The effect of fungal competition on colonization of soybeans by moulds of the genus Aspergillus, Trichothecium and Fusarium and the ochratoxin A accumulation as related to temperature and moisture content

2012 ◽  
Vol 11 (32) ◽  
Author(s):  
Lejla Duraković
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Fungal Competition

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.

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.

Isolation and identification of associated fungi of Aspergillus and Penicillium genus and quantification of ochratoxin(A) in raisins samples in Tripoli Area (Preliminary study)

2020 ◽  
Vol 2 (1) ◽  
pp. 65-76
Author(s):  
Almahdi Ahmed Sassi ◽  
Sawsen Altaher Alfetouri ◽  
Altaher Ahmed Abouhleqa ◽  
Mohamed Ahmed Alryani ◽  
Ahmed Omran Tarsean
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Animal Feed ◽  
Average Concentration ◽  
Enzyme Linked Immunosorbent Assay ◽  
Isolation And Identification ◽  
Study Results ◽  
Elisa Technique ◽  
Codex Standard ◽  
Preliminary Study

This preliminary study aimed to determine the moisture content and isolation and identification of some fungi- genus of Aspergillus and Penicillium in 19 raisins samples (10 locals and 9 imported) randomly collected from different local markets in Tripoli city, Libya. The study included the detection and quantification of ochratoxin (A) that could be present in the selected raisins samples using enzyme-linked immunosorbent assay technique. Results indicated that the imported samples recorded the lowest moisture content vs. local samples (9.30% and 20.51%, respectively). Study results indicated that only two "%" local raisins samples having more moisture content than 18%. As far as fungi isolates, 76 fungi isolates were detected in all samples. Based on morphological and cultural characteristics, four species of such isolates belong to the genus Aspergillus while 3 species belong to the genus Penicillium. Using ELISA technique with a detection limit higher than 1.25 ng/gram, results revealed that 10 raisins samples (26.35%) contained ochratoxin (A) with an average concentration of 3.10 ng/gram. With the exception of two local c raisins samples that their moisture level was more than 18%, generally, results of this study were in confirm with Libyan Specification number 683-2013 set for the maximum permitted level of ochratoxin (A) in food and animal feed. In addition to codex standard number 67-1981

Short Communication: Ochratoxin A in Swine Blood in Relation to Moisture Content in Feeding Barley at Harvest

1990 ◽  
Vol 40 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Torbjörn Holmberg ◽  
Anna Breitholtz ◽  
Anders Bengtsson ◽  
Karl Hult
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Short Communication

Effect of Temperature and Relative Humidity during Transportation on Green Coffee Bean Moisture Content and Ochratoxin A Production

2007 ◽  
Vol 70 (1) ◽  
pp. 164-171 ◽  
Author(s):  
HECTOR A. PALACIOS-CABRERA ◽  
HILARY C. MENEZES ◽  
BEATRIZ T. IAMANAKA ◽  
FREDERICO CANEPA ◽  
ALDIR A. TEIXEIRA ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ochratoxin A ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Coffee Bean ◽  
Green Coffee ◽  
Final Destination ◽  
Coffee Beans ◽  
Environmental Variations

Changes in temperature, relative humidity, and moisture content of green coffee beans were monitored during transportation of coffee from Brazil to Italy. Six containers (three conventional and three prototype) were stowed in three different places (hold, first floor, and deck) on the ship. Each prototype was located next to a conventional container. The moisture content of the coffee in the container located on the first floor was less affected by environmental variations (0.7%) than that in the hold and on the deck. Coffee located in the hold showed the highest variation in moisture content (3%); in addition, the container showed visible condensation. Coffee transported on the deck showed an intermediary variation in moisture (2%), and there was no visible condensation. The variation in coffee moisture content of the prototype containers was similar to that of the conventional ones, especially in the top layers of coffee bags (2 to 3%), while the increase in water activity was 0.70. This suggests that diffusion of moisture occurs very slowly inside the cargo and that there are thus sufficient time and conditions for fungal growth. The regions of the container near the wall and ceiling are susceptible to condensation since they are close to the headspace with its high relative humidity. Ochratoxin A production occurred in coffee located at the top of the container on the deck and in the wet bags from the hold (those found to be wet on opening the containers at the final destination).

scholarly journals Natural occurrence of aflatoxins and ochratoxin A in meju and soybean paste produced in South Korea

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Seong Eun Jeong ◽  
Soo Hyun Chung ◽  
Sung-Yong Hong
Keyword(s):  
South Korea ◽  
Ochratoxin A ◽  
Central Region ◽  
High Performance ◽  
Soy Sauce ◽  
Natural Occurrence ◽  
Immunoaffinity Column ◽  
Column Method ◽  
Soybean Paste ◽  
Fungal Competition

Abstract In this study, we investigated the occurrence of aflatoxins (AFs) and ochratoxin A (OTA) in meju and soybean paste produced in South Korea. Samples were collected from three regions divided on the basis of climate in South Korea. A total of 100 meju samples were analyzed over 3 years (2012–2015), and 45 soybean paste samples were analyzed in 2016. Mycotoxins were extracted with an immunoaffinity column method and quantified by high-performance liquid chromatography. AFs were detected in 10 of meju (10%) and 11 of soybean paste samples (24.4%) with concentrations of 0.2–48.3 μg/kg and 0.88–16.17 μg/kg, respectively. OTA was detected in 50 of meju (50%) and 22 of soybean paste samples (48.9%) with concentrations of 0.1–193.2 μg/kg and 0.88–26.29 μg/kg, respectively. Mycotoxin contamination in meju was more common in the central region than in the southern areas. Thus, more mycotoxins were produced in the central region owing to less fungal competition in meju during fermentation inside households. We also found that about 91% of AFs and 73% of OTA in meju were degraded after the production of soybean paste and soy sauce. Even after degradation of AFs and OTA, the levels of AFB1 and OTA were 0.5 µg/kg and 7.5 µg/kg in soy sauce and 11.9 µg/kg and 190.4 µg/kg in soybean paste, respectively. Thus, our results suggest the need for constant monitoring of meju and soybean paste for AFs and OTA.

Five-Year Study of Mycotoxins in Virginia Wheat and Dent Corn

1983 ◽  
Vol 66 (6) ◽  
pp. 1466-1469 ◽  
Author(s):  
Odette L Shotwell ◽  
Clifford W Hesseltine
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Wheat Sample ◽  
Aflatoxin Level ◽  
Corn Sample ◽  
Dent Corn ◽  
Reporting Service ◽  
Inspection Service

Abstract Every year during the 5-year period 1976-1980, approximately 100 samples each of corn and wheat from trucks delivering the grains at elevators in Virginia were collected by personnel of the Federal Grain Inspection Service and shipped to NRRC. Samples were analyzed as soon as possible for aflatoxin, zearalenone, and ochratoxin A. The 3 mycotoxins were not detected in any wheat sample. Zearalenone and ochratoxin A were not found in any corn sample; however, aflatoxin was detected in at least 25% of the corn samples from every crop year. In 1976-1980, the incidence of aflatoxin at levels of 20 ng/g or more (the Food and Drug Administration guideline) ranged from 18 to 61%; aflatoxin incidence above 100 ng/g was 5-29%. The average aflatoxin levels in corn samples collected in the 5 years varied from 21 to 137 ng/g. Moisture content of the samples was not determined, so aflatoxin levels given may be higher than they were at harvest. However, there are obviously differences from year to year. In freshly harvested corn samples collected by fieldmen of the Statistical Reporting Service in yield surveys in 1978 and 1979, aflatoxin incidence above the FDA guideline was 10 and 13%, and above 100 ng/g was 4 and 7%. The average aflatoxin level in all samples collected in 1978 was 13 ng/g and in 1979, 36 ng/g. Some aflatoxin can be expected yearly in Virginia corn, but the incidence and levels vary from year to year.

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

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.

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