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Food chain control - refined detection, improved assessment

21/2012, 14.06.2012

13^th BfR Consumer Protection Forum on challenges in food and feed analysis in the face of the global flow of goods

Trust is good, but reliable and regular controls are even better. Adopting this motto, Europe has succeeded in setting high standards in the area of food and feed safety. Good and notably legally secure monitoring of standards required by law is only possible, however, if reliable and, more importantly, officially recognised analytical methods are available for such complex matrices as food and feed. These methods must allow the detection of even very small quantities of undesirable contaminants and residues. The lines of development and requirements for official food analysis are therefore the subject of the 13^th Consumer Protection Forum of the Federal Institute for Risk Assessment (BfR) held on 14^th and 15^th June 2012. "We can now reliably detect traces of undesirable substances such as dioxins in food at the femtogram level. This is the equivalent of finding a sugar cube in the Baltic Sea", says BfR President Professor Dr. Dr. Andreas Hensel. "To ensure consumer protection, it is not necessary for us to develop even more sensitive analytical methods. However, it is important that these methods used in monitoring are suitable for daily use, that they are fast and, crucially, that they reliably identify undesirable contaminants and residues. For this purpose, validated, very well defined detection methods are required which ideally should be recognised both at the EU level and internationally. And what is even more important is that they are available globally and can also be applied in the countries in which our food and feed is produced." If European standards of food safety are to be established worldwide, producer countries, for example in South America, Africa and Asia, must be able to control their compliance with those standards using reliable analytical methods which are adjusted to the country-specific situation. A second important aspect is the availability of detection methods by which large quantities of samples can be quickly and reliably tested in critical situations. On that basis, an overall analytical picture of the hazard potential of a substance for risk analysis can then be presented for the purpose of official controls and self-monitoring of the industry.

Chemical analysis of food and feed and detection of undesirable substances suspected therein is a task that requires a great deal of expertise and experience. On the one hand, food consists of a number of individual substances which in the preparation of samples must be separated from the sought substance. On the other hand, environmental contaminants such as dioxins and PCB never occur in one form only. Instead, they constitute mixtures of substances for which the individual components must be identified individually due to their differing toxicity. Thus, patterns of distribution of individual substances, so-called “congener patterns”, can be defined which may provide clues to the additional presence of dioxins and PCB in a food or feed product. Under certain circumstances this makes it possible to determine the path by which dioxins and PCB entered the food supply chain.

Reference materials are firstly necessary to find out how accurate a method is and whether it reliably and invariably supplies the same measurement results within a pre-defined deviation limit (measurement uncertainty). Reference materials are samples with precisely defined substance concentrations which are used to validate a method prior to the analysis of samples with unknown quantities of unwanted substances/contaminants. Secondly, the results obtained by applying these methods in different laboratories must be identical. In order to find out if results of different laboratories are comparable, both at the national and European level, so-called round robin tests are performed. Reference laboratories are encountered with the task of performing in round robins and the creation ofreference materials as well as  the development and validation of new analytical methods. A good example of a milestone in method development and validation was the replacement of the mouse bioassay for detecting marine biotoxins in mussels. The National Reference Laboratory for Marine Biotoxins at the BfR made a significant contribution to ensuring that this animal experiment was replaced by a modern analytical chemical method.

Animal components in feed pose a special challenge for analysis. The goal here is to create applicable modern immunological and bimolecular methods for the monitoring authorities, so that animal species-specific distinctions can be made as well. One way to ensure a quick, reliable and easy-to-handle method for detecting animal proteins is an antibody-based test. The National Reference Laboratory for Animal Protein in Feed at the BfR has developed such an ELISA procedure in which a change in colour shows whether animal protein is present and if this is the case, what animal species is contained in the feed sample.

About the BfR

The Federal Institute for Risk Assessment (BfR) is a scientific institution within the portfolio of the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). It advises the Federal Government and Federal Laender on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks.

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