Evaluation of the effect of co-encapsulation with Thymus Vulgaris L. extract on viability of Lactobacillus acidophilus

Encapsulation of probiotic cells is a novel method for enhancing the viability of probiotics in food and simulated gastrointestinal environment. Probiotics and thymus vulgaris l. exctract (TVE) have numerous potential health benefits. TVE had also positive effects on the survival of some probiotic bacteria in food products or during exposure to gastrointestinal conditions. In this study, Lactobacillus acidophilus cells and TVE in different concentrations (500, 1000 and 1500 μg/ml) were co-encapsulated in chitosan coated alginate beads, and their ability to protect cells under high temperature (80 and 90 °C), stomach environmental condition (pepsin, pH=1/5) and intesine (pancreatin and bile salts, pH= 8) were investigated. Small spherical microparticles having antioxidant activities and high bacterial cells.The coating of these microparticles with chitosan along with TVE was an efficient way to protect cells from conditions encountered in the upper part of the gastrointestinal tract and high temperature and increased the survival of encapsulated bacteria in simulated gastrontestinal conditions compared with free and encapsulated bacteria without extracts (p < 0.05).The co-encapsulation of bacteria with 500 and 1000 μg/ml TVE provided an additional protection to the cells in gastric conditions (p < 0.05). This study indicates that chitosan-alginate beads could be a new carrier for the combined delivery of viable probiotic cells and TVE to the lower part of the gastrointestinal tract.