From Agro-Industrial Waste to Food Safety: Sustainable Biochars Derived from Orange Peel and Guava Leaves for the Removal of Aflatoxin B1 in Poultry Feed Using an In Vitro Model

Aflatoxin B1 (AFB1) contamination of feed used in poultry farming is an important issue in food safety since it compromises animal productivity and leads to the transfer of toxic waste to the food chain. In this sense, as an alternative to conventional mineral adsorbents, in the present study, two sustainable and low-cost biochars were obtained from agro-industrial waste of orange peel (B-OP) and guava leaves (B-GL) to evaluate their efficiency in the removal of AFB1 in an in vitro avian model. Biochars were obtained from pyrolysis and characterized in terms of particle size, surface area, morphology, surface charge, surface chemistry, and pore size. Furthermore, their adsorption capacity was evaluated in an avian in vitro model. The results showed that B-OP had a smaller particle size (55.30 µm), a larger specific surface area (31.50 m2/g), and a smaller pore size (2.38 nm) than B-GL (82.88 µm, 9.74 m2/g, and 6.24 nm). Furthermore, the biochars presented different morphologies, FTIR spectra, and zeta potentials. In the avian in vitro model, the feed matrix reduced the effectiveness of AFB1 removal compared to the in vitro model using only buffer solutions. However, B-OP (27.4%) significantly outperformed B-GL (22.7%) in the intestinal segment. The valorization of these agro-industrial wastes into biochar represents an economical and sustainable strategy for removing AFB1 and strengthening food security.