Improved chemical stability and cellular antioxidant activity of resveratrol in zein nanoparticle with bovine serum albumin-caffeic acid conjugate

In this study, bovine serum albumin (BSA)-caffeic acid (CA) conjugate was prepared with free radical-induced grafting method. The CA to BSA ratio of the conjugate was 115.7 mg/g. In vitro antioxidant activity assays suggested that BSA-CA conjugates had stronger antioxidant activity than BSA. Resveratrol-loaded zein encapsulated with BSA and BSA-CA conjugate core-shell nanoparticles were prepared with antisolvent method. Particle sizes were 206.3 nm, and 217.2 nm for BSA and BSA-CA, respectively. The encapsulation efficiencies (EEs) were 85.3% and 86.5% for zein-BSA and zein-BSA-CA nanoparticles, respectively. SEM results indicated that both nanoparticles were spherical with mean diameter approximately 200 nm and smooth surfaces. Both thermal and UV light stability of resveratrol was significantly improved after nanoencapsulation. BSA-CA conjugate showed remarkably greater protection than BSA against resveratrol degradation. Cellular antioxidant activity (CAA) study confirmed that resveratrol in both zein-BSA and zein-BSA-CA nanoparticles had significant higher antioxidant activities than resveratrol alone.