New DNA traceability test will improve food composition screening

Posted by AFN Staff Writers on 28th March 2013

German scientists have developed a novel screening procedure that accurately determines the amount of animal, plant and microbial substances in foods.

Almost all foodstuffs contain the genetic material of those animal and plant species that were used in their preparation. Researchers have adapted the latest techniques of DNA sequencing to determine precisely the levels of different substances in foods.

In pilot studies, the researchers from Johannes Gutenberg University Mainz (JGU) were able to use the new DNA method, which has been dubbed ‘All-Food-Seq’ by its developers, to detect the presence of 1 per cent content of horse meat in products. They also found slight traces of the DNA of added mustard, lupin and soy in a test sausage prepared for calibration purposes, and say this could be of great use for allergy testing of foods.

“The innovative aspect in comparison with conventional DNA detection methods such as polymerase chain reaction (PCR) is that by means of bioinforamatic analysis of all biological DNA data available worldwide we can identify the presence of material from species that we would not otherwise expect,” said molecular geneticist Dr Thomas Hankeln, who helped develop the method.

“And, using a simple digital method of counting short snippets of DNA, we will also probably be able to determine the relative incidence of individual species-related material more precisely than was previously the case,” he added.

The method, which Dr Hankeln developed in collaboration with bioinformaticist Professor Bertil Schmidt and colleagues at the German and Swiss food control authorities, has attracted the attention of food inspection experts.

“This method is very interesting in connection with efforts to promote the molecular traceability of food,” said spokespeople from the German Federal Institute for Risk Assessment and the Zurich Cantonal Laboratory in Switzerland.

The ‘All-Food-Seq’ method is expected to be validated,  by comparison with conventional detection techniques, in the near future.