Preparation and characterization of microcapsules and tablets for probiotic encapsulation via whey protein isolate-nanochitin complex coacervation

This research delved into the feasibility of utilizing three nanochitin—chitin nanocrystal (CNC), chitin nanofiber (CNF), and chitin nanosphere (CNS) in complexation with whey protein isolate (WPI) to fabricate complex coacervation and create microcapsules for probiotic encapsulation. The results showed that CNC, CNF, and CNS exhibited notable differences in morphologies, dimensions, and properties due to the respective synthesis methodologies. Nevertheless, all of them maintained a positive charge and were capable of assembling into microcapsules with WPI via electrostatic interactions at optimal pHs. The inclusion of Lactobacillus casei (L. casei) during the complex coacervation phase engendered a shell-like formation around the bacterium within the microcapsule, which enhanced probiotic viability and increased colony-forming unit count. Additionally, these probiotic-loading microcapsules were also processed into tablets, displaying robust structural integrity, augmented protective capabilities, and a distinctive sustained-release profile compared to the microcapsules alone. In summary, this study pioneered the employment of nanochitin formulations in complex coacervation to encapsulate L. casei, spearheading an innovative approach to the creation of a compressed probiotic supplement and contributing to the advancement in the design and fabrication of encapsulation vehicles for active ingredients. [Display omitted] •Three types of nanochitin have successfully formed complex coacervates with WPI.•WPI-CNC/CNF/CNS coacervates might have different protective effects on probiotics encapsulation.•WPI-CNC/CNF/CNS coacervates microcapsule tablets were established for encapsulating L. casei.•L. casei exhibited improved stability and high viability in complex coacervate microcapsule tablets.