山茶油微胶囊的复合凝聚制备工艺参数及其热氧稳定性研究

Preparation and Thermal-oxidative Stability of Camellia Oil Microcapsules by Complex Coacervation

以明胶和阿拉伯胶为壁材,茶多酚为固化剂,采用复合凝聚法制备山茶油微胶囊。通过单因素和正交试验考察壁材比、pH、壁材浓度、凝聚时间、芯壁比等复合凝聚条件对山茶油微胶囊包埋率和微观形态的影响,确定山茶油微胶囊复合凝聚的最佳制备工艺,并对微胶囊化前后的山茶油氧化稳定性进行分析比较。结果表明:山茶油微胶囊的最佳复合凝聚制备工艺参数为壁材比1∶1(W/W)、pH 4.2、壁材浓度1.0%、凝聚时间30 min、芯壁比3∶2(W/W),在此最佳条件下制备的山茶油微胶囊产品呈浅棕色粉末状,平均包埋率达82.36%,休止角39.2°,含水率3.67%。热稳定温度280℃,具有良好的流动性和热稳定性。同时,加速氧化贮藏试验表明微胶囊化显著提高了山茶油的氧化稳定性。

Camellia oil microcapsules were prepared by complex coacervation using gelatin and gum arabic as wall materials,tea polyphenols as the curing agent.The preparing process of camellia oil microcapsules was optimized by the orthogonal experiment on the basis of single factor experiments.The effects of the ratio of gelatin to gum arabic,concentration of wall material,pH,coagulation time and the ratio of core material to wall material on the microencapsulation efficiency and morphology of camellia oil microcapsules were investigated.The oxidative stability of the native and microencapsulated camellia oil were also analyzed and compared.The optimal preparation conditions of camellia oil microcapsules were obtained as follows:ratio of gelatin to gum arabic 1∶1,pH 4.2,concentration of wall material 1.0%,ratio of core material to wall material 3∶2,and coagulation time 30 min.Under the conditions,the prepared camellia oil microcapsules were in the form of light brown,and the average microencapsulation efficiency,the angle of repose,moisture content and the thermal stabilization temperature was 82.36%,39.2°,3.67%and 280℃,respectively,meaninging they were of good fluidity and thermal stability.Moreover,the higher oxidative stability of camellia oil microcapsules compared to native camellia oil were achieved according to the results of accelerated oxidation storage experiment.