Effect of a minimal processing route for the production of infant formulas on their sensory properties

Infant formulas (IF), the sole adequate substitute to human milk, undergo several thermal treatments during production that can damage milk proteins and promote the formation of Maillard reaction products, modifying nutritional and sensory properties. The aim of this study was to determine the effect of a minimal processing route based on membrane filtration associated with different levels of heat treatment, on the odor, taste, texture, and color attributes of IF, then to compare with those of commercial milks. Three experimental IF (produced with membrane filtration associated with low [T^-], medium [T⁺], or high thermal treatments [T⁺⁺⁺]) were evaluated. Triangular tests conducted with a panel of 50 adults highlighted clear disparities between all the IF. The same panel applied the check-all-that-apply (CATA) method to evaluate the IF: the range of variability between T^- and T⁺⁺⁺ was similar to that between the 2 commercial IF, and the sensory characteristics of the experimental IF were not far from the commercial brands for flavor and texture attributes. Analysis performed on the citation frequencies for each descriptor differentiated T^-/T⁺ from T⁺⁺⁺, but all the experimental IF were described with positive sensory characteristics, unlike one commercial IF. Volatile organic compounds (VOC) content of IF with low and high thermal treatments were analyzed. Forty VOC were identified by GC-MS. T^- contained a higher quantity of VOC than T⁺⁺⁺, except for benzaldehyde (Maillard reaction product), and aldehydes (oxidation-related products) were the most represented compounds. In conclusion, the processing was associated with sensory differences among IF, but no marked difference in flavors was found according to CATA and physicochemical analysis. Additionally, no unpleasant sensory descriptors were noted. This shows that the minimally processed route leads to IF that could fit well within the market from a sensory point of view.