Microencapsulation of Probiotic Lactobacillus Rhamnosus by Extrusion Technique with the Selected Coating Material

Abstract

Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Survival and stability in the gastrointestinal tract are being debated by scientists. To overcome these limitations, microencapsulation techniques are receiving considerable attention. Microencapsulation is a physicochemical or mechanical process to entrap a substance in material to produce particles with diameters of a few micrometers to a few millimeters. In the present investigation, an indigenous probiotic strain Lactobacillus rhamnosus MTCC 5462 was microencapsulated through the extrusion process using chitosan and ĸ- carrageenan as coating polymers. Based on cell viability and bead size, the microencapsulation process was optimized. Probiotic L. rhamnosus MTCC 5462 was activated in MRS broth, harvested and the biomass was adjusted to 1011 to 1012 cfu/ml in sterile saline and then cell concentrate was added to sodium alginate and encapsulation was done by spraying in calcium chloride solution. The extrusion process with concentration (1, 2, and 3 %) of chitosan or ĸ-carrageenan showed a significant effect on cell viability and bead size. The chitosan as coating material gave maximum cell viability and minimum bead size.