Aflatoxin Production in Moist Barley Treated with Suboptimal Doses of Formic and Propionic Acid

Abstract

Abstract Spores from three strains of Aspergillus parasiticus isolated in 1986 from acid treated grain were inoculated into newly harvested moist barley with the following treatments (I) propionic acid 0.3% by weight, (II) formic acid 0.5% by weight, (III) formic acid 0.5% and ethoxyquin 0.005% by weight, and (IV) no acid. The suboptimal doses of formic acid and propionic acid were used to study the risk for aflatoxin formation in connection with failures of acid preservation of moist grain. The results demonstrated a clear difference between formic acid and propionic acid treatment. Growth of A. parasiticus and aflatoxin production was restricted in propionic acid treated grain. In grain treated with formic acid alone or in combination with ethoxyquin, A. parasiticus totally dominated the fungal flora and produced high levels of aflatoxins. The highest aflatoxin content was found in grain treated with formic acid and ethoxyquin.