Effect of lecithin and calcium chloride solution on the microencapsulation process yield of calcium alginate beads

The physical protection by microencapsulation is a new method to increase the survival of probiotic bacteria. The size of beads containing probiotics has significant effect on organoleptic properties of foods. Reduction of the sphere size to less than 100 μm would be advantageous for texture considerations and allow direct addition of encapsulated probiotics to a large number of foods. In microencapsulation process, Tween 80 can be replaced by lecithin in order to prevent its detrimental effect on the viability of probiotic bacteria. Calcium alginate as an edible polymer was used for the microencapsulation of probiotic bacteria by emulsion technique. A modified microencapsulation method based on emulsion technique was investigated in this study to produce microcapsules with diameters below 100 μm. A completely randomized design (CRD) experiment was applied in triplicates to evaluate the effect of surfactant (0, 0.2, 0.4 and 1% lecithin with 0.2% Tween 80 as control) and calcium chloride solution (100 and 200 mL) on the microencapsulation process yield of microencapsulated Lactobacillus casei. Microsphere characterization was performed by scanning electron microscopy (SEM). The microencapsulation process yield increased with increasing the volume of calcium chloride solution and it decreased with increasing the amount of lecithin. The highest microencapsulation process yield was obtained when 0.2% Tween 80 was used as surfactant. The shape of beads was spherical and their mean diameter was 17.80±3.55 μm.