Nutritional and Physicochemical Attributes of Sourdough Breads Fermented with a Novel Pediococcus acidilactici ORE 5 Strain

This study evaluated the application of Pediococcus acidilactici ORE 5 (applied in free or immobilized form in a prebiotic matrix called “trahanas”) in sourdough bread production. Specific volumes of all the produced bread samples varied at approximately the same levels (2.50 to 2.54 mL/g), indicating a satisfactory dough expansion. In contrast, acidity differed significantly (p < 0.05). Sourdough bread produced with immobilized cells (IB) exhibited the lowest pH (4.30) and the highest titratable acidity (9.13 mL NaOH N/10), followed by the sourdough bread produced with free cells (FB) and the control bread (CB), reflecting the enhanced metabolic activity of immobilized cells supported by the prebiotic matrix. The organic acid analysis revealed higher levels of lactic (2.96 g/kg) and acetic acid (0.99 g/kg) in the IB sample, along with increased minor acids. The high organic acid content contributed to a delayed rope (14.7 days) and mold spoilage (7.3 days) compared to the CB sample, enhancing microbial stability. In addition, the nutritional properties of the produced sourdough breads containing P. acidilactici ORE 5 were improved significantly. The IB sample demonstrated the highest total phenolic content (85 mg GAE/100 g), followed by the FB sample (61 mg/100 g) and the CB sample (48 mg/100 g), while phytic acid levels were markedly reduced (93% in IB and 80% in FB). A sensory evaluation confirmed the maintained overall acceptability, with enhanced flavor scores for sourdough breads containing P. acidilactici ORE 5. These findings indicate that P. acidilactici ORE 5, particularly in immobilized form, could be an effective functional starter culture for sourdough bread, highlighting its potential for applications in functional bakery products.