Occurrence of Alternaria toxins in food products in The Netherlands

Alternaria toxins are mycotoxins that can contaminate cereals, oilseeds and various fruits and vegetables such as apples, tomatoes, citrus fruits and olives. The fungi can grow at low temperatures, thus causing spoilage even during transport and storage. Currently, there are relatively little occurrence data on Alternaria toxins in food products and in the Netherlands most data are limited to the presence of alternariol (AOH) and alternariol methyl ether (AME) in cereals. Tenuazonic acid (TeA), tentoxin (TEN) and altenuene (ALT) have been recently identified by the Standing Committee on the food Chain and animal health as Alternaria toxins of concern. A survey (95 samples) was conducted in the Netherlands in 2013. The aim was to screen the levels of the five Alternaria toxins in wine (n = 5), fresh apples (n = 11), apple juices (n = 7), fresh tomatoes (n = 19), tomato sauces (n = 8), fresh citrus (n = 11), dried figs (n = 5), olives (n = 10), sunflower seeds (n = 5) and cereals (n = 14). Multi-mycotoxin methods for the analysis of mycotoxins were adapted for this purpose. Their performance characteristics were assessed and were as follows: recoveries and precision ranged from 85 to 112% and from 4 to 20%, respectively. LOQs were between 1.5 and 5.0 μg kg−1. In the subsequent survey, AOH, AME, TeA, and TEN were detected in one or more food commodities, while ALT was not detected in any of the samples. TeA was found in 27% of the samples and at relatively high concentrations in sunflower seeds, tomato sauces and dried figs (up to 2345 μg kg−1). Alternaria toxins occurred regularly in cereals, tomato sauces, figs, wine and sunflower seeds. Only incidental occurrence of the Alternaria toxins was observed in fresh apples, fresh citrus fruits, fresh tomatoes and olives.