July 2008

Black-Light Grain-Screening For Toxins

It’s not foolproof, but it isn’t going to hurt anything either.

Black light is light in the invisible ultraviolet wavelengths. It can be used to screen feeds for aflatoxin contamination. It’s a pretty sad day when we have to consider making a black light a barn tool, but with the most recent horse feed scare (see page 3), it’s actually not a bad idea. Black light can also be useful in other ways.

Grains infested with the Aspergillus flavus mold that produces aflatoxin will fluoresce a greenish-yellow color under black light. The color is not due to the aflatoxin itself, but a substance called kojic acid that the infected grains produce. To determine actual aflatoxin level, the grain has to be sent…