Enzymatic fractionation of brewer’s spent grain and bioconversion of lignin-rich fractions in a colon model in vitro

 |  Login

Show simple item record

dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Poutanen, Kaisa, Prof., VTT Technical Research Centre of Finland
dc.contributor.advisor Buchert, Johanna, Prof., Natural Resources Institute Finland, Finland
dc.contributor.author Niemi, Piritta
dc.date.accessioned 2016-03-09T10:01:09Z
dc.date.available 2016-03-09T10:01:09Z
dc.date.issued 2016
dc.identifier.isbn 978-952-60-6700-1 (Aalto, electronic)
dc.identifier.isbn 978-952-60-6699-8 (Aalto, printed)
dc.identifier.isbn 978-951-38-8403-1 (VTT, electronic)
dc.identifier.isbn 978-951-38-8404-8 (VTT, printed)
dc.identifier.issn 1799-4942 (Aalto, electronic)
dc.identifier.issn 1799-4934 (Aalto, printed)
dc.identifier.issn 1799-4934 (Aalto, ISSN-L)
dc.identifier.issn 2242-1203 (VTT, electronic)
dc.identifier.issn 2242-119X (VTT, printed)
dc.identifier.issn 2242-119X (VTT, ISSN-L)
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/19831
dc.description.abstract The objectives of this thesis were to produce lignin-rich fractions from brewer's spent grain (BSG) and to study the interactions of the lignin in these fractions with colon microbiota in vitro. Different milling pre-treatments were studied to enhance enzymatic hydrolysis of BSG carbohydrates. Ball-milling, which was the most efficient treatment, increased carbohydrate solubilisation from 23 to 45 %. Thus, milling notably improved enzymatic solubility of cell wall polysaccharides but was not effective enough to enable their total hydrolysis. Two lignin-rich fractions (24 and 40 % lignin content) were obtained by enzymatic fractionation of BSG using carbohydrases and proteases. In addition, a separate alkaline extraction provided BSG-derived material with low ferulic acid content. BSG and the fractions were used to study if lignin is degraded and metabolised by colon microbiota in a metabolic model and if lignin suppresses microbial conversions in the colon. A number of mono- and dimeric phenolic metabolites were formed upon digestion of BSG and the fractions by the microbiota. It appeared that many of them were structurally lignin-related indicating their release from lignin and conversion by colon microbiota. However, the extent of lignin degradation was estimated to be low. No notable suppression of microbial conversions was detected based on the formation of linear short chain fatty acids. In addition, experiments with pure strains of lactobacilli and bifidobacteria showed no inhibition of growth by a lignin-rich fraction. Association of lignin with carbohydrates or proteinaceous material may have reduced the possible antimicrobial effects of lignin. The results of the present study provide new information on the significance of lignin as part of dietary fibre indicating its partial metabolism by colon microbiota. en
dc.description.abstract Tämän väitöskirjatyön tavoitteena oli valmistaa ligniinipitoisia jakeita panimomäskistä sekä tutkia näiden jakeiden avulla ligniinin ja suolistomikrobien vuorovaikutuksia. Erilaisten jauhatusten vaikutusta mäskin hiilihydraattien entsymaattiseen hydrolyysiin tutkittiin, ja kuulamyllytys osoittautui tehokkaimmaksi parantaen hiilihydraattien hydrolysoituvuutta 23 %:sta 45 %:iin. Jauhatus ei kuitenkaan ollut riittävän tehokas esikäsittely hiilihydraattien kokonaishydrolyysin kannalta. Kaksi ligniinipitoista jaetta (24 ja 40 % ligniiniä) valmistettiin hiilihydraatteja ja proteiineja pilkkovien entsyymien avulla. Lisäksi emäskäsittelyllä tuotettiin jae, josta ferulahapot oli lähes kokonaan poistettu. Mäskin ja sen jakeiden avulla tutkittiin paksusuolen olosuhteita simuloivassa metaboliamallissa, pilkkovatko suolistomikrobit ligniiniä ja estääkö ligniini mikrobien aineenvaihdunnan toimintoja. Metaboliamallissa muodostui pieniä, fenolisia aineenvaihduntatuotteita, joista useat olivat rakenteensa perusteella todennäköisesti ligniiniperäisiä. Ligniinin pilkkoutuminen vaikutti kuitenkin vähäiseltä. Lyhyiden, suoraketjuisten rasvahappojen muodostumisen perusteella ligniini ei haitannut mikrobien hiilihydraattifermentaatiota. Ligniini ei myöskään estänyt laktobasillien tai bifidobakteerien kasvua. Ligniinin sidonnaisuus hiilihydraatteihin tai proteiiniperäiseen materiaaliin saattoi suojata mikrobeja ligniinin mahdollisilta antimikrobisilta ominaisuuksilta. Tutkimuksen tulokset antavat uutta tietoa ligniinin hajoamisesta suolistossa sekä sen merkityksestä osana ravintokuitua. fi
dc.format.extent 86 + app. 48
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher Aalto University en
dc.publisher Aalto-yliopisto fi
dc.relation.ispartofseries Aalto University publication series DOCTORAL DISSERTATIONS en
dc.relation.ispartofseries 45/2016
dc.relation.ispartofseries VTT Science
dc.relation.ispartofseries 124
dc.relation.haspart [Publication 1]: Niemi P., Faulds C.B., Sibakov J., Holopainen U., Poutanen K., Buchert J. (2012) Effect of a milling pre-treatment on the enzymatic hydrolysis of carbohydrates in brewer's spent grain. Bioresour. Technol. 116, 155-160. DOI: 10.1016/j.biortech.2012.04.043
dc.relation.haspart [Publication 2]: Niemi P., Martins D., Buchert J., Faulds C.B. (2013) Pre-hydrolysis with carbohydrases facilitates the release of protein from brewer's spent grain. Bioresour. Technol. 136, 529-534. DOI: 10.1016/j.biortech.2013.03.076
dc.relation.haspart [Publication 3]: Niemi P., Tamminen T., Smeds A., Viljanen K., Ohra-aho T., Holopainen-Mantila U., Faulds C.B., Poutanen K., Buchert J. (2012) Characterization of lipids and lignans in brewer’s spent grain. J. Agric. Food Chem. 60, 9910–9917. DOI: 10.1021/jf302684x
dc.relation.haspart [Publication 4]: Niemi P., Aura A.-M., Maukonen J., Smeds A., Mattila I., Niemelä K., Tamminen T., Faulds C.B., Buchert J., Poutanen K. (2013) Interactions of a lignin-rich fraction from brewer’s spent grain with gut microbiota in vitro. J. Agric. Food Chem. 61, 6754‒6762. DOI: 10.1021/jf401738x
dc.relation.haspart [Publication 5]: Aura A.-M., Niemi P., Mattila I., Niemelä K., Smeds A., Tamminen T., Faulds C.B., Buchert J., Poutanen K. (2013) Release of small phenolic compounds from brewer’s spent grain and its lignin fractions by human intestinal microbiota in vitro. J. Agric. Food Chem. 61, 9744‒9753. DOI: 10.1021/jf4024195
dc.subject.other Biotechnology en
dc.title Enzymatic fractionation of brewer’s spent grain and bioconversion of lignin-rich fractions in a colon model in vitro en
dc.title Panimomäskin entsymaattinen fraktiointi ja ligniinijakeiden mikrobiaineenvaihdunta suolistomallissa fi
dc.type G5 Artikkeliväitöskirja fi
dc.contributor.school Kemian tekniikan korkeakoulu fi
dc.contributor.school School of Chemical Technology en
dc.contributor.department Biotekniikan ja kemian tekniikan laitos fi
dc.contributor.department Department of Biotechnology and Chemical Technology en
dc.subject.keyword brewer's spent grain en
dc.subject.keyword enzymatic fractionation en
dc.subject.keyword lignin en
dc.subject.keyword colon microbiota en
dc.subject.keyword colon metabolic model en
dc.subject.keyword panimomäski fi
dc.subject.keyword entsymaattinen fraktiointi fi
dc.subject.keyword ligniini fi
dc.subject.keyword suolistomikrobisto fi
dc.subject.keyword metabolinen paksusuolimalli fi
dc.identifier.urn URN:ISBN:978-952-60-6700-1
dc.type.dcmitype text en
dc.type.ontasot Doctoral dissertation (article-based) en
dc.type.ontasot Väitöskirja (artikkeli) fi
dc.contributor.supervisor Linder, Markus, Prof., Aalto University, Department of Biotechnology and Chemical Technology, Finland
dc.opn Bunzel, Mirko, Prof., Karlsruhe Institute of Technology, Germany
dc.rev Willför, Stefan, Prof., Åbo Akademi University, Finland
dc.rev Vincken, Jean-Paul, Associate Prof., Wageningen University, The Netherlands
dc.date.defence 2016-04-15


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search archive


Advanced Search

article-iconSubmit a publication

Browse

My Account