Formation of aldonic acid end groups during NO2/O2 treatment and alkali cooking of wood meal

Abstract

The increased carbohydrate yield after NaOH cooking of wood resulting from NO2/O2 pretreatment is related to the oxidation of reducing sugar end groups to aldonic acid groups during both the pretreatment and the subsequent alkali cook. This leads to a suppressed end-wise degradation during the alkali cook, reflected in a lowered formation of 3-deoxyaldonic and 2-C-methylglyceric acid end groups in competing reactions.