Encapsulation of rutin in Pickering emulsions stabilized using octenyl succinic anhydride (OSA) modified quinoa, maize, and potato starch nanoparticles

Pickering emulsions (PEs) stabilized with octenyl succinic acid (OSA) modified starch nanoparticles (SNPs) were investigated as a delivery system for rutin (a polyphenol). The nanoscale quinoa (Q, 92 nm), maize (M, 118 nm), and potato (P, 200 nm) starches were prepared by nanoprecipitation and they were OSA-modified as stabilizers. The PEs showed neither coalescence nor Ostwald ripening, as reflected by emulsion index, droplet size, and zeta- potential measurements. Confocal laser scanning microscopic analysis revealed rutin entrapped droplets surrounded by SNPs layer. Fourier-transform infrared spectroscopy, colorimetry, and rheological measurements confirmed the SNPs and rutin interactions, rutin retention, strong network formation, and long-term PE stability. In vitro studies (pH 7.4, 96 h) showed sustained rutin release from the PEs. After 31 days, the encapsulation efficiencies for PEs stabilized with QSNPs, MSNPs, and PSNPs were 99.3, 96.1, and 97.2 %, respectively. The results showed that rutin could be feasibly encapsulated in PEs stabilized with food-grade modified SNPs.