Microencapsulation for enhancing the survival of probiotic Lactobacillus paracasei S233.

摘要

Probiotic Lactobacillus paracasei S233 was microencapsulated using sodium alginate and starch. The organism survived better in the protected form at high temperatures (72, 85 and 90 degrees C). The normal cells were destroyed completely at 85 and 90 degrees C while the encapsulated cells registered 3.2 and 4.6 log cycles reduction. Homogenization did not affect the viability of the cells, but destroyed the protective encapsulating material around the cells. The salt tolerance tested at 1, 1.5 and 2% NaCl (w/v) showed decrease progressively for normal and encapsulated cells, the decrease being higher in the former. At simulated conditions of gastric pH (1.0, 1.5 and 2.0), encapsulated cells survived compared to normal cells (2.1 and 6.5 log cycle reduction, respectively at pH 2 after 3 h incubation). Similar results were seen at high bile salt concentrations (1.0, 1.5 and 2.0% w/v). As the bile salt concentration increased from 1.0 to 2.0%, the reduction in viable cells was between 2.6 and 3.7 log cycles after encapsulation as against 3.7 and 5.2 in the normal cells. The microencapsulated cells required 2.5 h at simulated colonic pH for release from the matrix material.