NOVELTY - Composition (C1), comprises: at least one water-soluble C5 oligosaccharide hydrolysate; optionally, at least one water-soluble C5 monosaccharide hydrolysate; and less than 3700 ppm in total by weight of elements including aluminum, arsenic, boron, barium, beryllium, calcium, cadmium, cobalt, chromium, copper, iron, potassium, lithium, magnesium, manganese, molybdenum, sodium, nickel, phosphorus, lead, sulfur, antimony, selenium, silicon, tin, strontium, titanium, thallium, vanadium or zinc, based on total weight of the C5 oligosaccharide hydrolysate and C5 monosaccharide hydrolysate.    USE - The composition is useful for producing/preparing feedstocks for the preparation of: fuels (including gasoline, jet fuel and butanol); chemicals (including acetic acid, acetic anhydride, acetone, acrylic acid, adipic acid, benzene, ethanol, ethylene, ethylene glycol, ethylene oxide, methanol, polypropylene, terephthalic acid, toluene, xylene, 1,3-propanediol and 1,4-butanediol); pharmaceuticals and foods (e.g. alanine, ascorbic acid, aspartic acid, glycerol, glycine, kojic acid, lysine, malonic acid, proline, propionic acid, serine, sorbitol, succinic acid, xylitol, and sugar acids including glucaric acid, gluconic acid and xylonic acids); specialty chemicals (including acontic acid, glutamic acid, malic acid and oxalic acid); textile applications (including formic acid); and industrial intermediates (including acetaldehyde, 3-hydroxypropionic acid, 2,5-furan dicarboxylic acid, furfural, glutaric acid, itaconic acid and levulinic acid).    ADVANTAGE - The composition utilizes C5 and C6 saccharides of varying degrees of polymerization and low levels of undesirable impurities (such as compounds containing sulfur, nitrogen or metals), which are processed from lignocellulosic biomass using supercritical fluid extraction, thus having high penetrability and good solvation.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a composition (C2), comprising: 75-90 wt.% of water-soluble C5 oligosaccharides, based on total weight of water-soluble C5 oligosaccharide hydrolysate and water-soluble C5 monosaccharide hydrolysate