Degradation of tropane alkaloids in baked bread samples contaminated with Solanaceae seeds

Solanaceae plant seeds, which contain high concentrations of tropane alkaloids, have not been studied in real conditions of proofing and baking processes. In this work both lab vial trials and buckwheat and millet flour samples, contaminated with two species of Solanaceae plants, Datura stramonium and Brugmansia arborea, were undergone to proofing (37 °C) and baking (190 °C) processes. For the determination of tropane alkaloids, a simple solid-liquid extraction with methanol:water 2:1 (v/v) containing 0.5% acetic acid was used to extract the targeted compounds, whereas a chromatographic method employing a Zorbax C₁₈ column coupled to an Exactive-Orbitrap analyser was used for their determination. The results indicate that concentrations of tropane alkaloids decrease under proofing conditions (degradation between 13 and 95%), while they are almost disappeared under baking conditions (degradation between 94 and 100%). Some degradation pathways have been clarified, showing that most of the compounds degrade into tropane and tropine, and into tropine and tropinone under proofing and baking conditions respectively.