Directed self-assembly of mesoporous starch-based microparticle: Characterization, antimicrobial activities, and digestibility

Porous starch has garnered increasing interest due to its distinctive properties and versatile applications. Here, we propose a sustainable and efficient method for producing highly uniform mesoporous starch-based microspheres (CSMP) with adjustable sizes through the directed self-assembly of short-chain glucan (SCG) using chitosan. Chitosan facilitates the layer-by-layer deposition of SCG nuclei in the circumferential direction, resulting in the formation of a porous structure on CSMP. By controlling the concentration of SCG, the particle size can be precisely tuned within the range of 400 nm–900 nm. The resulting CSMP exhibit enhanced properties compared to starch-based microspheres formed without chitosan, including a surface area of 20.54 m²/g, total pore volume of 0.13 cm³/g, average pore diameter of 25.5 nm, and water absorption capacity of 352.6%. Moreover, CSMP demonstrate remarkable antibacterial activity (over 93%) against Escherichia coli and Staphylococcus aureus, while containing a high level of resistant starch (over 60%), highlighting their potential for the development of functional foods.