Preparation and Characterization of Nanocapsules of Zeaxanthin Extracted from Lycium barbarum L.by Complex Coacervation

Using zeaxanthin extracted from Lyciumbarbarum L. as the core material,gelatin and CMC as the wall materials,zeaxanthin nanocapsules were prepared by complex coacervation in this study. The optimal process parameters,characterization and storage stability were studied. The optimum process parameters were as follows:The core material solvent concentration was 0.5%,the zeaxanthin concentration was 15 mg/mL core material solvent,the wall material concentration was 0.5%,the emulsifier concentration was 0.5%(Tween 80:Span 80=1:1,w/w),and the curing agent concentration was 20 U/g gelatin. Under these conditions,the embedding rate was 92.60%±2.91%,the average particle size was 210.7 nm,the polydispersity index(PDI)value was 0.063 and the Zeta potential was -11.5 mV. The micrograph showed a regular spherical shape. X-ray diffraction(XRD)analysis revealed that zeaxanthin existed in an amorphous state after complex coacervation so that the water solubility of zeaxanthin was improved. Moreover,the results of storage stability indicated that the structure of nanocapsules could protect zeaxanthin from the oxidative degradation caused by temperature,light,and oxygen and the preservatives potassium sorbate and sodium benzoate could coexist with zeaxanthin nanocapsules in the system.