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SSC-Natick Press Release

U.S. Army Soldier Systems Center-Natick
Public Affairs Office
Kansas Street
Natick, MA 01760-5012

Contact: Chief, Public Affairs Office
(508) 233-5340

Date: March 4, 2004
No: 04-06

Microwaves improve processed food quality

NATICK, Mass. -- Microwave energy, long used in homes to cook or reheat food, is gaining momentum in the United States as a method for processing more palatable shelf-stable foods for the military and commercial market.

Already successfully used overseas as an alternative to frozen or refrigerated packaged foods, a partnership between the Department of Defense Combat Feeding Directorate at the Soldier Systems Center in Natick, Mass.; Washington State University (WSU) in Pullman, Wash.; and several food processing, equipment and packaging companies to process food through a microwave sterilization system is moving ahead with a fresh influx of federal and private sector funding.

The microwave sterilization project commenced in 2000 under the federal government's Dual Use Science and Technology program with Kraft Foods Inc., Hormel Foods and Truitt Brothers Inc., a food processing company, along with packaging and equipment companies Rexam Containers, Graphic Packaging and Ferrite Components. Since then, Ocean Beauty Seafoods Inc. and Mars Inc. have joined the effort to raise the quality of processed Alaska salmon and other traditionally-processed products.

Designed and located at WSU, the pilot-scale microwave system has demonstrated the capability, and will now be able to take the next step of creating a pre-production plant for a larger-scale operation to conduct research for military and commercial foods, study shelf life, and work on gaining approval from the Food and Drug Administration (FDA).

Unlike home microwave ovens, the microwave sterilization system is high-powered and treats pre-packaged food submerged in water, allowing the microwaves to penetrate the food and uniformly cook packaged foods from the inside out, preventing burning around the edges. Sealed in its package before cooking, the idea is to kill all bacteria in the food quickly without damaging its texture or flavor.

"We're talking about a quantum leap in food quality," said Tom Yang, a senior food technologist at the Combat Feeding Directorate, comparing it to conventional retort processing, currently used for the Meal, Ready-to-Eat (MRE) entrees, tray rations and in canned commercial foods.

Microwave sterilization is a high-temperature, short duration form of processing. Instead of retort's 250 degrees F for 90 minutes, the microwave cooks at 265 degrees F in 10 minutes.

"We can introduce more variety of foods to warfighters," he said, while improving products that are currently fielded. "We'll be able to introduce a lot of products that we can't do with retorting. The MRE menu of 24 different entrees is continually being improved to keep only the best items."

Certain foods were out of the question until microwave sterilization.

"A challenge to us is to have a whole muscle product that looks and tastes like a freshly broiled fillet," said Patrick Dunne, senior technical advisor at the Combat Feeding Directorate. "With retorting, it often ends up being tough and overcooked to make sure all the bacteria has been killed. We also see this technology as doing a really great job with seafood and other products, such as macaroni and cheese, scrambled eggs and mashed potatoes."

Besides quicker processing and improved quality, other advantages of microwave sterilization are preserving nutritional benefits that are degraded during retort, and less need for freezers or refrigerators in the field, according to Yang.

First developed in the 1990s at WSU and led by Juming Tang, a professor in the Department of Biological Systems Engineering, food technologists at Combat Feeding contributed to the project by helping solve the problems of uneven heating and monitoring of heat distribution, and providing technical advice on quality and sensory evaluation. The companies are bringing their expertise in marketing to reach out to consumers with products they want, said Yang.

"We can tailor the energy distribution appropriate to each different food in a tray to have the ultimate quality," Yang said.

Although promising, the technology still has some challenges to overcome.

Formulation and preparation by culinary specialists before microwaving is still as important as ever, according to Dunne, or the product quality will suffer. He also said that the food industry, a conservative high-volume, low-profit-margin sector, will need to be convinced that the technology is worthwhile before making the financial investment.

"You have to demonstrate a huge advantage or they're not going to buy into it," Dunne said.

The microwave sterilization system now has the capacity to cook foods in small batches, but the plan is to transition to a "semi-continuous" process in another year and eventually a continuous process where food packages move out nonstop as is done now in many other countries, according to Yang.

Pending FDA approval and selection of a suitable packaging system, Yang said microwave processing would begin to supplement some retort-processed military rations.

For industry, a marketing campaign may be necessary to convince consumers of its appeal over conventionally-processed foods and quite possibly over the perceived freshness of widely-available frozen or refrigerated foods.

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This page last updated on 23 January 2004.