Abstract: Immune colostrum was fermented by Bifidobacterium adolescentis and then subjected to vacuum freeze-drying to obtain freeze-dried powder. The prepared freeze-dried powder was used as the core material and CAP Opadry was used as the wall material to prepare an enteric-coated preparation with both immune and microbial activity by an air suspension microencapsulation method with the addition of protectant. The optimal protectant composition for improved viable Bifidobacterium adolescentis count was determined by single factor and orthogonal array design to be trehalose of 6%, hydrolyzed casein of 6%, and emulsifier Span80 of 3%. The viable bifidobacteria count in the obtained microcapsules was 6.0 × 108 CFU/mL and the survival rate of bifidobacteria was 18.2%, which exhibited an increase of 16.8% when compared to the control with the addition of protectant.

Key words: bifidobacterium, microcapsule, protectant