Molecular Mass Distribution of Materials Solubilized by Xylanase Treatment of Douglas-Fir Kraft Pulp

1996 ◽  
pp. 44-62 ◽  
Author(s):  
Ed de Jong ◽  
Ken K. Y. Wong ◽  
Lori A. Martin ◽  
Shawn D. Mansfield ◽  
F. M. Gama ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Kraft Pulp ◽  
Molecular Mass Distribution ◽  
Douglas Fir

An improved procedure for isolation of residual lignins from hardwood kraft pulps

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 464-472 ◽  
Author(s):  
Ewellyn Augsten Capanema ◽  
Mikhail Yurievich Balakshin ◽  
Chen-Loung Chen
Keyword(s):  
Molecular Mass ◽  
Nitrogen Content ◽  
Mass Distribution ◽  
Kraft Pulp ◽  
Molecular Mass Distribution ◽  
Eucalyptus Grandis ◽  
Kraft Pulps ◽  
Carbohydrate Composition ◽  
Residual Lignin ◽  
Hydrolysis Of

Abstract Residual lignin preparations were isolated from birch, aspen and Eucalyptus grandis kraft pulp by enzymatic hydrolysis of the pulps with cellulase:hemicellulase mixture. Residual lignin preparations were characterized by investigation of nitrogen content, carbohydrate composition and molecular mass distribution. The use of enzyme with high activity and optimization of enzyme charge resulted in significant decrease in protein contaminants in residual lignin preparations as compared to previously published results. A second order law correlation between enzyme mass charge and nitrogen content in birch residual lignin preparations indicates a strong effect of enzyme charge on the amount of protein contaminants. However, the enzyme charge in the range studied does not appreciably affect either the yields of the residual lignin preparations or percentage and composition of carbohydrates in these preparations. The optimal enzyme charge was highest for Eucalyptus grandis pulp and lowest for birch pulp. It has been suggested that a significant part of the hardwood residual lignin in pulps, especially in E. grandis pulp, consists of low molecular mass lignin fragments bonded to pulp carbohydrates. Higher amount of glucose in E. grandis residual lignin preparation compared to those from birch and aspen implied a higher frequency of lignin-cellulose bonds in eucalypt pulp. Different fractions of birch residual lignin have rather similar molecular mass distribution, which was not affected by the charge of the enzyme. Eucalypt residual lignin preparation had higher molecular mass than birch residual lignin.

Fiber strength in relation to molecular mass distribution of hardwood kraft pulp

2001 ◽  
Vol 16 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Rickard Berggren ◽  
Fredrik Berthold ◽  
Elisabeth Sjöholm ◽  
Mikael Lindström
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Kraft Pulp ◽  
Molecular Mass Distribution ◽  
Fiber Strength

New approaches for the determination of dextran in the sugar production process

2018 ◽  
pp. 138-146 ◽  
Author(s):  
Karin Abraham ◽  
Eckhard Flöter
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Molecular Mass Distribution ◽  
Molecular Size ◽  
Mass Variation ◽  
Negative Effects ◽  
New Approaches ◽  
Precise Knowledge ◽  
Enzyme Application

The presence of polysaccharides in cane and beet raw juices causes several negative effects during the sugar manufacture. These are usually mitigated by enzymatic decomposition of dextrans. Such effects not only depend on the content, but also on the molecular mass distribution. This means that the different dextran fractions specifically affect the process. An accurate process control hence requires the most precise knowledge about the existing content and the molecular mass distribution present. A detailed understanding of the specific processing problems and also a targeted enzyme application hence requires the determination of a total dextran content and also its characterization including the differentiation between the different dextran fractions. An accurate analytical tool which equally satisfies industrial applicability is still lacking. To improve on this situation, two new approaches for the determination of dextran were developed and benchmarked against the commonly used and established Haze Method, which is rather inaccurate and also sensitive to molecular mass variation. The two new approaches are both based on polarimetry. These two methods indicate to be superior over the Haze Method with respect two molecular mass variation and hence enable the determination of a broader molecular size range including also low molecular mass dextrans.

Aspects of measurements of the hydrodynamics size and molecular mass distribution of humic and fulvic acids

2007 ◽  
pp. 51-62 ◽  
Author(s):  
Manfred Wolf ◽  
Gunnar Buckau ◽  
Horstr Geckeis ◽  
Ngo Manh Thang ◽  
Enamul Hoque ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Molecular Mass Distribution ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids

Molecular mass distribution of chitin and chitosan

1994 ◽  
Vol 262 (1) ◽  
pp. 161-166 ◽  
Author(s):  
Makoto Hasegawa ◽  
Akira Isogai ◽  
Fumihiko Onabe
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Molecular Mass Distribution ◽  
Chitin And Chitosan
Sign in / Sign up

Export Citation Format

Share Document