Almost all
foodstuffs1 contain the
genetic2 material of those animal and plant species that were used in their preparation. Scientists at the Institute of
Molecular3 Genetics, Genetic Security Research and Consulting at Johannes Gutenberg University Mainz (JGU) have developed a novel screening procedure that provides for highly sensitive, quantifiable analysis of animal, plant, and microbial substances present in foodstuffs. For this, the researchers have adapted the latest techniques of
DNA4 sequencing, which are otherwise currently employed in human genetics to
unravel5(解开,阐明) the genetic information of thousands of patients.
"The
innovative6 aspect in comparison with conventional DNA detection methods such as
polymerase(聚合酶) chain reaction, or PCR for short, is that by means of bioinformatic analysis of all biological DNA data available worldwide we can identify the presence of material from species that we would not otherwise expect. 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
precisely7 than was
previously8 the case," explained molecular geneticist Professor Dr. Thomas Hankeln, who developed the method in
collaboration9 with bioinformaticist Professor Bertil Schmidt, Ph.D. and colleagues at the German and Swiss food control authorities.
In pilot studies, the researchers were able to use the new DNA method to detect the presence of a 1% content of horse meat in products and to determine the actual amount with a high level of precision. The Mainz researchers even found slight traces of the DNA of added mustard,
lupin(羽扇豆), and soy in a test sausage prepared for calibration purposes, something that could also be of interest with regard to
allergy10 testing of foods.
Because of its potential, the method --
dubbed11 'All-Food-Seq' by its developers -- has already attracted the attention of food
inspection12 experts. "This method is very interesting in connection with efforts to promote the molecular traceability of food," said Hermann Broll of the German Federal Institute for Risk
Assessment13 in Berlin and Dr. René Köppel of the Zurich Cantonal Laboratory in Switzerland. The method developed by the Mainz scientists is thus to be
validated14 in comparison with conventional detection techniques in the near future.