Facing tropane alkaloid contamination in millet – Analytical and processing aspects

Abstract

Thorn Apple or Jimson Weed (Datura stramonium) is a tropane alkaloid containing widespread pest plant growing in central Europe. This pest predominantly occurs in millet, buckwheat and maize cultivation. Therefore, sound cleaning of these crops is just as pivotal as reliable analytics. The cleaning of millet at laboratory scale with commercial mechanical cleaning devices, such as sieves, indented separators or table sorters without using colour sorters, reduces the dark coloured Datura seed content by up to 99%. Nevertheless, the few remaining Datura seeds (up to one nut per 30 kg) could lead to an exceedance of the European Union (EU) limit values for tropane alkaloids in baby food. However, plant material other than seeds or even invisible abrasion of Datura seeds can contaminate the millet during harvest, handling, cleaning processes or crop transportation. Contamination originating from adhesive dust can be removed by dehulling the kernels, and a reduction below the EU detection limit could be achieved.