Influence of microencapsulated Streptococcus thermophilus ST-HSTU-FPP and Limosilactobacillus fermentum LS-HSTU-FPP strains on biochemical features of yogurt following in-vitro simulated gastrointestinal conditions

Microencapsulated starter cultures with known probiotic strains demonstrate significant effectiveness to be utilized in developing functional yogurt whereas conventional starter cultures comprising unknown strains exhibit their inability to survive in the yogurt. The current study intended to formulate probiotic yogurts with Streptococcus thermophilus ST-HSTU-FPP and Limosilactobacillus fermentum LS-HSTU-FPP strains encapsulated with whey protein, maltodextrin: gum Arabic and maltodextrin: whey protein: gum Arabic, as well as assess their effects on biochemical properties, mineral content, viability under simulated gastrointestinal conditions, and sensorial attributes. There was no significant (p ≤ 0.05) difference in pH, total soluble solid, water holding capacity, and syneresis between the yogurt prepared with encapsulated and conventional starter culture. The yogurt made with conventional starter culture had the lowest survival rate (5 log CFU/g) while all of the yogurt with encapsulated probiotics showed above 6 log CFU/g after 180 min in both the simulated gastric juice and intestinal juice conditions. Yogurt comprising probiotics encapsulated with maltodextrin, whey protein, and gum Arabic had the highest protein content (5.63%), calcium (9835.7 mg/kg), and magnesium (1874.6 mg/kg), while the probiotics encapsulated with maltodextrin and gum Arabic had the lowest protein (4.81%), calcium (2353.0 mg/kg), and magnesium (743.3 mg/kg). Conclusively, probiotics encapsulated with maltodextrin: whey protein: gum Arabic might be recommended for the commercial preparation of probiotic yogurt having viable functional food properties. Graphical abstract