亚麻籽二酯油乳液制备工艺优化及其微胶囊理化性质分析Optimization of preparation process of linseed oil diglyceride emulsion and physicochemical properties of its microcapsules

Abstract

为提高亚麻籽二酯油的稳定性和利用率，以抗性糊精和酪蛋白酸钠为复合壁材，单硬脂酸甘油酯（MG）和柠檬酸脂肪酸甘油酯(CITREM)为复合乳化剂，制备亚麻籽二酯油乳液，并进一步采用喷雾干燥法制备亚麻籽二酯油微胶囊。通过单因素实验考察固形物含量、MG与CITREM质量比、乳化剂添加量（以芯材质量计）和载油量对亚麻籽二酯油乳液粒径大小以及稳定性的影响，采用Box-Behnken设计响应面实验优化亚麻籽二酯油乳液的制备工艺，并采用钨丝灯扫描电子显微镜、傅里叶变换红外光谱仪、热重分析仪和体外模拟消化模型等对亚麻籽二酯油微胶囊的性质进行了分析。结果表明: 亚麻籽二酯油乳液最佳制备工艺条件为固形物含量50%、MG与CITREM质量比5∶ 4、乳化剂添加量2.5%、载油量50%，在此条件下亚麻籽二酯油乳液粒径为267.40 nm，亚麻籽二酯油微胶囊包埋率为97.85%; 亚麻籽二酯油微胶囊结构完整，整体呈球形，外部无明显损伤，且具有良好的热稳定性和溶解性；亚麻籽二酯油微胶囊在体外模拟胃肠道消化过程中芯材释放率达到84.59%。综上，微胶囊化有利于提高亚麻籽二酯油的稳定性，扩大其应用范围。 To improve the stability and utilization of linseed oil diglyceride, using resistant dextrin and sodium caseinate as composite wall materials, glycerol monostearate (MG) and citric acid fatty acid glyceride (CITREM) as composite emulsifiers, linseed oil diglyceride emulsion was prepared, and linseed oil diglyceride microcapsules were prepared by spray drying method.The effects of solid content, mass ratio of MG to CITREM, emulsifier dosage(based on core material mass) and oil load on the particle size and stability of linseed oil diglyceride emulsion were investigated by single factor experiment. Box-Behnken design response surface was used to optimize the preparation process of linseed oil diglyceride emulsion, the properties of linseed oil diglyceride microcapsules were analyzed by scanning electron microscope with tungsten filament lamp, Fourier transform infrared spectrometer, thermogravimetric analyzer and simulated digestion model in vitro.The results showed that the optimal preparation conditions of linseed oil diglyceride emulsion were obtained as follows:solid content 50%, mass ratio of MG to CITREM 5∶ 4, emulsifier dosage 2.5% and oil load 50%. Under these conditions, the particle size of linseed oil diglyceride emulsion was 267.40 nm, and the encapsulation rate of linseed oil diglyceride microcapsules was 97.85%. The linseed oil diglyceride microcapsules had complete structure, spherical shape, no obvious external damage, good thermal stability and solubility. The core material release rate of microcapsules in simulated gastrointestinal digestion in vitro reached 84.59%. In conclusion, microencapsulation is beneficial to improve the stability of linseed oil diglyceride and expand its application range