Tougher regulatory standards and the increased reporting of food contamination in restaurants, supermarkets and processing plants has pushed companies to put a higher priority on safety, shelf life and cleanliness. The trend has fueled the demand for more stringent testing and tracing of food products along the supply chain to the consumer.
The new test developed by scientists at the US agriculture's department research service relies on polymerase chain reaction (PCR) technology to detect food-contaminating microbes on a molecular level.
PCR has become one of the top laboratory methods for microbacterial detection in the food industry as it can detect small samples of contamination by amplifying the amount of DNA, the genetic code through which technologists can determine what is present in a product.
The unit's food technologist Jitu Patel and microbiologist Arvind Bhagwat compared their laboratory-developed "molecular beacon" test to a commercial rapid-detection test currently in use. While both tests can detect Salmonella in eight hours, the laboratory test is less expensive than commercial kits, the two claim.
"The ability of the molecular beacon test to detect very low levels of Salmonella contamination in eight hours will aid the food industry in quality assurance, helping prevent recalls of contaminated meats and produce by stopping the products from being introduced in the marketplace," the two stated in publicising their results. "Detection of contaminated foods could be achieved within a work shift--before shipment takes place."
The preliminary test is still being evaluated by agency researchers. Such US-government funded research developmsents are usually made available for commercial development.
Samples in broilers, ground chicken and ground turkey testing positive for salmonella at US slaughter and processing plants have surged since 2002, according to statistics compiled by the department's Food Safety and Inspection Service (FSIS).
Broilers had the highest rates of salmonella, with 16.3 per cent of samples testing positive in 2005, up from 11.5 per cent in 2002. The highest level was reached in 1998, when salmonella was found in 20 per cent of the broilers sampled.