Two-stage hot-water extraction of galactoglucomannans from spruce wood

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Andrey Pranovich, Bjarne Holmbom, Stefan Willför
Förläggare: Taylor & Francis Group
Publiceringsår: 2016
Tidskrift: Journal of Wood Chemistry and Technology
Volym: 36
Nummer: 2
Artikelns första sida, sidnummer: 140
Artikelns sista sida, sidnummer: 156
eISSN: 1532-2319


Abstrakt

In order to preserve the polymeric structure and the acetylation degree of extracted galactoglucomannans and, at the same time, achieve high yield, ground spruce wood was subjected to a series of sequential two-stage extractions with an Accelerated Solvent Extraction (ASE) apparatus using plain water at 170◦C. The total combined extraction time was one hour in all the extractions. The total yield of the dissolved material after 1 h extraction was almost the same, about 25% of the wood, irrespective of the time ratios between the first and the secondextractions. The yield of hemicellulose high polymers with the weight average molar mass of 8–10 kDa during the first extraction had a maximum at 20 min extraction time, amounting to about 7% on dry wood basis, and comprising about half of the total extract. Along with theprogress of the extraction, themolar mass of the hemicelluloses decreased and hemicellulosederived low polymers with the weight averagemolar mass of 6–2 kDa became dominating. The extracted substances were fractionated, mainly according to their molar mass, by sequential precipitation with ethanol, acetone, and methyl tert-butyl ether (MTBE). The hemicelluloses with some amount of pectins comprised 83–90% of the precipitated polymeric material and the content of galactoglucomannans was about 80%.


Nyckelord

Galactoglucomannans, hemicellulose characterization, hemicellulose isolation, hotwater extraction, pectins, spruce wood

Senast uppdaterad 2019-06-12 vid 02:38