Cyclodextrin glycosyltransferase-catalyzed products from starch enhance the stability of microencapsulated cinnamaldehyde emulsion

Cinnamaldehyde is popular due to its cinnamon flavor and antimicrobial activity, but is constrained by its instability. In this study, the cyclodextrin glycosyltransferase-catalyzed (CGTase-catalyzed) products from corn, tapioca, or potato starch were used for a new wall material for microencapsulating cinnamaldehyde emulsion. The sedimentation and dilution stability revealed that the emulsion prepared by the CGTase-catalyzed products from 1.5% of tapioca starch displayed the most uniform and stable properties, with a particle size of 195.18 nm and encapsulation efficiency of 92.5%. The fine structure analysis of these products revealed that no retrogradation, high cyclodextrin yield and conversation rate, and a high proportion of medium chains (the degree of polymerization 13–24) were conducive to the stability of the emulsion. Finally, the correlation between the emulsion's stability and the products' molecular structure was analyzed using the Person correlation coefficient. The results showed that the medium chains exhibited the highest correlation. This study combined the inclusion of the CGTase-catalyzed products with the emulsion embedding for a highly stable and low-cost microencapsulated cinnamaldehyde emulsion, which would provide a guidance for the microencapsulation of other essential oils.