New broth slices day away from listeria testing

Tracking the harmful foodborne pathogen Listeria in the food chain, UK firm Oxoid has designed a new broth that could accelerate detection time for the food industry.

Food makers are required to test each food batch where Listeria monocytogenes may be present, such as soft cheese and processed meat products, and in particular those kept refrigerated for a long time where the pathogen can grow at low temperatures.

But identifying low levels of this pathogen in food is a challenge, so industry is required to use enrichment techniques, such as broths.

The broth encourages growth and is generally repeated twice, on both occasions for 18 to 24 hours. In the second phase the findings are 'plated up' for 24 hours to achieve the final result.

"Our one broth product means a quicker result and greater levels of listeria," said a spokesperson for Oxoid.

She explained to FoodNavigator.com that their new product launched in December slices away one day from the detection procedure, by cutting back the broth time to just 24 hours.

"We're able to combine two days into one, and then provide a chromogenic plating with various diagnostic features to give higher confidence in the result," added the spokesperson.

Food safety experts estimate that 100 to 1,000 cells can cause the illness. Cooking kills most of the L. monocytogenes cells that can grow at refrigeration temperature, but ready-to-eat products, such as pates, smoked fish, cheeses and hot dogs, are not always cooked by consumers before consumption.

Oxoid's latest product 'One broth' is sold as a powder in 500g pots that provides 11.3 litres of the final broth. Standard food protocol usually requires 225ml of broth for 25g of food tested.

The incidence of foodborne pathogens can bring heavy costs to society. UN-backed World Health Organisation estimates that the medical costs and the value of the lives lost during just five foodborne outbreaks in England and Wales in 1996 were estimated at £300-700 million (€428-€999m) and the cost of the estimated 11 500 daily cases of food poisoning in Australia has been calculated at AU$ 2.6 billion (€1.5bn) annually.