Mac and cheese in the new plastic packaging from WSU. (Image courtesy of CAHNRS News.)
Researchers from Washington State University (WSU) have developed a process that could potentially increase the shelflife of a mealtime favorite in space. Current plastic packaging products can keep food safe at room temperature for only up to 12 months. WSU researchers have figured out how to triple the shelflife of ready-to-eat macaroni and cheese, a development that can largely benefit space travel and military use.
To survive the long travel between Earth and Mars, astronauts will need food that won’t spoil during the journey and while they’re on the planet’s surface.
“We need a better barrier to keep oxygen away from the food and provide longer shelflife similar to aluminum foil and plastic laminate pouches,” said Shaym Sablani, a professor in WSU’s Department of Biological Systems Engineering who lead the research.
The study took form when the team began working closely with the U.S. Army in efforts to improve the Army’s “Meals Ready to Eat” (MREs) to have a shelflife of three years. The Army recently put together a taste panel to test mac and cheese stored for the equivalent of three years and concluded that it was just as good as the current version, which can be stored only for nine months.
The researchers worked with packaging companies to develop new films that prevent oxygen and vapor from escaping for a longer period.
The food is sterilized using a process developed by WSU’s Juming Tang called the microwave assisted thermal sterilization (MATS) system. Instead of using metal, like tin cans, the food is sterilized in plastic. Since metal cannot be microwaved, it is the least preferred packaging for MREs. Similarly, glass is too fragile as well as too heavy for either military or space use.
Additionally, the researchers discovered that adding a metal oxide coating to the plastic film significantly speeds up the time it takes for oxygen and other gases to escape. Sablani notes that this compromises the food’s shelflife. While metal oxide coating technology has existed for almost 10 years, it can actually be detrimental to the preservation processes, creating cracks when subjected to sterilization.
The packaging films the WSU researchers developed along with packaging companies are composed of multiple layers of different plastics. According to Sablani, each micron thin layer serves a different purpose, such as acting as a barrier or a seal, and can be used for mechanical strength or for printing.
“We are excited that an over-layer of organic coating on metal oxide helped protect against microscopic cracks,” Sablani said. “Multiple layers of metal oxide coating have also increased the barrier performance. Our research guided development of newer high barrier packaging.”
The team did not actually wait three years to test the results of each new film. The packaged food was instead kept in a 100°F incubator, which rapidly speeds up the change in food quality at a consistent rate. According to Sablani, six months in the incubator is equivalent to three years at room temperature, while nine months is equivalent to five years.
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. (Image courtesy of CAHNRS News.)
The Army plans to conduct more testing under field conditions. “If they like the taste of the packaged food there, then that’s the ultimate test of new films,” said Sablani.
The team has already expressed plans to put the technology to use in space, specifically for Mars. While it’s still not possible to field-test the films through a trip to Mars, Sablani intends to reach out to NASA to discuss how his team can test the WSU films for space missions.
“NASA knows about our work, but we’re just now getting to the point where we can talk to them with a proven product,” explained Sablani. “We hope to work out a way to test these products on the International Space Station in the future to show that the food is safe after long-term storage.”
For food, NASA requires storage allocation of up to five years. The WSU team is currently working on meeting this stipulation. The researchers are also exploring other recipes that will be taste tested when the foods reach the five-year mark. With several types of mission plans proposed for a trip to Mars, Sablani adds that five-year food storage will need to include some built-in safety requirements.
A trip from Earth to Mars may involve approximately nine months of travel, plus five hundred days on or orbiting Mars, then another nine months of travel to return to Earth. Having food that can withstand extra storage time is also crucial in case of unexpected delays or the prolonging of a mission.
The study can be found in the Food and Bioprocess Technology journal. The research was supported by the USDA National Institute of Food and Agriculture Research, AFRI Foundational Grant Program.
For more on the latest developments in space travel, check out how China is building a gigawatt power station in space here.