Prebiotic potential of xylooligosaccharides derived from finger millet seed coat

The present study deals with the enzymatic production of xylooligosaccharides (XOS) from water-soluble xylan (WSX) extracted from finger millet CO9 seed coat and the evaluation of its prebiotic potential. The yield of XOS was 72%, when the WSX of the finger millet seed coat was treated with commercially available xylanase of Thermomyces lanuginosus. The XOS obtained when analyzed using high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) indicated a degree of polymerization (DP) of 2 and Electro Spray Ionization Mass Spectra (ESI-MS) revealed xylobiose as the major sugar. The presence of -glycosidic linkages of XOS was identified by Fourier Transform Infrared Spectrometer (FTIR) and Nuclear Magnetic Resonance (NMR) studies. The XOS exhibited an antioxidant activity of 75% and prebiotic efficacy. Prebiotic activity in the presence of probiotic strains was strain specific and differences in the prebiotic activity score (PAS) between strains were evident. The cell-free supernatant of Lactobacillus plantarum grown on the XOS from finger millet seed coat showed strong antibacterial activities against four pathogenic microorganisms compared with commercial XOS. Finger millet seed coat represents an abundant and alternative source for the extraction of xylan and its use for prebiotic XOS production.