The initiative entitled ‘New tools for groundnut aflatoxin control in Sahel Africa,’ headed by CIRAD (agricultural research for developing countries), has just been completed.
It has enabled the development of methodologies for improving varietal screening and growing groundnut under rainfed conditions, to reduce aflatoxin contamination both in the field and
post-harvest.
The peanut is of great nutritional importance in numerous African countries, where few crops have as many nutritional or financial advantages.
However, it is susceptible to aflatoxin, a highly toxic substance produced by the fungus Aspergillus flavus.
Infection is favoured by water stress towards the end of the cycle, and African regions regularly hit by drought, such as Senegal, Niger and Mali, are thus at particular risk. This brings
serious health risks, such as liver cancer, as local populations may consume large quantities of contaminated products.
In addition, with the tightening of European health regulations, the export value of peanuts has dropped considerably, and aflatoxins is an issue that has garnered increasing attention. This
month for example, the European food safety authority was asked by the EC to examine the possibility of a potential increase in consumers’ health risks if higher levels of aflatoxins would be
permitted for almonds, hazelnuts and pistachios.
EFSA’s scientific experts pointed out that it is essential to keep aflatoxin exposure from food sources as low as reasonably achievable by reducing exposure from the sources that are major
contributors to total dietary exposure to aflatoxins.
When it comes to peanuts however, varietal breeding programmes have failed to develop cultivars that are aflatoxin resistant and at the same time have high agronomic potential.
CIRAD picked two reference varieties for the study: a cultivar that gives average yields under drought conditions but has good aflatoxin resistance, and another that is higher-yielding but more
susceptible to the fungus.
The approach taken consisted in studying them under different environmental conditions: under water stress, in the field, in glasshouses, etc. The researchers studied the varieties on an
agronomic and physiological, and also biochemical and molecular, level.
With a view to peanut varietal improvement, five genes of interest in terms of aflatoxin resistance were identified, cloned and studied. The researchers found that varieties with improved
drought resistance could be developed from an aflatoxin-resistant parent.
Various studies of good practices that may control contamination before and after harvest have been conducted in conjunction with farmers. The researchers have pushed forward the concept of a
contamination risk analysis system, based on the ‘from farm to fork’ concept, at every stage of the production chain.
The results of this work are already being applied through an operation to develop a quality peanut production chain in Senegal. The approach taken is participatory and based on analysing
market demand.
One of the aims is to implement a system of fair contracts between producers’ organisations and the private sector, so as to optimise market value. The operation is being led by CIRAD, in
partnership with the main Senegalese producers’ organisation (ASPRODEB), with European Union funding.

By Anthony Fletcher

www.foodproductiondaily.com