A UCD team has discovered a way of identifying the country of origin of beef - and they believe they can prove whether it is organic, writes Dick Ahlstrom
You are what you eat has never been more true, given new technology being developed at University College Dublin. Researchers have discovered a way to authenticate the country of origin of beef based on what the animals ate before they were slaughtered.
This technique should also be able to prove whether beef has been raised in organic conditions, giving consumers assurance that they truly are buying organic beef.
It all has to do with carbon, nitrogen and sulphur atoms, explains Dr Frank Monahan, a senior lecturer in UCD's Food Science Department, who with Dr Olaf Schmidt of the university's environmental resource management department have developed the approach. Both departments are within UCD's faculty of agri-food and the environment.
"We are excited about these findings as it moves food-labelling and authentication to a full scientific verification," says Monahan. "Now for the first time we can obtain information about the feeds consumed by animals. We no longer have to rely on a paper trail to prove authentication of the origin of our beef or the feeds used."
The new system doesn't rely on the use of DNA fingerprinting. "The technique is a bit like being a detective, we are looking for the clues that each feed the animal eats leaves behind at the atomic level of the animals' tissues," explains Schmidt. The feedstuffs given to an animal leaves an atomic signature that helps to pinpoint where the animal was raised.
"It arose because of media interest in the foreign beef that was being traded as Irish beef," says Monahan. "We thought we would look at this as a way to differentiate between beef sources."
Schmidt was already using the technique, which relies on measuring ratios between stable isotopes of carbon and nitrogen. He wanted to learn what slugs were eating but it works equally well on beef and humans too, adds Monahan. "Our ratios depend on what we eat as well."
These are not radioactive isotopes but stable variant forms of these elements, for example carbon 13 and carbon 12. When plants absorb these elements they do so in a characteristic way, establishing slightly different ratios of this "heavy" and "light" carbon as they grow. "It is related to the plant itself," says Monahan.
"We had some evidence that cattle in the US and South America would consume different grasses and feeds compared to animals in Europe," says Monahan. Brazilian cattle mainly eat tropical grasses while animals in the US mainly eat maize. "We knew that maize carbon ratios are very different to grass carbon ratios," Monahan explains.
These ratios are in turn are very different to those arising in cattle reared on Irish grass. The UCD approach relies on these natural isotopic markers to indicate country of origin and the feeds given to an animal.
The two researchers have expanded the work with fresh funding from Teagasc and collaboration with Dr Aidan Moloney of Teagasc's Grange Research Centre in Co Meath. They are attempting to build isotopic marker profiles that will quickly identify where beef cattle were raised. The idea is to produce a range of markers not just one or two, involving isotopic ratios for carbon, nitrogen and sulphur and also looking at trace minerals such as selenium.
Their research has also shown that Irish organic and conventionally produced beef can be differentiated on the basis of differences in the isotopic markers. Organic systems tend to be "closed" systems with lower levels of inputs, says Monahan. The isotopic rations are different when the cattle are raised on lands that receive inputs such as commercial fertilisers. Monahan and Schmidt believe the research should lead to foolproof methods of assigning country of origin of beef and highlighting beef raised under different feeding and production systems.