Characteristics of Maltose Degradation by Hydrogen Peroxide

Maltose was degraded by hydrogen peroxide (H2O2) in this study. The pH of the reaction mixture initially remained unchanged (stage I) and then decreased (stage II) before it finally leveled off (stage III). The constant pH at the first stage indicated that H2O2 hydrolyzed the -(14) glucosidic linkage and did not oxidize the hemiacetal hydroxyl of maltose or glucose into carboxyl. The decreased pH of the reaction mixture verified that the hemiacetal hydroxyl in maltose or glucose was oxidized into carboxyl. The leveled off pH indicated that the reaction reached equilibrium. High-performance liquid chromatography and liquid chromatography-mass spectrometry analyses of the reaction mixture demonstrated that maltose and glucose were both present in stage I, whereas glucose and gluconic acid existed in stages II and III. Results showed that H2O2 first hydrolyzed the -(14) glucosidic linkage in maltose and then oxidized the hemiacetal hydroxyl in glucose into carboxyl.