• Journal of Food Hygiene and Safety
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• v.10 no.4
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• pp.225.2-262
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• 1995

Ochratoxin A was produced from Aspergillus ochraceus ATCC 18472 which was then orally administered into the experimental mice to study the toxic levels of ochratoxin A. AELISA (enzyme-linked immunosorbent assay) method which is more rapid and safe than conventional analytical method, was developed by using ochratoxin A antibody. This method was successfully used to measure the levels of ochratoxin Ain blood, liver and kidney of mice. In order to produce a large amount of ochratoxin A to study toxicity in the mice, Aspergillus ochraceus ATCC 18412 was incubated in the rice medium and as a result 0.5 g of ochratoxin A form rice medium (kg) was produced after extraction and purification Feed consumption and gain in body weight of mice with ochratoxin A at a level of $10 \mu\textrm{g}/g$ body weight was significantly (p<0.05) reduced as compared with control during period of 3 weeks. Ochratoxin A-BSA conjugate was made by putting 13 mole of ochratoxin A on I mole of BSA. This conjugate was used to develop ELISA method. The minmum detection level of ochratoxin A by established ELISA method was 0.5 ppb. After oral adminstraton of ochratoxin A dose of $10\;\mu\textrm{g}/g$ every two day for 3 weeks, concentration of ochratoxin A was measured in the blood, liver and kidney by ELISA method. The level of ochratoxin A was $11\;\mu\textrm{g}/dl,\;0.9 \mu\textrm{g}/g\;and\;3.7\;\mu\textrm{g}/g$ in the blood, liver and kidney, respectively.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.140-142
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• 2006

Because ochratoxin A recovery level of Makgeolli is lower (<50%) than those of other commodities such as rice, barley, and beer, Makgeolli was evaluated to improve the recovery and enable routine analysis. Use of 3% sodium bicarbonate instead of phosphate-buffered saline as homogenizing solution provided good recovery of ochratoxin A (>80%) spiked in Makgeolli at level of 1 ppb. To determine if this analytical method is reliable for ochratoxin A detection in Makgeolli, survey was conducted for ochratoxin A in 30 sterile Makgeolli samples retailed in Korea. Only two wheat-based Makgeolli samples contained detectable level of ochratoxin A (0.8 and 2.1 ppb) as confirmed by HPLC- electrospray ionization- mass spectrometry. Extraction of sample with 3% sodium bicarbonate for 3 min, followed by cleanup of extracts with immunoaffinity columns, and HPLC with fluorescence detection provided dependable detection of ochratoxin A in Makgeolli samples.

• Journal of Environmental Health Sciences
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• v.20 no.3
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• pp.54-60
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• 1994

We established ELISA method which is more rapid and safe than conventional analytical method, and then analyzed concentration of ochratoxin A in the rices by ELISA method. The results were as follows: 1. Since ochratoxin A molecular does not contain the group for coupling reaction, it was first proposed to have the function of an antigen. As a result of conjugation of ochratoxin A-BSA derivatives, one molecular of BSA was conjugated with 13 moleculars of ochratoxin A. 2. On the basis of established ELISA to apply for immuno analytical method of ochratoxin A, the minimal level of detection by ELISA method was at 0.5 ppb. 3. Rices (42) were collected from homes of Kyoungnam districts through November 1992 to December 1992, as a result of analysis, two of these were positive. Rice samples of R-1 and R-9 represented ochratoxin A levels of 6.0 ng/g and 10 ng/g, respectively.

• The Korean Journal of Mycology
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• v.19 no.2
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• pp.148-155
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• 1991

Fungal ochratoxin A wes extracted and measured from the Korean traditional and fermented soybean foodstuffs (12 samples of Maeju, 28 samples of Dwangjang and 28 samples of Kangjang) collected from the whole nation wide regions. The various fungi were isolated from the foodstuffs and they were also examined whether the isolates produce ochratoxin A (OA) under the artificial conditions or not. Determinations of OA produced by the fungi were done with the antibody-attached CIA method, which was accurate or sensitive at the range of 20 pg per sample with a ninty percent recovery. Out of the 222 fungal isolates, 39 isolates produced the OA under the artificial conditions, and were identified as species of Aspergillus, Penicillium, Paecilom­yces or other genera. The OA detected in all soybean foodstuffs was presumed to be originated from the first fermentation step of maeju.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1415-1419
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• 1998

In order to evaluate the safety of greenhouse horticultures, a large number sample sources were collected, and the fungi of Aspergillus sp. and Penicillium sp. were isolated from them. Indirect competitive ELISA method and high performance liquid chromatography (HPLC) were applied to confirm the ochratoxin A producing abilities of isolated strains. One hundred ninety two sample sources including soil, pepper, strawberry and water mellon were collected for fungi isolation from western Gyeongnam, Andong and Gyeongbok. One hundred forty two strains of Aspergillus sp. and one hundred fifty three strains of Penicillium sp. were isolated respectively from them. The isolated fungi were tested for the production of ochratoxin A by ELISA. After culture of them on the modified sucrose low salt medium at $28^{\circ}C$ for 15 days, we found that five strains of Penicillium sp. produced ochratoxin A at the levels of $0.084{\sim}2.128\;{\mu}g/mL$. Among them, #129-2 strain isolated from water melon, showed the highest level of ochratoxin A as $2.128\;{\mu}g/mL$ broth. However, all of isolated Aspergillus sp. didn't produce ochratoxin A. When we compared the results of ELISA method with HPLC method, ochratoxin A production of each isolated strains showed very similar levels.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.158-161
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• 2004

To determine rapid and reliable analytical method for ochratoxin A detection in cereal-based Korean traditional foods, ochratoxin A content was measured by high-performance liquid chromatography (HPLC) with immunoaffinity column clean-up. Recoveries of ochratoxin A in tested samples ranged from 68.4 to 85.3%. Occurrences of ochratoxin A were 15, 10, and 5% for Kochujang, Deonjang, and Kanjang, respectively. None was detected in Sunsik (mixed cereals). Average levels of ochratoxin A ranged from $0.5\;to\;1.3{\mu}g/kg$, lower than maximum residue level of $5-50{\mu}g/kg$ of ochratoxin A recorded in foreign food code.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.36-41
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• 2016

Ochratoxin A and aflatoxin may be detected from naturally fermented foods due to the contamination of the mycotoxin-producing molds or un-prudential use of the mycotoxin producing starter strains during the fermentation. This study was carried out to analyze the production of ochratoxin A and aflatoxin under the various environmental conditions. For the experiment, the effects of different temperature, culture media, and fermentation time on the production of ochratoxin A by Aspergillus usamii KFRI 999 and A. awamori KFRI 983 were analyzed. Additionally, the production of aflatoxin was assessed under the various temperature, initial pH, fermentation time and culture media during fermentation by A. flavus KACC 41403 and A. oryzae KACC 46471. The levels of ochratoxin A and aflatoxin were analyzed by HPLC. The result showed that the production of mycotoxin was greatly affected by the fermentation temperature. A. oryzae KACC 46471 did not produce aflatoxin. All of the mycotoxin producing strains showed the highest level of mycotoxin at $30^{\circ}C$. A. awamori KFRI 983 showed the lowest level of ochratoxin A in PDA media among the experimental medium. The results of the present study may be useful for the reduction of ochratoxin A and aflatoxin in various foods.

• Toxicological Research
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• v.7 no.1
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• pp.37-46
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• 1991

To evaluate the influence of ochratoxin A on the pharmarcokinetics of gentamicin, gentamicin concentrations in the serum, renal cortex and medulla together with parameters of the renal function and histological changes were compared between ochratoxin A-treated rats (0.1 mg of ochratoxin A/kg of body weight, ip, daily for 14 days) and normal rats. Gentamicin was given with a single intramuscular injection (10mg/kg of body weight). Ochratoxin A resulted in an increase of the half-life, the area under the concentration-time curve, the apparent volume of distribution and a decrease of the total body clearance of gentamicin, and accumulated significantly (p<0.01) more gentamicin in the kidneys.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.56-62
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• 2017

The aim of this study was to screen the contamination by ochratoxin A of mycotoxins in various medicinal herbs. We conducted a survey of ochratoxin A in medicinal herb on the retail market in Incheon in 2016. 116 medicinal herb samples were evaluated for the ochratoxin A contamination. They were analyzed for ochratoxin A using immunoaffinity column and high-performance liquid chromatography(HPLC)-fluorescence detection and the positive samples were confirmed using HPLC-tandem mass spectrometry. Ochratoxin A was detected in 4 medicinal herb samples; the concentrations of ochratoxin A were containing between 20.11 and $372.90{\mu}g/kg$. This study shows that in general, this kind of commodity may be contaminated by mycotoxins. Also this contamination is not limited to only aflatoxin of mycotoxins.

• Journal of Environmental Health Sciences
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• v.20 no.3
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• pp.49-53
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• 1994

To isolate the ochratoxin A producing strains from agricultural products and soil in Youngnam districts, rice (37), unhulled rice (10), barley (20), unhulled barley (3), corn (21), soil (26), meju (25), malt (8), soybean (26) and peanut (15) were collected from homes and markets of Youngnam districts through September 1992 to November 1992. 187 strains of Aspergillus spp. and Penicillium spp. were isolated from 191 samples. As a result of screening by TLC, 36 strains expressed fluorescent spot and a same Rf value of standard ochratoxin A, and 9 strains of them were identified as ochratoxin A producing strains by HPLC.