Control of the Maillard reaction and secondary shelf-life prediction of infant formula during domestic use

To control the Maillard reaction of infant formula (IF) during secondary shelf-life (SSL) and establish an SSL prediction model, the effects of storage temperatures (25 degrees C, 37 degrees C) and relative humidity (RH) levels (32%, 57%, and 75%) on the Maillard reaction products (MRPs) were evaluated. Visible color changes were observed during storage in samples stored at 37 degrees C and not at 25 degrees C. The available lysine loss was the largest, up to 64.14% and 69.40% after 4 weeks of storage at 37 degrees C and 57% RH. At the end of storage, the 5-hydroxymethylfurfural, 3-deoxyglucuronide, fluorescence of advanced Maillard products and soluble Tryptophan (FAST) index, and N-epsilon-carboxymethyllysine (CML) of two commercial IFs increased by 0.48-3.32, 1.26-12.65, 0.01-4.87, and 0.30-1.05 times, respectively. During storage, the glyoxal content in two commercial IFs tended to increase and then decrease in the range of 0.21-3.43 mg/100 g. The SSL of IFs was predicted using the multivariate accelerated shelf-life test and the Arrhenius model. At 25 degrees C, the estimated SLL of two commercial IFs were 10-9 and 7-6 weeks at 57% and 75% RH, respectively. MRPs and Delta E* could be used as indicators for predicting the SLL of infant formula. Practical ApplicationThe results of the study suggested that the increase in storage temperature and humidity during the SSL can promote the MR of IF, which affects the sensory and safety of IF. Therefore, consumers need to focus on controlling storage conditions during the SSL to avoid degradation of IF quality.