Effects of different reducing carbohydrate types on the physicochemical characteristics of infant formula food stored for special medical purposes

•Nutritional formulas were real trialed rather than models which mixed by ingredients.•Deeper dents and wrinkles were observed on the surface of formula with maltodextrin.•More fat globules were observed on surface of formula with lactose after storage.•Formula with maltodextrin had better physicochemical stability. The formula of food for special medical purpose has a direct impact on physicochemical stability, especially in hot climes and high temperature transport storage environments. An accelerated test (50 °C for 7 weeks) was used to analyze the mechanism of the physicochemical instability of formula A with lactose and maltodextrin, and formula B with maltodextrin. Deep dents and wrinkles were observed on the surface of the formula B, and more fat globules covered the surface of formula A particles after storage for a long time. Significantly higher amounts of furosine and Nε-carboxymethl-l-lysine (CML) were formed and the loss of available lysine was greater in formula A than in formula B. No significant difference was observed in lipid oxidation indicators between the two formulas. The results of this research demonstrated lactose was more active than maltodextrin and led to physicochemical instability.