Cereal Chem 61:48 - 52.  |  VIEW ARTICLE
Distribution of Sterigmatocystin and Fungal Mycelium in Individual Brown Rice Kernels Naturally Infected by Aspergillus versicolor.

H. Takahashi, H. Yasaki, U. Nanayama, M. Manabe, and S. Matsuura. Copyright 1984 by the American Association of Cereal Chemists, Inc. 

The distribution of fungal mycelium and the mycotoxin sterigmatocystin in individual brown rice kernels naturally infected by Aspergillus versicolor was studied with scanning electron and fluorescence microscopy. Mycotoxin content in the milled rice or rice bran at various milling stages was determined by fluorodensitometry. Scanning electron microscopy showed that invading mycelia were often in the adjacent germ, aleurone layer, or starchy endosperm. The fungus usually occurred around germ as an entagled mycelial mass, but it was rarely found in the major part of the endosperm unless the grain was cracked. Characteristic yellow fluorescence caused by the mycotoxin was found in the germ, aleurone layer, and starchy endosperm adjacent to them, and conspicuously around the germ. Concentrations of mycotoxin in brown rice were 3.8-4.3 ppm. Mycotoxin content in milled rice decreased gradually from 71.6 to 7.7%, depending on the milling yields from 97.7 to 56.4%. The major portion of mycotoxin produced in brown rice could be removed at the minimum milling yield (56.4%).