乳蛋白微胶囊包埋共轭亚油酸及其稳定性研究

Microcapsulation of conjugated linoleic acid with milk proteins and its stability

中文关键词:  牛乳浓缩蛋白  乳清浓缩蛋白  共轭亚油酸  微胶囊

英文关键词:milk protein concentrate  whey protein concentrate  conjugated linoleic acid  microcapsules

中文摘要:

      目的 比较不同乳蛋白作为微胶囊壁材包埋共轭亚油酸的效果, 并考察其产品的稳定性。方法 分别以牛乳浓缩蛋白MPC80(milk protein concentrate, MPC)和乳清浓缩蛋白WPC80(whey protein concentrate, WPC)为高蛋白壁材, 以多不饱和脂肪酸(共轭亚油酸, conjugated linoleic acid, CLA)为芯材, 制备微胶囊产品。在芯壁比(芯材和壁材质量比)分别为1:4和1:8的比例下将壁材溶液(蛋白浓度为16%)和芯材混合、均质, 经由喷雾干燥制备了共轭亚油酸微胶囊产品。通过扫描电子显微镜和气相色谱等检测方法对微胶囊产品的包埋率、表面形貌以及储藏过程中芯材的氧化稳定性进行研究。结果 当芯壁比相同时(1:4和1:8, m:m), MPC组微胶囊的芯材包埋率总是低于WPC组; 且MPC组微胶囊产品的表面凹陷程度和内壁疏松程度也更高。当芯壁比提高后, WPC和MPC组的微胶囊效率均有所上升。但是对不同芯壁比的微胶囊产品进行氧化稳定性检测后发现, 加速储藏(45 ℃)过程中MPC组微胶囊产品的质量都比WPC组差。 结论 牛乳蛋白种类对牛乳蛋白作为CLA微胶囊壁材的影响较大。WPC是CLA微胶囊的优质壁材, 而MPC虽然可以作为微胶囊壁材应用, 但是对敏感芯材CLA的包埋效率和保护效果都存在一定的局限性, 需要进一步改善以提高其应用性能。

英文摘要:

      Objective To compare the effects of using different milk proteins as wall material to encapsulate conjugated linoleic acid, and investigate the stability of the corresponding microcapsules. Methods High protein milk powders (milk protein concentrate MPC80 and whey concentrate protein WPC80) were used as wall materials, and conjugated linoleic acid (CLA) was used as core material. CLA microcapsules were produced through homogenizing and spray drying after mixing the core and wall material solution in the mass ratios of 1:4 and 1:8(m:m). The microencapsulation efficiency, surface morphology and oxidative stability of microcapsules were studied by scanning electron microscopy and gas chromatography. Results When the core-wall ratio was the same (1:4 and 1:8, m:m), the encapsulation efficiency of MPC microcapsule were always lower than that of WPC group, the surface sag of the microcapsules was deeper and the internal pores were more. When the core-wall ratio was raised, the microencapsulation efficiencies of WPC and MPC both increased. However, after testing the oxidation stability of the microcapsules with different core-wall ratios, it was found that: the qualities of MPC microcapsules in the accelerated storage (45 ℃) were worse than those of the WPC group. Conclusion The protein kind has great influences on using milk protein as wall materials to encapsulated CLA. WPC is a good wall material for CLA microencapsulation and although MPC can be used as wall material, and there are still some limitations on the microencapsulation efficiency and protection effect, which needs further improvement on its application.