Whether or not to serve food with genetically modified (GM) ingredients should be the personal choice of the European consumer. For this reason, the European Union has established strict thresholds for the application of gene technology to food and has mandated the labelling of such products.
Fundamentally, if more than 0.9 per cent of a specific food product is derived from genetically modified organisms (GMO), this must be labelled as such on the packaging. Also, the presence of GMO that is unapproved in the EU is strictly prohibited (in fact, a technical zero: for the applied methods, this consists either of the limit of detection or of the limit of quantification) for all food and feed products.
However, the possibility of effective enactment of such regulations may be questioned. Worldwide, the number of authorised GMOs is increasing rapidly. Since the introduction of mandatory labelling, problems raised by asynchronous approvals repeatedly have occurred with imports of raw materials containing GMO that is unapproved in the EU, such as ‘Herculex’ maize.
In addition to some GMOs, such as the LL601 rice that swiftly was approved in the USA after its discovery in fields and in exports, other GMOs, such as Bt63 Chinese rice, are still to be found in products imported into the EU. In the seed, food and feed industries, globalisation is a current reality and therefore directly implies the detection and measurement of possible unapproved GMO admixtures.
Legally – and, therefore, analytically – it is necessary within the EU market to discriminate between authorised and unauthorised GMOs. It also is necessary to quantify the legal GMOs to ensure proper labelling. Such regulations pose inherent challenges. Last week, approximately six hundred experts in the areas of economics and science gathered in Como, Italy, to describe the state of the art and search for solutions at the seminal global conference dedicated to GMO analysis.
Contributions to the conference illuminated existing fronts: while some participants discussed the ways in which the analysis of food products may be made more accurate and reliable, others proposed faster and easier tests in order to circumvent trade hindrances.
Sampling: the most critical point of traceability measures
The discussion of sampling methods provided lively debate. The extraction of the correct number of probes from the correct areas of a freight container, for example, remains a significant problem. "One simply cannot assume that GMO admixtures are evenly spread throughout the shipment,“ explained Kim Esbensen from Aalborg University in Dänemark. A non-representative extraction of samples may result in errors that are between fifty- and one-hundredfold as large as the errors that may occur in the analysis of individual probes.
Under the best conditions, new samples repeatedly should be taken from all freight storage spaces during the entire process of unloading. Importers regard this idea with scepticism. “The more precise, the more expensive,“ complained Klaus Schumacher from the company Töpfer International, who states that his company trades worldwide in cereals, oilseeds and animal feeds and that the charter fees for an appropriate ship are 70,000 dollars per day. Mr Schumacher regards the complete separation of products with and without GMOs to be an impossibility in any case and suggests instead “technical solutions that do not compromise trade“.
Progress towards the solution of this conflict may be expected from the EU research project known as Co-Extra. At the conference, a high number of researchers from this project presented the results of their work. Sampling challenges may be met most efficiently by the establishment of optimised protocols that are standard throughout the EU. With the help of statistical and software tools, Co-Extra researchers are optimising sampling plans for seeds, grains, ingredients and final food products. While maximising precision and certainty, such plans also are aimed towards the reduction of cost and effort.
GMO detection methods
Essentially, two ways exist in which the presence of genetically modified organisms may be substantiated. One may apply a method known as Polymerase Chain Reaction (PCR) to a sample in order to search directly for foreign genes. Conversely, one may search indirectly by analysing a sample for proteins that signify the presence of a product of a new gene. Comparably inexpensive test strips already are available for the second method. However, the second method is less precise than the first and, most importantly, such strips also are unable to indicate the exact type of GM product (e.g., Bt11 as opposed to Bt10 maize) that has been found in the freighter or grain-sack.
Representatives from the industry as well as conference participants from less-wealthy countries voiced support in Como for the simpler and easier tests. For example, Maria Mercedes Roca of the Pan American College of Agriculture in Honduras stated that, at one hundred dollars, the high cost of a PCR test was in itself a reason to question its necessity – particularly, in her opinion, with regard to the harmlessness of GMO admixtures.
Guy van den Eede, Chair of the Unit ‘Biotechnology & GMOs’ at the JRC and conference organiser, declared himself nonetheless to be “completely convinced“ that the EU will succeed in maintaining existing norms. “I certainly understand that such measures mean additional costs for countries that don’t require labelling. This will be used as an objection whenever possible,” stated Mr van den Eede with regard to conference debates. However, according to organiser, the adherence of the EU to labelling and controls remains justified. “One must not forget that numerous cases already have occurred in which unapproved GMOs turn up in Europe. This shouldn’t happen."
Inexpensive protein tests may be an expedient possibility for the occasional quick test of trucking freight. “Nonetheless, we have made it clear that we demand genetic analysis for import,” declared Mr van den Eede. “This is the only way to distinguish between GMO that is approved or unapproved in the EU."
Although EU agencies demand exact analyses, it must be noted that certainly not every import is tested at EU entry, although traders must conduct self-controls and provide traceability documents. State-of-the-art detection technologies remain time-consuming and each method can only be applied to one or a few GMOs. Methods and reference materials also are rarely available for detection of unauthorised GMOs. As explained by Mr van den Eede, closer controls currently must be justified with particular suspicion. This is the case, for example, with long-grain rice from the USA, which routinely has been tested since the discovery of contamination with LL601.
In response to such issues, Co-Extra researchers have created innovative techniques and guidelines to overcome the limits of current detection methodologies. As validated, cost-effective, fit-for-purpose methods for detecting GMOs, such technologies were presented in Como by Co-Extra representatives and may be expected to improve controls.
New technologies include screening procedures with which many various genetic sequences may be verified simultaneously. More than thirty distinct GMOs may be placed on the test surface of a micro-array that is only a few square centimetres in size. This is very practical, for example, for cases in which an import of soybean or maize must be tested for the many GM varieties that are approved in the USA. Such methods also have attracted particular attention due to their potential to identify and characterise unauthorised GMOs.
For routine laboratories, the screening of samples according to a method known since 1999 (as defined by INRA in the EU GMOChips research programme) as the ‘matrix approach’ may provide a list of candidate GMOs to be found. The consequent reduction of the need for event-specific quantitation rationalises the following analytical work. The matrix approach tests simultaneously for the presence of a large number of possible DNA fragments and compares the resulting combinations to a database of known GMOs. A possible unknown GMO is indicated by the presence of unusual combinations of DNA targets. This approach also may facilitate identification of samples that contain unauthorised GM material and may be extended by the inclusion of a screening micro-array that permits the detection of several thousand genetic elements.
Of course, the use of documentary traceability as foreseen in EU regulations not only decreases the controls costs, but also improves the decision-making process with regard to the presence of unapproved GMO in samples. This issue was presented in a talk which referred to the development by Co-Extra scientists of a DSS (Decision Support System) for GMO controls.
Finally, Co-Extra scientists pointed out the widely-hidden benefits of such GMO controls in several other detection areas relevant to pathogens, mycotoxins and allergen-producing organisms. It can thus be concluded that the cost-benefits analyses of labelling GMO products is largely positive for both companies and consumers, due to the contribution of better safety for all supply chains.
Sources: Co-Extra / Süddeutsche Zeitung (9 July 2008)