Eliminating toxins in staple food and feed crops
Maize and sorghum are the main staple food and feed crops in sub-Saharan Africa. In West Africa in particular they are often consumed in the fermented state. As with peanuts, maize and sorghum may contain a number of highly toxic substances, including aflatoxins, formed by fungi growing on commodities under storage conditions of high temperature and high humidity. Aflatoxins, classified as liver carcinogens, are among the five most toxic contaminants of food and feedstuffs. Moreover, studies have shown the persistence of these toxins in final maize and sorghum products. Various approaches aimed at eliminating them have been tried, including physical and chemical methods, multiple processing and decontamination, but most of these alter the final products drastically, rendering them unacceptable to both humans and animals.
Under the EU INCO (International Co-operation) research programme, scientists are working hard to address issues of desertification, food security and sustainable farming practices in the developing world. One INCO-funded project, called ‘Biological degradation of aflatoxins in fermented maize and sorghum products’ has taken a novel approach to making important food and feed products safer, using the natural activity of bacteria to break down dangerous toxins. Project partners, who tested hundreds of bacteria and fungi, including yeasts, say the new method does not alter the quality or nutritional value of final products. Several bacteria and fungi species that have the ability to metabolise aflatoxins, breaking them down into non-toxic substances, have been selected and partners are now concentrating on pinpointing the enzymatic activities of the best-performing organisms, paving the way for the design of improved fermentation systems.
Full project title: Biological degradation
of aflatoxins in fermented maze and sorghum products
Moses Mengu, World Association of Industrial and Technological Research
Science in society significance
During the 20th century, tangible elements such as capital, natural resources and labour were the driving forces behind economic growth. Today, many experts and policy-makers see investing in science and technology as a means of driving sustainable development. Initiatives such as the EU’s INCO programme aim to foster both social and economic progress, thus promoting global sustainable development. An important aspect of this work involves maintaining strong connections with local culture, knowledge and practices. New technologies and methods will not have lasting effects, say INCO officials, if they do not make sense to the people who live in the regions where they are applied. The sub-Saharan regions have an established history of using maize and sorghum in food and feed products. Their traditional customs, preferences, methods and technologies must be taken into account when developing new processes that will ultimately improve the lives and livelihoods of the people concerned. The project on the degradation of aflatoxins is a good example of work aimed at improving the health and nutrition of the poor, taking an intelligent approach to better food production systems while respecting and understanding the regional forces at play, in particular through close partnerships with local organisations.
The project successfully achieved the following:
- Development of new and reliable approaches for screening micro-organisms for their ability to degrade aflatoxins;
- Investigation and definition of capabilities of selected cultures and key factors involved in the degradation or modification of aflatoxins;
- Adaptation of selected cultures capable of aflatoxin degradation to steeping and fermentation and investigation of their suitability for use as starter cultures in industrial processing.