Airbrush encapsulation of Lactobacillus rhamnosus GG in dry microbeads of alginate coated with regular buttermilk proteins

Lactobacillus rhamnosus GG (L. rhamnosus GG) loaded calcium alginate microbeads were prepared via an airbrush system and subsequently coated with regular butter milk proteins (RBMP). Scanning electron micrographs and changes in zeta potential demonstrated the presence of RBMP on microbeads surface. Survivability of probiotics after microbead lyophilization was higher in coated microbeads (8.91 +/- 0.03 log cfu) than in the uncoated ones (7.67 +/- 0.09 log cfu). After storage at - 20 degrees C for 30 d, the coated and uncoated microbeads showed 0.4 log and 0.8 log cfu/g loss in cell number, respectively. RBMP also enhance the survival of L. rhamnosus GG after exposure to sequential simulated gastrointestinal conditions. These results suggest that coating alginate capsules with RBMP is an effective strategy for the survival of L. rhamnosus GG when encapsulated with an airbrush system.