Stability and viability of synbiotic microgels incorporated into liquid, Greek and frozen yogurts

The viability of Lactobacillus acidophilus when co-encapsulated with fructooligosaccharides in alginate-gelatin microgels, for incorporation into liquid, Greek, and frozen yogurts, during storage and in vitro-simulated digestion was studied. Liquid yogurt provided the highest viability for the encapsulated probiotics during storage, followed by frozen and Greek formulations when compared to free probiotics, highlighting the influence of microencapsulation, yogurt composition, and storage conditions. Addition of up to 20% of probiotic (AG) and symbiotic (AGF) microgels did not cause significant changes in the liquid and frozen yogurts' apparent viscosity (η_ap ); however, it decreased η_ap for the Greek yogurt, indicating that microgels can alter product acceptability in this case. Both AG and AGF microparticles improved viability of cells face to gastric conditions for liquid and frozen yogurts, delivering cells in the enteric stage. Summarizing, liquid yogurt was the most appropriate for probiotic viability during storage, while frozen yogurt presented better protection along digestibility.