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Aqueous two‐phase extraction using thermoseparating copolymer: a new system for phenolic compounds removal from hemicelullosic hydrolysate
Author(s) -
Hasmann Francislene A,
Santos Valéria C,
Gurpilhares Daniela B,
PessoaJunior Adalberto,
Roberto Inês C
Publication year - 2008
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.1779
Subject(s) - hydrolysate , chemistry , hemicellulose , xylose , hydrolysis , extraction (chemistry) , vanillin , cellulose , bioconversion , copolymer , lignin , aqueous solution , chromatography , nuclear chemistry , enzymatic hydrolysis , organic chemistry , fermentation , polymer
BACKGROUND: The hydrolysis of hemicellulosic material can provide liquor with high xylose concentration (which can be used as a fermentation medium) and phenolic compounds (Phs), potentially immunostimulating compounds. However, these hydrolysates must be detoxified in order to remove the Phs that can act as inhibitors in bioconversions. RESULTS: Aqueous two‐phase systems composed of thermoseparating copolymers were used for rice straw hydrolysate detoxification. The hydrolysis process was able to promote chemical breakdown of 85% of the total hemicellulose content, 14% of the cellulose, and 2% of the lignin. The hydrolysate obtained contained 19.7 g L −1 of xylose and several phenolic compounds, such as vanillin, vanillic acid, ferullic acid, etc. The phenolics extraction was studied as a function of copolymer molar mass (1100 g mol −1 , 2000 g mol −1 and 2800 g mol −1 ), their percentages (from 5% to 50%) and Phs initial concentration. Phenolic compounds extraction of around 80% was obtained under the following conditions: 20% (w/w) and 35% (w/w) copolymer 1100 g mol −1 , 35% (w/w) copolymer 2000 g mol −1 and 35% (w/w) copolymer 2800 g mol −1 at 25 °C. CONCLUSIONS: The results demonstrated the viability of this method for the removal of Phs from rice straw hydrolysate, which has potential uses in bioconversion processes. Copyright © 2007 Society of Chemical Industry