Resistance of Saccharomyces boulardii to technological process, and its in-vitro probiotic properties

Saccharomyces boulardii has good functional benefits as probiotic bacteria. The objective of the present work was to examine the resistance of S. boulardii to technological processes such as high temperature, viability under cold storage (4 and -18°C), and the in-vitro probiotic properties that enable them to remain viable after passage through the acidic environment of the gastrointestinal tract, and resistance against bile salts. Results showed that S. boulardii growth was significantly higher (p < 0.0001) at 25°C compared to at 37°C for all the incubation times investigated, except 48 h. Saccharomyces boulardii count increased significantly (p < 0.0001) at 4°C during storage. However, at -18°C, no yeast survived beyond the first day of storage. It was significantly more stable (p < 0.0001) at a 1% salt ratio than other salt ratios (3 and 7%) at all the incubation times tested. Saccharomyces boulardii showed statistically significant tolerance (p < 0.0001) at pH 7.2 than at pH’s 2.5 and 4.0 throughout the incubation times investigated. Saccharomyces boulardii tolerated 0.5% bile salt ratio significantly more (p < 0.0001) than the 1.5 and 2.5% bile salt ratios. In conclusion, the best conditions for S. boulardii were incubation at 25°C and storage at 4°C, but not freezing. It tolerated low pH (pH 2.5 and 4), high salt ratios (3 and 7%), and bile salts (0.5, 1.5, and 2.5%).