Abstract:

Two different microcapsules containing Bifidobacterium bifidum were individually prepared using alginate and
whey protein. Their characteristics, including particle size, microencapsulation yield, micrographs, buffering capacity and
protective effect on microencapsulated cells, were studied. The results showed that the particle size and microencapsulation
yield of whey protein microcapsules (202.5 μm, 87.8%) were both higher than those of alginate microcapsules (118.3 μm,
48.1%). At high concentration of bile salt solution, there was no significant difference in protective effect on
microencapsulated Bifidobacterium bifidum between these two microcapsules. However, the whey protein microcapsules provided
a better protection for microencapsulated Bifidobacterium bifidum than alginate microcapsules did when treated with acid
condition, simulated gastric juice and ambient storage condition, and the survival count of microencapsulated Bifidobacterium
bifidum in whey protein microcapsules was 5, 2, and 0.5 (lg (CFU/mL)) higher than that in alginate microcapsules, respectively.
There may be two reasons for this better protection: first, whey protein has higher buffering capacity at nearly neutral pH; and
second, whey protein microcapsules have better micrographs in terms of sphericity and density.

Key words: whey protein, alginate, microcapsules, probiotics