AFLATOXIN B1 ADSORPTION BY BENTONITE AND COMPOSITES WITH CHITOSAN AND SURFACTANT

Abstract

Aflatoxins (AFs), a group of closely related, extremely toxic mycotoxins produced by some strains of the molds - Aspergillus flavus and Aspergillus parasiticus, can occur as natural contaminants of food and feeds worldwide. In the current study adsorption of aflatoxin B1 (the most toxic representative of AFs), was followed by bentonite – B (supplied from Getraco, d.o.o), B modified with commercial low molecular weight chitosan (sample B–Ch) as well as B–Ch modified with surfactant – hexadecyltrimethyl ammonium bromide (sample B–Ch–S). The initial raw material B and both composites were characterized by thermal analysis (TG/DTG) and determination of zeta potential. Results confirmed presence of chitosan in sample B–Ch and both chitosan and surfactant in sample B–Ch–S. Adsorption of aflatoxin B1 by B, B–Ch and B–Ch–S was investigated at different amounts of each adsorbent in suspension in buffer solution at pH 3 and 7, at fixed contact time (30 min). Results showed that for all materials, aflatoxin B1 adsorption increased with increasing the amount of each adsorbent in suspension and adsorption was practically independent of the solution pH. Although B already has high affinity to adsorb aflatoxin B1, the presence of chitosan and/or surfactant slightly increased adsorption of investigated mycotoxin at pH 3 and 7. Since both chitosan and surfactant have potential antibacterial activity, specifically composite B–Ch–S has a potential for a practical application as an animal feed additive.