Hemicelluloses structure

Figure 18 O-Acetyl-4-O-methyl-D-glucuronoxylan, a type of hemicellulose, structure from angiosperms (Dekker, 1985) (reproduced by permission of Academic Press from Biosynthesis and Biodegradation of...

Depolymerization of hemicellulosic structure is still being developed. Because of its more complicated structure involving several kinds of sugar units in variously linked conformations, more than one specific enzyme is needed. More simple plant starches can be effectively broken down to sugars with combinations of enzymes, including amylases and glucoamylases. 

Figure 2.7. Some model hemicellulose structures (Fengel and Wegener, 1984). Softwood xylan is quite similar to hardwood xylan, the absence of acetyl groups on the softwood xylan being an obvious difference.

Dumitriu, S. (2005). Polysaccharides Structural diversity and functional versatility. In Hemicelluloses Structure and Properties (ed. Spiridon, I., Popa, V. I.,), Marcel Dekker, New York. Chapter 18,... 

According to Luz et al. [21], acid hydrolysis can be used for the treatment of fibers. The main effect of hydrolysis on lignocellulosic materials is breakage of the linkages between lignin, hemicellulose and cellulose. This results in dissolution of hemicellulose, structural modification of lignin and a reduction in the particle size of the material. 

---