Publication no. C-2003-1216-03R |  VIEW ARTICLE

Effect of Baking Method and Fermentation on Folate Content of Rye and Wheat Breads.

Susanna Kariluoto (1,2), Liisa Vahteristo (1), Hannu Salovaara (3), Kati Katina (4), Kirsi-Helena Liukkonen (4), and Vieno Piironen (1). (1) Viikki Food Science, Department of Applied Chemistry and Microbiology, P.O.Box 27, FIN-00014, University of Helsinki, Finland. (2) Corresponding author. Phone: 358-9-191-58252. E-mail: <susanna.kariluoto@helsinki.fi> (3) Viikki Food Science, Department of Cereal Technology, P.O.Box 27, FIN-00014 University of Helsinki, Finland. (4) VTT Biotechnology, P.O. Box 1500, FIN-02044 VTT, Finland. Cereal Chem. 81(1):134-139. Accepted July 22, 2003. Copyright 2004 American Association of Cereal Chemists, Inc.

The effect of baking method on folates of rye and wheat breads, as well as the effect of sourdough fermentation of rye, were examined. Sourdough fermentations were performed both with and without added yeast, and samples were taken throughout the baking process. Samples were analyzed microbiologically for their total folate content after trienzyme extraction. Individual folate vitamers were determined by HPLC after affinity chromatographic purification. The lowest folate contents for both rye and wheat breads were found from breads baked without added yeast. Total folate content increased considerably during sourdough fermentation due to increased amounts of 10-HCO-H(2)folate, 5-CH(3)-H(4)folate, and 5-HCO-H(4)folate. Baker’s yeast contributed markedly to the final folate content of bread by synthesizing folates during fermentation. Proofing did not influence total folate content but changes in vitamer distribution were observed. Folate losses in baking were approximately 25%. The variety of sourdoughs and baking processes obviously lead to great variation in folate content of rye breads. The possibilities to enhance natural folate content of rye bread by improving folate retention in technological processes and by screening and combining suitable yeasts and lactic acid bacteria should be further investigated.