title: Release of small phenolic compounds from brewer's spent grain and its lignin fractions by human intestinal microbiota in vitro.
abstract: Brewer's spent grain (BSG), the major side-stream from brewing, is rich in protein, lignin, and nonstarch polysaccharides. Lignin is a polyphenolic macromolecule considered resilient toward breakdown and utilization by colon microbiota, although some indications of release of small phenolic components from lignin in animals have been shown. The aim of this study was to investigate if the human intestinal microbiota can release lignans and small phenolic compounds from whole BSG, a lignin-enriched insoluble fraction from BSG and a deferuloylated fraction, in a metabolic in vitro colon model. The formation of short-chain fatty acid (SCFA) was also investigated. More lignin-related monomers and dilignols were detected from the lignin-enriched fraction than from BSG or deferuloylated BSG. SCFA formation was not suppressed by any of the fractions. It was shown that small lignin-like compounds were released from these samples in the in vitro colon model, originating most likely from lignin.
authors.affiliation: VTT Technical Research Centre of Finland , P.O. Box 1000, Tietotie 2, Espoo, Finland.
authors.forename: Anna-Marja
authors.initials: AM
authors.lastname: Aura
authors.forename: Piritta
authors.initials: P
authors.lastname: Niemi
authors.forename: Ismo
authors.initials: I
authors.lastname: Mattila
authors.forename: Klaus
authors.initials: K
authors.lastname: Niemelä
authors.forename: Annika
authors.initials: A
authors.lastname: Smeds
authors.forename: Tarja
authors.initials: T
authors.lastname: Tamminen
authors.forename: Craig
authors.initials: C
authors.lastname: Faulds
authors.forename: Johanna
authors.initials: J
authors.lastname: Buchert
authors.forename: Kaisa
authors.initials: K
authors.lastname: Poutanen
mesh_terms: D002849:Chromatography, Gas; D002523:Edible Grain / Q000737:chemistry*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D006801:Humans; D006868:Hydrolysis; D007422:Intestines / Q000382:microbiology*; D017705:Lignans / Q000737:chemistry; D008031:Lignin / Q000378:metabolism*; D055442:Metabolome; D064307:Microbiota; D010636:Phenols / Q000378:metabolism*; D018514:Plant Structures / Q000737:chemistry
chemical_list: D005232:Fatty Acids, Volatile; D017705:Lignans; D010636:Phenols; D008031:Lignin