Abstract
This study evaluated the survival of encapsulated and free probiotic strains (Lacticaseibacillus paracasei Shirota and Lacticaseibacillus rhamnosus GG) in orange juice during storage and in simulated gastrointestinal tract (GIT) conditions and their effect on the survival of Salmonella enterica. Samples were inoculated with free or encapsulated probiotics in whey protein isolate–gum Arabic matrix in 9.00 log CFU/mL population level and were stored at 4 °C and 12 °C for five days. Additionally, samples were co-inoculated with S. enterica 3-strain cocktail at 1.70 log CFU/mL. Samples were withdrawn daily, and microbiological analysis, pH, and sensory evaluation were conducted. Survival of probiotics and the pathogen were further assessed under GIT simulation conditions. Results demonstrated that both free and encapsulated probiotics maintained high population levels (9.00 log CFU/mL) during storage. During GIT simulation, free probiotic population reduced to 3.80 log CFU/mL, in contrast to the encapsulated cells that remained at 6.80–7.00 log CFU/mL after 2 h of the intestinal phase, confirming the protective role of microencapsulation. S. enterica population survived in control and when co-cultured with encapsulated probiotics until the end of storage in populations of 1.7 ± 0.06 log CFU/mL; however, it was reduced to 0.80 log CFU/mL when co-cultured with free probiotics. Salmonella survived during GIT simulation, in control samples, whereas the pathogen co-cultured with probiotics lead to complete S. enterica elimination. Notably, during the intestinal phase, the encapsulated probiotics effectively eliminated S. enterica, maintaining their viability in high population levels. These results highlight that encapsulating probiotics can improve both the functional and sensory characteristics of probiotic fruit juices while supporting high probiotic viability and thus suppression of pathogenic microorganisms in the intestinal environment.