This invention is directed to a process for making a thermally inhibited polysaccharide by dehydrating a polysaccharide to substantially anhydrous or anhydrous conditions and thermally inhibiting the substantially anhydrous or anhydrous polysaccharide at a temperature of 100.degree. C. or greater for a time sufficient to inhibit the polysaccharide in an oxygen enriched concentration of at least 6.5 moles/m.sup.3.