Alternaria mycotoxins in tomato products
Alternaria species are capable of producing a number of mycotoxins, several of which have been shown to be genotoxic, carcinogens. As part of the German food safety monitoring plan, the toxins produced by Alternaria in food were tested for the first time in 2019.

To date, more than 70 different mycotoxins have been shown to be produced by Alternaria species, but their physicochemical characterisation has not yet been performed, nor are detection methods available for all toxins from all food matrices. The most commonly studied toxins produced by Alternaria species are: alternariol (AOH), alternariol monomethyl ether (AME), altenuen (ALT), tenuazonic acid. Most of the mycotoxins produced by Alternaria are genotoxic, carcinogenic, AOH is mutagenic, carcinogenic, genotoxic, may affect the reproductive system.

For the first time, Alternaria toxins were examined for their presence in food in the German monitoring programme in 2019. Five individual substances were included in the study: alternariol, alternariol monomethyl ether, altenuen, tenuazonic acid, tentoxin. Tomato juices, ketchups and canned tomatoes were investigated, as reliable analysis methods are available for these. The highest total Alternaria toxin levels were recorded in tomato ketchup, followed by tomato strained canned, tomato chopped canned and then tomato juice. Tenuazonic acid makes up almost 100% of the total amount of Alternaria toxins in all tomato products, while altenuen was consistently not quantifiable.

Gotthardt et al. (2019) studied several cereal based infant foods and jars containing tomatoes, other vegetable mixes and found tenuazonic acid in tomato and/or cereal-based (mostly millet) products at levels that may already be harmful to infants and young children due to prolonged exposure to the toxin.

To what extent the process conditions and a possible enrichment, e.g. in tomato ketchup, could have an influence on the formation of Alternaria toxins in food, is reserved for further investigations. The available data also suggest that there is scope for minimizing these mycotoxins in the production and manufacture of food. In terms of precautionary consumer protection, the qualifications for the routine Alternaria toxin analysis of further matrices, including cereals, fruit, vegetables and meat products, should be created promptly. For future studies, reliable test methods should be developed for other food groups.

The case has already been sent as a short issue to EFSA's EREN 2021 spring meeting, and will be discussed in more detail at the autumn meeting.


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