Selective partition of caffeine from coffee bean and guaraná seed extracts using alcohol–salt aqueous two-phase systems

This work proposes the application of flexible alcoholic aqueous two-phase systems to manipulate the partition of caffeine. An optimization study was performed the caffeine partitioning towards top phase (60.0 wt% 2-propanol + 20.0 wt% K₃PO₄ at 303 K – K_caf = 3.4 and R_T = 89.1%) and bottom phase (60.0 wt% methanol + 17.5 wt% K₂HPO₄/KH₂PO₄ at 278 K – K_caf = 0.06 and R_B = 81.1%). These processes were evaluated by applying them to real biomass as guaraná seeds (purification factor (PF) = 6.59-fold) and coffee beans (PF = 3.24-fold) for the 2-propanol and K₂HPO₄/KH₂PO₄ system.