肉桂-丁香-百里香精油微胶囊的制备及表征

Preparation and Characterization of Cinnamon-Clove-Thyme Essential Oil Microcapsule

为了获得用于不同运输条件下对稻谷中的霉菌具有天然抑菌效果的精油微胶囊,以肉桂、丁香和百里香精油为芯材,以明胶、阿拉伯胶为壁材,采用复凝聚法制备肉桂-丁香-百里香精油微胶囊。通过热重分析法和扫描电镜分析精油微胶囊的结构和理化特性,并对精油微胶囊在霉变稻谷中的缓释抑菌效果进行比较。结果表明,制备精油微胶囊的最优工艺条件为:复凝聚pH 3.6,明胶∶阿拉伯胶=2∶3,壁材质量浓度1%,芯壁比1∶1,搅拌速率450 r/min,在此工艺条件下制备的精油装载量为58.61%,包埋率为82.52%,微胶囊产率为67.42%。精油微胶囊为表面光滑、囊壁完整的球形结构,可减缓精油的释放过程,对在霉变稻谷中主要的5种菌株(Aspergillus sydowii、Aspergillus candidus、Nigrospora oryzae、Aspergillus versicolor、Penicillium brocae)具有长久的抑菌效果。

To obtain the microencapsulated essential oil with natural inhibition effect on mould from rice under different transportation conditions,cinnamon-clove-thyme microencapsulated essential oil was made by complex coacervation where cinnamon,clove and thyme essential oil were used as core materials while gelatin and Arabia gum as wall materials.To be specific,the structure and physicochemical properties of microencapsulated essential oil were analyzed by thermogravimetry and scanning electron microscopy,and the sustained-release antibacterial effect of microencapsulated essential oil in moldy rice was compared.The results showed that the optimal process conditions were detailed as follows:complex pH 3.6,gelatin∶Arabic gum=2∶3,wall material concentration=1%,core-wall ratio=1∶1,stirring rate=450 r/min.Under these conditions,the loading capacity of essential oil was 58.61%,embedding rate was 82.52%and microencapsulated essential oil yield was 67.42%.The microencapsulated essential oil was a spherical structure with smooth surface and intact capsule wall,which might slow down the release process of essential oil.Hence,The present study was proven to have long-term antibacterial effect on five main strains(Aspergillus sydowii,Aspergillus candidus,Nigrospora oryzae,Aspergillus versicolor and Penicillium brocae)in moldy rice.