Freeze-dried Human Milk Microcapsules Using Gum Arabic and Maltodextrin: An Approach to Improving Solubility

Human milk (HM) is essential for newborns' food, but its low storage stability is a limiting factor so that microencapsulation may stabilize and protect compounds sensitive to degradation. This study investigated the action of maltodextrin and gum arabic on freeze-dried HM concerning its quality and solubility. Microencapsulation was evidenced by morphology, and all samples presented high encapsulation efficiency (>85 %), proving to be an efficient process. Furthermore, specific signals in the Fourier-Transform Infrared (FTIR) spectra indicate the interactions between the coating materials and the HM matrix. Gum arabic improved the reconstitution properties of freeze-dried HM (higher solubility, 3 % on average, and lower dissolution time, around 80 %), elucidating its high stabilization capacity, even at low concentrations (5 and 10 %). Despite the best results reached by gum arabic, the addition of maltodextrin proved effective; in other words, its low stabilization capacity enables combinations with gum arabic. A lower polidispersibility (difference of 20 % between samples: control and containing gum arabic) was also observed, which means that the encapsulated samples were more homogeneous. Therefore, through the analysis performed, we recommend using gum arabic alone or with maltodextrin to obtain HM microcapsules with a good quality of reconstitution.