Fermentative ability of alginate-prebiotic encapsulated Lactobacillus acidophilus and survival under simulated gastrointestinal conditions

Lactobacillus acidophilus was encapsulated in alginate-inulin-xanthan gum and its ability to grow in carrot juice and survive 8 weeks of storage at 4 _C and subsequent exposure to artificial gastrointestinal conditions were assessed. Encapsulation significantly enhanced cell viability after fermentation and storage (6 • 1012 and 4 • 1010 cells/ml versus 4 • 1010 and 2 • 108 for free cells, respectively). Encapsulation protected L. acidophilus from exposure to simulated gastric conditions; minor alterations in viability and the protein profile occurred after incubation in pancreatic juice. For free cells, viability decreased significantly and the expression of numerous proteins was lost after incubation in gastric and pancreatic juice. Thus, encapsulation preserved probiotic bacterial viability and activity; the addition of inulin as a prebiotic component could enhance the functional properties of food products containing this formulation.