Table 2.

Main types of polysaccharides present in hemicellulose (Alvarez et al. 2016; Zhou et al. 2017; Naidu et al. 2018; Singh et al. 2018)

Type	Backbone	Side chaina	Biological origin
Arabinoxylan	β-1,4-Xyl	ɑ-(1,2)/(1,3)-Ara	Herbage
Glucuronoxylan	β-1,4-Xyl	ɑ-(1,2)-GlcAOMe	Hardwood
Arabinoglucuronoxylan	β-1,4-Xyl	ɑ-(1,2)/(1,3)-Ara and ɑ-(1,2)-GlcAOMe	Herbage
Xyloglucan	β-1,4-Glc	ɑ-(1,6)-Xyl, ɑ-(1,2)-Fuc, ɑ-(1,3)-Gal, et al	Extensive
Glucomannan	β-1,4-Man/Glc	Rare	Softwood
Galactoglucomannan	β-1,4-Man/Glc	ɑ-(1,6)-Gal	Softwood

^aThis column only displays the carbohydrate side chains of hemicellulose