Extraction of ascorbic acid using alcohol/phosphate potassium salt – based aqueous two-phase system

摘要

Aqueous two-phase system (ATPS) is an interesting extraction procedure to obtained biomolecules. Therefore, in this study alcohol + potassium phosphate salts-based ATPS were used to extract L-ascorbic acid as a model to antioxidants. The alcohol-rich top phase (methanol, ethanol, 1-propanol, 2-propanol) and salt-rich bottom phase (K_3PO_4, K_2HPO_4 e KH_2PO_4/K_2HPO_4) was obtained after the equilibrium at 298.15 K. The system was evaluated for their effectiveness in L- ascorbic acid extraction. The phase formation occurred using alcohols with aliphatic chain; however K_2HPO_4/KH_2PO_4 buffer solution has a lower ability for the ATPS formation. Merchuck’s equations fitted satisfactorily the dates. L-ascorbic acid partitioned to bottom phase (K<1.0), but decreasing of pH value, a little portion of L-ascorbic acid trend to migrate to top phase.