JAOCS, Journal of the American Oil Chemists' Society, 2026 (SCI-Expanded, Scopus)
This study aimed to modify and characterize natural halloysite using six activation methods and to evaluate their performance in the bleaching of neutralized crude cottonseed oil (NCO), in comparison with a commercial bleaching earth (CBE). Among the modified samples, acid-activated halloysite (HS-AA) exhibited the highest specific surface area (114.01 m2/g), while surface and pore properties varied significantly depending on the activation method. Scanning electron microscopy revealed notable alterations in tubular morphology, whereas X-ray diffraction patterns indicated peak broadening, suggesting partial loss of interlayer water. Fourier-transform infrared spectroscopy showed higher crystallinity and reduced impurity levels in HS-AA and control (HS-CN) samples. The treated oils were evaluated in terms of oil loss, color parameters, bleaching efficiency, peroxide value, UV-specific absorbance, and free fatty acidity. The results demonstrated that thermally activated (HS-TA), acid-activated (HS-AA), and oxalic acid-activated (HS-OA) halloysites exhibited promising adsorption performance. Phytosterol and tocopherol analyses indicated minimal nutrient losses in oils treated with HS-TA and CBE. Overall, HS-TA is proposed as a simple, cost-effective, and efficient adsorbent for oil bleaching. Further optimization of activation conditions is recommended to enhance its performance.