Gelatin-maltodextrin microcapsules as carriers of vitamin D3 improve textural properties of synbiotic yogurt and extend its probiotics survival

Food fortification is one of the most essential processes to compensate for the deficiency of minerals and vitamins in customers’ body. Hence, this study aimed to fortify low-fat stirred yogurt via encapsulated vitamin D3 (VD3) in maltodextrin and gelatin matrix, characterize obtained microcapsules (encapsulation efficiency, zeta potential, particle size, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transformation infrared (FTIR) spectroscopy, release features, and explore the properties of resultant yogurt including its syneresis, prebiotic activity, sensory properties, and rheology. Encapsulation efficiency and loading efficiency of microcapsules were satisfactorily high (Up to 97% and 25%, respectively). Microscopy images of microencapsulated VD3 showed a smooth surface as well as spherical and slight cracks in the microcapsules. The microcapsules had strong negative zeta potentials (−27.29 mV), implying a considerable repulsive force between microcapsules and their good stability. The FTIR result showed strong interactions between VD3 and wall materials, confirming the presence of VD3 in the microcapsules. VD3 had an almost slow release in the gastric, while it was quickly released from microcapsules under simulated intestinal conditions. Fortification of yogurts with encapsulated VD3 led to an increase in textural parameters where syneresis value decreased and viscosity increased. The number of probiotics in fortified yogurts was also considerably higher than in the control sample. The sensory analyses revealed no major differences between the fortified and control samples, hinting that protein-polysaccharide microcapsules were suitable wall materials for VD3 microencapsulation, and these microcapsules could potentially have numerous applications in the food industry.