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Pressurized liquid ...
Pressurized liquid extraction of betulin and antioxidants from birch bark
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- Co, Michelle (författare)
- Uppsala universitet,Analytisk kemi
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- Koskela, Pirjo (författare)
- Uppsala universitet,Analytisk kemi
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- Eklund-Åkergren, Peter (författare)
- Uppsala universitet,Analytisk kemi
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Srinivas, Keerthi (författare)
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King, Jerry W. (författare)
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- Sjöberg, Per J.R. (författare)
- Uppsala universitet,Analytisk kemi
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- Turner, Charlotta (författare)
- Uppsala universitet,Analytisk kemi
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(creator_code:org_t)
- The Royal Society of Chemistry, 2009
- 2009
- Engelska.
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Ingår i: Green Chemistry. - : The Royal Society of Chemistry. - 1463-9262 .- 1463-9270. ; 11:5, s. 668-674
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Pressurized hot (subcritical) water and ethanol were used to extract betulin and antioxidants from birch bark. Betulin was found to be the major compound (around 26% (w/w)), which was able to be extracted with ethanol (120 degrees C, 50 bar, 15 minutes) but not with water at any of the temperatures tested (40-180 degrees C, 50 bar). The obtained extraction result for betulin is supported by theoretical solvation parameter calculations. Furthermore, high antioxidant activity of the extract was obtained using both ethanol and water as solvent. The antioxidant activity, as determined by a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, was found to be highest for the water extract of finely ground bark and it markedly increased with elevated extraction temperatures (90-180 degrees C). To elucidate if this was due to increased extraction efficiency or chemical reactions, a set of experiments was performed in which the samples were pre-treated with water at different temperatures before extraction. Results from liquid chromatography showed some differences in molecular composition between samples pre-treated at ambient and 180 degrees C, respectively. However, more detailed studies have to be performed to distinguish between hot-water extraction and reaction kinetics.
Ämnesord
- NATURVETENSKAP -- Kemi -- Analytisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Analytical Chemistry (hsv//eng)
Nyckelord
- Analytical chemistry
- Analytisk kemi
- Analytical Chemistry
- Analytisk kemi
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- art (ämneskategori)
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