Metal detection helps deliver safe products while saving time and money

Oakshire Mushroom Farm develops, grows and packs specialty mushrooms under both OAKSHIRE and private-label brands

Oakshire selected a Signature Touch metal detector from METTLER TOLEDO Safeline to help ensure final product quality and food safety. Source: METTLER TOLEDO.

Oakshire Mushroom Farm develops, grows and packs specialty mushrooms under both OAKSHIRE and private-label brands. Oakshire is also the exclusive licensee for all DOLE mushrooms in North America. The company is always looking for ways to improve its operations and deliver the best products. In 2015, Oakshire needed a new metal detector at its Kennett Square, PA packing plant and selected a Signature Touch from METTLER TOLEDO Safeline.

“Metal detection is crucial when producing mushrooms, because they’re grown in wooden beds held together with nails and screws. It’s extremely important that none of that metal gets mixed in with the product and goes out the door,” says Steven Lathe, maintenance manager for Oakshire.

With high-frequency advanced coil technology and filtering techniques, Signature Touch detects not only nails and screws, but also non-magnetic stainless steel fragments and non-spherical fine wire contaminants to help deliver a safe product, while saving time and money by decreasing false rejects.

“We check our metal detectors every hour by running test strips through to be sure they are maintaining the high performance we require,” says Mike Morrison, QC manager.

Mushrooms can be challenging for metal detectors because they tend to have changing moisture content and density. These vary from batch to batch, as well as from one mushroom type and size to another.

“This metal detector works equally well for all our mushrooms and handles most product variations without requiring adjustments,” says Lathe.

“The sensitivity on the Signature Touch is the best we’ve seen on any metal detector,” says Morrison. Also, Signature Touch has a “product clustering” capability, allowing numerous products to be inspected on one common setting.

The Signature Touch at Oakshire features an aperture 20 inches wide and 9 inches high that allows it to inspect 10-lb. bulk packages for foodservice customers and lugs of incoming product, as well as retail tills, while maintaining the highest sensitivity. Currently on this line, a variety of mushroom types are hand weighed and packed in 6-oz. to 24-oz. tills made of recycled and recyclable PET (RPET). The tills are wrapped in a breathable plastic wrap and sent through the metal detector before case packing.

This production line changes over as often as four times per shift, depending on the season. For changes that fall outside the metal detector’s product clustering capability, changeovers are handled in only 30 seconds by utilizing products settings from the memory. To run a new product not stored in the memory, the simple, single-pass auto-setup routine on the Signature Touch minimizes operator training requirements and increases uptime, while ensuring proper performance.

“Our Signature Touch was very easy to install. We did it ourselves. Just put it in place, level it and plug it in,” said Lathe. “I love our new metal detector because I never have to think about it. It just runs and runs.”

“The safety of our products is the most important objective. The Signature Touch is a huge part of how we ensure that,” says Morrison.