Evaluation of sensory and physicochemical characteristics of vitamin B₁₂ enriched whole-meal sourdough bread fermented with propionibacterium freudenreichii

The sustainable production of vegan or vegetarian food rich in vitamin B₁₂ is a challenge. Propionibacterium freudenreichii fermentation has been identified as an effective method for the enhancement of vitamin B₁₂ content in foods. However, limited studies have been conducted on the co-fermentation of P. freudenreichii with other bacteria. This study investigated the co-fermentation of P. freudenreichii with Lactic acid Bacteria (LAB) and its effects on the sensory characteristics of whole-meal sourdough bread (WMSB) in comparison to WMSB produced with LAB alone. The effects of P. freudenreichii co-fermentation on WMSB vitamin B₁₂ content were also evaluated. Results indicated that P. freudenreichii co-fermentation with LAB significantly reduced (p < 0.05) crumb hardness when compared with WMSB produced with only LAB (4532 ± 176 g and 5313 ± 846 g respectively). A significantly higher adhesiveness (p < 0.05) was also observed due to the presence of P. freudenreichii. Triangle testing showed that perceptible differences were observed between the two WMSB types investigated in this study (p < 0.05). Qualitative data from focus group testing indicated that WMSB produced with co-fermentation has a more homogeneous texture. However, improvement in aroma, texture, and taste was possible in both bread types. The co-fermentation of P. freudenreichii with Lactic acid Bacteria (LAB) was successful in producing bread with enriched vitamin B₁₂ levels (ranging from 0.89 to 1.44 µg 100 g‾¹). Overall, the co-fermentation of P. freudenreichii presents an opportunity to improve the nutritional value of WMSB