THE CHANGES OF SACCHARIDES in WILLOW WOOD (SALIX ALBA L.) DURING WATER PREHYDROLYSIS

In this study the changes of saccharides content of willow (Salix alba L.) wood during water prehydrolysis at temperature 180 degrees C and four different durations (30, 60, 120 and 240 min) were described. Samples of solid residues after water prehydrolysis were treated by Tappi T-222 om-88. Subsequently, incurred hydrolysates were analysed by means of high performance liquid chromatography (HPLC). They were identified and determined D-glucose, D-xylose and L-arabinose. The total content of saccharides in untreated wood was 79 % and the predominant sugar was the D-glucose (60 %). The concentration of D-glucose in solid residues increased with duration of hydrothermal treatment, especially into the time 120 minutes. The concentration of monosaccharides originated from hemicelluloses (D-xylose and L-arabinose) with increasing time of hydrolysis decreased, especially into the time 60 minutes. The changes in the content of hexoses to pentoses are described by logarithmic dependence y = 4.2508 In(x) - 8.6524 (R-2 = 0.9871).