Ochratoxin a production in Bavarian cereal grains stored at 15 and 19% moisture content

1992 ◽  
Vol 23 (2) ◽  
pp. 259-265 ◽  
Author(s):  
D. Abramson ◽  
W. Richter ◽  
J. Rintelen ◽  
R. N. Sinha ◽  
M. Schuster
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Cereal Grains

Bioproduction of ochratoxin A and penicillic acid by members of the Aspergillus ochraceus group

1972 ◽  
Vol 18 (5) ◽  
pp. 631-636 ◽  
Author(s):  
Alex Ciegler
Keyword(s):  
Quantitative Analysis ◽  
Low Temperature ◽  
Ochratoxin A ◽  
Acid Synthesis ◽  
Aspergillus Ochraceus ◽  
Cereal Grains ◽  
Liquid Media ◽  
Penicillic Acid ◽  
Group A ◽  
Fluorescent Derivatives

Various strains of species belonging to the Aspergillus ochraceus group (A. ochraceus, A. sclerotiorum, A. alliaceus, A. ostianus, A. melleus, and A. sulphureus) can produce two mycotoxins, ochratoxin A and penicillic acid, on liquid media and in cereal grains. The quantity of each toxin produced is influenced by temperature; low temperature (10 and 20C) favor penicillic acid synthesis and higher (28C), ochratoxin A production. Generally penicillic acid is produced in yields about one to three magnitudes greater than ochratoxin A. A simple fluorodensitometric method for concomitant quantitative analysis of the two toxins has been developed based on conversion of penicillic acid and ochratoxin A to fluorescent derivatives by treatment with ammonia fumes.

scholarly journals Aflatoxigenic contamination of freshly harvested white maize (Zea mays L.) from some selected Ugandan districts

2019 ◽  
Author(s):  
Timothy Omara
Keyword(s):  
Zea Mays ◽  
Moisture Content ◽  
Ochratoxin A ◽  
Zea Mays L ◽  
Lake Victoria ◽  
Total Aflatoxin ◽  
Strategic Adaptation ◽  
Maize Varieties ◽  
Agroecological Zones

The moisture content and total aflatoxin (AF) content of 27 samples of freshly harvested white maize (Zea mays L.) from Mubende (n = 3), Ibanda (n = 3), Jinja (n = 3), Mayuge (n = 3) , Buikwe (n = 3), Hoima (n = 3), Mpigi (n = 3), Masindi (n = 3) and Bugiri (n = 3) districts of Uganda representing the agroecological zones: Lake Victoria crescent, Western Highlands, South East and Lake Albert Crescent were determined in the second season harvest of January 2019 to March 2019. Moisture content ranged from 12.9 to 18.8% (mean moisture content varied from 13.9±0.35-17.2±1.55%) with the highest moisture recorded in maize from Ibanda. The highest mean AF contamination of 11.0±3.01 μg/kg was recorded in maize from Hoima while the lowest AF content of 3.8±1.30 μg/kg was recorded in maize from Mpigi. Despite the fact that all the samples had detectable aflatoxins, none of the maize samples had aflatoxin greater than WHO regulatory limit of 20 μg/kg. White maize in Uganda are precontaminated by aflatoxins prior to harvest. Whereas the spectre of aflatoxigenic contamination of foods remains a ticklish challenge to address, strategic adaptation and deployment of appropriate interventions can help secure a safe harvest. Farmers should plant maize varieties with established maturity periods to ensure timely harvesting. Further research should assess the presence of other mycotoxins as zearalenone, sterigmatocystin, ochratoxin A, citrinin, vomitoxin and diacetoxyscirpenol that may co-occur with aflatoxins in freshly harvested maize.

Effect of Moisture and Incubation Time on Ochratoxin A Production by an Isolate of Aspergillus ochraceus

1970 ◽  
Vol 53 (1) ◽  
pp. 89-91
Author(s):  
A F Schindler ◽  
Stanley Nesheim
Keyword(s):  
Statistical Analysis ◽  
Moisture Content ◽  
Ochratoxin A ◽  
Incubation Time ◽  
Maximum Yield ◽  
Water Levels ◽  
Aspergillus Ochraceus ◽  
Ambient Temperatures ◽  
Incubation Periods ◽  
Transfer Needle

Abstract Experiments were conducted to determine the culture requirements that would insure a probability of high ochratoxin production with a given isolate. Experiments at ambient temperatures (72 ± 2°F) determined the levels of the two most readily controlled variables, time and moisture content, during the growth of a high toxin-producing isolate (M298) of Aspergillus ochraceus. Tests were conducted in 2.8 L - Fernbach flasks containing 100 g shredded wheat and inoculated with spores on a transfer needle. Amounts of ochratoxin A/flask were determined by comparison against standards on TLC after chloroform extraction. Statistical analysis showed a relation between ochratoxin yield, water levels, and incubation periods. A water level of 40–70 ml/flask with an incubation period of 19-21 days at ambient temperatures should give a near to maximum yield of ochratoxin A.

scholarly journals Development of sandwich dot-ELISA for specific detection of Ochratoxin A and its application on to contaminated cereal grains originating from India

2015 ◽  
Vol 6 ◽  
Author(s):  
M. Venkataramana ◽  
R. Rashmi ◽  
Siva R. Uppalapati ◽  
S. Chandranayaka ◽  
K. Balakrishna ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Cereal Grains ◽  
Specific Detection ◽  
Dot Elisa

Survey of Ochratoxin A in Freshly Harvested Durum and Hard Red Spring Wheat in the United States, 2011 and 2012

2014 ◽  
Vol 77 (6) ◽  
pp. 1005-1009 ◽  
Author(s):  
JULIE A. KURUC ◽  
FRANK MANTHEY ◽  
SENAY SIMSEK ◽  
CHARLENE WOLF-HALL
Keyword(s):  
Durum Wheat ◽  
Ochratoxin A ◽  
Great Plains ◽  
High Performance ◽  
The United States ◽  
Cereal Grains ◽  
Hard Red Spring Wheat ◽  
The World ◽  
Food And Feed ◽  
The U.S

Ochratoxin A (OTA) is a toxin produced by some Penicillium and Aspergillus species around the world in a variety of food and feed, especially cereal grains, before harvest but primarily during storage. Durum and hard red spring (HRS) wheat samples were collected right after harvest as part of the U.S. regional crop quality survey in both 2011 (n = 560) and 2012 (n = 654) from the upper Great Plains. All samples were analyzed for OTA contamination using high-performance liquid chromatography with fluorescence detection. Overall, 2.1% of the samples were positive for OTA. In 2011, OTA was detected in 1.0% of the durum wheat samples but was not found in HRS wheat. In 2012, 8.3 and 1.4% of the durum and HRS wheat samples, respectively, were positive for OTA. Of the 25 samples that had detectable OTA, 3 samples (12%), all of which were durum wheat, had OTA that exceeded 5 ng/g.

Evaluation of the effect of moisture content on cereal grains by digital image analysis

2007 ◽  
Vol 40 (9) ◽  
pp. 1140-1145 ◽  
Author(s):  
A.R. Tahir ◽  
S. Neethirajan ◽  
D.S. Jayas ◽  
M.A. Shahin ◽  
S.J. Symons ◽  
...  
Keyword(s):  
Image Analysis ◽  
Moisture Content ◽  
Digital Image ◽  
Digital Image Analysis ◽  
Cereal Grains ◽  
Effect Of Moisture

Assessment of ochratoxin A stability following gamma irradiation: experimental approaches for feed detoxification perspectives

2016 ◽  
Vol 9 (2) ◽  
pp. 289-298 ◽  
Author(s):  
A. Mehrez ◽  
I. Maatouk ◽  
R. Romero-González ◽  
A. Ben Amara ◽  
M. Kraiem ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Moisture Content ◽  
Gamma Irradiation ◽  
Ochratoxin A ◽  
High Performance ◽  
Irradiation Dose ◽  
Initial Moisture Content ◽  
Absorbed Dose ◽  
Model Systems ◽  
Food Model

The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.

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