Risk of de‐novo formation of chlormequat and mepiquat in industrial cocoa products assessed by ion chromatography coupled with high‐resolution mass spectrometry

Summary Mepiquat (MQ) and chlormequat (CQ) are two main food contaminants that could be naturally present in various animal and plant foods due to heat treatments. Cocoa and its derivative products seem to be a matrix inclined, for both chemical characteristics and production technologies, to the formation of MQ and CQ. In this study, exploiting the selectivity and sensitivity of IC‐HRMS, a new reliable analytical method was developed and validated for MQ and CQ quantification. The LOD of the method was set at 1.9 μg kg−1 for both CQ and MQ, and the linearity was defined from 6.25 to 625 μg kg−1. Average recoveries, at 2 μg L−1, were 96.5% and 97.5% for CQ and MQ, respectively, while precision as repeatability (RSDr%) was 2.3% and 5.1% respectively. Subsequently, a laboratory‐scale experiment was conducted to assess, for the first time, the actual risk of MQ and CQ formation, confirming in cocoa products the presence of MQ at detectable concentration after 55 min at 180 °C, approximately 8 μg kg−1 for cocoa and 7 μg kg−1 for chips. However, the investigation of a wide variety of commercial cocoa and nuts products has fortunately ruled out the presence of such contaminants at detectable concentrations. Better not to overheat the cocoa! Schematic representation of possible formation of mepiquat in cocoa and commercial derivatives.