Multiple mycotoxin analysis in nut products: Occurrence and risk characterization

Nuts consumption plays an important role in Mediterranean diet, being a good source of proteins, vitamins, minerals and unsaturated fatty acids. However, nuts can be also a source of harmful mycotoxins with negative impact on human health. In this work, the occurrence of 16 mycotoxins belonging to different chemical classes, was assessed in several nut products. The analytical method used was based on modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. An extensive evaluation of different sorbents used in dispersive SPE (d-SPE) cleanup step of QuEChERS was performed. Detection limits achieved were less than 3.5 mu g/kg for all the compounds and the average recoveries varied from 70 to 91%, with relative standard deviations (RSD) <= 13%. Twelve out of sixteen mycotoxins under study were found in the 37 nut samples analysed. Overall, deoxynivalenol (DON), aflatoxin-G2 (AFG(2)), and fusarenon-X (FUS X) were the compounds more commonly detected. The higher contamination value was observed in a cashew sample containing 336.5 mu g/kg of DON. The combination of occurrence and consumption data allowed to assess the exposure and characterize the associated risk of nut products consumption by the Portuguese population.