Characterization of polyphenolic and oligosaccharidic fractions extracted from grape seeds followed by the evaluation of prebiotic activity related to oligosaccharides

The study was designed to characterize polyphenolic and oligosaccharidic fractions extracted from grape seeds. Polyphenols and oligosaccharides purification has been realized by using a multistep solid-phase extraction (SPE) (using C-18 cartridge followed by carbograph cartridge). The evaluation of the monomeric flavan-3-ol composition of polymeric chains and their relative mean degree of polymerisation (mDP) using the phloroglucinolysis method, combined with HPLC separation, has been realized. Then, the evaluation of the three different oligosaccharidic fractions as potential functional ingredients with prebiotic activity towards well-known probiotic bacteria, allowing to improve their growth during in vitro fermentation, has been deepened. These oligosaccharidic fractions extracted from seeds showed a significant prebiotic activity on probiotic bacteria such as Lactobacillus acidophilus.