Maillard reaction indicators formation, changes and possible intake in infant formula produced by different thermal treatments during domestic use

•Initial, intermediate and advanced indicators of Maillard reaction were measured.•IF produced by 75 °C, 2 min has lower 3-deoxyglucuronide (3-DG) and FAST index.•Visibly color change of IFs observed during storage at 37 °C, 57% RH and 75% RH.•The largest available lysine loss of IFs was 71.41% stored at 37 °C, 57% RH.•Maximum daily intake of 3-DG and glyoxal was 7.05 mg and 3.6 mg, respectively. This study investigated the Maillard reaction of infant formulas (IFs) produced by four thermal treatments during simulated consumption storage. Among the four sterilization conditions, seventy-five degrees, 2 min was considered the optimal sterilization treatment. The loss of available lysine, 3-DG content and FAST (fluorescence of advanced Maillard products and soluble tryptophan) index was lower in the initial IF produced by this treatment. After storage at 37 °C, 57% RH, the largest loss of available lysine was 71.41%. 5-hydroxymethylfurfural content increased to 7.28 mg/100 g with storage temperature and time, regardless of humidity. The content of α‑dicarbonyl compounds fluctuated during storage, and it was estimated that the maximum daily intake was 7.05 mg for 3-deoxyglucuronide and 3.6 mg for glyoxal. The average Nε-carboxymethyllysine concentration during storage at 37 °C was 615.844 ng/mL. At 37 °C, 75% RH, the highest FAST index was 87.11% and ΔE* was 29.95. Compared with thermal treatment, unfavorable storage conditions further promote the occurrence of the Maillard reaction. In particular, the storage temperature should be strictly controlled.