本文以宁夏枸杞提取的玉米黄质为芯材,明胶、羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC)作为壁材,利用复合凝聚法制备枸杞玉米黄质纳米胶囊,优化其制备工艺,并对纳米胶囊的性质表征及贮藏稳定性进行研究。结果表明,玉米黄质纳米胶囊的最佳制备工艺为:芯材溶剂浓度0.5%,玉米黄质浓度15 mg/mL芯材溶剂,壁材浓度0.5%,乳化剂浓度0.5%(Tween 80:Span 80=1:1,w/w),固化剂浓度20 U/g明胶。该条件下包埋率为92.60%±2.91%,平均粒径210.7 nm,多分散指数(polydispersity index,PDI)为0.063,Zeta电位为-11.5 mV。显微图像显示其呈现规则的球形结构;X-射线衍射分析结果表明,玉米黄质经包埋后以无定形的状态存在,水溶性得到了改善;贮藏稳定性结果表明,纳米胶囊结构能有效保护玉米黄质,从而抵抗温度、光照、氧气引起的氧化降解,防腐剂山梨酸钾和苯甲酸钠可与玉米黄质纳米胶囊在体系中共存。
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.