Certification of EH92-527-1 fraction and identity of non-modified and genetically modified potato powder : certified reference materials ERM-BF421a and ERM-BF421b

This report describes the preparation and certification of the potato powder Certified Reference Materials (CRMs) ERM-BF421a and ERM-BF421b, consisting of conventional and genetically modified EH92-527-1 potato powder, respectively. The CRMs were processed in 2005/2006 and were certified in 2006 by the European Commission, Directorate General Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Geel, Belgium. The EH92-527-1 genetic modification results in tubers containing nearly exclusively amylopectin (> 98 %) as the starch component, whereas conventional potatoes have starch composed of both amylose and amylopectin in a ratio of 1:3. For the processing of the CRMs, tubers of non-modified potato and EH92-527-1 potato, supplied by BASF Plant Science GmbH (Ludwigshafen, DE), were individually tested for the presence of the genetic modification, then brushed under tap water, cut into cubes and freeze-dried. After grinding, a pure non-modified potato powder and a pure EH92-527-1 GM potato powder were obtained. The certification of the CRMs was based on the individual testing of the potato tubers used for the production of the CRMs, using an amylose test as a measure for the presence of the genetic modification, and was furthermore confirmed by real-time PCR analysis of the CRMs. The identity of the EH92-527-1 specific modification was also confirmed by nucleotide sequence analysis of the junction region between the plant DNA and the genetic insertion. The CRMs are intended to be used as positive and negative controls for the detection of genetically modified EH92-527-1 potato in food and feed. The CRMs are available in glass bottles containing 1 g (ERM-BF421a) or 0.5 g (ERM-BF421b) of potato powder, closed under argon atmosphere.