Potential of Kale and Lettuce Residues as Natural Adsorbents of the Carcinogen Aflatoxin B(1) in a Dynamic Gastrointestinal Tract-Simulated Model

Adsorption of the carcinogen aflatoxin B(1) (AFB(1)) onto agro-waste-based materials is a promising alternative over conventional inorganic binders. In the current study, two unmodified adsorbents were eco-friendly prepared from kale and lettuce agro-wastes. A dynamic gastrointestinal tract-simulated model was utilized to evaluate the removal efficiency of the sorptive materials (0.5%, w/w) when added to an AFB(1)-contaminated diet (100 µg AFB(1)/kg). Different characterization methodologies were employed to understand the interaction mechanisms between the AFB(1) molecule and the biosorbents. Based on adsorption results, the biosorbent prepared from kale was the best; its maximum adsorption capacity was 93.6%, which was significantly higher than that of the lettuce biosorbent (83.7%). Characterization results indicate that different mechanisms may act simultaneously during adsorption. Non-electrostatic (hydrophobic interactions, dipole-dipole interactions, and hydrogen bonding) and electrostatic interactions (ionic attractions) together with the formation of AFB(1)-chlorophyll complexes appear to be the major influencing factors driving AFB(1) biosorption.