Abstract: In order to improve the stability and activity of anthocyanins from Lycium ruthenicum Murr., chitosan (CS) and casein phosphopeptide (CPP) composite gel system was used to prepare anthocyanin-loaded CS-CPP nanoparticles. The preparation conditions were optimized to be sequential addition of an equal volume of 2 mg/mL anthocyanins followed by 0.20–0.30 mg/mL CS to 0.5% CPP solution at pH 4 with stirring at room temperature. As a result, the CS-CPP nanoparticles containing anthocyanins were spontaneously formed by ionic gelation, which had an average particle size of 215.3 nm, surface potential of 36 mV and encapsulation efficiency of 65.0%–72.2%. The in vitro release test showed that the release percentage of anthocyanins from the nanoparticles was 24.3%–64.2% at pH 7.0. The in vitro cell test demonstrated that the nanoparticles with anthocyanin concentrations of 100–200 μg/L significantly elevated the survival rate of EAhy926 cells exposed to oxidized low-density lipoprotein (ox-LDL) (P＜0.05). Therefore, the CS-CPP composite gel system can encapsulate anthocyanins from Lycium ruthenicum Murr., and the nanoparticles containing anthocyanins have good antioxidant effect in vitro.

Key words: Lycium ruthenicum Murr., anthocyanins, nanoparticles, oxidative damage, EAhy926 cells