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A new method of drying fruit using microwave heating and vacuum technology is being tested in a wide range of fruits and berries. Cherry Central Cooperative, the nation’s largest marketer of red tart cherries and a leading supplier of dried cherries, is evaluating the technology.

A new method of drying fruit using microwave heating and vacuum technology is being tested in a wide range of fruits and berries. Cherry Central Cooperative, the nation’s largest marketer of red tart cherries and a leading supplier of dried cherries, is evaluating the technology.

A new method of drying fruit using microwave heating and vacuum technology is being tested with a wide range of fruits and berries. Cherry Central Cooperative, the nation’s largest marketer of red tart cherries and a leading supplier of dried cherries, is evaluating the ­technology.

On June 27, EnWave Corporation, of Vancouver, British Columbia, Canada, announced a collaboration with Cherry Central Cooperative, Traverse City, Michigan. EnWave has developed what it calls Radiant Energy Vacuum technology, which combines microwave heating and a partial vacuum to dehydrate fruits, vegetables, and berries, and is also being used in other ways.

Steve Eiseler, who came on board as president of Cherry Central in June (after 32 years with the cooperative), said Cherry Central has completed an initial evaluation and plans to expand testing.

The goal of the collaboration is to assess the market for a premium dehydrated cherry snack product that has superior flavor, color, and nutritional value to those currently available.

Cherry Central also plans to evaluate new opportunities for cherry and apple powders to be positioned as an alternative to conventional fruit purées. Cherry Central has the option to license the company’s REV technology for the production of red tart cherries and apple powders for commercial distribution.

Dried cherries

In a phone interview with Good Fruit Grower, Eiseler explained that, for nearly 40 years, consumption of red tart cherries in pie fillings and other dessert products has been declining, but the decline has been offset by a rise in consumption of juice and of dried tart cherries, a raisinlike product used in salads, cereals, energy bars, trail mixes, and other snack foods.

Current technology uses either vacuum freeze drying or hot air drying, with product moving on a continuous belt through a drying tunnel. Most dried tart cherries are infused with sugar or juice concentrate and dried with air heated using natural gas, Eiseler said, but demand is growing for nonsweetened dried cherries as well.

“Cherry Central has been a leader in the production, processing, and distribution of fruit and vegetable products for nearly four decades,” Eiseler said.

“Our continued goal is to supply the market with products of superior taste, texture, and appearance—three attributes that REV technology could potentially enhance.”

The technology could replace older technology, he said, or it could be used to create new products.

There may also be a cost benefit. When compared to freeze drying, EnWave claims that the Radiant Energy Vacuum process for foods, called NutraREV, reduced drying time from a day or longer to less than two hours, cut energy costs by 60 percent (from 66 to 23 cents per kilogram), and cut capital costs from $1.19 to 13 cents per kilogram. Costs using convection heating are much lower than freeze drying, Eiseler said, but energy cost is something Cherry Central is studying.

Tart cherry drying was pioneered in the 1970s by the Michigan company Graceland Foods, which was working with Ocean Spray on dried cranberries and from that base developed the drying ­technology for cherries. That company then was part of Cherry Central Cooperative, and Cherry Central did the marketing. Now, other members of Cherry Central use the drying technology, which is widely used for cranberries, blueberries, strawberries, and some vegetables.

About EnWave

EnWave is headed by co-chief executive officer Timothy Durance, who began work in the 1980s to perfect the REV dehydration technology as a food scientist and professor at the University of British Columbia.  Key challenges were to obtain uniform microwave heating in a large chamber and then to remove moisture from the product using vacuum.

The university later granted commercial rights to the technology to EnWave Corporation, a company started by Durance.

Durance refined the process, and in 2008 built the first machine capable of commercial scale production. EnWave then hired John McNicol as co-CEO to market the technology. In April, EnWave licensed REV technology to Milne Fruit Products, Yakima, Washington, its first major U.S. customer, which is using it to produce a line of MicroDried products.