Adsorption behavior of trace polycyclic aromatic hydrocarbons in vegetable oil by β-cyclodextrin-decorated activated carbon

Abstract

Polycyclic aromatic hydrocarbons (PAHs) pose a significant health burden when present in food, and their removal from oils without losing trace nutrients and oil flavor is a persistent challenge. This study introduces a novel approach to selectively eliminate trace PAHs from edible oil. A composite adsorbent, termed β-CD@AC, was meticulously engineered by decorating activated carbon (AC) with β-cyclodextrin (β-CD). Under optimized treatment conditions, β-CD@AC demonstrated exceptional detoxification capabilities, achieving remarkable removal rates of 95.03% for PAH4 (PAH markers) and 97.27% for benzo[a]pyrene (BaP). In comparison to its unmodified AC counterpart, β-CD@AC proved more effective in preserving tocopherols and sterols, while simultaneously retaining higher concentrations of desirable flavor compounds. Surface characterization confirmed that functionalization increased the density of oxygen-containing groups, thereby enhancing the surface chemistry and adsorption affinity of the material. Comprehensive analyses, including adsorption isotherm, kinetic, and thermodynamics, revealed a multi-interaction adsorption mechanism. This mechanism is primarily driven by hydrophobic interactions, pore-filling, π-π conjugation, and hydrogen bonding effects. This innovative development offers a promising strategy for mitigating the issue of PAH contamination in the oil industry.