Novel fructooligosaccharides of Dioscorea alata L. tuber have prebiotic potentialities

Abstract Dioscorea alata L. (Dioscoreaceae) is a versatile and popular tuber crop vegetable used across the globe. The main aim of the study is to extract and characterize the fructooligosaccharides (FOSs) fractions from the tuber of this plant and evaluate their prebiotic properties. The soluble FOSs were fractionated by the conventional solid-phase extraction method and were characterized by FT-IR, HPTLC, and ESI-MS analyses. In addition, the beneficial health attributes of these fractions were checked for prebiotic properties in vitro and in vivo in Swiss albino mice. The FT-IR, HPTLC, and ESI-MS analyses of the FOSs from the hot water and 80% ethanol fractions showed that both are rich in inulin-like prebiotics. Furthermore, these FOSs showed an excellent prebiotic activity score comparable to standard prebiotics, inulin. In addition, these FOSs had enhanced in vitro cholesterol-binding activities in the presence of probiotics LAB strains and had antioxidant efficacies. In vivo treatment in Swiss albino mice, these FOSs had significantly lowered total serum cholesterol, serum LDL, serum VLDL, triglyceride, and significantly enhanced serum HDL level and enhanced IgA mediated immunomodulation. The results were also more significant than the standard prebiotics, inulin. They also influenced the gut colonization of probiotic LAB strains. Thus, the study revealed that the FOSs from the storage tuber of D. alata possess some novel prebiotic that could contribute to human nutrition. This is the first report of the prebiotic FOS characterization from this plant.