Food Engineering

Field Report: Metal detector works magic on mushrooms

January 7, 2004
Record-breaking plant keeps contamination at bay.



All of Creekside’s mushrooms, both the sliced and whole varieties, are scanned for metal prior to being vacuum cooled for shipment. Source: Creekside Mushrooms.
Where would you find the world's largest mushroom farm? The answer lies, at least in part, 300 feet beneath the earth, in a 150-mile labyrinth of abandoned limestone tunnels nestled underneath the hills of southwestern Pennsylvania. Here in Worthington, PA, Creekside Mushrooms annually grows 25 million pounds of fresh mushrooms, including specialty mushrooms such as portabellas, shiitakes, oysters and enoki. Combine Creekside's underground farm with its 2,036-acre farm above ground, and you have a Guinness Book of World Records holder-the world's largest fully integrated, single site mushroom farm.

On this unique site, mushrooms are planted and harvested 365 days a year. Creekside markets its fresh mushrooms under the Moonlight mushroom brand and produces private label packages for various retail and foodservice operations. To ensure the quality of its products, the company developed a comprehensive food safety and HACCP program soon after opening in 1994. The program is designed to prevent any chemical, microbiological, or physical contamination from occurring during the growing, harvesting, packaging or shipping of its products.

As part of this program, Creekside installed metal detectors to further ensure the safety of its products, particularly its sliced mushrooms. Although the company harvests its mushrooms by hand and there is minimal exposure to metal, contamination could potentially occur when the mushrooms are sliced.

"One of the highest priorities in our food safety program was to make sure potential metal contamination is eliminated from all mushroom products," says Allen Leard, Creekside's quality assurance manager. "A possible source of metal contamination is the slicing blades, where a piece of the blade could break off."

To minimize this risk, Creekside installed two Eriez E-Z Tec metal detectors on its fresh cut mushroom packaging lines. The equipment is designed to detect even the most minute ferrous, nonferrous and stainless steel metals. With its sliced mushrooms monitored, Creekside later added three additional E-Z Tec metal detectors to install along its retail packaging lines. Now all product sizes, from the 4-oz. retail pack through 10-lb. boxes are scanned for metal prior to being vacuum cooled for shipment. "If we get detection, the product is rejected, isolated and corrective actions taken to assure no contaminated mushrooms leave our plant," says Leard.

To ensure accuracy, each metal detector and rejection device is checked and its operation verified prior to start-up of the lines. Throughout the day, sensitivity tests are performed using ferrous, non-ferrous and 316 stainless steel wands.

For more information:
Jeff Kaveney, 814-835-6000,
jkaveney@eriez.com