Potassium hydroxide reaction with glucose

Maillard reaction products were obtained by refluxing 100 ml of distilled water containing 0.1 mol L-histidine monohydrochloride mono-hydrate and 0.05 mol D-glucose for 20 h. The pH of the reaction mixture was adjusted to 7.0 with potassium hydroxide before starting the reaction. 

Additional tests with ammonium compounds were performed to address the effect of ammonium ion (see Fig. 8). It is clear that the catalyst inhibition was not based only on the presence of ammonium ion. Ammonium carbonate showed the largest inhibition of the glucose hydrogenation reaction, while chloride and hydroxide had lesser effects. Ammonium nitrate caused no apparent inhibition on glucose conversion. A similar lack of effect was shown with potassium nitrate. In the case of ammonium nitrate, the glucose conversion mechanism was affected, so that the sorbitol yield was reduced by about 20%, but numerous byproducts and overreaction products (lower molecular weight polyols) were evident. 

---