洋葱精油微胶囊喷雾干燥制备工艺优化及释放性能分析

Optimization of spray drying preparation and release property analysis of onion essential oil microcapsules

采用喷雾干燥技术,研究制备条件对洋葱精油微胶囊化的影响,以包埋率为指标,通过响应面分析法,优化微胶囊的制备工艺;对比喷雾干燥前后洋葱精油主要成分硫代亚磺酸酯含量的变化,并测定洋葱精油微胶囊的质量指标,对微胶囊制备工艺进行分析;对微胶囊实施体外模拟试验,同时对不同贮藏温度下精油的挥发率进行研究,分析微胶囊的释放效果及稳定性。结果表明:微胶囊最佳制备工艺为乳化温度61℃、进风温度177℃、进料流量900mL/h,该条件下微胶囊的包埋率为92.06%,喷雾干燥之后洋葱精油硫代亚磺酸酯保留率值与理论值相近;微胶囊的出粉率、含水率、密度、粒径及感官评分分别为22.34%、3.12%、0.79g/cm^3、15.3μm和92,出粉率高,含水量低,品质较佳,在胃肠液中的控释效果较好,易于吸收且刺激性小,洋葱精油微胶囊的释放过程与Avrami’s方程拟合良好,随着温度的升高微胶囊释放速率常数上升,微胶囊应在低温条件下贮藏。

Spray drying technology was used to study the effect of different preparation conditions on the microencapsulation of onion essential oil.Taking Arabia gum and beta cyclodextrin as wall materials,the encapsulation rate as the index,the preparation process of microcapsules was optimized by response surface analysis.The content of thiosulfate(TS)in onion essential oil before and after spray drying was compared,and the extraction of onion essential oil microcapsules was also determined.The preparation technology of microcapsules was analyzed.The in vitro simulation experiment was carried out on microcapsules,and the volatilization rate of onion essential oil in microcapsules at different storage temperatures was studied.The release effect and stability of microcapsules were analyzed.The results showed that the best preparation conditions of microcapsule were emulsification temperature 61 ℃,inlet air temperature 177 ℃,feed flow 900 mL/h.Under these conditions,the encapsulation rate of microcapsule was 92.06%,and the TS retention rate of onion essential oil was similar to that of theoretical value after spray drying.The yield,moisture content,density,particle size and sensory score of microcapsule were 22.34%,3.12%,0.79 g/cm^3,15.3μm,92,respectively.The release process of onion essential oil microcapsules fitted well with Avrami\s formula.With the increase of temperature,the release rate constant ofmicrocapsules increased,and microcapsules should be stored at low temperature.