Clay Minerals as An Amendment of Fumonisin B1.

Fumonisins are a group of aliphatic mycotoxins produced by Fusarium moniliform and F. proliferatum. Among the 28 forms of fumonisins, fumonisin B₁ (FB₁) is the most toxic and abundant. It occurs in cereal grains worldwide, mainly in maize. The FB₁ has been linked to leukoencephalomalacia (LEM) in horses and to esophageal cancer in humans. Various physical and chemical methods for decontamination have been investigated, which include density segregation, heat treatments, drying process, and ammoniation. Adsorbents such as calcium hydroxide and activate carbon are highly effective in removing FB₁. The main objective of this research is to identify clay minerals and zeolite as an amendment of fumonisin B₁. Four samples (three smectites and one zeolite) were investigated using x-ray diffraction and Fourier transform infrared. Without adsorbing FB_1, the smectites had basal spacings of greater than 1.2 nm at room humidity and the basal spacings reduced 0.2 nm at 0% humidity with N₂ purge.  Three scenarios on basal spacing were observed after adsorbing FB₁. One smectite expanded to 1.6 nm and one smectite kept its nearly 1.4 nm basal spacing. Their basal spacings were not reduced by N₂ purge, suggesting interlayer adsorption. The last one smectite collapsed from 1.3 nm at room humidity to 1.1 at 0% humidity. The following infrared bands suggested the presence of FB1 on the minerals:  2919 and 2848 cm^-1 (C-H); 1724, 1730, and 1628 cm^-1 (carboxyl groups); 1576 cm^-1 (N-H); 1465, 1396, and 1356 cm^-1. After two times of washing with water, the infrared bands remained, indicating the stability of the adsorbed FB1. The minerals are promising for using as an amendment of fumonisin B₁.