Chemical Fate of Ascorbic Acid in Wheat Flour Extract: Impact of Dissolved Molecular Oxygen (O), Metal Ions, Wheat Endogenous Enzymes and Glutathione (GSH).

Ascorbic acid (AH) is a commonly used additive in food products. In wheat breadmaking, it is, for example, added to flour for its dough strengthening and bread volume-enhancing effects. While these bread property-enhancing effects are well known, the final chemical fate of AH in breadmaking applications remains nearly undocumented. This study tries to shed light on the chemical fate of AH in wheat breadmaking by investigating the chemical and enzymatic conversion of AH and its reaction products using C NMR spectroscopy in combination with AH labelled with C on the C carbon. Following the chemical conversion of AH as function of time, in ultra-pure water, tap water, and wheat flour extracts, in the presence and absence of dissolved O and glutathione (GSH), the specific impact of the presence of trace metal ions, dissolved oxygen and endogenous GSH on the oxidation of AH could be elucidated.