Viability and stability of microencapsulated probiotic bacteria by freeze‐drying under in vitro gastrointestinal conditions

Probiotic bacteria were isolated from yogurt and cheese whey and used to prepare encapsulated probiotic bacteria with whey protein (WP), maltodextrin (MD), and gum Arabic (GA) as single, binary, and ternary encapsulation coating materials by freeze‐drying. Probiotic powders were characterized using FTIR, SEM, encapsulation efficiency, and survivability under simulated gastrointestinal conditions. Limosilactobacillus fermentum strain LF‐HSTU‐FPP and Streptococcus thermophilus strain ST‐HSTU‐FPP were identified by 16S RNA. Encapsulation with WP and GA had a high encapsulation efficiency of 94.69% and the least injury of cell viability of 2.8715 Log CFU/g and 2.85 Log CFU/g in simulated gastric juice and stimulated intestinal juice, respectively. Microcapsules showed broken glass, porous, and irregularly shaped structures. The stability of probiotic bacteria was confirmed by FTIR analysis of amide group I and II peak alterations. Binary encapsulation (WP and GA) was a suitable coating material for the stability of probiotic bacteria in the gastrointestinal tract during storage. Novelty impact statement Two isolated probiotic bacteria were encapsulated using whey protein, maltodextrin, and gum Arabic carrier material. Cell losses were minimal in protein‐based carrier materials during storage. Encapsulated probiotic bacteria showed minor damage when exposed to gastrointestinal fluid.