Organically modified clays as binders of fumonisins in feedstocks

Abstract

This study reports an investigation on the ability of organically modified clays to bind mycotoxins, fumonisins B₁ (FB₁) and B₂ (FB₂). Organically modified clays are commercia materials prepared from natural clays, generally montmorillonite, by exchanging the inorganic cation with an ammonium organic cation. A screening experiment conducted on 13 organically modified clays and 3 nonmodified clays, used as controls, has confirmed that the presence of an organic cation in the clay interlayer promoted the adsorption of both fumonisins. On the basis of the results of the screening test, four modified clays and a Na-montmorillonite were selected for the determination of the adsorption kinetics and isotherms. On all the tested materials adsorption took place within one hour of contact with fumonisins solutions. Adsorption isotherms have pointed out that the modified clays exhibited a higher adsorptive capacity than the unmodified clay. It was also demonstrated that, notwithstanding the reduced structural difference between FB₁ and FB₂, they were differently adsorbed on the modified clays. Addition of 2% modified clays to contaminated maize allowed a reduction of more than 70% and 60% of the amount of FB₁and FB₂ released in solution. Although in vivo experiments are required to confirm the effectiveness of the organically modified clays, these preliminary results suggest that these materials are promising as fumonisins binders.

Keywords:

• Mycotoxin binders
• fumonisins B₁ and B₂
• organically modified clays.

Acknowledgments

The authors wish to thank Chiara Gabriolotto and Daniela Vindrola for running the experimental part. This study has been performed with financial support of Regione Piemonte (CIPE 2006 Master Plan for the production of cereals for the food chain with low mycotoxin contamination) and of University of Turin (ex-60%).