桉叶多酚纳米微胶囊的制备及稳定性评价

Preparation of Eucalyptus Leaves Polyphenol Nanoparticles and Stability Evaluation

以酪蛋白酸钠为稳定剂,采用反溶剂法制备桉叶多酚-玉米醇溶蛋白/酪蛋白酸钠纳米微胶囊。首先对制备过程中的玉米醇溶蛋白、桉叶多酚及酪蛋白酸钠浓度进行了优化研究,确定最优的工艺参数,然后对最佳配方条件下桉叶多酚-玉米醇溶蛋白/酪蛋白酸钠纳米微胶囊产品的稳定性、微观结构与生物利用度进行了评价。研究表明,桉叶多酚纳米微胶囊的最佳制备配方为:玉米醇溶蛋白浓度10 mg/mL、桉叶多酚浓度1 mg/mL和酪蛋白酸钠2 mg/mL,在此条件下,制备得到了粒径160 nm、包埋率62.89%的纳米微胶囊。该桉叶多酚纳米微胶囊在80℃加热3 h及0~100 mmol/L NaCl条件下粒径仍保持在160 nm左右,且PDI值均小于0.2,显示出较好的稳定性,同时能有效改善玉米醇溶蛋白等电点条件下的聚集沉淀情况。扫描电镜结果显示桉叶多酚纳米微胶囊粒径为100~200 nm,与分散液中粒径基本一致,且表面均一,呈球形。最后通过模拟体外消化实验发现,经包埋后的桉叶多酚纳米微胶囊与游离桉叶多酚相比,其溶解度在模拟胃液与肠液消化阶段分别提高了41.7%与49.1%,显著提高了其生物利用度。因此,在最佳工艺配方条件下制备的桉叶多酚微胶囊具有良好的品质,为桉叶多酚纳米微胶囊的应用提供了理论基础。

In this research,eucalyptus leaves polyphenols-loaded zein nanoparticles that stabilized by sodium caseinate(SC)were fabricated by anti-solvent method.The concentration of zein,eucalyptus leaves polyphenols and sodium caseinate concentration during fabrication were optimized.Then the stability,microstructure and bioavailability of the product were evaluated.The results showed that the optimal formula was zein concentration of 10 mg/mL,eucalyptus leaves polyphenol concentration of 1 mg/mL and sodium caseinate concentration of 2 mg/mL.Under the condition,the particle size and encapsulation efficiency were 160 nm and 62.89%,respectively.Even under the conditions of heating at 80℃for 3 h and solvent of 0~100 mmol NaCl,the particle size of was still around 160 nm and the PDI value was less than 0.2.So the nanocapsules has good stablity under the condtion of heating and high salt medium,and it also prevented the aggregation and precipitation of zein at the isoelectric point.The results of SEM showed that the particle size of the nanoparticles was 100~200 nm and basically the same as that in the dispersion,and its surface was uniform and spherical.Finally,compared with the free eucalyptus leaves polyphenols,the solubility of nanocapsules was increased 41.7%and 49.1%respectively,in the digestion stage of stimulated gastric and small intestinal fluids,indicating that the bioavailability of eucalyptus leaves polyphenols was significantly improved by the nanocapsules.Therefore,the eucalyptus leaf polyphenol nanoparticles prepared under the optimal condition showed a high quality,which provides the experimental basis for the application of eucalyptus leaves polyphenol nanoparticles.