Study on the Browning Mechanism of Multivitamin Iron Oral Solution Based on Sucrose-Lysine Maillard Reaction.

Severe browning often occurs in Multivitamin Iron Oral Solution during storage, which directly leads to the decline of product quality. To clarify the main mechanism of browning in this preparation, the contents of 5-hydroxymethylfurfural (5-HMF) and carbohydrates, as well as the relevant characteristic parameters such as color and fluorescence, were determined at different storage times in this study. Subsequently, four reaction models, namely sucrose-lysine, sucrose-citric acid, sucrose-niacin, and sucrose-folic acid, were constructed according to the formulation of the preparation to systematically investigate the effects of each system on browning. The results showed that the sucrose-lysine model was the main color-forming reaction system of the preparation. Citric acid could significantly promote the hydrolysis of sucrose to produce two reducing sugars, glucose and fructose, which not only provided sufficient substrates for the Maillard reaction (MR), but also led to the massive accumulation of 5-HMF. Further analysis revealed that heating temperature and heating time were significantly positively correlated with the contents of 5-HMF, browning index (BI), color density (CD), and reducing sugars in the solution, while significantly negatively correlated with sucrose content (