Aflatoxin in corn

Low incidence and levels of aflatoxin were identified in corn of all grades grown in the Midwest in 1964, 1965, and 1967. Later surveys indicate that corn grown in southern regions is subject to invasion byAspergillus flavus and subsequent aflatoxin formation. This mycotoxin is formed either in the field or in storage. In the field, such factors as insect damage and weather conditions probably influence aflatoxin formation. In storage, temperatures must be above 25 C and moisture levels above 16% if toxin is to form. Aflatoxin formed in a hot spot in stored corn in the Midwest when temperatures rose early in the summer and when the grain became wet because of leaks in the storage building. Analytical methods to detect and determine aflatoxin fall into three categories: presumptive tests indicating the presence ofA. flavus and the possible occurrence of aflatoxin, rapid screening tests establishing the presence or absence of the toxin, and quantitative procedures determining toxin levels. Detoxification methods being studied include ammoniation and roasting. Ammoniated corn is being fed domestic animals to determine whether it has adverse effects and whether toxic compounds are transmitted in animal tissues.