CONTROL OF ERGOT ALKALOIDS IN INDUSTRIAL MILLING THE ROLE OF ADVANCED GRAIN CLEANING Matthias Graeber1, Bärbel Kniel2, Max Moser2, and Peter Striegl3 1 Bühler Sortex, London, UK 2 Biotask AG, Esslingen, Germany 3 Bühler AG, Uzwil, Switzerland Managing the risk of ergot and its toxic ergot alkaloids is an ongoing challenge for the grain processing industry. This article provides an overview on the current situation, including recent amendments of the European Regulation on maximum levels for certain contaminants in food and the resulting requirements for grain cleaning measures. It also presents in detail test results performed in two German rye mills, to show how the level of ergot alkaloids can be influenced by grain cleaning and milling processes. Immediate conclusions can be drawn from this data, on the effectiveness of individual cleaning steps undertaken in the mills to reduce the level of ergot alkaloids in rye flour.
Ergot and its toxic ergot alkaloids (EAs) have been a continuous issue within the grain processing chain, for the last three years, in particular for rye. Fortunately, the mass poisonings of earlier centuries are a thing of the past, thanks to a number of measures, including better quality assurance and optimised cleaning processes in mills. After a lengthy period, with virtually no discussion on this topic, the situation abruptly changed with the extensive health evaluation of EAs by the European Food Safety Authority (EFSA) in 2012. The consequences for the entire grain processing chain were considerable,1 because two values were established: a TDI (tolerable daily intake) of 0.6 µg/kg body weight (b.w.) and an ARfD (acute reference dose; the amount of a substance that can be consumed with a meal or within a day, without identifiable risk) of 1 µg/kg b.w. Based on the EFSA’s scientific opinion, the German Federal Institute of Risk Assessment (BfR) concluded that the short-term intake of medium to large amounts of rye bread, with an increased EA concentration can, in particular, have a detrimental effect on the health of children age 2 to <52. According to the BfR, children of this age group have the highest exposure, because of the ratio of low body weight and consumption levels. For children age 2 to <5 which are said to be high consumers of rye bread and rye rolls, a daily intake of up to 250 g was assumed. Another consequence of this is that some authorities in Germany classify baked goods, with an EA level greater than 64 µg/kg, as unsafe3. They base their decision on the EFSA opinion and the BfR statement, according to which, children of the above mentioned age group have already reached the acute reference dose (ARfD) of 64 µg/kg, with a daily consumption of 250 g of bread. After this assessment practice became public, some retailers defined their own “limiting values” of less than 64 µg/kg of baked goods for their suppliers. The result is that more and more mills are being requested to deliver flours with EA levels of less than 100 to 150 µg/kg flour, which is derived purely mathematically from the usual dough recipes. Unfortunately, there is currently no consistent evidence available on the factors relevant for the processing of EA-containing milled grain products into food such as bread. According to earlier studies, EAs were assumed to be significantly degraded, in particular in the baking process; but large differences between the degradation rates were reported1. Current studies, however, indicate that no degradation takes place during the baking process4,5.
46 | December 2016 - Milling and Grain