Viability and survival of free and encapsulated probiotic bacteria in Cheddar cheese

Four batches of Cheddar cheese were made incorporating Lactobacillus acidophilus CSCC2401 and Bifidobacterium infantis CSCC1912 (probiotic strains from CSIRO, Australia), and commercial probiotic strains of L. acidophilus 910 and B. lactis 920 (DSM Food Specialities, Australia). The probiotic strains were added as adjunct cultures, either free or encapsulated. Survival of the probiotic bacteria was monitored over a period of 24 weeks of storage at 8-10 degrees C. The results showed that after 24 weeks storage, with the exception of L. acidophilus 910, the encapsulated cell counts decreased by approximately 1-2 log cycles compared with free cell counts. L. acidophilus strains showed better survival than bifidobacterium strains during the storage of the cheese. This study showed that free cells of probiotic bacteria survived better than encapsulated cells in the Cheddar cheese matrix, hence encapsulation does not significantly increase the survival of probiotic bacteria during Cheddar cheese maturation and storage.