Mycotoxins are toxic metabolites produced by several fungi species, with the aflatoxins,
fumonisins, zearalenone, trichothecenes and ochratoxin A being the most important found
in feedstuffs. The economic impact caused by mycotoxins motivated the investigation of
detoxification strategies to reduce its bioavailability by enterosorption. Although there are
several types of adsorbents, the efficiency of the adsorption depends on the physical
and chemical characteristics of both the adsorbent and the mycotoxin. This review describes
the most important types of mineral adsorbents [aluminosilicates, HSCAS]
Hydrated sodium calcium aluminosilicate (HSCAS) is one of the most effective adsorbents for aflatoxins, and is also commonly used as an anti-caking additive in animal feed.
This compound is considered a type of Ca-montmorillonite that can be obtained naturally or by means of heat treatment of calcium clay. It has, in its structure, water molecules bound to a metal center or crystallized with a complex metal. The
deficiency in positive charges characteristic of aluminosilicates creates a potential to adsorb positively charged compounds (Huwig et al., 2001; Ramos & Hernandez,
1997; Tapia-Salazar et al., 2010).
The hypothesized mechanism of AFL sorption by HSCAS is based on an electron donor acceptor (EDA) process. The adsorption involves sharing electrons of metallic cations from the negative surface of the clay with the carbons comprising the bcarbonyl system in
AFL (partially positive) forming a complex (Phillips, 1999).
Evidence suggests that AFL may react at multiple sites on HSCAS particles, especially the interlayer region, but also at edges and basal surfaces (Jaynes et al., 2007). Thus, the
optimal orientation of AFB1 is probably planar on interlayer surfaces of HSCAS. Other mechanisms of AFB1 sorption by HSCAS surfaces may involve the chelation or interaction of AFB1 with interlayer cations (especially Ca) or various
edge-site metals (Phillips et al., 2008).