Construction of novel porous starch microparticles loaded with curcumin oleogel: Improving colon-targeted delivery potential of curcumin.

Curcumin, a natural polyphenol with antioxidant and anti-inflammatory properties, benefits from colon-targeted delivery in its amorphous form. In this study, porous starch (PS) was used to adsorb curcumin oleogel, forming novel porous starch microparticles loaded with curcumin oleogel for enhanced colon-targeted delivery potential. The effects of various curcumin oleogel/PS ratios (1:8, 1:6, 1:4, 1:2) on microparticle properties were systematically investigated. Microparticles were mainly formed by pore-filling and surface adhesion, retaining PS crystallinity and reducing curcumin thermal loss. The 1:8 ratio microparticles showed the lowest bioaccessibility (31.02 ± 0.76%), significantly lower than curcumin oleogel (50.37 ± 2.91%), indicating improved protection and colon-targeting efficiency. Additionally, the 1:8 group produced the highest total short-chain fatty acids (SCFAs) and showed superior modulation of gut microbiota, increasing beneficial genera (e.g., Bifidobacterium, Prevotella) and inhibiting harmful ones (e.g., Escherichia). Overall, porous starch microparticles loaded with curcumin oleogel, especially at 1:8 ratio, demonstrated optimal colon-targeted delivery potential.