Partitioning of açaí anthocyanins using liquid–liquid equilibrium based on deep eutectic solvents

The açaí anthocyanin is one of the most attractive natural compounds in industrial applications and is mainly used as a natural food colorant due to its red, purple, and blue shades. The use of liquid–liquid equilibrium (LLE) systems is an alternative technique for biomolecule extraction, comprising deep eutectic solvents (DESs) characterized by economy and low toxicity. Thus, this study aimed to determine the LLE data of DES-based systems: choline chloride:glucose (ChCl:GLU) + 2-propanol + water and ChCl:sucrose (ChCl:SUC) + 2-propanol + water at 298.15 K and 308.15 K and evaluate their efficiency in açaí anthocyanin partitioning. The systems were characterized as quaternary, because the DESs hydrogen bonds were broken during LLE formation and the experimental data were correlated with the non-random two-liquids model, obtaining a root-mean-square deviation of 0.44%. Finally, the new quaternary system was named as ChCl + GLU + 2-propanol + water and ChCl + SUC + 2-propanol + water. During the anthocyanin partition of the extract obtained in the solid–liquid extraction process, it was possible to observe that the biomolecules had a greater affinity for the lower phase obtaining partitioning coefficient values (K) above 20 and extraction efficiency (EE) above 96% in the bottom phase of the systems at 298.15 K. For the total polyphenols partitioning, the partition coefficient and extraction efficiency (2.44 and 70%, respectively) were higher for the system consisting of ChCl + GLU + 2-propanol + water at 308.15 K, which confirms the potential of these systems in extracting natural pigments.