NOVEL TECHNOLOGIES FOR PRODUCING RENEWABLE CHEMICALS AND POLYMERS FROM CARBOHYDRATES DERIVED FROM AGRICULTURAL FEEDSTOCKS
Location: Renewable Product Technology Research Unit
Title: Galactoglucomannan Oligosaccharides (GGMO) from a Molasses Byproduct of Pine (Pinus taeda) Fiberboard Production
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 13, 2011
Publication Date: May 30, 2011
Citation: Price, N.P., Hartman, T.M., Faber, T.A., Vermillion, K., Fahey, Jr., G. 2011. Galactoglucomannan oligosaccharides (GGMO) from a molasses byproduct of pine (Pinus taeda) fiberboard production. Journal of Agricultural and Food Chemistry. 59:1854-1861.
Interpretive Summary: Dietary supplements for pets are an important domestic market for agricultural products. In this work an oligosaccharide mixture (called temulose molasses), obtained as a by-product from fiberboard production, was tested to measure the content of beneficial prebiotic sugars. Following mild treatment with acid the molasses was found to contain high concentrations (up to 57%) of valuable galacto--glucomannan (GGMO) sugars, with especially high concentrations of mannose. Our previous results have shown a positive dietary effect for GGMO when included in a high quality dog food. Because the molasses is produced in large amounts (about 9 tons per day) this offers a good potential source of novel prebiotic sugars for the US pet food industry.
“Temulose” is the trade name for a water-soluble molasses produced on a large scale (300 - 400 tonnes per year) as a byproduct of the fiberboard industry. The feedstock for temulose is predominantly a single species of pine (Pinus taeda) grown and harvested in stands in southeastern Texas. Because of the method of production the molasses was predicted to consist of water-soluble hemicelluloses, mainly arabinoxylan-type and galactoglucomannan-type oligosaccharides, plus minor components of lignin, but no detailed structural study had been reported. The structure and composition of the molasses has now been deduced by a combination of MALDI-TOF mass spectrometry, size-exclusion chromatography, proton and 13C NMR techniques, and classic carbohydrate analysis. Limited acid hydrolysis released a series of galactoglucomannan oligosaccharides (GGMO) that were selectively recovered from the acid-labile arabinogalactan by precipitation with ethanol. The precipitate was named “temulose brown sugar” because of its appearance, and is shown to consist of GGMO with a degree of polymerization (dp) from 4 – 13, with the major component being dp 5 – 8. The structure of these oligosaccharides is a beta-1,4-linked backbone of Man and Glc residues, with occasional alpha-1,6 branching by single galactosyl units. Select biological activities of the purified GGMO’s are reported in an accompanying paper.