Extraction and Advanced Adsorbents for the Separation of Perillaldehyde from Perilla frutescens (L.) Britton var. crispa f. viridis Leaves

Hydrodistillation was carried out from fresh leaves, air-dried leaves in shade, sun-dried leaves, frozen leaves and salted leaves. It was observed that air-dried in shade was the optimal choice for prolonging the pre-processing storage with the advantage of low cost and simplicity. Nine different macroporous resins (DM-21, LS-305, LS-305A, HPD-100, D001CC, XAD-16, XAD-7HP, FPC3500 and SK1B) were evaluated for the adsorption properties of perillaldehyde from hydrodistillation condensate of Perilla frutescens (L.) Britton var. crispa f. viridis leaves. The influences of phase contact time, initial perillaldehyde concentration and ethanol concentration were studied by the static adsorption/desorption method. The adsorption isotherm data were fitted well to the Freundlich model. The kinetic data were modeled using the pseudo-first order, pseudo-second order and intraparticle diffusion equations. The experimental data were well described by the pseudo-second order kinetic model. Column studies were also carried out to investigate the breakthrough and elution behavior at three different flow rates. Continuous column adsorption regeneration cycles indicated negligible capacity loss of LS-305 during operation.