自组装原花青素纳米复合物的构建及表征

Construction and Characterization of Self-assembled Proanthocyanidin Nanocomposites

原花青素是一种具有极强抗氧化活性的天然多酚化合物,该文利用酪蛋白和麦芽糊精进行分子自组装得到一种两亲性生物聚合物,将其与原花青素结合形成纳米复合物。通过接枝度、褐变度、蛋白溶解度以及红外光谱和圆二色谱分析酪蛋白与麦芽糊精之间的相互作用机制。以包埋率为指标,优化原花青素纳米复合物构建的工艺条件,对原花青素纳米复合物的粒径、电位和多分散指数进行表征,并采用扫描电镜观察其包埋前后表观的形貌变化。结果表明,酪蛋白与麦芽糊精成功地进行自组装反应,该反应有效地提高了酪蛋白的溶解度。当原花青素/接枝物的质量比为2∶5,接枝物浓度为25 mg/mL,溶液pH值为7.0时,制备得到的原花青素纳米复合物包埋率达到93.48%,平均粒径为158.69 nm,Zeta电位为-30.58 mV,呈现一种表面光滑的紧凑球状结构。

Proanthocyanidin is a natural polyphenol compound with strong antioxidant activity.In this paper,casein and maltodextrin were used for molecular self-assembly.Amphiphilic biopolymers obtained were used to combine with proanthocyanidins to form nanocomposites.The interaction mechanism between casein and maltodextrin was analyzed by grafting degree,browning degree,protein solubility,infrared spectrum and circular dichroism.The encapsulation efficiency was taken as indexes to optimize the technological conditions for the construction of proanthocyanidin nanocomposites.The particle size,Zeta potential and polydispersity index of proanthocyanidin nanocomposites were characterized,and the morphological changes of the nanocomposites before and after embedding were observed by scanning electron microscopy(SEM).The results showed that casein and maltodextrin were successfully self-assembled,which effectively improved the solubility of casein.When the mass ratio of proanthocyanidins to grafts was 2∶5,the concentration of the grafts was 25 mg/mL and the solution pH was 7.0,the encapsulation efficiency of the prepared proanthocyanidins nanocomposites reached 93.48%,the average particle size was 158.69 nm,and the Zeta potential was-30.58 mV.Proanthocyanidin nanocomposites exhibit a compact spherical structure withsmooth surface.