Effects of Bifidobacterium longum CCFM5871 as an adjunct starter culture on the production of fermented milk

Bifidobacterium has been widely studied for its probiotic properties. In our previous study, Bifidobacterium longum CCFM5871 (CCFM5871) showed potential to relieve inflammation and constipation. In current study, we investigated the application of CCFM5871 as an adjunct starter culture for the production of fermented milk. First, genome analysis indicated that CCFM5871 possess various carbohydrate metabolic pathways, including the Leloir pathway of galactose metabolism and galactose related genes GH2 and GH27. Comparative genomic analysis shows that similar functional gene were detected in other bifidobacteria strains applied in dairy fermentation. Then the sugar metabolism phenotype experiment verified the result of genomic analysis. Subsequently, we evaluated the effects of CCFM5871 supplementation on the production and storage of fermented milk by monitoring changes in multiple parameters over 14 days of storage at 4 °C, including pH, titratable acidity, physical properties, volatile flavor compounds, and sensory quality. The bacterial level was significantly higher at the fermentation termination than the fermentation initiation, indicating that CCFM5871 can be regarded as a candidate for adjunct start culture. Compared to the control group, supplementation with CCFM5871 increased acidification and solidification of fermented milk. Moreover, we revealed that there was no other significant difference between the yogurt fermented with CCFM5871 and the yogurt with culture only in flavor and taste. In summary, our results identified that CCFM5871 may be an appropriate co-culture for fermented milk, and the genomic analysis may be instructive for future to filter the culture in fermented milk.