Acid hydrolysis of hot-water wood extract was investigated. Sugar maple wood extract was obtained by hot-water extraction at 160 degrees C for 120 min, followed by further concentration and solid removal by membrane filtration. Acid hydrolysis was performed at different temperatures (85 degrees C, 95 degrees C and 105 degrees C) and concentrations of sulfuric acid (wt.%: 1.5%, 3.1% and 6.2%). Hydrolyzate was analyzed by (1)H NMR spectroscopy. The concentrations of several major substances in the hydrolyzate were discussed in detail. Higher temperature, higher acid concentration and longer residence time all favor the depolymerization of hemicellulose wood extracts. Mainly xylose and acetic acid are recovered from the hydrolysis process. (c) 2010 Elsevier Ltd. All rights reserved.