Investigation of HT2 and T2 mycotoxins in oats from the 2014 harvest

Abstract

The European Commission published a Recommendation in 2013 on the fusarium mycotoxins HT2 and T2. The Recommendation states that Member States, in collaboration with industry, should monitor the levels of these mycotoxins in cereals and cereal products and where levels are detected above published indicative limits of the combined concentration of HT2 and T2 (HT2+T2), investigations should be conducted to determine why the indicative limits were exceeded and to determine the measures to be taken to avoid or reduce such exceedances in the future.

In 2014, oat millers detected exceedances of the indicative limit for unprocessed oats (1000 ppb HT2+T2) in oat samples analysed at mill intake. In collaboration with the Food Standards Agency (FSA), AHDB Cereals & Oilseeds and the British Oat and Barley Millers Association (BOBMA) funded the investigation detailed in this report. The aim of the investigation was to identify why exceedances had occurred and what mitigation could be used to avoid such exceedances occurring in the future.

BOBMA sent details of 113 oat consignments for which HT2 and T2 analysis had been completed. Details included the growers’ location and the variety, if reported. Growers were contacted for further agronomic information and details were provided for a subset of 38 samples. There was limited traceability of the associated agronomy for these oat samples due to the storing of oats from multiple fields in unsegregated stores. This reduces the ability of a retrospective investigation, such as this study, to determine the factors that influenced the concentration of HT2 and T2 in harvested oats.

The average HT2+T2 level of samples was 804 ppb and 26% of samples exceeded the indicative limit of 1000 ppb. The low number of samples limited the statistical strength of the investigation, however statistical differences in location (defined at country or regional level), oat type (winter/spring), variety and crop rotation were detected. For regional differences there were higher concentrations in Scotland and in particular in northern Scotland. Fluctuations between years and regions indicate that weather is a key determining factor of HT2+T2 levels in UK cereals. There was a higher concentration in winter oats compared to spring oats and a significant effect of rotation with an increasing mean HT2+T2 with increasing numbers of cereals in the previous 4 years of the rotation.

Overall, results are in agreement with previous studies on the impact of agronomy on the HT2+T2 content of UK oats. Another study that considered the economic implications of mitigation strategies to reduce HT2+T2 content of UK oats by reducing the intensity of cereals in a rotation and/or a switch from winter to spring oats identified that these were currently not realistic or viable options for wide spread adoption. There should be careful consideration as to what is reasonably achievable as a strategy for the mitigation of HT2 and T2 risk in UK oat production.