Young culm of Dendrocalamus asper, Bambusa tuldoides and B. Vulgaris as source of hemicellulosic dietary fibers for the food industry

Abstract

Bamboo is a grass that has gained economic attention in the food industry as a source of dietary fiber, and the young bamboo culm may be an alternative to supply fibers to the market. The objective was to evaluate and characterize different portions (bottom, middle and top) of the young bamboo culm fibrous fractions from Dendrocalamus asper, Bambusa tuldoides and B. vulgaris regarding their color parameters, physicochemical composition and hemicellulosic polysaccharide characterization. Fibrous fractions were obtained after starch extraction and results showed high amounts of total dietary fiber (79-89%). The hemicellulosic polysaccharide contents (35.4-41.5%) demonstrated great potential for commercial extraction and so, we extracted them with alkali and fractionated regarding their solubility in cold-water. Insoluble polysaccharides (KP fractions) were obtained in higher yields (from 21.2% to 38.5%) than the soluble ones (KS fractions, yields from 2.3% to 5.2%). Monosaccharide composition showed mainly xylose and arabinose, with some minor amounts of mannose and galactose in some fractions. In a detailed NMR analysis, the presence of neutral xylans and arabinoxylans could be observed in all studied bamboo species, which can be used in food products and also in the production of xylooligosaccharides (XOS), biomaterials and biofuels.

Keywords: Arabinoxylan; Dietary fibres; Hemicellulose; Xylan; Young bamboo culm.