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

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

International perspectives on crowdfunding: positive, normative and critical theory

International audienceCrowdfunding as an entrepreneurial phenomenon substitutes traditional sources of finance (banks, financial markets, governments) for the crowd. Socially and economically, it is challenging the traditional boundaries that have been set for centuries between industry, the financial sector, and the public. Though its basic principle cannot be considered as a radical innovation, crowdfunding as a rapidly growing practice calls for renewed management, legal, and governance patterns.Descriptive inquiries on how to do it are multiplying but crowdfunding remains a fuzzy subject for research and reflexivity. This book gathers the best recent research outcomes on the managerial and social impact of this new practice

International perspectives on crowdfunding: positive, normative and critical theory

International audienceCrowdfunding as an entrepreneurial phenomenon substitutes traditional sources of finance (banks, financial markets, governments) for the crowd. Socially and economically, it is challenging the traditional boundaries that have been set for centuries between industry, the financial sector, and the public. Though its basic principle cannot be considered as a radical innovation, crowdfunding as a rapidly growing practice calls for renewed management, legal, and governance patterns.Descriptive inquiries on how to do it are multiplying but crowdfunding remains a fuzzy subject for research and reflexivity. This book gathers the best recent research outcomes on the managerial and social impact of this new practice

ASSESSMENT OF THE RISK FACTORS ASSOCIATED WITH AFLATOXIN CONTAMINATION DURING THE MARKETING OF PEANUTS IN CÔTE D'IVOIRE

This study was conducted to assess the different risk factors related to practices of sale of peanuts for better control of aflatoxin contamination and also to improve the safety of peanuts during marketing. The sales practices are similar regardless of the area surveyed. Of all the respondents in this survey, 61.7% were men as against 38.3% women and 70% of the respondents do not have any formal education. The marketing of peanut seeds is generally an activity done by men (100%) while that of peanut paste is assigned to women (100%). The unsold peanut paste is kept from 1 day to 3 months at room temperature until sale, mainly in market stalls used to sell it (42.4%) or in stores (39.4%). The losses are mainly due to fungi (37.9%) and insects (13.6%) followed by humidity and high temperature (4.5%). During sale of peanut paste, the site, the surroundings of sales points and the storage containers are potential fungi growth factors and eventual risk points for mycotoxin contamination. Proper handling and hygiene might reduce the aflatoxin contamination of peanut to ensure better sanitary quality of peanuts and protect consumer’s heath

Molecular determinants involved in the allosteric control of agonist affinity in the GABAB receptor by the GABAB2 subunit.

The gamma-aminobutyric acid type B (GABAB) receptor is an allosteric complex made of two subunits, GABAB1 (GB1) and GABAB2 (GB2). Both subunits are composed of an extracellular Venus flytrap domain (VFT) and a heptahelical domain (HD). GB1 binds GABA, and GB2 plays a major role in G-protein activation as well as in the high agonist affinity state of GB1. How agonist affinity in GB1 is regulated in the receptor remains unknown. Here, we demonstrate that GB2 VFT is a major molecular determinant involved in this control. We show that isolated versions of GB1 and GB2 VFTs in the absence of the HD and C-terminal tail can form hetero-oligomers as shown by time-resolved fluorescence resonance energy transfer (based on HTRF technology). GB2 VFT and its association with GB1 VFT controlled agonist affinity in GB1 in two ways. First, GB2 VFT exerted a direct action on GB1 VFT, as it slightly increased agonist affinity in isolated GB1 VFT. Second and most importantly, GB2 VFT prevented inhibitory interaction between the two main domains (VFT and HD) of GB1. According to this model, we propose that GB1 HD prevents the possible natural closure of GB1 VFT. In contrast, GB2 VFT facilitates this closure. Finally, such inhibitory contacts between HD and VFT in GB1 could be similar to those important to maintain the inactive state of the receptor

Synthesis and pharmacological characterization of aminocyclopentanetricarboxylic acids : new tools to discriminate between metabotropic glutamate receptor subtypes

International audienceThe four stereoisomers of 1-aminocyclopentane-1,3,4-tricarboxylic acid {ACPT-I (18) and -II (19), (3R,4R)-III [(-)-20], and (3S,4S)-III [(+)-20]} have been synthesized and evaluated for their effects at glutamate receptors subtypes. ACPTs are ACPD analogues in which a third carboxylic group has been added at position 4 in the cyclopentane ring. None of the ACPT isomers showed a significant effect on ionotropic NMDA, KA, and AMPA receptors. On the other hand, ACPT-II (19) was found to be a general competitive antagonist for metabotropic receptors (mGluRs) and exhibited a similar affinity for mGluR1a (KB ) 115 ( 2 íM), mGluR2 (KB ) 88 ( 21 íM), and mGluR4a (KB ) 77 ( 9 íM), the representative members of group I, II and III mGluRs, respectively. Two other isomers, ACPT-I (18) and (+)-(3S,4S)-ACPT-III [(+)-20], were potent agonists at the group III receptor mGluR4a (EC50 ) 7.2 ( 2.3 and 8.8 ( 3.2 íM) and competitive antagonists with low affinity for mGluR1a and mGluR2 (KB > 300 íM). Finally, (-)-(3R,4R)-ACPT-III [(-)-20] was a competitive antagonist with poor but significant affinity for mGluR4a (KB ) 220 íM). These results demonstrate that the addition of a third carboxylic group to ACPD can change its activity (from agonist to antagonist) and either increase or decrease its selectivity and/or affinity for the various mGluR subtypes

Determination of the absolute configuration of phosphinic analogues of glutamate

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