Germ Trackers

When bad bacteria invade good hamburger, they produce stomach-turning stuff with names such as putrescine and cadaverine.

In large doses, the stuff is colorful, stinky and toxic — nature's way of telling us that something is wrong.

However, consumers can't always smell spoiled meat through plastic wrap in the grocery store or even spot a telltale change in color because of new packaging techniques.

Battelle scientists say there is a way to see past packaging.

The research giant recently filed for patents for a sensor that could be packaged with meat to alert consumers when the meat is spoiled.

"If this is effective close to 100 percent of the time, it would be a useful tool for consumers, especially given the way the meat industry is packaging meats these days," said Chris Waldrop, director of the Food Policy Institute at the Consumer Federation of America.

"The industry is packaging the meats with carbon dioxide or other gases that keep the meat red past the time of spoilage."

Two years ago, Battelle chemists Donald Zehnder and John R. Shaw became concerned when a number of food safeguards failed to prevent a widespread illness caused by spinach contamination.

Zehnder builds synthetic molecules of varying shapes to interact with specific targets. Shaw uses chemical changes to cause color changes in materials. The two joined forces and decided first to create a detector for meat.

When bacteria such as achromobacter, micrococcus and pseudomonas feed, they release chemicals called amines.

"We came up with a doughnut-shaped molecule that binds with specific amines given off by bacteria," Zehnder said.

If there is no amine, the sensor stays yellow. If there is enough to bind because the meat is spoiled, the sensor turns red.

Source: Columbus Dispatch