Ultrasound-assisted preparation of a human milk fat analog emulsion: Understanding factors affecting formation and stability

The aim of this work was to investigate the application of ultrasound in the formation of a stable human milk fat (HMF) analog emulsion with macronutrients (lecithin and protein) as emulsifiers required for infant formula, at low levels and within the ranges of infant formula standards; in addition, the aim was to evaluate the stability of the emulsion to various environmental stresses. Increasing the lecithin concentration and decreasing the HMF analog amount yielded a stable HMF analog emulsion with a smaller mean particle size. Increasing the ultrasonic power and time favored decreasing particle sizes. The emulsion obtained under optimized conditions was stable at a pH of 6.4-8.0, at heating temperatures of 50 °C-90 °C, and with sugar levels and sodium ion strengths that met infant formula standards. Storage below 25 °C for 7 days did not substantially change the physicochemical stability of the emulsion. The results provide information useful for manufacturing high-quality infant formula; ultrasonic emulsification can be used to produce a stable HMF analog emulsion using protein and lecithin at low levels to meet infant formula standards.