This study investigated the effects of fermenting plum pulp with Bifidobacterium animalis ssp. lactis (BAL) on its physicochemical and bioactive properties, as well as the optimization of the freeze-drying (FD) process to develop a fruit-based probiotic delivery system. Fermentation significantly reduced the pH and total acidity of the pulp, achieving a cell viability of 11 log CFU/mL. The FD process was optimized using a factorial design, with maltodextrin concentration (3, 5, and 7%) and freezing temperature (−150, −100, and −50 °C) as variables. The P2 experiment, which used 7% maltodextrin and freezing at −150 °C, showed the best results in terms of yield (25.67%), cell viability (8 log CFU/g), and probiotic survival rate (97.66%). Samples P5, P6, and P7, prepared with 5% maltodextrin and freezing at −100 °C, exhibited the highest levels of bioactive compounds and antioxidant activity (p < 0.05). During 28 days of storage, all samples maintained cell viability without significant logarithmic reduction. In summary, probiotic plum powders offer an excellent plant-based alternative for probiotic consumption, providing safe levels of beneficial bacteria and bioactive compounds with antioxidant action, meeting health and nutrition needs.
