Occurrence and Co-occurrence of Alternaria toxins in tomato-based products collected in China

A total of 174 tomato-based products collected in China in 2021 were analyzed for the natural occurrence of four Alternaria toxins: alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and tentoxin (TEN) by ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry. The results showed that TeA was the predominant toxin (average: 37.6 μg/kg and maximum: 770.1 μg/kg). The positive samples showed a decreasing order of average, maximum, and median concentrations of the four Alternaria toxins: TeA > AOH > AME > TEN. There was a significant correlation between AOH and AME in all analyzed samples (r = 0.785, p < 0.05). Almost 95% of samples were with Alternaria toxins, specifically, 16.1% with one kind of toxin, 24.7% with two, 12.1% with three, and 41.4% with four toxins. Higher concentrations of toxins were in dried tomatoes compared to other types of tomato-based products. Moreover, there was no significant difference in Alternaria toxins concentrations of products made in China, Europe, America, Asia, and Australia. This survey revealed that the co-contamination of the four Alternaria toxins in commercially tomato-based products was very common. Ongoing surveillance of tomato-based products from China is necessary to gather more data, so specific regulations for Alternaria toxins in tomato-based products can be set in the future.