UVC Safely Eliminates Bacteria

Installation took place in February 2007 in conjunction with a general remodeling of the packaging line, allowing Washington Potato to adjust the layout of the line to accommodate the new UVC tumbling drum. The potato dice comes out of the freeze tunnels, passes an electronic defect remover and metal detector, and is then conveyed into the drum for germicidal treatment just prior to packaging into 1,400-pound totes or 40-pound poly-lined cases.

After initial installation, Reyco and Washington Potato went through a test period to work out the best retention times and operating conditions. “We were able to enhance ‘kill’ rates by adjusting the speed and angle of the drum and the amount of time spent tumbling each type of product,” said Brian Scott, sales and marketing manager at Reyco.

The production line operates 24/7, with a weekly shift-down for re-sanitizing of the entire line, including the tumbling drum. The UVC Emitter tubes were replaced, as recommended by the manufacturer, after approximately one year of service. In addition to the IQF diced product, Washington Potato uses the UVC drum for added protection on all products that go through the line, including partially dried and roasted potato pieces. No adjustments to the drum are needed to accommodate the different products.

Results, Savings Documented

Washington Potato reports numerous benefits since adopting the technology. “We have eliminated any coliform bacteria on the line, a fact confirmed by microbiological tests that we conduct on samples from every shift,” said Ross. “Basically, the quantity of product held for microbiological reasons has been reduced to zero. As an added benefit, total plate counts, which measure any type of bacteria that will grow aerobically, have been reduced tenfold since we started using the UVC drum,” he added.

“As an interesting side note,” he said, “shortly after initial installation, we took the drum out of service for modifications. During that period, we quickly saw a sporadic reappearance of coliform bacteria and an increase in total plate counts, occurrences that disappeared as soon as we reinstated the UVC drum on the line. This provided further proof that it is doing its required germicidal job.”

Ross added that the amount of money saved was “significant,” because they eliminated the many costs resulting from held or rejected product. “We have also eliminated the related worries associated with potential customer dissatisfaction, loss of business, or even liability. With the UVC providing continuous microbial control, we have the confidence that all product going through the line comes out clean.”

Approved for Organic Processing

Washington Potato has recently received approval from the Washington State Department of Agriculture to use UVC for decontamination of organic products. “We are using UVC on an increasing basis for organic processing of our own private-label stock items and those manufactured on a contract basis for other processors, wherever approved by the customer,” Ross said.

Reyco’s Scott said his company’s UVC decontamination drums can be used on a wide range of raw, cooked, or frozen food products prior to incoming storage, processing, or packaging. “Products that can benefit from treatment with UVC include meats, poultry, seafood, vegetables, fruits, dairy products, and nuts,” he added. “Proven benefits include increased product yield and safety, longer product shelf life, and the ability to reduce or eliminate the use of chemicals and/or preservatives.”

Dr. Scheir is president and chairman of Steril-Aire Inc. Reach him at [email protected] or (818) 565-1128.