Prebiotic potential of pectins and pectic oligosaccharides derived from lemon peel wastes and sugar beet pulp : A comparative evaluation

Sugar beet pulp (SBP) and lemon peel wastes (LPW) were used to obtain two mixtures of pectic oligosaccharides (denoted as SBPOS and LPOS, respectively). Oligogalacturonides in LPOS showed a larger molecular weight, higher degree of methylation and lower degree of acetylation than the ones in SBPOS. The suitability of pectic oligosaccharides, pectins from SBP and LPW and commercial FOS for causing prebiotic effects were compared by in vitro fermentation and fluorescence in situ hybridization using human faecal inocula and eight different probes. The joint populations of bifidobacteria and lactobacilli increased from 19% up to 29%, 34% and 32% in cultures with LPOS, SBPOS and FOS, respectively. Faecalibacterium and Roseburia also increased their counts with all the substrates (especially with LPOS). The highest concentrations of organic acids were observed in media containing oligosaccharides. This work confirms that pectic oligosaccharides present better prebiotic properties than pectins, and similar or better than FOS.