Effect of two types of wall matrix on viability of lactobacillus plantarum under simulated gastrointestinal fluids

The viability of probiotic cells decreases during passage through the gastrointestinal tract and storage. Thus, to protect probiotics strains against harsh conditions, it is necessary to encapsulate them. Lactobacillus plantarum was entrapped in Sodium Alginate/Chitosan (SA/Chi) and Sodium Alginate/ Nano-Chitosan (SA/NChi) wall materials. SA/Chi and SA/NChi beads under FE-SEM were spherical and morphologically compact with the appearance of a crack for the SA/NChi beads. The survival rate of free cells rapidly reduced during 240 min in simulated gastrointestinal fluids and reached 29%, furthermore, the survival of bacterial cells in SA/Chi and SA/NChi beads after exposure to Simulated Stomach Fluid (SSF) and Simulated Intestinal Fluid (SIF) for 240 min was 81.61% and 87.04% respectively. Coating bacteria cells in encapsulants improved the survivability of the cells under adverse environmental conditions. At the same time, the hydrogel beads were characterized by FT-IR and DSC. The vigorous electrostatic interaction between sodium alginate and nanochitosan as well as, the high melting point for nano-chitosan resulted in a higher melting point for SA/NChi beads. The distinctive properties possessed by the SA/NChi coating make it an excellent candidate for use in food processing and as polymeric carrier in probiotics delivery system.