No abstract

Zein/pectin core-shell nanoparticles with average diameter of about 235 nm and polydipersity index (PDI) of 0.24 were developed to encapsulate, protect and deliver resveratrol. Biopolymer nanoparticles could be formed containing up to 10.2% (w/w) resveratrol, with a particle yield of 91.7% and a resveratrol loading efficiency of 77.9%. The nanoparticles formed were spherical and had good redispersibility in aqueous solutions. The encapsulated resveratrol had a higher in vitro antioxidant activity than free resveratrol as determined by DPPH•, ABTS• + scavenging ability, and iron (III) reducing power. The encapsulated resveratrol also exhibited higher antiproliferative activity when tested using human hepatocarcinoma Bel-7402 cells than free resveratrol, with IC 50 values of 17.6 µg/mL (77.2 µM) and 25.6 µg/mL (112.0 µM) respectively. The colloidal form of resveratrol developed in this study may be particularly useful for application in functional foods and beverages, as well as in dietary supplements and pharmaceutical products.

No abstract

Curcumin has strong antioxidant activity, but poor water-solubility and chemical stability, which limits its utilization as a nutraceutical in many applications. Previously, we developed a core-shell (zein-pectin) nanoparticle delivery system with high curcumin loading efficiency, high particle yield, and good water dispersibility. However, this system was unstable to aggregation around neutral pH and moderate ionic strengths due to weakening of electrostatic repulsion between nanoparticles. In the current study, we used a combination of alginate (high charge density) and pectin (low charge density) to form the shell around zein nanoparticles. Replacement of 30% of pectin with alginate greatly improved aggregation stability at pH 5 to 7 and at high ionic strengths (2000mM NaCl). Curcumin encapsulated within these core-shell nanoparticles exhibited higher antioxidant and radical scavenging activities than curcumin solubilized in ethanol solutions as determined by Fe (III) reducing power, 1, 1-Diphenyl-2-picrylhydrazyl free radical (DPPH·), and 2, 2'-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid radical cation (ABTS·) scavenging analysis. These core-shell nanoparticles may be useful for incorporating chemically unstable hydrophobic nutraceuticals such as curcumin into functional foods, dietary supplements, and pharmaceuticals.