Dipstick Test Detects Spoiled Food

American research team develops a format that spots the bacterial breakdown of food.

By Jeffrey Perkel
HealthDay Reporter
Monday, March 26, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

MONDAY, March 26 (HealthDay News) -- Imagine using a "dipstick" test to find out if your food is spoiled.

If things work out as John Lavigne hopes, it just might be possible.

Lavigne, an assistant professor of chemistry and biochemistry at the University of South Carolina, and his research team have developed a polymer sensor that detects biogenic amines, the breakdown products of proteins that are a hallmark of food spoilage.

However, some experts are skeptical, saying it would be hard to improve upon good, old-fashioned food hygiene and a sensitive nose.

The findings were presented Sunday in Chicago at the American Chemical Society's national meeting.

Targeting nonvolatile amines -- the breakdown products that you cannot smell -- the test is about 90 percent accurate, Lavigne said, and can detect spoilage in different kinds of meats, vegetables, fruits and beverages.

"Hundreds, thousands, millions of people per year in the U.S. get sick, because they cannot tell when food goes bad. So, there's a lot of opportunity out there to short circuit some of these illnesses," Lavigne said.

The test works much as pH paper does. A small sample of what Lavigne called "the food's natural liquid" (his team used fish) is added to a purplish, dark-red solution of polymer. If the food is starting to turn, the solution changes color, from red to orange to yellow, depending on the extent of spoilage.

Though the test is currently solution-based, Lavigne is working on a dipstick test for consumer use. "There are a couple of different formats that we're looking at," he said. "All would require a small, liquid-based sample from the food. If it's a beverage, that's easy. If it's chicken or fish, we're working on developing a method to very easily extract a small bit of liquid and directly introduce it into the sensor."

Lavigne described the current format as "very discrete," pencil-sized, but shorter.

Some experts questioned the utility of the system.

"What's wrong with your nose?" asked Philip M. Tierno, director of Clinical Microbiology & Immunology and associate professor of Microbiology & Pathology at New York University Medical Center. "Your nose is a very sensitive mechanical device that can detect amines. If it's bad, you'll know it."