Foxtail millet prolamin-pectin nanoparticles enhanced the stability and bioavailability of β-sitosterol

Herein, β-sitosterol-loaded foxtail millet prolamin (FMP)-pectin composite nanoparticles (FSNs) were successfully produced using an antisolvent precipitation method to encapsulate β-sitosterol and improve its bioaccessibility. Results indicated that the nanoparticles prepared at a FMP-to-pectin mass ratio of 10:2 not only showed lower particle size (401.7 ± 14.7 nm, p < 0.05) and higher net zeta potential (-33.3 ± 6.1 mV, p < 0.05) but also exhibited higher encapsulation efficiency (81.5 % ± 0.3 %, p < 0.05). FSNs successfully encapsulated β-sitosterol through electrostatic and hydrophobic interactions and hydrogen bonding. β-sitosterol changed from a crystalline to an amorphous state. Meanwhile, FMP-pectin composite nanoparticles (FNs) and FSNs displayed similar irregular lamellar structures and exhibited excellent physical stability at different environments (pH > 4, salt ions <100 mM, different temperatures and storage at 4 °C). The simulated digestion result showed that FSNs could target the release of β-sitosterol at the intestinal stage with a release rate of 72.23 ± 1.19 % (p < 0.05). Moreover, the bioaccessibility of β-sitosterol in FSNs significantly increased by about 68.58 ± 2.39 % (p < 0.05) compared with free β-sitosterol. Nonetheless, this study provided a novel β-sitosterol delivery system based on FMP-pectin complexes with a broad prospect in the processing of food, pharmaceuticals and nutrition.