Folate concentrations in yogurts vary widely and are normally considered low due to an inadequate
selection of starter cultures and fermentation conditions. In this study, folate producing Lactobacillus
delbrueckii subsp. bulgaricus (3 strains) and Streptococcus thermophilus (2 strains) were combined and
used to elaborate 15 different yogurts. Samples were taken at different time points during the
fermentation process and folate concentrations were determined. The yogurt elaborated with strains
CRL871 þ CRL803 þ CRL415 and incubated at 42 C had significantly higher folate concentrations
(reaching 180 10 mg/L) which implies almost a 250% increase in respect to non-fermented milk, and
about 125% compared to commercial yogurts. No variations in folate concentration were observed during
28 days of storage at 4 C. This is the first report of a yogurt naturally bio-enriched in folate using native
folate producing starter cultures.