明胶-海藻酸钠制备薄荷油微胶囊的工艺优化

Optimization of Preparation Technology of Peppermint Oil Microcapsules in Gelatin-Sodium Alginate

文中对以明胶和海藻酸钠为壁材,薄荷油为芯材用复凝聚法制备微胶囊的工艺进行了优化,通过对2种壁材复凝聚行为和微胶囊化工艺参数的优化,得到了最佳制备工艺:复凝聚pH值为4.3,明胶与海藻酸钠的质量比为4∶1,乳化剂体积分数为0.5%,均质时间为9 min,壁材浓度1.75%,复凝聚速度为600 r/min。经过优化后的微胶囊形态良好,为完整规则的圆球形,壁材对芯材包埋良好,产率为85.64%,含油率为50.00%,壁材利用率为78.75%,经热重(TG)测试表明,相比150℃以内就能完全损失的纯薄荷油,制得的薄荷油微胶囊在250℃以下可在外壳的保护作用下使内部薄荷油达到缓慢释放,从而赋予薄荷油良好的热稳定性。

The optimisation of peppermint oil microcapsules with gelatin(GE) and sodium alginate(SA) as wall-material through complex coacervation was studied. The final optimized technology was achieved by the coacervation and microencapsulation behaviour study. And the specific parameters are as follows: pH of 4.3, mass ration of GE and SA of 4∶1, volume fraction of emulsifier 0.5%, homogenization time of 9 min, wall-materials concentration of 1.75%, coacervation stirring speed of 600 r/min. It’s found that the microcapsules under the optimum preparation conditions have satisfying morphology which appear in a perfectly regular round ball with the encapsulation yield of 85.64%, payload of 50.00% and utilization ratio of wall-materials of 78.75%. The result of thermal gravimetric(TG) analysis shows that the peppermint oil with the protection of wall-materials of the microcapsule has good thermal stability which achieves the slow release under 250 ℃ compared to the peppermint oil without any protection that almost completely losses within 150 ℃.