How to tell if your food's authentic? Use DNA test kit

Genetic barcoding can ensure what you eat is safe, and even tell fish species apart
Shobana Kesava, Straits Times 28 Jun 08;

THE proof of the pudding may no longer just be in the eating.

Scientists are developing genetic test kits that could show - on the spot - whether food is authentic, even before customers take their first bite.

Diners would be assured that they had the real deal with, say, exclusive beluga caviar rather than an inferior variety of salty fish eggs; and buyers could rest easy that the Kobe beef they purchased was not just run-of-the- mill marbled meat, for example.

DNA barcoding has been used increasingly in the past decade by biologists to identify different animal species based on their unique genetic blueprints. With such techniques getting faster and cheaper, new uses are coming up, said Associate Professor Rudolf Meier, an evolutionary biologist at the National University of Singapore.

Small and simple test kits are already being developed in Europe and America. In San Diego, for example, high school students as young as 16 were able to distinguish between dried jerky of ostriches, turkeys and cows in their science laboratory, via DNA fingerprinting. This year, they teamed up with East African graduate students to identify bushmeat from endangered species in local African markets.

Interest in DNA barcoding has taken off in the last two to three years, said Prof Meier, with international foundations fuelling research.

A single test costs about $10 currently, but prices are likely to plummet as technology improves.

Such molecular tests are being touted as the modern alternative to the age-old scientific technique of using an animal's morphology or physical form to distinguish one creature from another.

But Prof Meier pointed out that only about 20,000 animal species have been barcoded so far, out of five million or so identified in the world.

On the upside, the system is proving invaluable in food-quality assurance, he said.

In the United States, for example, scientists testing 'snapper' from restaurants and sushi bars in California and Washington found recently that eight in nine pieces had been substituted with cheaper or over-fished species such as tilapia or rockfish.

The Agri-Food and Veterinary Authority of Singapore said that it is evaluating the use of DNA barcoding to ensure food is safe and that labels are accurate.

AVA spokesman Goh Shih Yong said that the authority was looking at such methods together with GenoMar, a Norwegian marine lifesciences company.

The interest in the technique is not confined to food.

In the aquarium trade, such tools could be used as a method for identifying expensive fish. A red Asian arowana, for example, develops its sought-after crimson sheen only as an adult. As a 15cm juvenile, it costs $2,500 but is indistinguishable from its garden variety red-tail golden cousin which costs $350.

Local ornamental-fish provider Qian Hu is working with Temasek Life Sciences Laboratory to come up with DNA barcodes for its dragon fish.

Said Qian Hu's executive chairman Kenny Yap: 'We hope to use this technique commercially by the end of the year, so that more buyers will come to us for absolute assurance that they are getting genuine dragon fish.'