Anotace:
Probiotics play an important role in human gut health. However, it remains a challenge to maintain the viability of probiotics throughout the gastrointestinal transit. Hence, this study aimed to microencapsulate Bifidobacterium lactis Bi-07 with galactooligosaccharides (GOS) using the co-extrusion technique. Optimization of calcium chloride (1.0% w/v to 3.0% w/v) and GOS concentration (1.0% w/v to 5.0% w/v) were performed in the encapsulation of B. lactis Bi-07 based on bead size and microencapsulation efficiency. The study found that microbead prepared with 1.5% (w/v) sodium alginate, 2.0% (w/v) calcium chloride and 3.0% (w/v) GOS showed the highest microencapsulation efficiency. The size of the bead produced was 735.69 μm with the highest microencapsulation efficiency of more than 94%. Besides, the microencapsulation efficiency and bead size were compared between B. lactis Bi-07 beads with or without GOS. Results showed that the encapsulated B. lactis Bi-07 with GOS was had a larger bead size and lower microencapsulation efficiency than encapsulated probiotic cells without GOS. Furthermore, the encapsulated B. lactis Bi-07 and free cells were subjected to simulated gastrointestinal treatment where the cell viability was evaluated. Encapsulated B. lactis Bi-07 with GOS showed higher cell viability than encapsulated B. lactis Bi-07 without GOS and free cells after the simulated gastrointestinal treatment. The viable cell count of encapsulated B. lactis Bi-07 with GOS remained more than 107 CFU/mL. This showed that the optimized encapsulated B. lactis Bi-07 with GOS could survive the human gastrointestinal to confer health benefits and the potential to be incorporated into functional foods.