Making safer meat
Advanced animal feed markers can reveal food contamination culprits.
28 October 2010
Food security also includes food safety, and although food poisoning outbreaks are rare in the UK when they do occur they can be serious.
In September 2005 a child died from food contaminated by the bacterium E. coli O157; the same outbreak affected 158 people. A much worse outbreak in Scotland in 1996 – again O157 was the culprit – led to 21 deaths, and 496 cases of food poisoning, some of them severe.
Scientists based at the Institute of Biological, Environmental and Rural Sciences (IBERS), an institute of BBSRC based at Aberystwyth University, are developing dietary markers for cattle and sheep that could lead to safer meat.
“We don’t want to scare people. We are very good in the UK with regards to food safety from the abattoir down the food chain,” says Dr Michael Lee, who leads the project at IBERS. “But this project is to increase safety further.”
Technologies developed in the UK could be used to enhance food safety anywhere in the world where UK beef or lamb is eaten, or the technique itself could be exported to benefit consumers around the world.
Contamination often occurs in the abattoir when the animals are slaughtered. Tiny particles of dried faeces on hide or hair can disperse into the air as an aerosol, even when the most stringent hygiene practises are employed. The dirty aerosol particles can then contaminate meat with a number of pathogens including Salmonella, Listeria and Campylobacter.
Scanning electron microscope image of E. coli bacteria.
Image: US Agricultural Research Service
To track contamination, Lee’s approach is simply to follow the faeces. A fluorescent marker added to the animals’ feed just before they are culled will pass through the animal and if any marker-containing faeces comes into contact with meat it can be seen under UV light after the meat is processed.
Lee’s marker is based on the natural plant pigment chlorophyll. The clever science involves making the marker resistant to breakdown as it passes through the animal whilst retaining an atomic structure that will fluoresce brightly when light is shone on it so the contamination can be seen clearly.
Lee and his colleagues and partners in industry (see ‘Industrial partnerships' below) are now looking at the best delivery systems to get the marker into the animals. “We’re at the stage of making lamb finishing feeds with the marker. That will add 5% to the overall cost of the feed,” he says. “To begin with I was quite happy with that – it’s only going to go down from there.”
Dr Michael Lee with his chlorophyll-based feed markers.
Keeping costs down is crucial, and one way to do this might be to add the marker to the lambs’ water, or to mineral licks that animals lap in barns to satisfy their needs for minerals like salt for example. “Adding the marker to a mineral lick might be more efficient and an easy way to get the marker consumed. This is why we are working with partners to get the costs down.”
The consortium that is supporting the research includes animal feed manufacturers and abattoir owners, so the whole chain is involved from farm to factory to supermarket shelf. “This way we can process the animals with and without the marker and see how many more instances of faecal contamination we see, how it affects the pathogen status of the meat, and also look at the shelf life,” says Lee, who adds that all the work is ongoing in sheep and cattle, but sheep are an easier vehicle to work with.
On 19 July 2010 the Improved Food Safety research project was launched and brought together representatives from industry, academia and agriculture to mark the start of the programme that aims to drastically reduce incidences of meat contamination in abattoirs.
Funding for the £460,000 research project, to be undertaken by scientists at IBERS (which receives core funding from and is an institute of BBSRC), is split between the Welsh Assembly Government (£230,000) and the other half between partners across the agri-food industry including British Chlorophyll, Castell Howell Foods, Randall Parker Foods, Waitrose and the Wynnstay Group.
The project is funded through the Welsh Assembly Government’s Academic Expertise for Business (A4B) programme, which aims to encourage collaborative research between industry and academia, and is closely linked to the European Commission-funded ProSafeBeef Project which has the reduction of pathogen contamination in carcasses as one of its key objectives.
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