Resources and Isolation of Xylans

Potential resources of xylans are by-products produced in forestry and the pulp and paper industries (forest chips, wood meal and shavings), where GX and AGX comprise 25-35% of the biomass as well as annual crops (straw, stalks, husk, hulls, bran, etc.), which consist of 25-50% AX, AGX, GAX, and CHX [4]. New results were reported for xylans isolated from flax fiber [16,68], abaca fiber [69], wheat straw [70,71], sugar beet pulp [21,72], sugarcane bagasse [73], rice straw [74], wheat bran [35,75], and jute bast fiber [18]. Recently, about 39% hemicelluloses were extracted from vetiver grasses [76]. 

From recent literature it is known that the disintegration of lignified cell walls can be achieved by steam explosion treatments resulting in solubilization of partially depolymerized hemicelluloses [91,92]. The application of this method on wheat bran yielded feruloylated GAX with different feruUc acid content [93]. Partly depolymerized water-soluble, acetylated AGX was obtained from spruce wood by employing microwave treatment [94]. 

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