Improvement of Probiotic Viability by Mixing with Ultrasound-Treated Yeast Cells and Spray Drying

The objective of the study was to determine the efficacy of ultrasound-treatment Saccharomyces cerevisiae and spray drying in preserving the viability of Lactiplantibacillus plantarum. The combination of ultrasound-treated S. cerevisiae and L. plantarum was evaluated. Next, the mixture was blended with maltodextrin and either Stevia rebaudiana-extracted fluid, prior to undergoing spray drying. The L. plantarum viability was assessed after the spray drying process, during storage, and in simulated digestive fluid (SDF) conditions. The results showed that the impact of ultrasound caused the crack and holes in the yeast cell wall. Besides, the moisture content values were not significantly different in all samples after spray drying. Although the amount of powder recovery in stevia-supplemented samples was not higher than that of the control sample, the L. plantarum viability was significantly improved after the spray drying process. The density of L. plantarum tended to be stable during the first 30 days of storage and decreased more rapidly after that. The results reveal that there was no statistically significant difference in the trend of the samples before and after storage. In the SDF test, the L. plantarum viability mixing with ultrasound-treated yeast cells in the spray drying samples was significantly improved. Besides, the presence of Stevia showed positive efficiency on the L. plantarum viability. The L. plantarum viability mixing with ultrasound-treated yeast cells and stevia-extracted fluid by spray drying process showed potential application due to making powder form which helped to improve the L. plantarum stability during the storage time.