缓释型茶树精油-壳聚糖微胶囊的制备、表征及体外释放规律

以三聚磷酸钠（sodium tripolyphosphate，TPP）为交联剂，采用离子凝胶法制备茶树精油-壳聚糖（chitosan，CS）微胶囊，研究茶树精油微胶囊的结构和功能特性，并分析茶树精油微胶囊在不同食品模拟体系中的释放规律。结果表明，茶树精油添加量和CS与TPP质量比对微胶囊粒径和茶树精油包埋率有显著影响，通过优化得到CS与TPP质量比5.3∶1、茶树精油添加量11.30 mg/mL时，茶树精油微胶囊的粒径最小为（0.74±0.03）μm，包埋率最大为（53.15±0.32）%。该条件下微胶囊的粒径范围在0.2～2.3 μm之间，且呈正态分布；并且可以明显提高茶树精油的稳定性，表现为与茶树精油相比，茶树精油微胶囊在0～15 d时，有更稳定的体外杀菌性和抗氧化性。另外，茶树精油微胶囊在不同的食品模拟体系中均能快速释放，并在30 min后逐渐稳定。说明该工艺可以用于对茶树精油的微囊化包埋，从而提高茶树精油的稳定性。

Preparation,Characterization and in Vitro Release Characteristics of Sustained-Release Chitosan Microcapsules Containing Tea Tree Oil

In this experiment, chitosan (CS) microcapsules containing tea tree oil (TTO) were prepared using sodium tripolyphosphate (TPP) as the crosslinking agent by the ionic gelation method. The structure, functional properties and release profiles in different food model systems of the microcapsules were analyzed. The results showed that the encapsulation efficiency was strikingly affected by TTO concentration and mass ratio between CS and TPP. The optimized values of the two parameters were 11.30 mg/mL and 5.3:1, respectively, which resulted in a minimum particle size of (0.74 ± 0.03) μm and a maximum encapsulation efficiency of (53.15 ± 0.32)%. The particle size of the microcapsules obtained under these conditions was normally distributed in the range of 0.2–2.3 μm, and the stability of TTO was significantly improved by the encapsulation. The antimicrobial and antioxidant effects of the microcapsules were more stable for 15 d than TTO. In different food model systems, the microcapsule powder was rapidly released, and reached a stable sate after 30 minutes. Therefore, this process can be used for microencapsulation of tea tree oil to improve its stability.