Microcapsules loaded with the probiotic Lactobacillus paracasei BGP-1 produced by co-extrusion technology using alginate/shellac as wall material: Characterization and evaluation of drying processes.

Microcapsules containing Lactobacillus paracasei BGP-1 were produced by co-extrusion technology using alginate and alginate-shellac blend as wall materials. Sunflower oil and coconut fat were used as vehicles to incorporate BGP-1 into the microcapsules. The microcapsules were evaluated with regard the particle size, morphology, water activity and survival of probiotics after 60days of storage at room temperature. Fluidized bed and lyophilization were used to dry the microcapsules and the effect of these processes on probiotic viability was also evaluated. Next, dried microcapsules were exposed to simulated gastrointestinal fluids to verify the survival of BGP-1. Microcapsules dried by fluidized bed had spherical shape and robust structures, whereas lyophilized microcapsules had porous and fragile structures. Dried microcapsules presented a medium size of 0.71-0.86mm and a ranging from 0.14 to 0.36, depending on the drying process. When comparing the effects of drying processes on BGP-1 viability, the fluidized bed was less aggressive than lyophilization. The alginate-shellac blend combined with coconut fat as core effectively protected the encapsulated probiotic under simulated gastrointestinal conditions. Thus, the production of microcapsules by co-extrusion followed by drying using the fluidized bed is a promising strategy for protection of probiotic cells.