WSU graduate student Juhi Patel, an author on the mac and cheese paper, puts packages of purple potatoes into an incubator, which speeds up the food quality changes at a consistent rate. Source: Washington State UniversityScientists from Washington State University have devised a method for tripling the shelf life of premade foods like mac and cheese, with possible implications for space travel and military applications.

The packaging has the potential to preserve foods at room temperature for three years versus the currently available plastic packaging that keeps food safely stored for one year. The team of scientists sterilized the food using a process dubbed the microwave-assisted thermal sterilization (MATS) system, developed by Washington State University’s Juming Tang.

During the process, the team added a metal oxide coating to the layers of plastic film surrounding the food. This layer reportedly prolongs the time it takes for oxygen and other gases to penetrate the barrier and thus contaminate the food. Although the metal oxide coating technology has been around for roughly a decade, the layer tends to develop cracks during the sterilization process, eventually compromising the shelf life of food.

To remedy this, the Washington State University team developed packaging made up of several plastic layers in addition to the metal oxide coating. Each of the plastic layers serves a function such as acting as a barrier or offering sealing or mechanical strength or a layer that is suitable for printing, for example. In addition to the layers and the metal oxide coating, the team then added yet another over-layer of organic coating to the metal oxide to prevent the microscopic cracking that tends to occur during sterilization.

In addition to its potential for use in space travel, offering astronauts safe foods when they eventually travel to Mars, the team is also exploring the packaging’s potential for use by the Army, improving the shelf life of their “Meals Ready to Eat” (MRE).

To determine how well the packaging works, the Army conducted taste panels of mac and cheese packaged for three years in the Washington State film and they reported that the food was just as good as a version that had been stored for nine months.

"We need a better barrier to keep oxygen away from the food and provide longer shelf-life similar to aluminum foil and plastic laminate pouches," said Shyam Sablani, who led the team working on the protective film. "We've always been thinking of developing a product that can go to Mars, but with technology that can also benefit consumers here on Earth."

A paper detailing the packaging was published in the journal Food and Bioprocess Technology.