Effect of microencapsulation on viability and other characteristics in Lactobacillus acidophilus ATCC 43121

Lactobacillus acidophilus ATCC 43121 were microencapsulated with sodium alginate by dropping method. The effects of microencapsulation on the changes in survival rate of the L. acidophilus ATCC 43121 during exposure to artificial gastrointestinal and on the change in heat susceptibility of L. acidophilus ATCC 43121 during the heat treatment were studied. In addition, cholesterol assimilation and intestinal adhesion of non-encapsulated and encapsulated L. acidophilus ATCC 43121 were also investigated to explore the effect of microencapsulation on health beneficial effect of lactic acid bacteria. Non-encapsulated cells were completely destroyed when exposed to artificial gastric juice (AGJ) of pH 1.2 and 1.5, while the treatment declined the viable count of encapsulated samples only by 3 log. Encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice (AIJ) and heat treatment than non-encapsulated samples. The assimilative reductions of cholesterol by non-encapsulated and encapsulated L. acidophilus ATCC 43121 were 35.98% and 32.84%, respectively. However, encapsulation did not significantly (P>0.05) affect the adherence of L. acidophilus ATCC 43121 onto the human intestinal epithelial cell lines HT-29. The microencapsulation effectively protected the microorganisms from heat and acid treatment in delivering the viable cells to intestine without any significant adverse effect on their functionalities.