Preparation and characterization of chitosan/palygorskite for the adsorption of ochratoxin A

Mycotoxins represent a persistent global challenge, posing a significant threat to human health and food safety. However, the application of effective detoxification strategies for various mycotoxins, particularly non-polar ochratoxin A (OTA), remains highly scarce. In this work, a chitosan/palygorskite (C-A₁) was successfully synthesized via hydrothermal method, using palygorskite (Pal) as a template and chitosan (CS) as a modifying agent. The introduced functional groups (-OH and -NH₂) on the composite surface provided abundant active sites for OTA adsorption. The introduced functional groups (-OH and -NH₂) on the composite surface provided abundant active sites for OTA adsorption. The adsorption capacity for OTA increased from 0.94 mg/g in Pal raw ore to 1.94 mg/g. Meanwhile, C-A₁ demonstrated remarkable adsorption stability, with negligible desorption under simulated gastrointestinal pH conditions. Kinetic and isotherm adsorption studies were further conducted, indicating that the OTA adsorption by C-A₁ was primarily governed by hydrophobic interactions, partitioning effects, electrostatic interactions, and hydrogen bonding. The adsorption process followed pseudo-second-order kinetic model and a linear isotherm model, suggesting that chemical bonding played a dominant role. In conclusion, these findings highlight the good adsorption performance of C-A₁ toward OTA and establish its potential as an effective adsorbent for nonpolar mycotoxins in the adsorption system.