Monitoring of Alternaria mycotoxins in tomato paste: method development, validation, and dietary risk assessment in Egypt

Alternaria toxins—particularly alternariol (AOH), alternariol methyl ether (AME), and tenuazonic acid (TeA)—are among the most concerning mycotoxins frequently detected in tomato paste, posing potential health risks to both adults and children. This study provides the first comprehensive investigation in Egypt assessing dietary exposure and the toxicological implications of these toxins in tomato paste, employing a rapid and streamlined analytical approach. The proposed method involves a 10 min sample preparation step followed by LC-ESI-MS/MS analysis with a 6 min run time. Method validation demonstrated robust analytical performance, with recovery rates ranging from 82% to 114%. Repeatability and intermediate precision (RSDs) ranged from 2.8% to 10.9% and 3.0% to 11.0%, respectively. Limits of detection (LOD) and quantification (LOQ) were in the ranges of 0.15–5 µg/kg and 0.5–20 µg/kg, respectively. Excellent linearity was achieved (R2 = 0.9999). The validated method was applied to 200 tomato paste samples collected across Egypt. The results revealed a widespread occurrence of AOH, AME, and TeA, with AOH identified as the predominant toxin, followed by AME and TeA. Although the estimated dietary intake (EDI) and the 95th percentile exposure levels for AOH and AME exceeded the threshold of toxicological concern, the calculated hazard quotient (HQ) values remained below unity, indicating no immediate health risk under current consumption patterns. Nevertheless, potential concerns remain for AOH and AME, particularly among high consumers and children. These findings provide a scientific basis for future mitigation strategies and further research aimed at reducing Alternaria toxin contamination in tomato paste.