Hydrolysis of Dialdehyde Starch with Sulfurous Acid

A systematic investigation of the sulfurous acid hydrolysis of dialdehyde starch (DAS) was made in which temperature, time and concentration of reagents were varied. Optimum yields of apparent D-erythrose and of glyoxal of 78 and 81 % of theory were obtained by hydrolyzing 1.8% of DAS in water containing 14.7 moles of sulfur dioxide per mole of DAS for 1.33 hr at 100.⁰C. Increased reversion and degradation at higher concentrations of DAS and at higher temperatures of hydrolysis rapidly decreased the yields of apparent D-erythrose and glyoxal.