CONTROL MECHANISMS FOR MYCOTOXIN PREVENTION IN PEANUTS AND THEIR ROTATION CROPS
Location: Peanut Research
Title: Management and Prevention of Mycotoxins in Peanuts
Submitted to: Journal of Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 19, 2007
Publication Date: February 1, 2008
Citation: Dorner, J.W. 2008. Management and Prevention of Mycotoxins in Peanuts. Journal of Food Additives & Contaminants. 25:203-208.
Interpretive Summary: : Contamination of peanuts with mycotoxins, particularly aflatoxins, is a worldwide problem that affects both food safety and agricultural economies. Strict regulatory guidelines have been established in most developed countries regarding the amount of aflatoxins allowed in food products. Meeting those guidelines ensures the safety of food with regard to aflatoxin contamination, but doing so can mean the loss of much produce from the edible market. To ensure that peanuts meet the guidelines without undue economic hardship on the peanut industry, techniques have been developed to manage and prevent aflatoxin contamination of peanuts. Management techniques include lot segregation, screening, kernel sizing, density segregation, electronic color sorting, and blanching followed by electronic color sorting. The best way to manage aflatoxin contamination is to prevent it in the first place. This can be done by controlling peanut kernel moisture, early harvesting, and use of newly developed biological control technology. Commercial use of the biocontrol technology has been shown to prevent 85% of preharvest aflatoxin contamination with reductions in shelled peanuts of up to 98%.
Contamination of peanuts with mycotoxins, particularly aflatoxins, is a worldwide problem that affects both food safety and agricultural economies. Most countries have adopted regulations that limit the quantity of aflatoxins in food and feed to 20 'g/kg or less; however, environmental conditions in most of the world where peanuts are produced and stored often make it difficult or impossible to attain such low concentrations. In addition to aflatoxins, peanuts are often contaminated with cyclopiazonic acid (CPA). Both mycotoxins are produced by Aspergillus flavus, a ubiquitous fungus that can infect and grow in peanuts under both preharvest and postharvest conditions. Management of mycotoxin contamination in peanuts generally involves removal of high-risk components from shelled lots or the removal of individual, highly contaminated nuts. This is accomplished by various processes such as screening, kernel sizing, electronic color sorting, hand sorting, and blanching followed by electronic color sorting. Recently, biological control technology has been developed that prevents much of the contamination that might otherwise occur. Biocontrol is based on competitive exclusion whereby a dominant population of a nontoxigenic strain of A. flavus is established in the soil before peanuts are subjected to conditions favoring contamination. The applied strain competes with toxigenic strains for infection sites, resulting in significantly reduced concentrations of aflatoxins in peanuts. Monitoring of the first commercial use of the technology showed that aflatoxins were reduced by an average 85% in farmers= stock peanuts and by as much as 98% in shelled, edible grade peanuts.