NOVELTY - Increasing (M1) level of 6C monosaccharides and 6C oligosaccharides produced from lignocellulosic biomass, comprises: (a) providing lignocellulosic biomass having first solid and liquid fractions; (b) optionally, separating first solid and liquid fractions; (c) mixing first solid fraction with water to form slurry; (d) pre-heating slurry at 210-240 degrees C; (e) contacting slurry with second reaction fluid to form second reaction mixture having second solid fraction and liquid fractions; (f) reducing temperature of slurry to less than 140 degrees C; and (g) optionally, hydrolyzing second liquid fraction.    USE - The methods are useful for: increasing the level of 6C monosaccharides and 6C oligosaccharides produced from lignocellulosic biomass; controlling the rate of cellulose hydrolysis; reducing the rate of glucose degradation; converting the 6C saccharides to a fermentation product and/or catalysis product (all claimed); and producing fuels (e.g. gasoline and jet fuel), chemicals (e.g. acetic acid and acrylic acid), pharmaceuticals and foods (e.g. acetoin, alanine, arabitol and ascorbic acid), industrial intermediates (e.g. acetaldehyde), and formic acid (used in textile applications).    ADVANTAGE - The method: prevents the formation of undesired degradation products; and increases the yield of glucose which is at least 63% of theoretical yield.    DETAILED DESCRIPTION - Increasing (M1) the level of 6C monosaccharides and 6C oligosaccharides produced from lignocellulosic biomass, comprises: (a) providing lignocellulosic biomass containing a first solid fraction having cellulose and lignin, and a first liquid fraction; (b) optionally, separating the first solid fraction and the first liquid fraction; (c) mixing the first solid fraction with water to form a slurry; (d) pre-heating the slurry to a temperature of 210- 240 degrees C at a pressure of 225-250 bar; (e) contacting the slurry with a second reaction fluid to form a second reaction mixture containing a second solid fraction having lignin, and a second liquid fraction having soluble 6C saccharides including 6C monosaccharides and/or 6C oligosaccharides, where the second reaction fluid comprises hot compressed water and, optionally, carbon dioxide, and the second reaction fluid is at a temperature of at least 373 degrees C under a pressure sufficient to maintain the second reaction fluid in supercritical form; (f) reducing the temperature of the slurry to a temperature less than 140 degrees C; and (g) optionally, hydrolyzing the second liquid fraction to form a composition containing at least one 6C saccharide including 6C oligosaccharide having lower mer units (relative to 6C oligosaccharides in second liquid fraction), glucose, galactose, mannose and/or fructose. INDEPENDENT CLAIMS are also included for:    (1) a product produced by the method (M1);    (2) converting (M2) the 6C saccharides to a fermentation product and/or catalysis product, comprises: steps (a)-(g) as above per se; and converting the 6C saccharides to a fermentation product and/or catalysis product, by fermentation and/or catalysis;    (3) a product produced by the method (M2); and    (4) a composition, comprising: glucose; water; glyceraldehyde; and glycolic acid, where the glyceraldehyde is present at a level of less than 13 wt.%, the glycolic acid is present at a level of less than 2 wt.%, based on the total weight of the composition, and the glucose is produced from the lignocellulosic biomass using supercritical or near critical fluids.