Process for manufacturing sweetened liquors and derivatives thereof from cellulose-containing vegetable substrates

A process for manufacturing a sweetened aqueous liquor from a cellulose-containing vegetable substrate, comprising the essential steps of:

• (a) treating said vegetable substrate with an aqueous solution of an acid under hydrolysis conditions for the cellulose contained in said substrate, up to formation of 10 to 45% of the potential reducing sugars, said acid being phosphoric acid or a mixture of phosphoric acid with sulfuric acid, said mixture comprising not more than 30% by weight of sulfuric acid, the concentration of said acid being from 2 to 10% by weight with respect to the vegetable substrate, thereby forming reducing sugars in said aqueous solution, and
• (b) adding an enzyme able to hydrolyse cellulose to the resultant treated substrate from step (a) and maintaining temperature and pH conditions allowing enzymatic hydrolysis of cellulose for a sufficient time to form an additional amount of reducing sugars, thereby obtaining a sweetened aqueous liquor.