Time has value, whether it’s spent in the home or the factory. Saving time is the essential value of microwave technology.
For the frazzled individual who craves a quick meal before scrolling through Tinder or binge watching Orange is the New Black, microwave’s benefits begin and end with time savings. For food processors, saving time is just the start. A smaller production footprint, higher throughput and greater yield also are potential benefits and are setting the stage for expanded applications for industrial microwave systems.
Bacon fixation has been a boon for the industrial microwave, which excels at crisping raw bacon. Pork processors are expanding their production capacity and replacing older microwave units, some of which have been in service for three decades. Microwave pasteurization also is growing, while microwave sterilization of shelf-stable foods is inching forward.
“Tempering is by far the most popular application for microwave in food,” offers Mark Fitzgerald, COO of Ferrite Microwave Technologies, Nashua, N.H. Culling of domestic cattle herds in recent years is helping to expand use, as food companies turn to frozen beef imports. Waiting for a pallet of 60 lb. blocks of beef to thaw wreaks havoc with production schedules and waste rates. Microwave may be the best option to accelerate the process.
“It’s very inefficient to let the meat thaw on its own, and it leads to a lot of drip loss,” Fitzgerald points out. “By the time the meat in the middle reaches 30° F, the outside is soup.”
Bacon may be a sweet spot, but pork and poultry often becomes rubbery when bombarded with 500-800 kW of power (home microwaves, by comparison, deliver 1 kW). Poor outcomes may have more to do with processor impatience than technical limitations, suggests Tim Scheurs, president of Applied Microwave Technologies, Cedar Rapids, Iowa. “Some products require a certain process time,” he notes, and extending the hold time instead of cooking chicken or pork as quickly as possible can resolve texture issues.
As a temperature booster prior to an impingement oven, microwave is mining another opportunity, particularly with fully cooked, bone-in chicken. Conventional cooking either leaves blood spots near the bone or forces processors to overcook the exterior meat, points out Ron Mickey, vice president of Grandview, Mo.-based RMF Steel, resulting in loss of yield. Microwave energy at 915 MHz penetrates the meat to begin internal cooking, cutting cooking time as much as 50 percent.
Microwave boosters will be “the next growth area” for industrial applications, Fitzgerald predicts. Boneless products like meatballs also benefit, with wave penetration heating the center to about 110° before conventional cooking.
Product drying is another emerging application, particularly for spices and other ingredients requiring a dewatering process. A drying rule of thumb is that input of 1,200 btus is needed to remove 1 lb. of water, he says. With Ferrite’s microwave feed system, only 1,000 btus are required.
Amtek exhibited a microwave unit-conventional oven combination with Unitherm at the recent International Production and Processing Expo in Atlanta. Lower capital cost, higher throughput and reduced operating costs are the pluses, according to Scheurs. Moisture removal from nuts is another successful application.
One of the world’s leading manufacturers of magnetrons, applicators and other microwave components, Amtek has roots in the genesis of industrial microwave. Former managers of Amana, which commercialized Raytheon’s microwave technology in the mid-1960s, founded the firm. Ferrite ultimately acquired Amana’s intellectual property, while Amtek focused on component and equipment manufacturing.
Several of today’s microwave systems for food tout partnerships with Amtek, including Industrial Microwave Systems (IMS), which has focuses on aseptic processing. “I’ve seen more excitement (over the IMS system) than for any product we’ve ever released,” says Scheurs
Microwave’s most intriguing application is food sterilization, and the first bona fide commercial success gives reason to believe the technology will play a bigger industry role in the coming years. Three groups are actively developing and refining microwave technology for sterilization.
IMS, Harahan, La., has built a seven-year commercial track record. IMS scientists collaborated with counterparts at USDA and North Carolina State University to develop a continuous flow microwave thermal process that was validated by FDA to produce shelf-stable sweet potato puree.
Approximately half of the nation’s sweet potato crop is produced in North Carolina. Three growers recognized the commercial potential in converting excess harvest and cosmetically marred tubers into a paste that could be stored unrefrigerated until sold. They named their enterprise Yamco LLC and began aseptic production in early 2008 in Snow Hill, N.C.