Microencapsulation of Lactobacillus acidophilus la-5 increases relative survival under simulated gastrointestinal tract stress

This paper focused on increasing the relative survival of Lactobacillus acidophilus LA-5 when exposed to a sequential simulated gastrointestinal tract stress by the immobilization in microparticles of alginate formed by an emulsification and external gelation method. The aqueous phase consisted of 4% alginate and the oil phase consisted of mineral oil and Span 80 at 1%. The microparticles were manufactured at 250 rpm, at 20°C for 30 min. The relative survival of the free microorganism was not detectable at the end of the stress period. In contrast, despite the stress-induced disintegration of the microparticles, the relative survival of L. acidophilus LA-5 was 46.9%. The generated microparticles had the ability to protect and liberate probiotics, making then suitable for use as protective agents for probiotics sensitive to gastrointestinal stress, which may have applications in the food or pharmaceutical industries.

Keywords: microencapsulation, viability, controlled release, gastrointestinal transit, probiotics.