Trichothecenes occurrence

Jemmali M, Ueno Y, Ishii K, Frayssinet C, Etienne M (1978) Natural occurrence of trichothecenes, nivalenol, deoxynivalenol, T-2 toxin and zearalenone in corn. Experientia 34 1333-1334 Josephs RD, Schuhmacher R, Krska R (2001) International interlaboratory study for the determination of the Fusarium mycotoxins zearalenone and deoxynivalenol in agricultural commodities. Food Addit Contam 18 417-430... 

Contamination occurs primarily in wheat, barley, rye, and maize. Type A trichothecenes include mainly T-2 toxin, HT-2, and diacetoxyscirpenol (DAS) mycotoxins of the group B include mainly 4-deoxynivalenol (DON), commonly known as vomitoxin, and nivalenol (NIV). Toxic effects include nausea, vomiting, visual disorder, vertigo, throat irritation, and feed refusal in farm animals. The most toxic is T-2, followed by DAS and NIV, with DON being the least toxic in acute toxicity studies but the most widespread in grains worldwide and therefore the most studied. Issues related to chemical and physical data, occurrence, toxicity, absorption, distribution, and metabolism of trichothecenes are reviewed in WHO (89) and IARC (34). Physicochemical data for some selected Fusarium toxins is given by Sydenham et al. (90). The molecular structures of the main trichothecenes are shown in Fig. 9. 

Scott PM The natural occurrence of trichothecenes in Beasley VD (ed) Trichothecene Mycotoxicosis. Pathophysiologic Effects. Boca Raton, CRC Press, 1989, pp 1-26. 

Several surveys suggest that the most prevalent trichothecenes are deoxynivalenol (DON), nivalenol, 3-acetyl-DON (3-AcDON) and 15-acetyl-DON (15-AcDON), as type-B trichothecenes, and HT-2 toxin and T-2 toxin, as type-A trichothecenes. They are mainly found on maize, oats, barley, and wheat. The latter, espedally durum wheat, which is used nearly exclusively for the production of pasta, is susceptible to Fusaria infection and is often highly contaminated with DON. In European agricultural commodities type-A trichothecenes usually occur less frequently and at lower concentrations than DON. The simultaneous occurrence of DON with other Fusarium mycotoxins mainly type-B trichothecenes and zearalenone, has been reported for a variety of agricultural commodities (Gareis et al., 1989 Petterson, 1992, as cited in Krska et al., 2001). 

From the point of view of known inddenoe, the most important trichothecene is DON. It may also co-occur in grains and feeds with other trichothecenes and zearalenone and other combinations of toxins are possible. The carryover of DON and other trichothecenes into human foods is considerable and a cause of concern for food safety agencies. The carryover of trichothecenes or their metabolites into farm animal products would not ap>p)ear to be a major problem from experimental studies and no cases of their natural occurrence in meat, milk or eggs have been reported (Scott, 1989). 

Trichothecene levels in different matrices vary from pg/kg up to mg/kg depending on a toxin, matrix, climatic condition, as well as other factors. Since toxins can never be completely removed from the food supply, and since they are potential health risks for humans and animals, the European Union has implemented regulations for some of them. The co-occurrence of different trichothecenes (type-A and type-B) in one same foodstuff, could provoke additive or even synergistic effects on human or animal health however, the knowledge regarding this aspects is still scarce. In order to be able to monitor several toxins. 

Scott, P.M. (1989). The natural occurrence of trichothecenes. In Frichothecene mycotoxicosis pathophysiologic effects 1, Beasley, V.R., pp. 1-26, CRC Press, ISBN 0-8493-5088-3, Boca Raton, FL, USA. 

Deoxynivalenol (DON) is the most important trichothecene worldwide and is often detected in small cereal grains such as barley, oats and wheat. Due to relatively good thermal stability DON can be transmitted from contaminated barley into the final product (Schwarz et al., 1995). DON is frequently detected in barley and in commercial beer (discussed in Section 6.6.2). The occurrence of DON is largely dependent on weather conditions in the particular location and year. DON is predominantly produced by F. culmorum and F. graminearum species. 

Ibanez-Vea, M., Lizarraga, E., Gonzalez-Penas, E., Lopez de Cerain, A. (2012). Co-occurrence if type A and type B trichothecenes in barley from a northern region of Spain. Food Control, 25, 81-88. 

Nivalenol (NIV) belongs to the B-type trichothecene mycotoxins produced by Fusarium species. The occurrence of NIV contamination is limited to certain areas around the world, such as Japan, Korea, New Zealand, and a part of Europe, where it has had adverse effects on human and animal health. This chapter focuses on the mycology, occurrence, biosynthesis, toxicology, methods of analysis, and risk assessment of NIV. 

Ryu JC, Yang JS, Sraig YS, Kwon OS, Park J, Chang IM (1996) Survey of natural occurrence of trichothecene mycotoxins and zearalenone in Korean cereals harvested in 1992 using gas chromatography/mass spectrometry. Food Addit Contam. 13 333... 

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