Determination of mycotoxins and their metabolites is performed by U-HPLC-MS/MS multidetection method, which can include up to 60 mycotoxins and their metabolites, although usually the analysis is focused only on selected substances or groups according to the purpose of the analysis or individual needs of the customer.
The most common samples analysed are cereals and feed, fruit and vegetable products, food supplements (nutraceuticals) and herbal extract-based medicines, as well as so-called novel foods, baby-food, oilseeds, nuts, but also beverages, coffee and herbal teas. Commission Regulation (EU) 2023/915 set maximum levels for aflatoxins, ochratoxin A, patulin, deoxynivalenol, zearalenone, fumonisins, citrinin and ergot alkaloids. The analytical methods used comply with the requirements of the Regulation (EU) 2023/2782 laying down methods of sampling and analysis for the control of mycotoxins in foodstuffs.
Aflatoxins
Aflatoxins are produced by micromycetes of the genus Aspergillus, mainly Aspergillus flavus and Aspergillus parasiticus species. The main representatives of aflatoxins are aflatoxins B1, B2 and G1, and G2. The most commonly contaminated commodities are nuts, spices, cereals, etc. Contamination occurs mainly in the subtropical region where humidity is high and proper post-harvest processes are often not applied to prevent the growth of micromycetes. Chronic exposure to aflatoxins is associated with hepatotoxicity and carcinogenicity, and the IARC classifies aflatoxins as a proven human carcinogen.
Deoxynivalenol
The main producers of deoxynivalenol are Fusarium culmorum and Fusarium graminearum, and it is one of the most commonly occurring mycotoxins in a wide range of cereals. Like other mycotoxins, it is relatively stable, so it is also found in heated foods such as baked products, etc. Acute intoxication is associated with nausea and possibly vomiting, hence it was formerly known as vomitoxin, and is rapidly metabolised in the human body and excreted in the urine. The most commonly occurring metabolite is deoxynivalenol-3-glucoside in cereals and derived products. For some of these conjugated mycotoxins, release from the conjugate bond and hence a higher toxicological burden for the consumer of contaminated food has already been described.
Zearalenone
is a mycotoxin produced mainly by the mycotoxin Fusarium graminearum, but also by other species of the genus Fusarium. It is an important contaminant of cereals and derived products. Zearalenone is mainly associated with chronic toxicity and, due to its structural similarity to the hormone estradiol, causes reproductive and developmental problems. Long-term exposure poses a risk, especially to pregnant women. Other toxic properties of zearalenone are hepatotoxicity and immunotoxicity, haemotoxicity and bleeding disorders.
Fumonisins
are produced by various species of fungi of the genus Fusarium, mainly F. verticillioides and F. proliferatum. The most commonly contaminated commodity is maize and maize products, and to a lesser extent other cereals. They are relatively thermostable. In total, more than 28 representatives are known, the most important being the fumonisins B1 and B2, which are classified by the International IARC as possible human carcinogens, with toxic effects mainly on the kidneys or liver.
T-2 and HT-2 toxin
is an important representative of the fusarium mycotoxins produced mainly by Fusarium sporotrichioides and Fusarium poae. Their occurrence in cereals, especially oats and oat products, is characteristic. These are the most toxic mycotoxins of the trichothecene group, with nausea and vomiting in acute intoxication and developmental and reproductive toxicity in chronic intoxication. The TDI is set at only 0.02 µg/kg bw.
Ochratoxin A
is produced by the micromycetes Aspergillus ochraceus and, to a lesser extent, by other micromycetes of the genera Aspergillus and Penicillium. Commonly contaminated commodities are cereals, coffee or grapes (and subsequently wine) and spices. Ochratoxin A is highly thermostable and normal processes in the food industry are not sufficient to significantly reduce its content in final products. Like the fumonisins, it is classified as a possible human carcinogen, and is particularly toxic to the kidneys.
Patulin
is produced by Penicillium, mainly P. expansum, and by some representatives of the Aspergillus genera. It occurs in fruit, most commonly in apples and apple products (apple juice, baby food). Patulin is stable in heat processes up to 100 °C and degrades when sulphur dioxide is used as a preservative. Despite showing significant antibiotic activity, patulin is associated with acute toxicity and possible immunotoxicity, genotoxicity and teratogenicity.
Citrinin
is produced by the micromycete Penicillium citrinum, and to a lesser extent by other members of the genera Aspergillus and Penicillium, including Aspergillus oryzae, used in the production of soy sauces, and Penicillium camemberti in the production of mould cheese. It is therefore present in these processed products as well as in cereals and fruit. It is nephrotoxic and is rapidly absorbed and metabolised in the human body
Ergot alkaloids
The ergot alkaloids are produced mainly by Claviceps purpurea micromycetes. Due to the taxonomic affiliation of the producer, they are more likely to be classified as mycotoxins despite their structural similarity to other types of alkaloids. The most frequent occurrence is associated with rye and, to a lesser extent, other cereals. Acute intoxication is associated with nausea and vomiting, and in chronic exposure their occurrence is associated with the first described mycotoxicosis in humans, ergotism.
Alternaria mycotoxins
Alternaria micromycetes produce more than 70 different toxins, but only a few are classified as food contaminants and are toxicologically significant, the most important being alternariol, alternariol methyl ether, tenuazonic acid and tentoxin. They are found in fruits, vegetables and processed products, oilseeds and cereals. Some of the representatives are cytotoxic, genotoxic, carcinogenic and mutagenic.
Enniatins and beauvericin
Enniatins and beauvericin are structurally cyclic depsipeptides produced by several species of the genus Fusarium (F. avenaceum, F. trincinctum, etc.). They occur in a wide range of crops and foods with very high incidence, but their toxicity to humans is low, e.g. cytotoxicity has been found in laboratory studies.