x Abu Dhabi, UAE Thursday 20 July 2017

DNA tests rise in Dubai shops and restaurants after horse meat scandal

Shops and restaurants across the UAE are increasingly subjecting their food to DNA testing to check it is what it says it is.

DUBAI // A specialist laboratory in Dubai has been testing 20 food samples a day for traces of horse DNA in the wake of the European food scandal.

Products such as burgers and pies being sold in Europe as beef have been found to contain horse meat or pork.

Food authorities say the meat substitution is not a threat here, but food outlets are still taking precautions and sending samples for DNA testing.

"We never previously did the testing for horse meat but we've been receiving 20 samples a day from food companies and supermarkets," said Dr Mohsin Sulaiman Al Amiri, founder of the Advanced Biotechnology Centre and a DNA fingerprinting and biodiversity expert. "They've all been negative so far."

The centre receives more than 100 samples of food and water a day but it limits its testing to 100 to avoid human error. DNA testing can take up to 24 hours.

Once the lab receives a sample, a tiny amount - less than a tenth of a gram - is placed in a sterile pouch and then into a machine that breaks it down into a smooth slurry. Then it is chemically broken down further, so the DNA can be extracted.

The extracted DNA is fed into a machine that creates millions of copies of the genetic material. "This makes it easier for us to see if the amount of DNA present is small," said Dr Sanjeet Mishra, the centre's technical manager.

They also put a control sample - of something known to be beef, for example - through the same amplification process, to enable them to compare the results.

If they get a positive match for a substance that should not be present, they re-run the test to check.

The procedure, which can take up to six hours and costs an average of Dh600, is 100 per cent accurate and can detect even the tiniest traces of DNA.

"We mostly find E. coli in samples of rice that are eaten for breakfast, like porridge, from hotels or distributors," said Thulasi Ratheesh, a food microbiologist at the centre who has been in the industry for three years.

"It's dangerous and can cause diarrhoea, so we inform the outlet concerned and they have to destroy the products."

If a micro organism cannot be recognised, it is sent to the centre's DNA sequencing lab to find out what bacteria or fungi are present.

The centre receives between 60 and 100 samples a day to test for legionella, a type of bacterium, and up to 10 for pork. "The municipality sometimes asks us to double check some samples for legionella," said Dr Al Amiri.

cmalek@thenational.ae