College of Liberal Arts and Sciences at Iowa State University

Safer food

Jacob Petrich has invented and patented imaging technology which could lead to safer food.
The USDA Food and Inspection Service has a zero tolerance policy for meat.

"The USDA is concerned about food safety and is always looking for ways to better find contamination on meat and other food products," said Jacob Petrich, associate professor of chemistry.

Currently however the system utilized by the USDA in meat packing plants across the country is not 100 percent efficient. Inspectors visually check out meat for possible contaminants, making it easier for E. coli and other harmful bacteria to go undetected on meat leaving the plants.

"The current method utilized by the USDA to detect contamination takes a while," Petrich said. "The problem is the inspectors and the employees on the line can't look at every carcass coming out of the plant."

Petrich and two staff members of the National Animal Disease Center in Ames have developed a prototype which is used to detect feces on fresh meat (the primarily cause of meat contamination). A thin fiber optic cable is equipped with a laser and attached to a small handheld box. The instrument uses specific wavelengths or colors of light to illuminate the carcass. Collected light returned from the carcass is electronically analyzed to determine if fecal matter is present.

The prototype focuses on grass that has been digested by the animal. If fecal matter has gotten on the carcass during the slaughtering stage, Petrich's prototype will detect it. "What's so nice about the technology is that it's very simple," Petrich said.

That collaborative team includes Petrich and National Animal Disease Center microbiologists Mark Rasmussen and Thomas Casey. The prototype has not only been tested in the lab, but was successful at a large Iowa beef packing plant.

After patenting their idea, the trio has begun licensing the product with a Florida based company, eMerge Vision Systems, Inc. Under a cooperative and development agreement with Iowa State, the device should be on the market by next year.

The device has also been awarded a 2000 R&D 100 Award, which honors the top 100 products of technological significance that were marketed or licensed during the previous calendar year. The awards are the only awards for applied science and scientists.

There are still a few details to work out before the meat packing plants can utilize the fecal detector. Petrich says that the average meat packing plant produces nearly 500 carcasses an hour ®¢ far more than the fecal detector can monitor in its current state.

"Our goal is to develop a scanner so that the plants can scan an entire carcass at one time," he said. "We want to be able to look at every carcass before it leaves the plant. But the prototype is still useful. If there is a disagreement on the plant floor about possible contamination on a carcass, the prototype will be able to see if it is feces, oil or blood."

The fecal detector could have other uses as well. Petrich is looking for ways to modify it to work on other animals. The current system focuses on the grass eaten by a beef cow. Grass however is not the main diet for hogs and chickens. Additional ways of detecting contamination on fruits and vegetables are also being explored.

Petrich is also exploring ways to reduce the spread of hepatitis and other diseases. The fecal detector could be used in restaurants, day care centers and hospitals to scan individuals hands after they have used the restroom.

"The detector can be modified into a scanner which would determine if an individual has washed his or her hands before going back to work," Petrich said.