Raffinose family oligosaccharides and sucrose contents in 13 Spanish lupin cultivars

The contents of raffinose family oligosaccharides (RFOs) and sucrose in 13 Spanish cultivars of lupin (Lupinus albus, Lupinus luteus and Lupinus angustifolius) were studied, with the aim of selecting those with highest amounts of these oligosaccharides in order to obtain pure RFOs for use as ingredients in functional foods. The levels of sucrose and RFOs (raffinose, stachyose and verbascose) were determined using high perfornnance liquid chromatography (HPLC). There were large variations in the levels of individual RFOs between lupin cultivars. L. albus seeds were characterised by the lowest verbascose content (∼0.4%), L. luteus seeds by the highest contents of stachyose (∼7.4%) and verbascose (∼3.1%) and the lowest of sucrose (∼1.2%),and L. angustifolius seeds by the highest sucrose (∼3.4%) and the lowest stachyose (∼4.6%) contents. Furthermore, there was a wide variation in total α-galactosides between species, with a remarkably high content found in L. luteus (9.5-12.3%) which was about twice that of other lupin cultivars. For this reason, L. luteus seeds are the best choice for obtaining pure RFOs for use as prebiotics in functional foods.