Abstract
Microencapsulation by spray drying of oil-in-water (o/w) emulsions provides a means to encapsulate functional lipophilic ingredients. The active ingredient is dispersed in continuous solid phase providing protection. However, the encapsulation efficiency depends on the microstructure and morphology of the dry particles influenced by several mechanisms occurring during processing such as oil droplet breakup during atomization, ingredient diffusivity, interfacial adsorption of surface active ingredients, and drying kinetics. In this work, sunflower oil (model for lipophilic compounds) was encapsulated in solid particles composed of acacia gum and maltodextrin DE12. Three powders with different initial emulsion size (e.g. about 0.1 and 1 μm) and atomized under high and low shear rate were analysed for the morphology and distribution of oil droplets and matrix constituents within the solid particle (20–100 μm). The microscopic (optical, SEM, LVSEM, confocal Raman), spectroscopic (XPS) and analytical (solvent extraction) techniques used were either qualitative or quantitative. Their combination made it possible to determine both the composition at the surface and inside the particle. The surface differs from the bulk in composition, confirming the constituent segregation during spray drying, and depended on the initial emulsion size and atomization conditions that must be controlled for an efficient encapsulation. Especially, the use of confocal Raman microscopy is promising for the study of processstructure-properties relationship.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.