Natural riboflavin fortification of a fermented dairy product using Propionibacterium freudenreichii.

SMID E.J.,; LEBLANC J.G.,; BURGESS C,; RUTTEN G.,; BRUINENBERG P.,; SESMA F.M,; SAVOY DE GIORI G.,; VAN SINDEREN D.

Wadahl, Norway

Simposio; 2nd International Symposium on Propionibacteria and Bifidobacteria: Dairy and Probiotic Applications.; 2007

Norwegian University of Life Sciences

The use of riboflavin-producing cultures in the production of dairy products Duch as fermented milk, yogurt, and cheese is feasible and would decrease the costs involved during conventional vitamin fortification. In addition, it would satisfy consumer demands for healthier natural foods. We have used the toxic riboflavin analogue roseoflavin for the selection and isolation of natural riboflavin-overproducing variants of common Propionibacterium freudenreichii strains. Propionibacterium freudenreichii NIZO B2336 is one of the natural overproduces which shows over 15 times more riboflavin production as compared to the wildtype parent strain P. freudenreichii NIZO B374. A rat bioassay was employed to assess the response of administration of yogurt containing a riboflavin-producing strain of Propionibacterium freudenreichii on the riboflavin status of deficient rats. Rats were fed a riboflavin-deficient diet for 21 d (depletion period), after which this same diet was supplemented with conventional yogurt, yogurt containing the riboflavin-producing strain (B2336), or the parental low-producing strain (B374) and fed to animals for 28 d (repletion period). As controls, rats were fed the same diet with different concentrations of commercial riboflavin. The novel fermented product containing P. freudenreichii B2336, with increased levels of riboflavin, eliminated most physiological manifestations of ariboflavinosis such as stunted growth, high erythrocyte glutathione reductase activation coefficient values, and hepatomegaly that were observed when using a riboflavin depletion-repletion model. The product fermented with the non–riboflavinproducing strain did not show this beneficial effect. Consumption of such products with increased levels of riboflavin on a regular basis may help prevent deficiencies of this essential vitamin.