Scientists targeting disease-causing bacteria present on cows' skin in attempt to prevent contamination

Feb 20, 2013 by Sergio Pistoi
Scientists targeting disease-causing bacteria present on cows’ skin in attempt to prevent contamination
Credit: Jon Anderson

If you can't kill them, trap them. Such is the fate that scientists are reserving to pathogenic bacteria, such as the infamous E. coli. These bacteria may contaminate meat in abattoirs, when small traces of excrement on the hide come into contact with the carcass. "Some microbial contamination of the carcass, including food-borne pathogens, can occur even when best hygiene practices are followed," says Laura Wyness, senior Nutrition Scientist at the British Nutrition Foundation, UK, which is a partner to ProsafeBeef, a EU-funded research project designed to advancing beef safety and quality.

To get rid of bacteria, and improve the safety of , project scientists have developed an ingenious solution. Their idea is to spray the carcasses before skinning them with a liquid product called shellac. This is a natural resin produced by the female lac bug. When dissolved in ethanol, shellac forms a sticky glaze that is used to covers the hide, thus entrapping dirt and bacteria, and preventing them from contaminating the meat. Shellac, a sort of natural plastic, has been used for more than 3,000 years, and is still employed today in liquid solutions to coat furniture and musical instruments. Besides, it is edible, making it suitable as a glazing agent; it is sold commercially as additive E904, used in foods and drugs.

"Shellac may be a better alternative to disinfectants such as lactic acid, which is used in some countries to wash the carcasses but is not permitted in the EU," Geraldine Duffy tells youris.com, "Indeed, our data show that immobilising bacteria with shellac is more effective than other hide decontamination methods." Duffy is the Head of food safety at the Teagasc Food Research Centre in Dublin, Ireland, the institution coordinating the project. Current rules in the EU provide for a "clear-cattle" policy, which include visual inspection, clipping dirt and water washing of . "Disinfectants are not allowed on the rationale that they may mask unruly practices," says Duffy.

To date, researchers have tested the shellac solution in abattoirs in Serbia and in the UK. They found that it reduced the amount of in meat up to 100 fold, better that what they could achieve with . Duffy cautions that further steps are needed before shellac becomes a commercially viable strategy in the meat industry. "We will need to develop this treatment into a cost-effective solution, and figure out the best way to fit it into the abattoir line," she says.

Experts welcome this solution. "[The shellac-based] technique represents a paradigm shift from killing the microorganisms on the hide to actually immobilising them [...]. It has good potential for improving the microbial safety of beef," says Aubrey Mendonça, an associate professor at the department of food science and human nutrition at Iowa State University, in Ames, USA.

This approach should, however, be considered in the future along with other technologies, according to Timothy Bowser, a food process engineer at Oklahoma State University, in Stillwater, USA, affiliated with the Intota Expert Network. However, he points out that moisture may limit the efficacy of the treatment: "in the winter, many cattle would often enter the plant covered with about 5 cm of frozen mud. […] Moisture control, or finding an immobiliser that is more effective in the presence of moisture, may be a key to future success."

Explore further: Certain virus-derived genomic elements have now been shown to actively regulate important developmental processes

add to favorites email to friend print save as pdf

Related Stories

Clean animals result in fewer E. coli

May 04, 2012

Sigrun J. Hauge has studied the effect of the measures implemented on farms and in slaughterhouses. The aim of the project "Uncontaminated Carcasses" was to uncover data that would help to improve the hygienic ...

Ridding meat of E. coli

Jul 03, 2008

You may be able to enjoy a rare hamburger soon, thanks to a discovery made by a team of University of Alberta researchers.

Food bug forensic tracking

Jan 14, 2013

Detective-style high-tech methods are being used in meat factories to trace harmful microbial contaminants.

EU says too early to impose meat labelling

Feb 12, 2013

The European Commission said Tuesday it is too early to require labelling on meat used in processed foods despite growing uproar over horse meat being passed off as beef in frozen hamburgers and lasagne.

Recommended for you

Crowdsourced power to solve microbe mysteries

Oct 22, 2014

University of New South Wales scientists hope to unlock the secrets of millions of marine microbes from waters as far apart as Sydney's Botany Bay and the Amazon River in Brazil, with the help of an international ...

Reading a biological clock in the dark

Oct 21, 2014

Our species' waking and sleeping cycles – shaped in millions of years of evolution – have been turned upside down within a single century with the advent of electric lighting and airplanes. As a result, ...

User comments : 0