Surfactant-Free <scp>d</scp>-Limonene Encapsulation in Spray-Dried Alginate Microcapsules Cross-Linked by In Situ Internal Gelation

Microencapsulation facilitates incorporating bioactive volatile compounds into products throughout the food, health, and cosmetics industries. To minimize number of ingredients when microencapsulating oils, we examined surfactant-free encapsulation d-limonene in cross-linked alginate microcapsules (CLAMs) via situ cross-linking during spray drying. Surfactant-free CLAMs (SF-CLAMs) were prepared by forming a Pickering emulsion stabilized calcium carbonate nanoparticles (CaCO3-NPs), combining with alginates, then CaCO3-NPs served as both emulsifier reservoir agent. SF-CLAMs, retention 73.1 ± 4.7% total limonene content 13.6 8.6% (w/w, d.b.), exhibited core–shell morphology where surrounded large cores (∼5 μm) encased densely shells. Limonene was fully retained for up to 4 h SF-CLAMs water at 37 °C. Moreover, microencapsulation minimized release simulated gastric fluid (2.2 0.3% 2 h) while releasing