Stability of ergot alkaloids during the process of baking rye bread

Changes in the concentrations of six major R-configuration ergot alkaloids (EA) and their S-configuration epimers were studied during the entire process of rye sourdough bread production. The EA were practically stable at the sourdough and dough preparation stages; however, significant reductions (a = 0.05) were noted after the thermal processing stage (baking): on average, the EA concentration dropped by 22%, from 3970 +/- 582 mu g/kg in the flour to 3090 +/- 144 mu g/kg in the baked bread. It was an outcome showing two opposite trends: the concentration of R-configuration enantiomers dropped by 46%, while that of their S-configuration counterparts increased by 21%. It seems that the process of baking bread, which creates S-configuration epimers of EA, contributes to reducing the toxicity of the final product. However, given their potential cytotoxicity and the possible reversibility of the reaction (during further processing of the bread) towards the formation of R-configuration epimers, both enantiomeric forms should be considered with regards to food safety. The high stability of EA during bread-making processes and lack of any European Union regulations concerning their maximum permissible levels in foodstuffs may pose a risk to the health of people whose diet is based on rye grain-based products.