Évaluation des pratiques post récolte favorables à la contamination de l’arachide par les mycotoxines dans trois régions de Côte d’Ivoire

Objectif: Les techniques post récoltes jouent un rôle déterminant dans la contamination de l’arachide par les aflatoxines. Cette étude a pour objectif de contribuer à réduire la contamination de l’arachide par les aflatoxines en Côte d’Ivoire par l’identification des pratiques post récoltes à risque.Méthodologie et résultats: Un questionnaire a permis de recueillir les renseignements sur lesdites pratiques dans trois régions : nord, centre et ouest. Le séchage de l’arachide se fait au soleil quel que soit la localité et dure en moyenne 4 à 14 jours. Les arachides sont séchées et conservées en coques dans le nord. Dans les zones de centre et ouest, les gousses sont soit séchées puis décortiquées, soit décortiqués avant séchage. Le stockage des graines ou des gousses se fait dans des sacs en polyéthylène dans les maisons (86%) ou en vrac dans des greniers (14%). La récolte peut être conservée jusqu’à 9 mois avant consommation ou vente. 58,1% des productrices ont des pertes dues à l’effet des moisissures. La contamination fongique de l’arachide s’opère dans 55,8 % des cas, durant le séchage et le stockage, et dans 34,9 % des cas au cours de l’apparitiondes fleurs au champ.Conclusion et application des résultats: Les étapes de séchage et de stockage représentent un risque de contamination par les aflatoxines. Une maitrise des techniques post récolte permettrait de réduire la contamination par les aflatoxines. Il ressort de cette étude qu'une formation des productrices aux bonnes pratiques de production réduirait la contamination parcours aflatoxines.Mots clés: post-récolte, séchage, conservation, arachide, aflatoxinesEnglish Title: Evaluation of post-harvest practices favorable to the contamination of peanut by mycotoxins in three regions of Côte d'IvoireEnglish AbstractObjective: Post harvest techniques take a decisive role in peanuts by aflatoxins contamination. The aim of this study is to help to reduce aflatoxin contamination of groundnuts in Côte d'Ivoire by identifying post-harvest practices at risk.Methodology and results: A survey permit to collect information on post-harvest practices in three regions: north, center and west. Peanuts are dried at sun whatever the locality and lasts on average 4 to 14 days. Peanuts are dried and kept in pods in the north. In the central and western areas, pods are either dried and then shelled, or shelled before drying. The storage of seeds or pods is done in polythene bags in homes (86%) or bulk in granaries (14%). Peanuts can be kept until 9 months before consumption or sale. 58.1% of producers have losses due to effect of molds. Fungal contamination of peanuts occurs in 55.8% of cases, during drying and storage, and in 34.9% of cases during flowering in the field.Conclusion and application of results: Drying and storage stages represent a risk of contamination by aflatoxins. Mastering post-harvest techniques would reduce aflatoxin contamination. This study shows that training producers in good production practices would reduce aflatoxin contamination.Keywords: post-harvest, drying, storage, peanut, aflatoxin

Visualisation and quantification of fumonisins bound by lactic acid bacteria isolates from traditional African maize-based fermented cereals, ogi and mahewu

Consumption of fumonisin-contaminated foods has a negative influence on the health of humans (carcinogen; oesophageal cancer in Eastern Cape in South Africa). Lactic acid bacteria (LAB) have emerged as a promising natural detoxification agent against mycotoxins. The aim of this study was to visualise the interaction between fumonisins (FB1 and FB2) and LAB: Lactobacillus plantarum FS2, L. delbrueckii subsp. delbrueckii CIP 57.8T and Pediococcus pentosaceus D39, isolated from traditional fermented maize-based products (ogi and mahewu) using confocal laser scanning microscopy (CLSM) and to then quantify the LAB-bound fumonisin using high performance liquid chromatography (HPLC). The objective was to obtain a physically visible and quantifiable binding interaction between fumonisins and LAB strains with the aim of utilising LAB as a possible detoxifying agent. Fumonisins were derivatised using naphthalene-2,3-dicarboxaldehyde (NDA) and then combined with non-fluorescent LAB cells (viable and non-viable). For the quantification of bound fumonisins, viable and non-viable cells were incubated in the presence of predetermined concentrations of fumonisins and the level of fumonisin in the suspension was determined. CLSM showed the derivatised green fluorescent fumonisins binding to the surface of each of the LAB cells. For viable cells, L. plantarum FS2 bound FB1 most effectively while P. pentosaceus D39 bound the least level of FB1. The highest levels of FB2 were bound by L. plantarum R 1096 and the least by L. delbrueckii CIP 57.8 T. For non-viable cells, L. plantarum FS2 was also the most effective for binding both fumonisins with P. pentosaceus D39 and L. delbrueckii CIP 57.8 T being the least effective for FB1 and FB2, respectively. To our knowledge, this is the first study to visualise the interaction between LAB and fumonisins. We demonstrate that LAB isolates from indigenous fermented maize-based beverages bind fumonisins and thus present a potential strategy for their reduction in these traditional foods.This publication is resulting from a research project funded by the European Union (FP7 245-025) called African Food Revisited by Research (AFTER – http://www.afterfp7.eu/) and from a French-South African PHC Protea project (Project N° 29769VL).http://www.tandfonline.com/loi/tfac202020-01-24hj2019BiochemistryConsumer ScienceFood ScienceGeneticsMicrobiology and Plant Patholog

Visualisation and quantification of fumonisins bound by lactic acid bacteria isolates from traditional African maize-based fermented cereals, ogi and mahewu

Consumption of fumonisin-contaminated foods has a negative influence on the health of humans (carcinogen; oesophageal cancer in Eastern Cape in South Africa). Lactic acid bacteria (LAB) have emerged as a promising natural detoxification agent against mycotoxins. The aim of this study was to visualise the interaction between fumonisins (FB1 and FB2) and LAB: Lactobacillus plantarum FS2, L. delbrueckii subsp. delbrueckii CIP 57.8T and Pediococcus pentosaceus D39, isolated from traditional fermented maize-based products (ogi and mahewu) using confocal laser scanning microscopy (CLSM) and to then quantify the LAB-bound fumonisin using high performance liquid chromatography (HPLC). The objective was to obtain a physically visible and quantifiable binding interaction between fumonisins and LAB strains with the aim of utilising LAB as a possible detoxifying agent. Fumonisins were derivatised using naphthalene-2,3-dicarboxaldehyde (NDA) and then combined with non-fluorescent LAB cells (viable and non-viable). For the quantification of bound fumonisins, viable and non-viable cells were incubated in the presence of predetermined concentrations of fumonisins and the level of fumonisin in the suspension was determined. CLSM showed the derivatised green fluorescent fumonisins binding to the surface of each of the LAB cells. For viable cells, L. plantarum FS2 bound FB1 most effectively while P. pentosaceus D39 bound the least level of FB1. The highest levels of FB2 were bound by L. plantarum R 1096 and the least by L. delbrueckii CIP 57.8 T. For non-viable cells, L. plantarum FS2 was also the most effective for binding both fumonisins with P. pentosaceus D39 and L. delbrueckii CIP 57.8 T being the least effective for FB1 and FB2, respectively. To our knowledge, this is the first study to visualise the interaction between LAB and fumonisins. We demonstrate that LAB isolates from indigenous fermented maize-based beverages bind fumonisins and thus present a potential strategy for their reduction in these traditional foods.This publication is resulting from a research project funded by the European Union (FP7 245-025) called African Food Revisited by Research (AFTER – http://www.afterfp7.eu/) and from a French-South African PHC Protea project (Project N° 29769VL).http://www.tandfonline.com/loi/tfac202020-01-24hj2019BiochemistryConsumer ScienceFood ScienceGeneticsMicrobiology and Plant Patholog

Evaluation of an alternative spectroscopic approach for aflatoxin analysis: Comparative analysis of food and feed samples with UPLC-MS/MS

Increasing research has highlighted the effects of changing climates on the occurrence and prevalence of toxigenic Aspergillus species producing aflatoxins. There is concern of the toxicological effects to human health and animal productivity following acute and chronic exposure that may affect the future ability to provide safe and sufficient food globally. Considerable research has focused on the detection of these toxins, based on the physicochemical and biochemical properties of the aflatoxin compounds, in agricultural products for human and animal consumption. As improvements in food security continue more regulations for acceptable levels of aflatoxins have arisen globally; the most stringent in Europe. These regulations are important for developing countries as aflatoxin occurrence is high significantly effecting international trade and the economy. In developed countries analytical approaches have become highly sophisticated, capable of attaining results with high precision and accuracy, suitable for regulatory laboratories. Regrettably, many countries that are affected by aflatoxin contamination do not have resources for high tech HPLC and MS instrumentation and require more affordable, yet robust equally accurate alternatives that may be used by producers, processors and traders in emerging economies. It is especially important that those companies wishing to exploit the opportunities offered by lucrative but highly regulated markets in the developed world, have access to analytical methods that will ensure that their exports meet their customers quality and safety requirements. This work evaluates the ToxiMet system as an alternative approach to UPLC–MS/MS for the detection and determination of aflatoxins relative to current European regulatory standards. Four commodities: rice grain, maize cracked and flour, peanut paste and dried distillers grains were analysed for natural aflatoxin contamination. For B1 and total aflatoxins determination the qualitative correlation, above or below the regulatory limit, was good for all commodities with the exception of the dried distillers grain samples for B1 for which no calibration existed. For B1 the quantitative R2 correlations were 0.92, 0.92, 0.88 (<250 μg/kg) and 0.7 for rice, maize, peanuts and dried distillers grain samples respectively whereas for total aflatoxins the quantitative correlation was 0.92, 0.94, 0.88 and 0.91. The ToxiMet system could be used as an alternative for aflatoxin analysis for current legislation but some consideration should be given to aflatoxin M1 regulatory levels for these commodities considering the high levels detected in this study especially for maize and peanuts. (Résumé d'auteur

Simultaneous multi-mycotoxin determination in maize and poultry feeds from Brazil by liquid chromatography/tandem mass spectrometry

A multi-mycotoxin method based on High Performance Liquid Chromatography coupled with tandem Mass Spectrometry detection (HPLC-MS /MS) was applied to investigate the occurrence of toxic fungal metabolites in samples collected from a poultry feed factory and integrated poultry farms, in Brazil. A total of 119 samples were analyzed including 38 maize grain samples collected from the factory reception, 36 maize grain samples and 9 maize by- product samples collected during the factory processing, and 36 poultry feed samples collected from poultry farms. Twenty mycotoxins were detected and quantified in the investigated samples: aflatoxins B 1 , B2, G 1 , G2, fumonisins B 1 , B2 and B3, hydrolyzed fumonisin B 1 , zearalenone, agroclavine, chanoclavine, deoxynivalenol, nivalenol, enniatin A, A I , B, B,, beauvericin, kojic acid and moniliformin. All samples were contaminated with fumonisins B 1 , B2 and B3. Contamination levels were low (near the LOD) most of toxins, except for FB I and FB 2 that reach 6,000 mg.mU l and 2,450 mg.mL"' in maize and 1,120 mg.mL"' and 54 mg.mL" 3 in feed, respectively. This is the first study dealing with agroclavine, chanoclavine, enniatin A, A 1 , B, B 1 , beauvericin and kojic acid contamination of maize and poultry feeds from Brazil.MYCOTOX - INCO-DEV project (ICA4-CT-2002-10043

Global sourcing of low-inorganic arsenic rice grain

Arsenic in rice grain is dominated by two species: the carcinogen inorganic arsenic (the sum of arsenate and arsenite) and dimethylarsinic acid (DMA). Rice is the dominant source of inorganic arsenic into the human diet. As such, there is a need to identify sources of low-inorganic arsenic rice globally. Here we surveyed polished (white) rice across representative regions of rice production globally for arsenic speciation. In total 1180 samples were analysed from 29 distinct sampling zones, across 6 continents. For inorganic arsenic the global x ~ x~ was 66 μg/kg, and for DMA this figure was 21 μg/kg. DMA was more variable, ranging from < 2 to 690 μg/kg, while inorganic arsenic ranged from < 2 to 399 μg/kg. It was found that inorganic arsenic dominated when grain sum of species was < 100 μg/kg, with DMA dominating at higher concentrations. There was considerable regional variance in grain arsenic speciation, particularly in DMA where temperate production regions had higher concentrations. Inorganic arsenic concentrations were relatively consistent across temperate, subtropical and northern hemisphere tropical regions. It was only in southern hemisphere tropical regions, in the eastern hemisphere that low-grain inorganic arsenic is found, namely East Africa (x ~ x~  < 10 μg/kg) and the Southern Indonesian islands (x ~ x~  < 20 μg/kg). Southern hemisphere South American rice was universally high in inorganic arsenic, the reason for which needs further exploration