Aqueous two phase extraction for purification and concentration of betalains

Abstract

As a natural food colorant, betalains are finding increased importance. The presence of free sugars accelerates the degradation of betalains, hence it is desirable to separate the sugars from the beet extract. Aqueous two-phase extraction was employed for the first time as an attractive alternative for the downstream processing of betalains, mainly for the removal of sugars without the need of additional steps. The effect of different parameters such as tie line length, phase volume ratio, concentration of phase forming components on the partitioning behavior of betalains was studied. The differential partitioning of betalains and sugars was achieved in aqueous two phase extraction at higher tie line length (34%), wherein betalains (about 70–75%) and sugars (about >90%) are partitioned in the top and bottom phases, respectively. Further, the betalains was successfully separated from the polymer employing organic–aqueous extraction resulting in 3.4 fold increase in concentration.