Quality Characteristics of Novel Sourdough Breads Made with Functional Lacticaseibacillus paracasei SP5 and Prebiotic Food Matrices

Lacticaseibacillus paracasei SP5, isolated from kefir, was assessed as a starter culture for sourdough bread making in freeze-dried form, both free (BSP5 bread) and immobilised on wheat bran (BIWB) and on a traditional flour/sour milk food, 'trahanas' (BITR). Physicochemical characteristics, shelf-life, volatilome, phytic acid, and sensory properties of the breads were evaluated. The BITR breads had higher acidity (9.05 +/- 0.14 mL of 0.1 M NaOH/10 g) and organic acid content (g/Kg; 2.90 +/- 0.05 lactic, 1.04 +/- 0.02 acetic), which justifies the better resistance against mould and rope spoilage (>10 days). The highest number of volatiles (35) and at higher concentration (11.14 mu g/g) were also found in BITR, which is in line with the sensory (consumer) evaluation regarding flavour. Finally, higher reduction of phytate (an antinutrient) was observed in all L. paracasei SP5 sourdoughs (83.3-90.7%) compared to the control samples (71.4%). The results support the use of the new strain for good quality sourdough bread.

Automated summary

Lacticaseibacillus paracasei SP5, isolated from kefir, was evaluated as a starter culture for sourdough bread making. The study found that the strain immobilised on a traditional flour/sour milk food, 'trahanas', showed improved resistance against mould and rope spoilage and had higher concentrations of volatiles, which correlated with better consumer evaluations of flavor. Additionally, the L. paracasei SP5 sourdoughs exhibited higher phytate reduction compared to the control samples, suggesting the potential use of this new strain for producing high-quality sourdough bread.