Enhancing Bioavailability of Probiotics using Microencapsulation

Abstract

Microencapsulation is a process of coating tiny solid particles or droplets of liquid or gaseous material with a continuous film of polymeric material. By microencapsulation, the core material is prevented from coming in to direct contact with the surrounding atmosphere. This process offers advantages like sustained release, taste masking, increased stability and smaller particle size. Its applications are commonly found in nutraceutics, cosmetics, perfumery, textiles, paint industry and especially in pharmaceutical and food industries. Biologically active species need to be protected from enzymes present in the body as degradation prior to reaching their targeted site can lead to decreased bioavailability. One of the most trending research areas in this regard is microencapsulation of probiotics. Probiotics are microorganisms found in the digestive system and are known to provide immunity and health benefits. However, when consumed orally, they are reported to have poor viability against the gastric pH, with almost 65% of strains of probiotics having low or moderate tolerance. This emphasizes on the need to develop effective delivery systems of probiotics into the gastrointestinal tract by by-passing the highly acidic gastric conditions, which is the major degradation site of these bacteria. Different microencapsulation techniques, like spray drying, spray congealing, extrusion method, complex coacervation and materials like chitosan, carrageenan, alginate, starch have been explored for the effective delivery of probiotics. Synthetic polymers like ethyl cellulose, hydroxypropyl cellulose, acrylates and polyvinyl acetate phthalate are also promising coating agents in microencapsulation. More techniques and material are under study to develop effective systems for delivery of probiotics. This review presents the recent advances in microencapsulation process and the coating materials being studied for increased survival and targeted delivery of probiotics.