This study presents a comprehensive in vitro and in silico evaluation of safety of strain Lactiplantibacillus plantarum Jb21-11 and the genomic confirmation of its probiotic potential, together with its application in a functional frozen-dairy matrix. Genomic analysis identified multiple exopolysaccharide (EPS) biosynthesis gene clusters, antimicrobial-related genes, and an expanded set of stress-response elements, which distinguish Jb21-11 and suggest potential resilience in gastrointestinal and processing environments. In silico screening did not detect known virulence factors or clearly transferable antibiotic-resistance determinants, supporting the strain's in vitro safety test results. Phenotypically, Jb21-11 was able to produce EPS in the ice-cream mix (up to 2082.78 ± 37.03 μg/L; approximate molecular weight ~ 1.05 × 105 Da) composed primarily of glucose, galactose and mannose (ratio ≈ 2:1.5:1). Three formulations were compared: a control (F1), a non-fermented probiotic formulation (F2) and a fermented probiotic formulation (F3). Incorporation of Jb21-11 was associated with changes in physicochemical properties (acidity, viscosity, and melting resistance) and maintained microbial viability (> 9 log CFU/g after 90 days at -20 °C). The high-molecular-weight EPS was associated with structural stabilization and improved rheological behaviour in the low-fat matrix, acting as a natural biothickener. These results position Lp. plantarum Jb21-11 as a promising probiotic candidate with dual technological functionality; moreover, the strain and its EPS represent promising clean-label ingredients for further development. Importantly, this study did not assess in vivo or clinical health outcomes, and claims of health benefit therefore remain provisional pending targeted biological and clinical validation.
