山羊乳-FOS/GOS库德毕赤酵母DS8-1微胶囊的制备及体外评价

Preparation and in vitro Evaluation of Goat Milk-FOS/GOS Pichia kudriavzevii DS8-1 Microcapsules

前期从新疆传统乳制品酸驼乳中筛选得到一株具有潜在益生特性的库德毕赤酵母DS8-1(Pichia kudriavzevii DS8-1),为增加菌株对体外环境的抗性,以海藻酸钠为壁材使用锐孔法制备酵母菌微胶囊。将干燥的藻酸盐(SA)微胶囊外包山羊乳或在微胶囊壁材中添加低聚果糖(fructooligosaccharides,FOS)/低聚半乳糖(galactooligosaccharides,GOS)分别制备3种酵母菌微胶囊:SAM微胶囊、SAMF微胶囊和SAMG微胶囊。对微胶囊进行傅里叶红外光谱和扫描电子显微镜表征、模拟胃液的耐受性、消化液的释放特性和贮藏稳定性实验,研究冻干微胶囊对菌株活性的影响。结果表明:使用羊乳包衣的3种冻干微胶囊(SAM微胶囊、SAMF微胶囊和SAMG微胶囊)的菌株活力为7.16~7.67(lg(CFU/g))。与SA微胶囊相比,SAMF微胶囊在连续的模拟消化液处理后能够延缓酵母菌的释放,提高菌株存活率,以及对α-淀粉酶和α-葡萄糖苷酶具有较高的抑制活性。SAMG微胶囊在-20、4、25℃贮藏30 d后菌株活力在7(lg(CFU/g))以上。结论:在海藻酸钠中添加FOS/GOS且使用羊乳包衣可用于包埋库德毕赤酵母,制备的酵母菌微胶囊具有提高菌株活性的作用,在功能性食品输送体系中具有一定的应用前景。

To improve its in vitro environmental resistance,Pichia kudriavzevii DS8-1,a strain with probiotic potential previously prepared by our research group from traditional fermented camel milk in Xinjiang,was microencapsulated by a piercing-solidifying method.Three types of microcapsules coated with goat milk,SAM,SAMF and SAMG,were prepared using sodium alginate alone and with added fructooligosaccharides(FOS)or galactooligosaccharides(GOS)as the wall material,respectively.Uncoated microcapsules(SA)with sodium alginate as the wall material were used as the control.The microcapsules were characterized by Fourier-transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM).Their tolerance to simulated gastric juice,release characteristics in simulated digestive juice and storage stability were evaluated.Besides,the effect of freeze drying on the survival of microencapsulated yeast cells was investigated.Results showed that the viability of lyophilized SAM,SAMF,and SAMG microcapsules was 7.16–7.67(lg(CFU/g)).Compared with SA microcapsules,SAMF microcapsules could delay the release of yeast cells,improve the survival rate,and have stronger inhibitory activities on α-amylase and α-glucosidase after continuous exposure to simulated digestive juice.After SAMG microcapsules were stored at−20,4 or 25℃for 30 days,the cell viability was higher than 7(lg(CFU/g)).In conclusion,addition of FOS or GOS to sodium alginate and goat milk coating can be used to microencapsulate Pichia kudriavzevii with improved viability.The prepared microcapsules show promise as a delivery system for functional foods.