Effect of Crosslinking Agent on Neem (Azadirachta Indica A. Juss.) Seed Oil (NSO) Encapsulated Microcapsules kappa-Carrageenan and Chitosan Polyelectrolyte Complex

Microencapsulation of neem (Azadirachta Indica A. Juss.) seed oil (NSO) was carried out by polyelectrolyte complexation of kappa-carrageenan and chitosan. The microcapsules were crosslinked by using three different crosslinking agents - glutaraldehyde, genipin and tannic acid. The lowest and highest water uptake capacities were exhibited by glutaraldehyde and tannic acid crosslinked matrices, respectively. The release behavior of NSO from encapsulated crosslinked microcapsules followed the order: tannic acid > genipin > glutaraldehyde. Polyelectrolyte complex formation and its interaction with crosslinker was studied. Crosslinking improved thermal stability without affecting crystallinity. Roughness appeared on microcapsule's surface indicated interaction between microcapsules and crosslinker.