Mechanism of high glycine dosage promoting degradation and oxidation of sorbitol for browning.

The browning phenomenon of foods caused by alditol additives has aroused people's concern about the stability of low-calorie foods. The browning mechanism caused by sorbitol during its thermal treatment with glycine was researched. The dehydration of sorbitol was observed, and the products were identified as 2-deoxy-d-glucose, 1,5-anhydrosorbitol, isosorbide, and others. The increase in glycine dosage significantly promoted dehydration, oxidation, and other reactions of sorbitol, inducing pronounced browning. When the molar ratio of glycine to sorbitol increased from 0.2 to 3.0, the concentration of 1,5-anhydrosorbitol increased by 2.86 times, which induced further browning of the system with A420 increased by 6.67 times. The concentration of glyoxal and 3-deoxyglucosone in the system increased by 187 %. These results indicated that the presence of glycine improved the reactivity of sorbitol involved in the Maillard reaction and provided a theoretical basis for optimization of the processing and storage of foods containing alditols.