Another nutritional challenge for space food
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You may have read yesterday’s story about the food scientists at NASA who have their hands full trying to figure out what astronauts will eat when they blast off on a three-year mission to Mars sometime after the year 2030. For a variety of reasons, the food served on the space shuttle and International Space Station won’t cut it – it’s too heavy, too bulky, and its chemistry makes it prone to spoilage after only a couple of years.
And now the NASA scientists have identified another problem: many of the essential vitamins, amino acids and fatty acids in the foods will degrade over the course of such a long mission.
This is no small potatoes, they write in the September issue of the Journal of Food Science: “Destruction of even a single vitamin in the space food system could be catastrophic to astronauts on a 3-y mission to Mars.”
The research team studied five foods commonly eaten in space – freeze-dried broccoli au gratin, thermostabilized salmon, and regular tortillas, almonds and dried apricots – along with Centrum Silver multivitamins and Nature’s Way vitamin D supplements. Six servings of each were packed into four bags and sent into orbit aboard the space shuttle in July 2006.
The first bag returned to Earth 13 days later when the shuttle landed. The other three were transferred to the space station and returned to Earth after 353 days, 596 days and 880 days. All of the items were analyzed for their nutrient content and compared with identical bags that were stored in environmental chambers at NASA facilities.
Among the findings: Tortillas lost 54% of their thiamine and 47% of their folic acid content over nearly 2½ years of space flight. The broccoli dish lost 72% of its beta carotene and 21% of its vitamin C.
In some cases, the nutrient value increased during flight. For instance, the amount of beta carotene in the dried apricots jumped from 4.67 milligrams per 100 grams to 7.98 mg/100 g during their sojourn in orbit. The researchers also noted that the amount of a compound called hexanal in almonds tripled while they were in space. That could make them taste rancid, thus reducing their nutrient value to zero if astronauts refused to eat them.
The scientists anticipated that the vitamins in food would be vulnerable to space radiation. But they found that the foods remaining on Earth lost almost the same amount of nutrients as those that flew in space. It turns out that the passage of time is the real problem.
-- Karen Kaplan