Scientists formulate fortified drinks to address astronauts’ nutrient gaps in microgravity

Space programs are anticipating longer off-planet journeys following the success of the Artemis II launch, which will pose new health and nutritional challenges for astronauts. As present-day space foods rely on dried, shelf-stable items, new research suggests fortified beverages could help fill nutrient gaps and add variety to astronauts’ diets. 

Scientists have created drinks using emulsions that are stable in Earth’s gravity and microgravity. Their formulas deliver omega-3 fatty acids with customizable sweetness levels and flavors.

The recipes were designed to address astronauts’ loss of bone mass and muscle density while traveling to outer space due to the lack of gravity. Svenja Schmidt, a co-lead author of the study, notes that high-resistance exercises can help mitigate this loss, but so can incorporating nutrient-enriched foods into the astronauts’ diets.

“Fortified beverage emulsions could potentially help, especially when providing nutrients at levels not met by normal nutrition,” says Schmidt. “We suggested omega-3 fatty acids to help protect against space radiation and increase the bone formation rate.”

Stabilizing flavors and nutrients

The study was published in ACS Food Science & Technology and focused on beverage emulsions that blend water-soluble components, such as sugar, and oil-soluble components, like essential oil flavorings and omega-3 fatty acids, into a stable mixture. 

These emulsions are most often used to stabilize commercially available water-based drinks like lemonade and sodas. The researchers then tested a system that continuously combines small amounts of oil and water, utilizing capillary forces, and creates well-dispersed emulsions.

Co-lead study author Volker Hessel notes that this microfluidic system is a suitable technology for making beverage emulsions both on Earth and in microgravity environments like the International Space Station.

Future beverage systems in space could deliver personalized levels of essential nutrients with customizable sweetness levels and flavors.After testing several combinations of coconut oil fats, emulsifiers, fruit acids, sugar, flavorings, and omega-3 fatty acid-rich fish oil, the researchers settled on six drink recipes with customizable components.

The recipes present two sweetness levels and three taste options, including floral and citrus flavors. An 11-fluid-ounce (330-mL) serving of each new beverage contains up to one-third of the recommended daily omega-3 fatty acid intake. Schmidt highlights that the final consistency of the emulsified drinks resembles a flat soda that has lost its carbonation.

Next, the researchers want to determine how these beverages taste — in gravity and in microgravity — and what the shelf life would be during space travel. Hessel says that “being one small piece in the big puzzle of human space exploration and helping astronauts to stay healthy is a visionary privilege.”

Future formulation directions

Based on current trends in the food industry, the researchers anticipate combining food personalization will help address astronauts’ food monotony during space missions while closing critical nutrition gaps.

For instance, they hypothesize novel beverage dispensers that could offer a choice in flavor with personalized food fortification options.

The study received funding from Australia’s Ph.D. Program of the Nottingham-Adelaide Alliance, the Australian Research Council Centre of Excellence, “Plants for Space,” and the Biotechnology and Biological Sciences Research Council.

Previous research on astronaut health revealed specific challenges space travelers face in the environment of low Earth orbit. While studying the nutritional composition of space-grown crops, scientists have warned that astronauts are more prone to intestinal permeability, or leaky gut syndrome, which further blocks nutrient absorption.

Meanwhile, Indian researchers have been investigating the effects of microgravity and space radiation on edible microalgae, which is considered a high-potential, nutrient-rich food source under these conditions.