Investigation of ochratoxin A in commercial cheeses and pork meat products by liquid chromatography-tandem mass spectrometry.

Abstract

Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium and commonly detected in a wide range of foodstuffs. The purpose of this work was to monitor the presence of OTA in cheeses and pork meat products. A simple and accurate "dilute and shoot" method with no need of immunoaffinity column and isotopic labeled internal standard, by liquid chromatography-tandem mass spectrometry, was validated in accordance with the criteria set out in Commission Regulation (EC) No. 401/2006. The method showed good linearity in solvent and in matrix (R2 ≥0.995), limit of detection was 0.2µg/kg for cheese and 0.3µg/kg for pork meat products, limit of quantification was fixed at 1µg/kg, and recovery was estimated at two different concentration levels (1 and 5µg/kg) and ranged from 75% to 101%. The interday and intraday laboratory precisions were lower than 7%. The matrix effect, the recovery of the extraction process, and the overall process efficiency were evaluated. No significant ME was observed in the two matrices considered. This method was applied to the analysis of 75 samples, coming from official controls implemented by the Lazio Region (Central Italy). In one sample of dry-cured ham, the concentration found (69.3µg/kg) was well above the guidance value recommended by the Italian Ministry of Health (1µg/kg). These data together with the detection of OTA in three grated cheeses suggest the importance of monitoring these products. Considering the high dietary intake of these matrices, especially among vulnerable populations, further research should be devoted to estimate exposure and risk assessment for OTA.