New BSE test could help allay meat safety fears

A test to instantly detect beef that has been contaminated with tissue from a cow's brain or spinal cord during slaughter could improve control of Bovine Spongiform Encephalopathy (BSE) in the food supply chain, claims a US study.

A test to instantly detect beef contaminated with tissue from a cow's brain or spinal cord during slaughter could improve control of Bovine Spongiform Encephalopathy (BSE) in the food supply chain, claims a US study.

Researchers, who worked in conjunction with the National Animal Disease Center of the US Agriculture Department’s Agricultural Research Service, said a new real-time monitoring test of possible central nervous system (CNS) contamination during slaughter would provide an additional, science-based tool for sanitation measures in abattoirs. This could have applications in helping to prevent the onset of BSE.

Scientists believe that the human illness, Variant Creutzfeldt-Jakob Disease (vCJD) - discovered in 1996 - is caused by the consumption of BSE-infected meat. As of June 2008, 166 probable or definite cases of vCJD had been diagnosed in the UK.

The researchers claim their light-based spectroscopic monitoring technique is rapid and non-invasive, requiring no sample preparation as opposed to existing methods. This development could offer an advance in protecting against possible spread of vCJD, they added.

“No currently available method enables the real-time detection of possible central nervous system (CNS) tissue contamination on carcasses during slaughter," claims lead researcher Jürgen A. Richt from Iowa State University.

“A benefit to the beef production industry would be an improved product quality assurance and would result in increased consumer protection,” added the researchers.

The study suggested that the drawbacks of conventional detection based on ELISA and PCR techniques are the high costs involved as well as the need for varying degrees of access to laboratory environments and equipment, which they claim make them unsuitable for on-site monitoring during the slaughter process.

Findings

In the study, published in the Journal of Agricultural and Food Chemistry, the researchers point out that removal of brain, spinal and other central nervous tissue after slaughter is "one of the highest priority tasks to avoid contamination of the human food chain with bovine spongiform encephalopathy (BSE).”

The researchers said their test is based on detection of the fluorescent pigment lipofuscin, a substance that appears in high concentrations in the nervous tissue of cattle, which they believed was a dependable indicator for the presence of brain and spinal tissue in bovine carcasses and meat cuts.

"Small quantities of bovine spinal cord were reliably detected in the presence of raw bovine skeletal muscle, fat and vertebrae. The research lays the foundation for development of a prototype device allowing real-time monitoring of CNS tissue contamination on bovine carcasses and meat cuts," the report says.

US recalls

Food safety is a vital issue for meat processors in the US at present.

At the start of this year, 143 million pounds of raw and frozen meat products were recalled that originated from the Hallmark/Westland Meat Packing Company. Fears were raised that non-ambulatory cattle forced to slaughter might have bought BSE into the food chain.

Several recalls, amounting to millions of pounds of beef, from Nebraska Beef related to E. coli have also been instigated in the past few months.

Concerns have also been voiced that the USDA is not taking adequate measures to ensure the safety of the nation's meat supply.

Source: Journal of Agricultural and Food ChemistryPublished online ahead of print“Fluorescence-Based Method, Exploiting Lipofuscin, for Real-Time Detection of Central Nervous System Tissues on Bovine Carcasses”Authors: H. Schonenbrucher, R. Adhikary, P. Mukherjee, T. A. Casey, M. A. Rasmussen, F. D. Maistrovich, A. N. Hamir, M. E. Kehrli Jr, J. A. Richt, J. W. Petrich