单分散液滴发生器(MDDG)结合静电自组装制备益生菌微胶囊

Monodisperse Droplet Generator(MDDG) Combined with Electrostatic Self-assembly to Produce Probiotic Microcapsules

本研究利用单分散液滴发生器(MDDG),以海藻酸钙凝胶(-)为基质,壳聚糖(+)和阿拉伯胶(-)为涂层原料,利用静电引导的逐层自组装法制备多层益生菌微胶囊。研究结果表明,多层包埋的微胶囊具有更高的机械强度,多层益生菌微胶囊在乳酸细菌培养基(MRS)中培养9 h后依然维持完整的球形结构,包载的益生菌数量也提高了2.06 log cfu/g。此外,多层包埋还延长了微胶囊在胃肠液中的崩解时间,单层海藻酸钙微胶囊在模拟肠液中快速崩解,消化1 h时益生菌的释放量已达到8.23 log cfu/g。壳聚糖,壳聚糖-阿拉伯胶涂层的益生菌微胶囊在消化3 h后才达到相应对数值,分别为8.42 log cfu/g和8.33 log cfu/g。此外,相比于单层益生菌微胶囊,多层益生菌微胶囊在4℃和25℃下均表现出更高的贮藏稳定性,在4℃下贮藏12 d后,海藻酸钙-壳聚糖-阿拉伯胶三层胶囊内的活菌数仅由8.90 log cfu/g下降到8.81 log cfu/g。实验表明,MDDG结合静电引导的逐层自组装是高效制备均匀稳定的多层益生菌微胶囊,实现益生菌肠道输送的有效手段。

In this study,monodisperse droplet generator(MDDG)was utilized to produce multilayered probiotic microcapsules through using calcium alginate gel(-)(as the matrix),chitosan(+)and gum Arabic(-)(as the coating materials),and adopting a layer-by-layer approach based on electrostatic self-assembly.The results showed that the multilayered probiotic microcapsules had higher mechanical strength,and still maintained intact spherical structure after 9 h of culture in MRS liquid medium,with an increase(by 2.06 log cfu/g)in the number of probiotics contained in the microcapsules.In addition,multilayer structure prolonged the existence time of microcapsules prior to disintegration in the gastrointestinal juice.The single-layered calcium alginate microcapsules collapsed rapidly in the simulated intestinal fluid,with the amount of released probiotics reaching 8.23 log cfu/g after 1 h of digestion.Whereas,the probiotic microcapsules coated with chitosan,chitosan and gum arabic gum did not reach the corresponding logarithmic values(8.42 log cfu/g and 8.33 log cfu/g,respectively)until 3 h after digestion.Compared with the single-layer probiotics microcapsules,the multilayered microcapsules showed a higher storage stability at both 4℃and 25℃,with the number of viable cells in the three-layered microcapsules coated with calcium alginate-chitosan-gum arabic decreasing from 8.90 log cfu/g to 8.81 log cfu/g after a storage at 4℃for 12 days.The experimental results showed that MDDG combined with electrostatic-guided layer-by-layer self-assembly was an effective method for efficient preparation of homogeneous and stable probiotic microcapsules to enable the delivery of probiotics into the intestines.