Cereal Chem 58:124 - 127. | VIEW
Use of Bright Greenish Yellow Fluorescence as a Presumptive Test for Aflatoxin in Corn.
O. L. Shotwell and C. W. Hesseltine. Copyright 1981 by the American Association of Cereal Chemists, Inc.
Corn samples from 1978 crop were examined under ultraviolet light (365 nm) for the bright greenish yellow (BGY) fluorescence associated with Aspergillus flavus or A. parasiticus and possibly the aflatoxin produced by these fungi. Two methods were used to test 248 samples for BGY fluorescence. First, whole-kernel samples were examined in a black light viewer, and BGY particles were counted. Then, the corn samples were coarse-ground in a disk mill; the BGY particles were counted as the stream from the mill was examined under ultraviolet light (365 nm). The counts obtained by the two methods were similar. Particle counts were identical in 61% of the samples and differed by one in 20%, two in 8%, three in 6%, and four in only 5%. Tinopal BHS, a compound that is stable to air, can be used as a color reference standard in the BGY test. In samples of 1978 corn having one BGY particle per kilogram, 92% had less than 20 ng of total aflatoxin per gram, the Food and Drug Administrations's action guideline. In 1978 samples having four or more particles per kilogram, only 25% had less than 20 ng/g. In an examination of 1973 South Carolina corn, 98% of the samples in which no BGY fluorescence was detected had aflatoxin levels less than 20 ng/g; the two samples that were BGY-negative had 21 and 27 ng/g.