Method for purifying oses without adjusting pH

A method for purification, the method comprising the steps of:

• reacting lignocellulosic biomasses and at least one acid catalyst so as to form an acid hydrolysate, a cellulosic matrix, solid residues and suspended matters;
• removing said cellulosic matrix, said solid residues and said suspended matters from said acid hydrolysate so as to obtain a clarified hydrolysate;
• filtering said clarified hydrolysate, without any addition of a basic chemical reagent to increase pH so as to obtain a filtrate and a retentate,
• wherein the step of filtering is selected from a group consisting of ultrafiltration and nanofiltration,
• wherein said filtrate is comprised of said at least one acid catalyst and a plurality of oses, and
• wherein said retentate is comprised of organic molecules, said organic molecules being reactive to an increase in pH;
• and
• treating said filtrate with electrodialysis so as to separate said at least one acid catalyst in an acid-enriched solution from said oses and so as to obtain said oses in a deacidified filtrate.