A review of shellac-based carrier design for food application: From the perspective of core materials

This review systematically explores shellac-based encapsulation with an emphasis on various core substances, primarily polyphenols, followed by probiotics, essential oils, and proteins. Polyphenol encapsulation predominantly utilizes nanoparticles, with encapsulation efficiency and bioavailability generally exceeding 70 %, including single-walled shellac nanoparticles and composite systems. These nanoparticles are typically fabricated through pH-driven or antisolvent precipitation methods. While single-walled shellac nanoparticles face challenges such as instability in low-acidic environments, composite nanoparticles—formed by integrating shellac with polysaccharides or proteins—offer enhanced stability and functional performance. For probiotics, shellac is mainly employed in microencapsulation, significantly improving survival across various conditions, except during the spray-drying process. Current applications of shellac-based carriers are centered around food preservation, and extend to fat replacement and functional food development. Furthermore, relevant regulatory standards governing shellac usage are summarized. Future research directions are given critically. This review is expected to stimulate the development and application of shellac-based encapsulation technologies for a broad spectrum of bioactive compounds. • Shellac-based carrier design is reviewed from the perspective of core materials. • Shellac nanoparticles demonstrate the high encapsulation efficiency of polyphenol. • Blending of polysaccharide/protein enhances the performance of shellac nanoparticles. • The encapsulation of probiotics by shellac is mainly microcapsules. • The application of shellac-based carriers is mainly food packaging for preservation.