Hydrogen peroxide (H2O2) is a strong oxidant that oxidizes the hemiacetal hydroxyl to carboxyl group in glucose. In this study, gluconic acid was prepared by oxidation of glucose with H2O2, and the pH of the mixture was monitored during the preparation. The pH of the mixture was affected by the reaction time, temperature and H2O2 concentration. Under the optimal conditions, i.e. reaction time of 70 min, reaction temperature of 80C and 12% H2O2, the minimum pH of the reaction mixture was 3.28. Extended reaction times, high temperatures and high H2O2 concentrations did not further decrease the pH of the mixture. High‐performance liquid chromatography and liquid chromatography‐mass spectrometry indicated that the resulting product contained 79.02% gluconic acid and 14.48% glucose. Results demonstrated that the oxidation of glucose with H2O2 could be a promising method for the preparation of gluconic acid.
Gluconic acid can be prepared by oxidation of glucose with H2O2 and could be of practical food and medicine applications.