Influence of fermentation and storage on the content of opium alkaloids in poppy seed yoghurt

Abstract

There is a current trend to make yoghurts with seeds such as poppy seeds to enhance their nutritional benefits. These seeds may be contaminated with opium alkaloids (OAs) present in the own latex of the plant (Papaver somniferum L.). Food processing such as heat treatment, grinding or washing may reduce them, but lactic fermentation has not been studied. In this work, an analytical methodology was optimised based on a solid-liquid extraction (SLE) with water, a purification by magnetic solid-phase extraction (MSPE) with a mesostructured silica magnetic composite with β-cyclodextrin (Fe3O4 @SiO2 @mSiO2 @β-CD) and subsequent analysis by liquid chromatography coupled to a tandem mass detector (HPLC-MS/MS). The methodology was successfully validated in terms of linearity, limits of detection and quantification, matrix effect, precision, recovery tests, and selectivity. Therefore, it was applied to determine OAs in commercial yoghurts, detecting morphine, papaverine and noscapine in all of them but below the limit of quantification. Besides, the effect of fermentation was studied (6 and 18 h) and storage (1 week/ 4ºC), showing a considerable degradation effect (33–80%) in the first hours.