Original Articles: 2011 Vol: 3 Issue: 4
Enhancement of acid tolerance of entrapped probiotic bacteria by polyoxyethylene (80) sorbitan monooleate
Abstract
Recently there has been an explosion of probiotics as important nutraceuticals. In order for the probiotic organisms to exert a positive health effect, they have to reach the large intestine of the host, alive and in sufficient numbers. However, considerable losses in cell numbers of probiotics occurs in the stomach due to low pH. The objective of this study was to explore a method to enhance the survival of probiotic bacteria in adverse gastric conditions of low pH. Three strains of probiotic bacteria including Lactobacillus casei, Lactobacillus rhamnosus and Lactobacillus bulgaricus were grown in De Man, Rogosa and Sharpe medium incorporated with 1 g l–1 polyoxyethylene sorbitan mono-oleate (Tween 80) and were subsequently immobilised using alginate. The viability of the cultures in acidic conditions was assessed over a 2 hour incubation
period. Electron microscopy was used to determine the surface texture of the alginate beads before and after acid exposure. Inclusion of Tween 80 in the growth media revealed that it could improve the subsequent survival of encapsulated probiotic cultures up to 10-100 fold following 90 minutes of acid exposure.