复合壁材布拉酵母微胶囊的制备

为提高布拉酵母对环境的耐受能力,采用复合壁材制备布拉酵母微胶囊。利用正交法考察了变性淀粉、β-环糊精和明胶3种材料的比例对微胶囊有效活菌数的影响。在此基础上,通过单因素法和正交实验对复合壁材浓度、进风温度、通气量和上料速度等工艺参数进行优化,观察微胶囊形态并考察对模拟消化液的耐受能力。结果表明：布拉酵母质量分数为10%时,变性淀粉、β-环糊精和明胶的最佳配比为6∶3∶5。喷雾干燥最佳工艺参数为：复合壁材质量分数16%、进风温度80℃、通气量550L/min、上料速度15mL/min。各因素对喷雾工艺的影响程度为：进风温度>复合壁材浓度>上料速度>通气量。采用最优条件制备的布拉酵母微胶囊呈球形,表面紧密无裂缝,平均大小为138.65μm,具有耐受能力强和体内缓释的特点。研究结果为布拉酵母微胶囊的工业化生产奠定了基础。

Preparation of compound wall materials microcapsules of Saccharomyces boulardii

To enhance the resistance of Saccharomyces boulardii （S.boulardii） to the environment, its microcapsule was prepared by compound wall materials. Based on the application of modified starches, β-cyclodextrin and gelatin as compound wall materials, the effect of the ratio of three blended wall materials was assayed on colony-forming units in S. boulardii microcapsules using the orthogonal experimental method. Then an optimization was performed concerning several spray drying processing parameters, such as compound wall material concentration, inlet temperature, air flow, and feeding speed via the single factor process and the orthogonal test. Further, corresponding morphology and tolerance to artificial digestive juice were observed. The results showed that the optimal ratio of modified starches, β-cyclodextrin and gelatin was 6∶3∶5 with the 10% concentration of S. boulardii. The optimal spray drying processing parameters were as follows: the compound wall material concentration of 16%, inlet temperature of 80℃, air flow of 550L/h, and feeding speed of 15mL/min. Besides, the leading influence factor on the production of S. boulardii microcapsules was inlet temperature, followed by compound wall material concentration and feeding speed, and finally air flow. Under those conditions, S. boulardii microcapsules were spherical without holes and cracks on the surface, and with an average size of 138.65μm. Moreover, S. boulardii microcapsules were also found to be good tolerance to artificial digestive juice, as well as slow-release in simulated gastrointestinal conditions. Collectively, the present study lays a foundation for the commercial production of S. boulardii microcapsules.