Effect of baking and fermentation on added folic acid and endogenous folates stability in rye and wheat breads

摘要

In Poland fortification of food products with folic acid is not mandatory. Bread as a staple food both made from wheat and rye flour can be a potential product for future fortification with folic acid. The objective of this study was to examine the effect of fermentation and baking method on added folic acid and some endogenous folates stability during breadmaking of rye and wheat breads. Breads were produced using the formulation containing enriched flours with 0.2 mg folic acid/100 g product, baker's yeast and additionally lactic acid for rye bread. Folates were extracted with Hepes/Ches buffer (pH = 7.85) followed by deconjugation with rat serum conjugase and destruction of matrix by amylase and protease. Affinity chromatography (FBP bovine milk)was used to purify and concentrate samples. The folates were separated by HPLC with C(18) column and with a combination of fluorescence and UV detection. For both rye and wheat bread products there was a significant decrease of folic acid from flour tobread stage. The total loss depends on baking process and ranged from 12 to 21%. Some changes in the level of different folate forms during the stage of baking process were also observed.