Enzyme-Modified Soy Protein/Maltodextrin Microcapsules Embedding Cinnamaldehyde: Structure, Release Characteristics, and Antibacterial Activity

Cinnamaldehyde (CIN) is a natural organic compound known for its antimicrobial and antioxidant properties. However, its susceptibility to environmental degradation has restricted its practical application. This study aimed to microencapsulate CIN using soy protein isolate hydrolysates and maltodextrin as wall materials through emulsion preparation and spray drying, and to characterize the microstructure, controlled-release properties, antibacterial efficacy, and preservation performance of the resulting microcapsules. Under optimized condition, the encapsulation efficiency reached 70.72%. The microcapsules displayed smooth spherical structures, improved thermal stability, and an average particle size of 291.01 ± 33.64 nm. They demonstrated enhanced storage stability and sustained-release characteristics. Furthermore, the microcapsules exhibited significant antibacterial and antioxidant activity, which effectively delayed lipid and protein oxidation in pork loin for up to 6 days. Collectively, the results confirm the successful encapsulation of CIN and indicate the strong potential of these microcapsules for food industry applications requiring preservative and controlled-release functions.