Biofortification of fermented foods with riboflavin-overproducing Bifidobacterium longum subsp. infantis strains

Fermented food matrices with probiotic cultures capable to enrich the content of riboflavin in the final product, and capable to deliver metabolically active strains, is an appealing alternative to prevent the issues associated with this vitamin deficiency. In this work two riboflavin-overproducing B. longum subsp. infantis strains, IPLA60015 and IPLA60012, were investigated for the elaboration of fermented drinks based on dairy and almond drink matrices. Dairy fermented products showed the highest riboflavin concentrations upon one month of refrigerated storage. The concentration of vitamin in milks fermented with a single riboflavin overproducing bifidobacterial culture, was higher than that obtained in co-culture with several yogurt starters, or that present in commercial yogurts. Besides, following simulated in vitro digestion of the biofortified products, between 59.8 and 84.6 % of the riboflavin present in the fermented foods were detected, the highest recovery occurring in the fermented dairy matrix fermented with strain IPLA60012. These results set the ground to facilitate the incorporation of novel riboflavin producing bifidobacterial cultures into fermented matrices.