title: Purification, characterization, and prebiotic properties of pectic oligosaccharides from orange peel wastes.
abstract: Pectic oligosaccharides (POS) were obtained by hydrothermal treatment of orange peel wastes (OPW) and purified by membrane filtration to yield a refined product containing 90 wt % of the target products. AraOS (DP 3-21), GalOS (DP 5-12), and OGalA (DP 2-12, with variable DM) were identified in POS mixtures, but long-chain products were also present. The prebiotic potential of the concentrate was assessed by in vitro fermentation using human fecal inocula. For comparative purposes, similar experiments were performed using orange pectin and commercial fructo-oligosaccharides (FOS) as substrates for fermentation. The dynamics of selected microbial populations was assessed by fluorescent in situ hybridization (FISH). Gas generation, pH, and short-chain fatty acid (SCFA) production were also measured. Under the tested conditions, all of the considered substrates were utilized by the microbiota, and fermentation resulted in increased numbers of all the bacterial groups, but the final profile of the microbial population depended on the considered carbon source. POS boosted particularly the numbers of bifidobacteria and lactobacilli, so that the ratio between the joint counts of both genera and the total cell number increased from 17% in the inocula to 27% upon fermentation. SCFA generation from POS fermentation was similar to that observed with FOS, but pectin fermentation resulted in reduced butyrate generation.
authors.affiliation: Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense) , As Lagoas, 32004 Ourense, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Gómez
authors.forename: Beatriz
authors.initials: B
authors.lastname: Gullón
authors.forename: Connie
authors.initials: C
authors.lastname: Remoroza
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
authors.forename: Juan C
authors.initials: JC
authors.lastname: Parajó
authors.forename: José L
authors.initials: JL
authors.lastname: Alonso
mesh_terms: D001439:Bacteroides / Q000235:genetics / Q000378:metabolism; D001644:Bifidobacterium / Q000235:genetics / Q000378:metabolism; D032084:Citrus sinensis / Q000737:chemistry*; D003013:Clostridium / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D005374:Filtration / Q000379:methods; D005638:Fruit / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D007220:Industrial Waste; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism; D009844:Oligosaccharides / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D010368:Pectins / Q000737:chemistry; D056692:Prebiotics; D012336:RNA, Ribosomal, 16S
chemical_list: D005227:Fatty Acids; D007220:Industrial Waste; D009844:Oligosaccharides; D056692:Prebiotics; D012336:RNA, Ribosomal, 16S; D010368:Pectins
keywords: FISH; FOS; POS; SCFA; orange peel wastes; pectin; prebiotics