Probiotic encapsulation in CaCO3 microparticles: Enhancement of viability under heat treatments and simulated gastrointestinal conditions

The aim of this study was to evaluate the effect of microencapsulation on the viability and stability of Lactobacillus plantarum TISTR 543 using calcium carbonate microparticles (CaCO 3 -MPs) produced by co-precipitation. Free bacterial and encapsulated cells were freeze-dried with or without lactose and skim milk as lyoprotectants. The survivability of encapsulated probiotics was evaluated under different heat treatments, during storage, and under simulated gastrointestinal conditions, along with their intestinal adhesion to Caco-2 cells and their inhibition of Escherichia coli adhesion. The results showed that L. plantarum -encapsulated CaCO 3 -MPs were efficient, enabling the recovery of a high number of entrapped cells. Moreover, the presence of lyoprotectants significantly enhanced the survival rate of encapsulated L. plantarum during lyophilization ( P < 0.05). The viability of the encapsulated probiotics was maintained at over 10 6 CFU/g under thermal conditions and simulated gastrointestinal conditions. In the adhesion experiment, encapsulated L. plantarum exhibited a concentration-dependent ability to adhere to Caco-2 cells. Encapsulated probiotics also effectively reduced E. coli in exclusion and competitive adherence tests. CaCO₃-MPs serve as a robust delivery platform for protecting probiotics under various hostile conditions while maintaining probiotic viability in the gastrointestinal tract. These CaCO₃-MPs can be included in suitable functional food products. • Co-precipitation technique was a feasible technology to protect L. plantarum in the CaCO 3 crystals. • CaCO 3 -MPs increased the survivability of probiotics under gastric conditions and neutralized gastric pH. • Encapsulated L. plantarum exhibited enhanced adherence to Caco-2 cells and inhibited E. coli adhesion.