Polarimetric studies of D-glucose solutions were carried out at low temperature (2 degrees C). This procedure allowed us to stabilize the solutions of D-glucose and to differentiate the behaviour of the two main dissolved anomeric forms (alpha or beta). In particular, the dependence of their stability on the pH of the electrolytic solutions was followed and their electrochemical reactivity was tested. Using cyclic voltammetry it was possible to demonstrate that, of the two possible pyranic forms of D-glucose, only beta-D-glucose exhibited an appreciable reactivity at platinum electrodes, i.e. alpha-D-glucose was almost unreactive at low temperature. This difference in reactivity between anomers has never been shown clearly in any of the previous electrochemical studies of glucose. Long-term electrolysis was also performed. Ionic chromatography as well as in situ IR spectroscopic experiments allowed us to conclude that the oxidation of D-glucose in basic media at low temperature leads selectively to formation of the delta-gluconolactone, which later undergoes hydrolysis forming D-gluconate as a final product. Mechanisms are proposed and discussed.