Abstract
Norway spruce (Picea abies) is an important raw material
for the forest industry in Nordic countries. The chemical
composition and hot water extraction of spruce bark was
studied to find out its potential as an industrial source
of condensed tannins. Industrial bark was found to
contain a high amount of wood (up to 21%), a sufficient
amount of tannin for industrial extraction (10.7% of
wood-free bark), and a high amount of non-cellulosic
glucose, varying according to the felling season
(7.7-11.5% of wood-free bark). Temperature had a major
effect on the overall extraction yield. Selective
extraction of only tannins or water-extractable
carbohydrates was not possible. The extraction was scaled
up to pilot-scale and an extract was produced having a
promising 50% tannin content. Glycome profiling performed
on bark and hot water extracts showed the presence of
xyloglucan, pectic polysaccharides and arabinogalactan in
bark. In addition the extracts were characterized using
size exclusion chromatography and 31P nuclear magnetic
resonance spectroscopy. Spruce bark appears to be a
promising new source of tannins, however the high content
of free, glycosidic, and polymeric sugars in the raw
extract may need to be tackled prior to use in
applications.
| Original language | English |
|---|---|
| Pages (from-to) | 158-168 |
| Number of pages | 11 |
| Journal | Industrial Crops and Products |
| Volume | 52 |
| DOIs | |
| Publication status | Published - 2014 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- extraction
- glycome profiling
- non-cellulosic carbohydrates
- pilot-scale
- spruce bark
- tannin