Calcination Enhances the Aflatoxin and Zearalenone Binding Efficiency of a Tunisian Clay

Synthesis and characterization of tannic acid pillared bentonite composite for the efficient adsorption of aflatoxins

Tannic acid (TA) is a hydrolysable polyphenol with established antioxidant and antibacterial activity along with its tendency to bind both organic and inorganic ions/molecules. In the present study, the sequestration performance of TA pillared bentonite for various aflatoxins (AFs) including AFB1, AFB2, AFG1 and AFG2 from aqueous solutions and simulated poultry gastrointestinal model solution was studied via adsorption. The adsorbents were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), N₂ adsorption-desorption study and X-ray photoelectron spectroscopy (XPS). The reaction conditions including pH, agitation time, initial toxin concentration and temperature were systematically optimized. The Langmuir adsorption capacity of the adsorbent reached to 86, 71, 74 and 149 mg/g for AFB1, AFB2, AFG1 and AFG2 respectively. Adsorption kinetics and thermodynamic studies showed rapid AFs uptake and the exothermicity of the adsorption reaction respectively. Simultaneous removal of AFs by BTA3 revealed their independent and uninterrupted adsorption and the adsorption mechanism of AFs over BTA3 was elaborated with the help of XPS results. The outstanding AFs sequestering capability of BTA3 in aqueous solution and simulated poultry gastrointestinal model can be envisioned of great promise for the remediation of AFs and other hazardous pollutants from food and poultry industrial products.

Calcination Improves the In Vivo Efficacy of a Montmorillonite Clay to Bind Aflatoxin G1 in Broiler Chickens: A Toxicokinetic Approach

The goal of this study was to investigate the toxicokinetic characteristics of aflatoxin G1 (AFG1) in broiler chickens and the effect of calcination of a Tunisian montmorillonite clay on the in vivo absorption of AFG1. In this study, broiler chickens were randomly distributed into four groups of 10 animals. Group 1 was administered AFG1 (2 mg/kg body weight (BW)) by single intravenous injection (IV), group 2 received an intra-crop bolus (PO) of AFG1 without any clay, group 3 was dosed AFG1 PO together with an oral bolus of purified clay (CP), and group 4 received AFG1 PO with an oral bolus of calcined clay. A significant difference in the area under the curve (AUC_0-t) was observed for group 4 (6.78 ± 4.24 h*ng/mL) in comparison with group 2 (12.83 ± 4.19 h*ng/mL). A significant reduction of the oral bioavailability of AFG1 was observed for group 4 (7.61 ± 4.76%) compared with group 2 (14.40 ± 4.70%), while no significant effect was observed of CP. In this experiment, no phase I nor phase II metabolites of AFG1 were observed. These findings confirm that calcination of the purified montmorillonite clay enhances the adsorption of AFG1 in the gastrointestinal tract after oral administration, thereby reducing its bioavailability, thus reducing its toxic effects.

Assessing the Aflatoxins Mitigation Efficacy of Blueberry Pomace Biosorbent in Buffer, Gastrointestinal Fluids and Model Wine

Blueberry (BB) and cherry pomace were investigated as new biosorbents for aflatoxins (AFs) sequestration from buffered solutions, gastrointestinal fluids and model wine. Among the tested biosorbents, BB exhibited the maximum adsorption performance for AFs and hence was further selected for the optimization of experimental parameters like pH, dosage, time and initial concentration of AFs. Material characterizations via scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, N2 adsorption-desorption isothermal studies, thermogravimetric analysis (TGA) and X-ray photon spectroscopy (XPS) techniques revealed useful information about the texture and chemical composition of the biosorbents. The fitting of isothermal data with different models showed the model suitability trend as: Sips model > Langmuir model > Freundlich model, where the theoretical maximum adsorption capacity calculated from the Sips model was 4.6, 2.9, 2.7 and 2.4 mg/g for AFB1, AFB2, AFG1 and AFG2, respectively. Kinetics study revealed the fast AFs uptake by BB (50-90 min) while thermodynamics studies suggested the exothermic nature of the AFs adsorption from both, single as well as multi-toxin buffer systems, gastrointestinal fluids and model wine. Accrediting to the fast and efficient adsorption performance, green and facile fabrication approach and cost-effectiveness, the newly designed BB pomace can be counted as a promising contender for the sequestration of AFs and other organic pollutants.