명(比較究明)하기 위하여, 한국산(韓國産) aflatoxin $G_1$과 표준(標準) Aflatoxin $G_1$을 各各 1포(圃)씩 오리병아리에 경구투여(經口投與)해서 얻은 결과(結果)는 다음과 같다. 1. Aflatoxin $G_1$의 독성(毒性)에 의(依)하여 유발(誘發)되서 간장(肝臟)에 나타난 병리조직학적(病理組織學的) 병변(病變)은 출혈(出血), 지방변성(脂肪變性) 및 경(輕)한 담관세포(膽管細胞)의 증식등(增殖等)이었다. 2. 출혈(出血)은 $75{\mu}g$의 한국산(韓國産) aflatoxin $G_1$의 투여(投與)로 폐사한 오리에서 가장 현저하였다. 담관세포(擔管細胞)의 증식(增殖)은 $75{\mu}g$과 $50{\mu}g$의 aflatoxin $G_1$을 투여(投與)한 경우에 경(輕)하게 나타났다. 3. 독량(毒量)이 같은 경우에도 Aflatoxin $B_1$에 비(比)해 Aflatoxin $G_1$의 병변(病變)이 훨씬 가볍게 나타났다. 4. 한국산(韓國産) aflatoxin $G_1$을 투여해서 발생(發生)된 병변(病變)은 표준(標準) aflatoxin $G_1$을 투여해서 발생(發生)된 병변(病變)과 유사(類似)하였으며, 그 정도(程度)도 비슷하였다.

• Journal of Food Hygiene and Safety
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• v.1 no.2
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• pp.157-162
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• 1986

ABSTRACT-This study was designed to observe the effects of temperature cycling on the aflatoxin production by Aspergillus parasiticus R-716 in modified SLS medium. Temperature cycling resulted in total aflatoxin production more than did constant incubation at either $28^{\circ}C$, which was considered to be optimum for aflatoxin production, or $17.5^{\circ}C$, which had the same total thermal input as the temperature cycling. The aflatoxin biosynthesis correlated with the color intensity of media, but was controversal with lipid biosynthesis, and aflatoxin concentration is not related to changes in the fatty acid compositions of used strain.strain.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.352-356
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• 1986

A study was carried out to determine the effect of ginseng saponin an its related materials on aflatoxin production by Aspergillus parasiticus NRRL2999 in glucose-salts(GS) medium. Maximal growth of the mold and AF froduction in the medium occurred after 5 and 9 days at $28^{\circ}C$, respectively. When various concentrations of saponin added to the medium aflatoxin synthesis were significantly reduced (p<0.05) compared to the control after 9 days at $28^{\circ}C$. 0.05% of saponin inhibited aflatoxin production most effectively in the low concerntrations of saponin (0.01-0.2%) and the toxin synthesis reduced with an increasing concentrations of saponin in the high concentrations (0.03-5.0%). Various concentrations (0.01-1.0%) of saponin diol and triol in the media also caused to reduce aflatoxin synthesis by the mold (p<0.05). All saponin fractions were found to decrease aflatoxin production significantly. Saponin fraction numbers of 1,2,4 and 6 were shown to reduce aflatoxin production effectively, and the number 1 was the most effective. Addition of 0.05% of nucleic acid related materials to the medium reduced aflatoxin production (p<0.05). Aflatoxins could not be found in broth at all, but in mycelia when 0.05% of caffeine was added to the medium. Aflatoxin synthesis was well correlated with total lipid synthesis, growth and glucose uptake. When aflatoxin synthesis inhibited (5.0% of saponin) both total lipid synthesis and growth were stimulated and the efficiency of glucose utilization was reduced.