Integrating Suspect and Nontargeted Screening for Food Safety Testing: A Case Study of Bee Pollen Supplements

Natural food supplements, including bee pollen supplements, are increasingly popular, yet they may hide safety issues arising from concentrated chemicals, ranging from natural toxins to anthropogenic contaminants. To assess their safety, methods are needed to chemically characterize both their exposome and metabolome. Hence, we developed and validated a nontargeted screening method based on liquid chromatography high-resolution mass spectrometry (NTS LC-HRMS), combined with computational strategies to comprehensively annotate and simultaneously (semi)quantify contaminants and bioactive compounds in bee pollen. The method was validated for 15 target compounds spiked at 0.3-3 mg/kg in the bee pollen, including pesticides, pyrrolizidine alkaloids, and mycotoxins (log P range of -1.4 to 5). These compounds were accurately annotated using the developed nontargeted workflow (100% accuracy when MS2 data were acquired) and semiquantified with a mean prediction error of 2.42. Concurrently, the method successfully annotated more than 4000 compounds in bee pollen by integrating suspect screening and nontargeted screening approaches. These results demonstrate the robustness and added value of integrated targeted and nontargeted screening strategies applicable to complex food matrices, effectively replacing several matrix-specific targeted methods. Moreover, this comprehensive characterization provides crucial information for the next steps of the risk assessment.