沙枣花精油微胶囊制备工艺优化及缓释性能

本文以沙枣花精油为芯材,β-环糊精(β-CD)为壁材包埋制备沙枣花精油微胶囊,综合考察壁芯比、乙醇与精油体积比、β-CD与加水量比、包埋温度、包埋时间5个因素对微胶囊包埋得率的影响,并通过响应面法优化工艺条件。结果表明,确定沙枣花精油最佳包埋条件为:壁芯比5:1 (g/mL)、乙醇与精油比30:1(mL/mL)、加水量与β-CD比8:1 (mL/g)、包埋时间2 h、包埋温度46 ℃,此工艺条件下的微胶囊包埋得率为75.15%±0.24%,与预测值接近。红外光谱和扫描电子显微镜结果显示沙枣花精油在β-CD中的存在。缓释性能研究表明,沙枣花精油微胶囊的精油挥发率(7.22%)与过氧化值(19.7%)都有明显下降,因此可延长沙枣花精油的使用寿命,提高精油的利用率,从而为沙枣花精油在食品领域中广泛使用提供一定的方法支持。

Optimization of Microencapsulation Preparation Process and Controlled- release Properties of Elaeagnus angustifolia Flowers Essential Oil

In this study,β-cyclodextrin(β-CD)with porous structures was prepared and used as a food grade polymer for the microencapsulation of essential oil from Elaeagnus angustifolia flowers. The oil was impregnated in microspheres,and loading ratio was optimized by investigating the restrictive factors,including the ratios of oil to β-CD,ethanol to oil and β-CD to water,as well as the embedding temperature and time.Based on the screening of single-factor experiment design,four experimental factors were optimized for the Box-Behnken experimental design combined with response surface methodology. The results showed that the optimal extraction conditions were:the ratios of oil to β-CD,ethanol to oil and β-CD to water were 5∶1 (g/mL),30∶1 (mL/mL)and 8∶1 (mL/g)on the embedding temperature of 46 ℃ for 2 h.Under these conditions,the experimental loading ratio was 75.15%±0.24%,which was close to the predicted value. The presence of oil in the β-cyclodextrin was confirmed by Fourier transform infrared(FT-IR)spectroscopy and scanning electron microscopy(SEM). During the antioxidant experiments,the porous β-CD based microencapsulation exhibit a stable oil loading ratio(7.22%)and a significant improvement in oxidative stability(19.7%)compared with free oil. The newly-proposed process used in this work was easy to scale up for developing a new and attractive method for oil protection in the food industry.