scholarly journals Occurrence and Distribution of Aflatoxin in Maize from Selected Counties, Eastern Region, Kenya

2020 ◽  
Vol 3 (2) ◽  
pp. 7-20
Author(s):  
Nicholas M. Jacob ◽  
Shem O. Wandiga ◽  
David K. Kariuki ◽  
Vincent O. Madadi
Keyword(s):  
Aflatoxin B1 ◽  
High Performance ◽  
Aflatoxin Contamination ◽  
Human Consumption ◽  
Eastern Region ◽  
Policy And Practice ◽  
Fluorescence Detector ◽  
Total Aflatoxin ◽  
Mean Values ◽  
Maize Sample

Purpose: The study aimed to assess the occurrence and distribution of aflatoxin contamination on dry maize in different types of stores in Meru, Embu, Isiolo, Makueni and Machakos Counties of Eastern region of Kenya.Methodology: Automatic spear sampler was used to collect maize samples from each bag at even intervals. 280 maize samples were collected from 29 stores in five Counties. 100 g of each maize sample was ground, resampled into 50g, blended, extracted, centrifuged, filtered and a quantified for Aflatoxin B1, B2, G1 and G2. Samples were prepared and extracted with methanol/water. The bulky of the samples were analyzed with enzyme-linked immunoassay test kits. Confirmation of positive samples was done with high performance liquid chromatography (HPLC) coupled with fluorescence detector.  Data analysis was done with SPSS and Microsoft excel.Findings: Maize samples from Counties in eastern region of Kenya had significantly high levels of (93.10%) aflatoxin contamination. The mean values for aflatoxin B1, B2, G1 and G2 were: 50.08± 4.42, 17.26±1.08, 30.17±2.06 and 10.54± 1.52 (ng/g) in that order. Only nine samples had total aflatoxin within the accepted limit for human consumption of 15 ng/g. The highest total aflatoxin contamination recorded was 198.45ng/g in Makueni county and the lowest recorded was 8.76ng/g in Embu county. Makueni and Embu had mean values for aflatoxin B1, B2, G1 and G2 being (83.07±7.53, 22.15± 1.36, 49.38±3.11, 20.52± 0.70 ng/g) and (18.71 ±2.63, 8.07 ±0.64, 17.02 ±1.38, 8.86 ±1.62 ng/g). Makueni NCPB depot had the highest mean contamination with aflatoxin B1 of 92.67± 5.78 ng/g and Embu had the lowest with 6.26 ± 4.14 ng/g. All the county markets recorded high aflatoxin B1 contamination with exception of Embu county which had a mean of 4.0 ±0.84, Makueni (83.67± 10.42 ng/g), Isiolo (51.27± 32.29 ng/g), Meru (46.02± 23.88 ng/g) and Machakos (36.34± 26.27 ng/g). The stores had aflatoxin load varied from on store to the other and county to county.Unique contribution to theory, policy and practice: The counties in the region had high occurrence and distribution of aflatoxin B1, B2, G1 and G2 in maize in all stores where samples were picked. Location for maize stores should be in areas with low levels of carbon dioxide because mycotoxins are produced under aerobic conditions. The design for maize threshing machines should not course shocks, breakage and cracks on maize grains to decrease chances of mycotoxins infestation during their storage.

scholarly journals Changes in Fungal Population and Aflatoxin Levels and Assessment of Major Aflatoxin Types in Stored Peanuts (Arachis hypogaea Linnaeus)

2013 ◽  
Vol 2 (5) ◽  
pp. 10 ◽  
Author(s):  
John Maina Wagacha ◽  
Charity K. Mutegi ◽  
Maria E. Christie ◽  
Lucy W. Karanja ◽  
Job Kimani
Keyword(s):  
Moisture Content ◽  
Aflatoxin B1 ◽  
Fungal Pathogens ◽  
Aflatoxin Contamination ◽  
Fungal Population ◽  
Total Aflatoxin ◽  
Regulatory Standards ◽  
Polyethylene Bags ◽  
Jute Bags ◽  
The Eu

<p>Peanut kernels of Homabay Local, Valencia Red, ICGV-SM 12991 and ICGV-SM 99568 cultivars were stored for six months in jute, polypropylene and polyethylene bags to assess the effect of storage bags, temperature and R.H. on fungal population and aflatoxin contamination. Moisture content (M.C.), fungal population and aflatoxin levels were determined before storage and after every 30 days during storage. Isolates of <em>Aspergillus flavus</em> and <em>A. parasiticus</em> were assayed for production of aflatoxin B1, B2, G1 and G2. The correlation between MC, population of <em>A. flavus</em> and <em>A. parasiticus</em> and aflatoxin levels in peanuts was also determined. Six fungal pathogens were commonly isolated from the peanut samples and occurred as follows in decreasing order: <em>Penicillium</em> spp. (106.6 CFU/g), <em>A. flavus</em> L-strain (4.8 CFU/g), <em>A. flavus</em> S-strain (2.9 CFU/g), <em>A. niger </em>(2.6 CFU/g), <em>A. parasiticus </em>(1.7 CFU/g) and <em>A. tamarii </em>(0.2 CFU/g). The overall population of <em>A. flavus</em> L-strain was 66% higher than that of <em>A. flavus</em> S-strain. Ninety one percent of <em>A. flavus</em> and <em>A. parasiticus</em> isolates produced at least one of the four aflatoxin types assayed, with 36% producing aflatoxin B1. Total aflatoxin levels ranged from 0 - 47.8 µg/kg with samples stored in polyethylene and jute bags being the most and least contaminated, respectively. Eighty nine percent and 97% of the peanut samples met the EU (? 4 µg/kg) and Kenyan (? 10 µg/kg) regulatory standards for total aflatoxin, respectively. Peanuts should be adequately dried to safe moisture level and immediately packaged in a container - preferably jute bags - which will not promote critical increases in fungal population and aflatoxin contamination.</p>

A 2019 STUDY ON TOTAL AFLATOXINS IN ROMANIAN MAIZE (ZEA MAYS L.) SAMPLES

2020 ◽  
Vol 13 ◽  
pp. 1-8
Author(s):  
Irina Zmeu ◽  
Elena Mirela Cucu ◽  
Alina Alexandra Dobre ◽  
Hellene Casian
Keyword(s):  
Cropping Systems ◽  
Aflatoxin Contamination ◽  
Health Concern ◽  
Human Consumption ◽  
Physical Treatment ◽  
Agronomic Practices ◽  
Commission Regulation ◽  
Maize Sample ◽  
Food And Feed ◽  
Risk Areas

Mycotoxin contamination represents a clear public health concern. In this context, a maize survey was conducted in Romania, to monitor the occurrence of total aflatoxins in maize samples collected during the 2019 growing season from fields located in all counties. A total of 95 maize samples were collected along with information regarding the specific location of fields, the applied agronomic practices and cropping systems. ELISA method was used for the quantification of AFs. The results showed 88 contaminated samples. Only one sample registered aflatoxin levels higher than the limit of 10.00 μg/kg, settled by the Commission Regulation (EC) No 1881/2006 for maize to be subjected to soring or other physical treatment before human consumption or use as an ingredient in foodstuffs. The highest AFs level was 77.59 μg/kg, noted by a maize sample from Argeș County (the South-Muntenia development region, macro region 3). When referring to the analysed samples, the total aflatoxin contamination was independent of the type of hybrid, but strongly influenced by the pedo-climatic differences between counties. The southern counties proved to represent critical risk areas for aflatoxin contamination when referring to maize crops. These results highlight the importance of an effective and sustainable mycotoxin management along the food and feed chain, as well as the need of mapping the mycotoxin risk areas.

scholarly journals Enzyme Immunoassay for Measuring Aflatoxin B1 in Legal Cannabis

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 265 ◽  
Author(s):  
Fabio Di Nardo ◽  
Simone Cavalera ◽  
Claudio Baggiani ◽  
Matteo Chiarello ◽  
Marco Pazzi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Aflatoxin B1 ◽  
Analytical Methods ◽  
Limit Of Detection ◽  
Direct Analysis ◽  
Aflatoxin Contamination ◽  
Throughput Capacity ◽  
Human Consumption ◽  
The European Union ◽  
Coefficients Of Variation

The diffusion of the legalization of cannabis for recreational, medicinal and nutraceutical uses requires the development of adequate analytical methods to assure the safety and security of such products. In particular, aflatoxins are considered to pose a major risk for the health of cannabis consumers. Among analytical methods that allows for adequate monitoring of food safety, immunoassays play a major role thanks to their cost-effectiveness, high-throughput capacity, simplicity and limited requirement for equipment and skilled operators. Therefore, a rapid and sensitive enzyme immunoassay has been adapted to measure the most hazardous aflatoxin B1 in cannabis products. The assay was acceptably accurate (recovery rate: 78–136%), reproducible (intra- and inter-assay means coefficients of variation 11.8% and 13.8%, respectively), and sensitive (limit of detection and range of quantification: 0.35 ng mL−1 and 0.4–2 ng mL−1, respectively corresponding to 7 ng g−1 and 8–40 ng g−1 ng g−1 in the plant) and provided results which agreed with a HPLC-MS/MS method for the direct analysis of aflatoxin B1 in cannabis inflorescence and leaves. In addition, the carcinogenic aflatoxin B1 was detected in 50% of the cannabis products analyzed (14 samples collected from small retails) at levels exceeding those admitted by the European Union in commodities intended for direct human consumption, thus envisaging the need for effective surveillance of aflatoxin contamination in legal cannabis.

scholarly journals Removal of Aflatoxin B1 by Edible Mushroom-Forming Fungi and Its Mechanism

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 668
Author(s):  
Min-Jung Choo ◽  
Sung-Yong Hong ◽  
Soo-Hyun Chung ◽  
Ae-Son Om
Keyword(s):  
Aflatoxin B1 ◽  
High Performance ◽  
Edible Mushroom ◽  
Biologically Active ◽  
Cell Debris ◽  
Fluorescence Detector ◽  
Whole Cells ◽  
Cell Lysates ◽  
Naturally Occurring ◽  
Aspergillus Sp

Aflatoxins (AFs) are biologically active toxic metabolites, which are produced by certain toxigenic Aspergillus sp. on agricultural crops. In this study, five edible mushroom-forming fungi were analyzed using high-performance liquid chromatography fluorescence detector (HPLC-FLD) for their ability to remove aflatoxin B1 (AFB1), one of the most potent naturally occurring carcinogens known. Bjerkandera adusta and Auricularia auricular-judae showed the most significant AFB1 removal activities (96.3% and 100%, respectively) among five strains after 14-day incubation. The cell lysate from B. adusta exhibited higher AFB1 removal activity (35%) than the cell-free supernatant (13%) after 1-day incubation and the highest removal activity (80%) after 5-day incubation at 40 °C. In addition, AFB1 analyses using whole cells, cell lysates, and cell debris from B. adusta showed that cell debris had the highest AFB1 removal activity at 5th day (95%). Moreover, exopolysaccharides from B. adusta showed an increasing trend (24–48%) similar to whole cells and cell lysates after 5- day incubation. Our results strongly suggest that AFB1 removal activity by whole cells was mainly due to AFB1 binding onto cell debris during early incubation and partly due to binding onto cell lysates along with exopolysaccharides after saturation of AFB1 binding process onto cell wall components.

scholarly journals Comparison of Three Methods for Determining Aflatoxins in Melon Seeds

1996 ◽  
Vol 79 (6) ◽  
pp. 1330-1335 ◽  
Author(s):  
Vincent P Diprossimo ◽  
Emil G Malek
Keyword(s):  
Aflatoxin B1 ◽  
Aflatoxin Contamination ◽  
The Other ◽  
Contamination Level ◽  
Total Aflatoxin ◽  
The Third ◽  
Acetone Water ◽  
Melon Seeds ◽  
Layer Chromatography ◽  
Better Than

Abstract The suitability of 3 methods for determining aflatoxins in melon seeds was examined. The first 2 are the Contaminants Branch (CB) method and the Best Foods (BF) method, both official methods for determining aflatoxins in peanuts and peanut products. The third method, the modified CB method–Rapid Modification of the Cottonseed (CB-RCSMod) method, devised in this work, was derived by combining steps from the CB method and the Rapid Modification of the Cottonseed method. The CB method was superior to the other 2 methods for quantitation of aflatoxins. It gave better recoveries and cleaner extracts that exhibit less fluorescent interference for thin-layer chromatography (TLC) than the BF method. Also, its solvent efficiency was better than that of the CB-RCS-Mod method. With the CB method, recoveries from spiked samples were 85.0% for aflatoxin B1 and 90.0% for anatoxin B2. Recoveries of G1 aflatoxins were more variable, averaging 90.0% for aflatoxin d and 72.5% for aflatoxin G2. Total aflatoxin recovery was 86.5% for the CB method. At a low aflatoxin contamination level (8 μg B1/kg sample), aflatoxin B1 was detectable by the CB method but not by the BF method. Detection of aflatoxins in BF method sample extracts by TLC was not improved by the use of chloroform–acetone–water (88 + 12 + 1), benzene–ethanol–water, or ether–methanol–water (96 + 3 +1) in place of the standard chloroform–acetone (88 + 12) developer. Use of ether–methanol–water (96 + 3 + 1) for detecting aflatoxins by TLC in the CB method extracts increased interference compared with the standard chloroform–acetone (88 + 12) developer.

scholarly journals Biological Degradation of Aflatoxin B1 by Cell-Free Extracts of Bacillus velezensis DY3108 with Broad PH Stability and Excellent Thermostability

Toxins ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 330 ◽  
Author(s):  
Xian Shu ◽  
Yuting Wang ◽  
Qing Zhou ◽  
Minghao Li ◽  
Hao Hu ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Degradation Products ◽  
Sodium Dodecyl ◽  
Aflatoxin Contamination ◽  
Proteinase K ◽  
Biological Degradation ◽  
Bacillus Velezensis ◽  
Degrading Bacteria

(1) Background: Aflatoxin contamination in food and grain poses serious problems both for economic development and public health protection, thus leading to a focus on an effective approach to control it; (2) Methods: Aflatoxin B1 (AFB1) degrading bacteria were isolated using a medium containing coumarin as the sole carbon source, and the biodegradation of AFB1 by the isolate was examined by high performance liquid chromatography, and liquid chromatography mass spectrometry; (3) Results: a bacterial strain exhibiting strong AFB1 degradation activity (91.5%) was isolated and identified as Bacillus velezensis DY3108. The AFB1 degrading activity was predominantly attributed to the cell-free supernatant of strain DY3108. Besides, it was heat-stable and resistant to proteinase K treatment but sensitive to sodium dodecyl sulfate treatment. The optimal temperature for the maximal degradation of AFB1 was 80 °C. Even more notable, the supernatant showed a high level of activity over a broad pH (4.0 to 11.0) and exhibited the highest degradation (94.70%) at pH 8.0. Cytotoxicity assays indicated that the degradation products displayed significantly (p < 0.05) lower cytotoxic effects than the parent AFB1; (4) Conclusions: B. velezensis DY3108 might be a promising candidate for exploitation in AFB1 detoxification and bioremediation in food and feed matrices.

Rapid and Sensitive Detection of Aflatoxin B1, B2, G1 and G2 in Vegetable Oils Using Bare Fe3O4 as Magnetic Sorbents Coupled with High-Performance Liquid Chromatography with Fluorescence Detection

2020 ◽  
Vol 58 (7) ◽  
pp. 678-685
Author(s):  
Hui-Xian Zhang ◽  
Ping Zhang ◽  
Xiao-Fang Fu ◽  
You-Xiang Zhou ◽  
Xi-Tian Peng
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Vegetable Oil ◽  
Vegetable Oils ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Solid Phase ◽  
Simultaneous Detection ◽  
Fluorescence Detector ◽  
Relative Standard

Abstract This paper reports a simple, sensitive and reliable method for the simultaneous detection of aflatoxin B1, B2, G1 and G2 in vegetable oils. Aflatoxins were extracted by magnetic solid phase extraction followed by high-performance liquid chromatography, then postcolumn photochemical derivatization and finally detected by fluorescence detector. Vegetable oil samples were first diluted with hexane and then commercial bare Fe3O4 nanoparticles were directly employed as sorbents to extract aflatoxins from complex vegetable oil samples, which significantly simplified the procedure of sample preparation and largely improved the sample analysis throughput. The effects of various parameters such as the amount of sorbent, loading, washing and eluting conditions were carefully optimized to improve the extraction efficiencies of aflatoxins. Under the optimal conditions, the limits of detection of four aflatoxins ranged from 0.01 μg/kg to 0.16 μg/kg, and squared regression coefficients (R2) &gt;0.9990 were obtained within the linear range of 0.1–20 μg/kg (except for aflatoxin G2 with 0.5–20 μg/kg). Furthermore, the recoveries spiked at four concentration levels in a blank vegetable oil sample were from 82.6 to 106.2%, with inter- and intraday relative standard deviations &lt;9.8%, indicating good accuracy and precision of the proposed method.

Removal of Aflatoxin B1 and Inhibition of Aspergillus flavus Growth by the Use of Lactobacillus plantarum on Olives

2014 ◽  
Vol 77 (10) ◽  
pp. 1760-1767 ◽  
Author(s):  
FATEN KACHOURI ◽  
HAMIDA KSONTINI ◽  
MOKTAR HAMDI
Keyword(s):  
Lactobacillus Plantarum ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Environmental Scanning Electron Microscopy ◽  
Total Phenolic ◽  
Environmental Scanning ◽  
Fluorescence Detector ◽  
Natural Microflora ◽  
The Impact

Olives can be contaminated with a wide variety of molds (Aspergillus and/or Penicillium) that can be occurring naturally on fresh and processed olives and could support mycotoxin production. The aim of this work was to investigate aflatoxin B1 (AFB1) production by fungi and its bioaccumulation in olives during storage and to study the impact of the application of Lactobacillus plantarum on the inhibition of mold development and production of AFB1. Two different treatments were applied: (i) olives with natural microflora and (ii) olives inoculated with Aspergillus flavus after elimination of natural microflora. AFB1 has been extracted from olives and quantitated by high-performance liquid chromatography using a fluorescence detector. Results showed the absence of this metabolite in the olives for the season 2008 to 2009. In 2009 to 2010, AFB1 was detected at the level of 11 μg/kg. The application of L. plantarum during the storage of olives favors the reduction of the level of AFB1 to 5.9 μg/kg correlated with a decrease in the amount of molds (86.3%). The images obtained by environmental scanning electron microscopy showed that L. plantarum was able to adhere to the olive surface and probably produce a biofilm that inhibits the multiplication of yeast and fungi by oxygen competition. Results showed an increase of antioxidant activity and amount of total phenolic compounds of olives, respectively, by 24 and 8.6%. In many olives contaminated with A. flavus, AFB1 was present at an initial level of 5.15 μg/kg and increased to 6.55 μg/kg after 8 days of storage. The biological detoxification of AFB1 in olives by L. plantarum is confirmed by the reduction of the level of AFB1 to 2.12 μg/kg on day 0 and its absence after 4 days of storage.

scholarly journals Occurrence and Exposure Assessment of Aflatoxin B1 and Ochra-toxin A in Pearl Millet (Pennisetum glaucum L.) from Tunisia

2020 ◽  
Author(s):  
S. Lasram ◽  
Z. Hamdi ◽  
A. Ghorbel
Keyword(s):  
Pearl Millet ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Pennisetum Glaucum ◽  
Statistical Tests ◽  
Daily Intake ◽  
Dietary Exposure ◽  
Contamination Rate ◽  
The European Union ◽  
Fluorescence Detector

Background: Ochratoxin A (OTA) and Aflatoxin B1 (AFB1) are toxic secondary  metabolites produced by certain mold species. In this primarily survey, we examined the OTA and AFB1 contamination of pearl millet grains distributed in Tunisia. Methods: Twenty-five pearl millet (Pennisetum glaucum L.) samples from different regions of Tunisia were analyzed by High Performance Liquid Chromatography coupled with fluorescence detector in order to evaluate the contamination with of AFB1 and OTA. Statistical tests were performed with XLSTAT 2018. Results: AFB1 and OTA were detected in 32 and 28% millet samples, respectively. Mean amounts of these mycotoxins in the contaminated samples were of 24.54±17.54 µg/kg for OTA and 22.72±23.09 µg/kg for AFB1. Approximately, 28 and 24% of analyzed samples were found above the European Union limits for AFB1 and OTA, respectively. The estimated daily intake of OTA and AFB1 were 3.76 and 3.89 ng/kg b.w. per day, respectively. No significantly (p>0.05) difference in OTA and AFB1 contamination rate was found between samples taken from different regions. Conclusion: Consumption of millet in Tunisia might be an important contributing factor to the risk of dietary exposure to OTA and AFB1

scholarly journals The Influence of Weather on the Occurrence of Aflatoxin B1 in Harvested Maize from Kenya and Tanzania

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 216
Author(s):  
Benigni A. Temba ◽  
Ross E. Darnell ◽  
Anne Gichangi ◽  
Deogratias Lwezaura ◽  
Philip G. Pardey ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Random Forests ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Early Stage ◽  
Weather Conditions ◽  
Aflatoxin Contamination ◽  
Warning Signs ◽  
Logistic Regression Models ◽  
Average Value

A study was conducted using maize samples collected from different agroecological zones of Kenya (n = 471) and Tanzania (n = 100) during the 2013 maize harvest season to estimate a relationship between aflatoxin B1 concentration and occurrence with weather conditions during the growing season. The toxins were analysed by the ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. Aflatoxin B1 incidence ranged between 0–100% of samples in different regions with an average value of 29.4% and aflatoxin concentrations of up to 6075 µg/kg recorded in one sample. Several regression techniques were explored. Random forests achieved the highest overall accuracy of 80%, while the accuracy of a logistic regression model was 65%. Low rainfall occurring during the early stage of the maize plant maturing combined with high temperatures leading up to full maturity provide warning signs of aflatoxin contamination. Risk maps for the two countries for the 2013 season were generated using both random forests and logistic regression models.

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