Simple method of isolation and purification of alpha-galactosides from legumes

Abstract

A simple method for the isolation and purification of alpha-galactosides, raffinose family oligosaccharides (RFOs), from legumes has been developed. The method includes (i) imbibition of seeds, (ii) extraction with 50% ethanol, (iii) precipitation of RFOs, (iv) purification of RFOs on diatomaceous earth and charcoal, and (v) cation-exchange chromatography. The described method allows one to obtain high purity RFO preparations (90% for lentil and 80% for pea seeds, determined by HPLC-RI analysis) in the form of white, fine powder. Yields of alpha-galactosides isolated from 100 g of seeds of lentil and pea were 5.6 and 4.3 g, respectively.