German scientists develop new DNA test to determine ingredients in foods

Researchers at Johannes Gutenberg University Mainz (JGU) in Germany have developed a new DNA screening method for the accurate determination of the amount of animal, plant and microbial ingredients in foods.

Almost all food items contain the genetic material of the animal and plant species that were used in their production.

The new screening procedure, dubbed ‘All-Food-Seq’ by its developers at the Institute of Molecular Genetics, Genetic Security Research and Consulting at JGU, offers scientific analysis of animal, plant and microbial substances present in foods with the help of the latest DNA sequencing techniques.

These techniques are currently used in human genetics to determine the genetic information of patients.

JGU molecular geneticist professor Thomas Hankeln said that the newly developed procedure differs from conventional DNA detection methods such as polymerase chain reaction (PCR) in identification of the presence of material from species through bioinformatic analysis of all biological DNA data available across the world.

"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," Hankeln said.

The new DNA method, in pilot studies, could detect the presence of a 1% content of horse meat in products and determined a more precise actual amount.

Additionally, the Mainz researchers found minor traces of the DNA of added mustard, lupin and soy in a test sausage prepared for calibration purposes – a process that can be useful with regard to allergy testing of foodstuffs.

According to food inspection experts, the method can be useful in connection with efforts to promote the molecular traceability of food, and therefore needs to be validated in comparison with conventional detection techniques in the near future.