ARS | Publication request: Production of xylooligosaccharide (XOS) coproducts from Miscanthus x giganteus

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 30, 2012
Publication Date: October 3, 2012
Citation: Chen, M., Dien, B.S., Rausch, K.D., Tumbleson, M.E., Singh, V. 2012. Production of xylooligosaccharide (XOS) coproducts from Miscanthus x giganteus. American Association of Cereal Chemists International Meeting.

Technical Abstract: Miscanthus x giganteus (MG), a perennial grass, has potential as a new bioenergy crop due to its cellulose and hemicellulose content. Currently, MG has been tested in central Illinois and has been reported to attain an average yield of 36 MT/ha/year (1). The process for converting MG to ethanol only is not cost effective and not ready for commercialization. There is a need to make this process more economical by recovering high value coproducts in addition to ethanol. Xylooligosaccharides (XOS) are sugar oligomers made from xylose units and can be produced during the hydrolysis of xylan, one of the main hemicellulose components. The growing commercial importance of these nondigestive sugar oligomers is based on their prebiotic effect to human health. We recovered XOS through an autohydrolysis process using MG. Miscanthus from the University of Illinois research farm was oven dried overnight to 2.6% moisture and milled to pass through a 0.25 mm screen. Hot water pretreatment was performed in a 25 mL tubular reactor with solid: liquid ratio (1: 9); temperatures varied from 140 to 200°C. XOS could be effectively produced at 160, 180 and 200°C at different reaction times. Depending upon reaction conditions, an XOS yield up to 13.9% (w/w) of initial dry biomass was observed. In gel permeation chromatography (GPC), molecular weight distribution migration at different reaction time and temperatures was observed. Further purification trials showed that using water/ethanol solution at the ratio of 50/50 and 30/70 could effectively recover XOS from carbon adsorption.