Cereal Chem 66:445-448   |  VIEW ARTICLE

Postharvest Contamination of Thai Corn with Aspergillus flavus.

P. Siriacha, K. Kawashima, S. Kawasugi, M. Saito, and P. Tonboon-Ek. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

About 4.5 tons of ear corn were collected from three farmers and divided into four groups: 1) stored on the farm as ear corn for eight weeks, 2) shelled by hand and kept for two weeks in gunnysacks without drying, 3) mechanically shelled and kept for two weeks in gunnysacks without drying, and 4) mechanically shelled and kept for eight weeks in gunnysacks after drying. The undried, mechanically shelled kernels were infected quickly by Aspergillus flavus if the initial moisture content was over 20%, but infection did not occur if moisture was less than 17%. Similarly, in the undried, hand-shelled kernels, infection proceeded rapidly if moisture content was over 23% or stopped if it was less than 20%. Kernels that were sun-dried immediately after mechanical shelling on a drying floor (moisture content less than or around 15%) were stored without significant A. flavus infection for more than eight weeks after sun-drying. Wet corn could be stored for more than two months without A. flavus infection as long as the corn was stored as ear corn and not shelled. The infection by A. flavus clearly started in kernels that were damaged by shelling and not dried enough afterward.