Show/Hide Menu
Hide/Show Apps
anonymousUser
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Açık Bilim Politikası
Açık Bilim Politikası
Frequently Asked Questions
Frequently Asked Questions
Browse
Browse
By Issue Date
By Issue Date
Authors
Authors
Titles
Titles
Subjects
Subjects
Communities & Collections
Communities & Collections
Enzymatic production of xylooligosaccharides from cotton stalks
Date
2007-07-11
Author
Akpinar, Ozlem
Ak, Ozlem
Kavas, Aysegul
Bakir, Ufuk
Yılmaz, Levent
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
2
views
0
downloads
Xylooligosaccharide (XO) production was performed from xylan, which was obtained by alkali extraction from cotton stalk, a major agricultural waste in Turkey. Enzymatic hydrolysis was selected to prevent byproduct formation such as xylose and furfural. Xylan was hydrolyzed using a commercial xylanase preparation, and the effects of pH, temperature, hydrolysis period, and substrate and enzyme concentrations on the XO yield and degree of polymerization (DP) were investigated. Cotton stalk contains about 21% xylan, the composition of which was determined as 84% xylose, 7% glucose, and 9% uronic acid after complete acid hydrolysis. XOs in the DP range of 2-7 (X6 approximate to X5 > X2 > X3) were obtained with minor quantities of xylose in all of the hydrolysis conditions used. Although after 24 h of hydrolysis at 40 degrees C, the yield was about 53%, the XO production rate leveled off after 8-24 h of hydrolysis. XO yield was affected by all of the parameters investigated; however, none of them affected the DP of the end product significantly, except the hydrolysis period. Enzyme hydrolysis was maintained by the addition of fresh substrate after 72 h of hydrolysis, indicating the persistence of enzyme activity. The optimal hydrolysis conditions were determined as 40 degrees C, pH 5.4, and 2% xylan. The obtained product was fractionated via ultrafiltration by using 10, 3, and 1 kDa membranes. Complete removal of xylanase and unhydrolyzed xylan was achieved without losing any oligosaccharides having DP 5 or smaller by 10 kDa membrane. After a two-step membrane processing, a permeate containing mostly oligosaccharides was obtained.
Subject Keywords
Xylooligosaccharides
,
Cotton stalk
,
Xylan
,
Enzymatic hydrolysis
,
Agricultural waste
URI
https://hdl.handle.net/11511/39635
Journal
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
DOI
https://doi.org/10.1021/jf063580d
Collections
Department of Chemical Engineering, Article