GM detection and quantification in feed
- Berben, G. (2007). GM detection and quantification in feed. CRA-W. Proceedings in: FEED SAFETY International Conference 2007: Methods and Challenges, Namur - Belgique, 27-28/11/2007, 33.
|Year of conference||2007|
|Title||GM detection and quantification in feed|
|Conference name||FEED SAFETY International Conference 2007: Methods and Challenges|
|Conference location||Namur - Belgique|
|Abstract||Since 18 april 2004, with the application of the European regulation 1829/2003 there has been no longer a great difference between food and feed in the way authorized GMO?s or GM derived products have to be labelled. Like in food the threshold level for technically unavoidable contamination is set at 0.9%. It has also as consequence that detection methods should be quantitative. There may however still exist some differences between feed and food for authorization of certain events. A rapid overview of the main detection methods will be done stressing the fact that as only events (and not traits!) are authorised, this means that basically only DNA-based techniques can be applied even if for some special purposes other techniques may have an interest but remain in essence screening techniques. In practice, it has been observed at European level that GM material is much more frequent in feed than in food and therefore the feed sector is also subject to more GMO detection analyses than the food sector. It should also be stressed that according to recommendation 2004/787/EC the unit for quantification is in copy number of the construct per haploid genome equivalent. This is the most natural unit taking into consideration that DNA-based technique have to be considered as the reference method for quantification of GMO?s or GM derived products. However, this way of working may present some disadvantages in special occasions. When, for instance, feedingstuffs are used in which there is very few or almost no longer DNA, it is hard to work with the copy number unit and fundamentally it is the transgenic origin that is important. Another difficulty raises with the concept of botanical impurities in feedingstuffs. As long as the amount of contaminating plant species (e.g. presence of soybean in rapeseed oilcake) in a feedingstuff does not exceed 5 % in weight, the feedingstuff is considered as pure. However expressed in the copy number unit, the contaminant might largely exceed the threshold level of 0.9% of GM material. Among the challenges to be faced in the future for GMO detection in general is the increasing number of upcoming events, this will need more cost-efficient techniques. Unauthorized events and among them especially unknown ones are also a problem that will have to be dealt with by special techniques that are now being developed. This is problem common to food and feed but it might be more acute in feed than in food. Another future difficulty is linked to the increasing tendency in use of stacked events, i.e. events obtained by breeding of several GM lines and therefore accumulating more than one new trait. The PCR techniques when to be used on processed kernels are unable to distinguish a stacked event from a mix of their parental lines. As long as the authorizations of use between stacked events and the parental lines are not in conflict it is not a huge problem (unless for defining if the threshold level is exceeded or not) but if they don?t match, then the question of detection of stacked events is a problem that remains unsolved. Finally it should be stressed that, even if there are critics against the applicability of the threshold level of 0.9% for organic productions (regulation EC/834/2007 entering in application on 1st of January 2009), it seems that the level for technically unavoidable contamination is in fact higher than 0.9% in feed.|
|Author address||Berben Gilbert, Quality Department of Agro-food Products, Walloon Agricultural Research Centre (CRA-W), Chaussée de Namur, 24, B-5030 Gembloux, firstname.lastname@example.org|