Impact of yacon landraces cultivated in the Czech Republic and their ploidy on the short- and long-chain fructooligosaccharides content in tuberous roots

Fructooligosaccharides (FOS) are important tuberous root constituents of yacon (Smallanthus sonchifolius) with beneficial nutritional and prebiotic effects on human health. That is why landraces originally cultivated in Andes are explored with the aim to obtain new ones with high FOS content. In this study eighteen octoploid and five dodecaploid landraces were for the first time evaluated in terms of their tuberous root contents of short-chain fructooligosaccharides GF3-GF10 (Sc-FOS) and long-chain fructooligosaccharides >GF10 (Lc-FOS) by high performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD). Significant differences between individual landraces were found; eleven of them contained high Sc-FOS and Lc-FOS, whilst twelve showed low Lc-FOS contents. Comparison of octoploid and dodecaploid groups showed that degree of ploidy level can affect FOS content and the distribution according to degree of polymerisation. High correlations between the contents of Sc-FOS, Lc-FOS and total carbohydrates (r2 = 0.97, r2 = 0.98 and r2 = 0.95, respectively) have been found.