Commercial recovery of natural pigments from plant materials is
usually solvent extraction after homogenization. For examples, acidified
solutions of methanol, ethanol, acetone, water, and a mixture of
acetone/methanol/water are traditionally used to extract anthocyanins.
From these methods, the extraction with acidified methanol is the most
efficient [6-8]. Nevertheless, in food industry ethanol is preferred due
to the toxicity of methanol. In addition, the extraction method needs
large amount of organic solvents and much energy for recovering the
solvent. Thus, there is a need for an efficient, economical and large-scale
bioseparation method that can achieve high purity as well as high yield,
while preserving the biological activity of these molecules. Aqueous
two-phase extraction (ATPE) is likely to be developed as one extraction
method to meet the above criteria.