During human space travel to date, spoilage of food has not been an issue since missions have been relatively short. For example, astronauts aboard the International Space Station get regular food shipments. But on more extended space missions like those proposed to Mars, food planning becomes complex. One conundrum is that while fatty foods are essential for mental sharpness, they are challenging to store, with a short shelf life before going rancid. Once en route to Mars or another long-distance destination, “we’re not going to get any support from Earth,” notes University of British Columbia food science postdoctoral fellow Roxanne Fournier. So she and colleagues are at work to develop food storage methods and extend the shelf life of healthy omega-3 fatty acids.
Fournier, an expert in space health, teamed up with assistant professor Dr. John Frostad in the Food Science program at UBC’s chemical and biological engineering department and Cody Rector, a master’s student in Frostad’s lab. Fournier has not eaten astronaut food but has analyzed its nutritional contents, finding much of it fat deficient. That’s because many fatty acids, like omega-3s, are sensitive: they rapidly break down. “So you have the option of having something nice and delicious with some fats in it,” says Fournier, but “take that to Mars, [and] it’ll go rancid.” So their team is grappling with that dilemma: how do we prevent spoilage yet still provide the nutrients astronauts need on a three to five-year journey?
One current focus of NASA and other space agencies, notes Frostad, is growing fresh food in space. “But even if you could do that right now, you still are gonna have to store that food,” he says. Imagining a season of crop failure on Mars, he notes, “we need to have good stable sources of food storage.”
To tackle a small slice of the food storage problem, his team is examining chemical stability by experimenting with interfacial phenomena — “putting things at the interfaces of liquids with other liquids or liquids with air, and utilizing that science in a meaningful way,” he explains. For omega-3 fatty acids, Frostad’s team is working on increasing safe storage time through encapsulation of fats with a starch layer.
Working on flaxseed oil, which is high in omega-3s and other polyunsaturated fats, Frostad explains that you can visualize the role of starch as a protective barrier by imagining an oil droplet the size of a swimming pool. “You want to put starch particles the size of basketballs on top of the swimming pool to prevent things from getting into the pool,” he says, but notes there will still be gaps between basketballs, “so you throw some tennis balls in there, too.” Even then, gaps remain, and the ideal scenario is a layer with no gaps.
With that in mind, starch’s advantage is that it swells when heated in water. So the team is working on controlling the degree of swelling to fill the gaps effectively. Starch — beneficial because it is digestible — could be combined with another barrier like novel nanoparticles or cellulose, they propose.
“Down the road, what we envision is a combination of the packaging and our encapsulation as kind of a double barrier,” says Fournier. Testing their experimental coatings is still in the early phases. They plan to test shelf life by exposing coated omega-3s to challenges like high temperatures and humidity.
One expert who has eaten foods prepared for space missions is Canadian physician and scientist-astronaut Shawna Pandya, who participated in analog missions at the Mars Desert Research Station and aquanaut missions under the sea. Space foods, she explains, need to be designed to be lightweight with a high nutritional and caloric value per unit weight and not go rancid quickly. Additional challenges concern food flavour and texture. Astronauts physiologically experience fluid shifts, resulting in a “puffy moon face,” she says, due to congestion, which compromises their sense of smell and taste. Consequently, “[space] food needs to be more savoury, more spicy, more flavourful, and more textured,” says Pandya.
Pandya recalls a Simpsons episode where Homer opens a bag of chips in space and its crumbs catastrophically clog up the instruments, “and that’s kind of a real possibility,” she says. So the conundrum is how do you make something that meets your design constraints palatable, has a long shelf life and is also adaptable so that its chemistry isn’t altered in the micro-G environment? Or can you produce fresh food in situ? These are critical questions not just for food but also for pharmaceuticals in space. There are so many questions, says Pandya, “so for anyone who’s curious and wants to contribute to building that future of food in space, this is the time to get involved.”