木姜子精油微胶囊制备工艺优化及其品质分析

以木姜子精油为主要原料，采用真空冷冻干燥法制备木姜子精油微胶囊，并以包埋率为指标，在单因素实验基础上结合正交试验，进行木姜子精油微胶囊包埋工艺的优化，以确定最佳工艺参数。同时进行木姜子精油微胶囊的质量评定，分析其理化性质、微观结构、及在储藏过程中精油的挥发率及过氧化值。结果表明，木姜子精油微胶囊包埋的最佳工艺参数为:复合壁材比（大豆分离蛋白:β-环糊精）为1:1（g/g）、芯壁材比1:5（g/g）、固形物含量15%、乳化剂含量3%、乳化剂配比1:4（g/g）、乳化温度40 ℃，在此条件下制备出的木姜子精油微胶囊包埋率可达到84.68%，水分含量、溶解度及堆积密度分别为3.05%、91.04%和0.35 g/cm3。扫描电子显微镜结果显示，木姜子精油微胶囊呈不规则块状。随着储藏时间的延长，木姜子精油微胶囊的挥发率和过氧化值均低于木姜子精油，表明木姜子精油通过微胶囊化，能够有效减缓精油的挥发速度，降低精油氧化程度。

Preparation Process Optimization and Quality Analysis of Litsea pungens Hemsl Essential Oil Microcapsules

The essential oil of Litsea pungens Hemsl was used as the main raw material, and the method of vacuum freeze-drying was used to prepare the microcapsules of essential oil of Litsea pungens Hemsl, and the embedding rate of the microcapsules was used as an index. Optimizing the microcapsule embedding process of essential oils to determine the best process parameters. At the same time, the physical and chemical properties, microstructure, volatile rate and peroxide value of essential oil were analyzed during storage. The results showed that the best parameters of the microcapsules of essential oil were as follows: Composite wall material ratio (soy protein isolate: β-cyclodextrin) was 1:1 (g/g), core wall material ratio was 1:5(g/g), solid content was 15%, emulsifier content was 3%, emulsifier ratio was 1:4 (g/g), emulsifying temperature was 40 ℃, embedding rate of the microcapsules was 84.68%, its water content, solubility and bulk density were 3.05%, 91.04% and 0.35 g/cm3, respectively. The results of SEM showed that the microcapsules of Litsea pungens Hemsl essential oil were irregular in shape. With the extension of storage time, the volatilization rate and peroxide value of microcapsules of Litsea pungens Hemsl essential oil were lower than those of essential oil, which indicated that the microencapsulation of Litsea pungens Hemsl essential oil could effectively slow down the volatilization rate and reduce oxidation degree of essential oil.