3.4. AfB1 Retention by Nutrient-Compound Surface-Modified Clays
Samples of SWy treated with the nutrient compounds, choline and carnitine, retained more AfB1 from corn flour than untreated SWy (Figure 5a). The choline-treated, high-charge, SAz montmorillonite (SAz-Choline) retained more AfB1 than untreated SAz (Figure 5b) and comparable amounts as Novasil plus (Figure 3a), but much less than SWy-Choline or SWy-PTMA. The reduced-charge 0.35LiSAz-Choline montmorillonite retained amounts of AfB1 comparable to SWy-PTMA and SWy-Choline and considerably more than SAz-Choline. Lithium charge reduction would likely be impractical for the production of low-charge feed additives, but demonstrates that layer charge is an important factor in selecting clay additives to bind aflatoxins in feed. Naturally-occurring, low-charge montmorillonites or other low-charge smectites would be more effective feed additives than higher-charge clays. Treatment of low-charge clays with small, non-toxic organic compounds, such as choline and carnitine, produce surface-modified clays (or organoclays) that might