Finding foreign objects

Although metal detectors help commercial food processors keep metal fragments from ending up in finished products, these detectors can't identify plastic and other foreign objects.

And as plastic becomes more widespread, used in everything from conveyor belts to latex gloves, plastic contamination is a growing concern for many food processing operations.

For the past year, John Stewart, a research engineer at the Georgia Tech Research Institute, has been leading a development team in building a computer-vision system that identifies plastic and other unwanted elements in finished food products.

The system, now in final development stages, is scheduled to begin field-testing later this summer.

Incidences of plastic contamination are infrequent, but when they occur, fallout can be extensive. Recalls are expensive, not only in terms of logistics and returned product, but also because recalls can tarnish a company's brand image and reduce consumer confidence.

Even if contamination is caught before a product leaves the factory, it can take a toll, depending on the extent of the problem and when it occurred. "When you have 6,000 to 8,000 pounds of poultry moving along the production line every hour, that's a lot of chicken to reprocess or write-off," Stewart said.