IAG ring test visual detection of ergot sclerotia in rye 2015

Ergot alkaloids are recognised as seriously toxic compounds, which caused a series of outbreaks in the past. In the EU, enforcement is implemented by visual detection and quantification of ergot sclerotia produced by moulds of the genus Claviceps. On behalf of the IAG section Feedstuff Microscopy, RIKILT organised a ring test for the visual detection of ergot sclerotia in two unground rye samples in September 2015. In this report the results from the ring test for ergot in rye 2015 are presented. The ring test ergot sclerotia in rye was designed to test the capability to visually detect sclerotia or parts thereof at relatively high levels. One sample was based on a level of approx. 400 ppm, and the second sample contained an amount of approx. 1000 ppm (EU legal limit for feeds and ingredients: 1000 ppm = 1 gram/kg = 0.1%). An amount of approx. 250 grams of rye grains was chosen as sample size. All samples were individually spiked. Thirty participants enrolled for the ring test. Participants were requested to report the number of recovered (fragments of) sclerotia and the total weight per sample. The percentage of recovery for every sample was calculated. A dedicated IAG method as well as other (lab internal) methods were allowed for application. Principally, methods are based on sieving (preferably with a mesh size of 0.5 mm), examination of every particle (grain) in the fraction with full grains or particles larger than 0.5 mm, selection of sclerotia fragments supported by documentation, and weighing the final selection of bodies. The average recovery for both samples was approx. 97%. All results except one were between the expected recovery limits (80 – 110 % w/w). Supporting data from an intralaboratory validation study of the IAG method showed trueness at different low spike levels between 98 and 105% w/w. Limit of detection was established at 7 ppm. It can be concluded that examination by visual detection of sclerotia is a valuable indicator of the expected pre