1) Cellulose having a DP (degree of polymerization) of 150 or less [i.e., smaller molecules with fewer "building blocks"]. A collective term for beta and gamma cellulose; cellulose that is soluble in hot alkali (Hawley). 2) A number of shorter-chain polysaccharides. Hemicellulose (along with degraded cellulose) is further conveniently categorized... according to DP: beta cellulose - DP 15-90 gamma cellulose - DP less than 15 By contrast to cellulose, which is a polymer only of glucose, the hemicelluloses are polymers of five different sugars: glucose, mannose, galactose, xylose and arabinose (condensed from Smook, p. 5). The contribution of hemicelluloses to development of initial strength in paper is well recognized. It is related to fibrillation and bonding. But hemicellulose-rich pulps have a strong tendency to discolor during thermal aging. This tendency can be countered with borohydride treatment (condensed from Feller, p. 301-3C4).

Partially branched polysaccharide; main structural units are pentoses and hexoses such as xylose and glucose; major component of biomasses; component of plant fibres; hydrolyzes and dissolves partially during delignification in the Chempolis process.

Any of a number of cell-wall polysaccharides occurring in nearly all vegetable fibres.