Novel approach for purification of major betalains using flash chromatography and comparison of radical scavenging and antioxidant activities

Abstract

The present study focused on the development of a new purification protocol suitable for betanin and other major betalains, vulgaxanthin I, indicaxanthin and neobetanin, using flash chromatography which is a convenient and fast method to isolate unstable materials. Following preliminary tests, a gradient procedure using 0-60% acetonitrile, with 0.1% (v/v) formic acid as mobile phase, was selected for the purification. Different fractions were collected based on UV detection at 254 and 280 nm and purities were confirmed by reverse-phase HPLC analysis to be 97%, 95%, 79% and 52% for betanin, indicaxanthin, vulgaxanthin I, and neobetanin, respectively, with pigment yields ranging from 120 to 487 mg per 100 g of powdered raw material. Comparative assessment of antioxidant and radial scavenging properties of individual betalains indicated highest potential for betanin followed by neobetanin, vulgaxanthin I and indicaxanthin.

Keywords: Antioxidant and radical scavenging activity; Betalains; Betanin (PubChem CID: 12300103); Flash chromatography; HPLC; Indicaxanthin (PubChem CID: 6096870); Neobetanin (PubChem CID: 102401026); Purification; Vulgaxanthin I (PubChem CID: 135438599).