Electrical stimulation is being used to improve sheep meat quality.

In the last two years, more than 10 sheep abattoirs have installed new technology which uses electrical stimulation technology to improve sheep meat quality.

But what does electricity have to do with meat?

According to NSW Department of Primary Industries Principal Research Scientist, Dr David Hopkins, electricity applied to carcases of any species soon after death changes the rate of onset of rigor mortis – and altering this rate affects qualities such as meat tenderness.

The earliest reported use of electricity for this purpose was by Benjamin Franklin who, in 1749, electrocuted turkeys, with the result that they were 'uncommonly tender'.

Although it was shown that electrical stimulation could improve meat tenderness during the 1950s, no commercial application of the process occurred.

It is only in the last few years that significant developments based on Australian research and development have occurred – and research by NSW DPI scientists has been instrumental in the validation and optimisation of this technology.

The slow adoption of this technology in Australia was partly due to technical and work safety limitations of the high-voltage systems favoured for high-throughput abattoirs.

High voltage systems must be physically isolated to protect workers against electrocution and consume large amounts of energy. They must also be able to stimulate several carcases simultaneously, averaging voltage and current across them.

To avoid these problems, a new approach was developed in which a controlled amount of electricity in a low-energy form that is safe for workers is administered to individual carcases.

The system is designed so that each carcase is stimulated individually using segmented electrodes to ensure each segment only contacts one carcase at at ime.

This allows computer-controlled electronics to give a precise, but adjustable electrical input to each carcase, which matches the requirements of particular carcase types while also maintaining the delivery of a pre-determined level of current.

In effect, a feedback system which detects the level of resistance is used.

This approach also reduces the installation costs because the power levels and pulse widths used eliminate the need for isolation of the unit, a requirement of high voltage systems.

The DPI Meat Science team at Cowra is currently running projects in two NSW abattoirs to further enhance the application of electricity to carcases with funding from the Australian Sheep Industry CRC and Meat Livestock Australia.

Contact: Dr David Hopkins, NSW DPI, Cowra, (02) 6349 9722 or david.hopkins@dpi.nsw.gov.au.

This story appears in Agriculture Today.