An aflatoxin is a poisonous cancer
-causing compound produced by the fungal species Aspergillus flavus
and Aspergillus parasiticus
, both of which grow easily on beans
s (particularly corn
), and peanuts
when they are inappropriately stored in warm
conditions. The fungi
occur naturally in soil
and decaying leaves
, and other vegetation
; if they infect
a growing plant, they usually do so through a wound
created by an insect
This toxin is a powerful liver carcinogen. The presence of aflatoxins in contaminated food supplies is thought to contribute to the high levels of liver cancer in undeveloped and developing countries in the tropics.
There are over a dozen different types of aflatoxin, but aflatoxin B1 is considered to be the most poisonous.
The United States tests domestic corn, sorghum, wheat, peanuts and soybeans for the presence of Aspergillus toxins, and the USDA requires that all corn grown for export must be tested. One previously-common testing method looked for the toxin indirectly by looking for kojic acid, another Aspergillus compound, which will glow under a black light. The kojic acid test has been found to be unreliable, so today more expensive laboratory methods to find aflatoxin directly in grain or bean samples are used.
Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals
Simpson, Beryl Brintnall and Molly Conner-Ogorzaly. 1986. Economic
Botany: Plants in Our World. New York, NY, McGraw-Hill Publishing Co.