Porous starch as tablet excipients for β-carotene delivery: Impact of amylose content on structural stability and release performance.

Porous starch is widely recognized as a promising carrier for bioactive compounds, but its potential as a tablet excipient remains unexplored. Herein, porous starches prepared from waxy maize (PWMS, 4% amylose), 50% (PHA50) and 75% (PHA75) high-amylose maize were enzymatically prepared and used as excipients to fabricate β-carotene (BC)-loaded tablets. The effects of amylose content on structural characteristics, powder rheology, BC encapsulation, storage stability and release behavior of tablets were systematically investigated. PHA50 had a compressed bulk density of 0.49 and uniformly interconnected mesoporous structures, achieving the highest BC encapsulation efficiency (61.30%). PHA50-based tablets showed desirable stability under harsh conditions, while PWMS-based tablets exhibited rapid matrix hydration during digestion due to structural collapse. Moreover, the BC release fitted well with the Higuchi model, indicating a diffusion-controlled mechanism of all tablets. These findings suggest that amylose content regulates the properties of porous starch, and PHA50 is ideal as the tablet excipient for BC delivery, providing insights for the applications of bioactive compounds.