Astronauts Are Finding Their Taste Has Become Dull, and ISS VR Hints at Why

Astronauts on the International Space Station tend to prefer spicy foods and add things like Tabasco sauce or horseradish-spice shrimp cocktail sauce. “Anecdotally, they’ve said that food in space is less flavorful,” said Grace Locke, a food scientist at RMIT University in Melbourne, Australia. “This is a way to compensate for that.”

Luke’s team conducted a study to take a closer look at these anecdotal reports and test whether our perception of flavor really does change in an environment similar to the International Space Station. It probably does, but only certain flavors are affected.

Taste with all senses

“There are many environmental factors that can contribute to how we perceive taste, from the size of an area to the color and intensity of lighting, the volume and type of sounds present, the smell of our surroundings, and even the size and shape of our cutlery. Many other studies have covered each of these factors in one way or another,” Locke said.

That’s why her team set out to unravel the mystery of ISS food by recreating the ISS environment in virtual reality. “Some environments, like the ISS, are difficult to replicate, which led us to look for digital solutions to simulate how we feel,” she said. [to be] “Living and working in these areas,” said Julia Low, a nutritionist and food technologist at RMIT University and co-author of the study.

Once the VR version of the ISS was ready, the team asked 54 participants to smell vanilla, almond, and lemon flavors. The first round of tests took place in a fairly standard room, and the second round involved wearing VR goggles and playing a simulated ISS environment, complete with sterile, crowded spaces, sounds found on the real ISS, and objects floating in zero gravity.

Participants said the lemon flavor seemed the same in both rounds. On the other hand, the almond and vanilla flavors seemed more intense when participants were in the VR environment. While this is the opposite of what we might expect from astronauts’ eating habits, it is useful. “The bottom line is that we may smell differently in a space-like environment, but we are selective about what odors we smell,” Locke said. “We’re not entirely sure why this happens, but knowing there’s a difference is the first step to learning more.”

Then Locke and her colleagues took out the mass spectrometer and took a closer look at the composition of the flavors they used in the tests.

Space Ready Components

The lemon flavor in Locke’s team’s tests was lemon essential oil that was applied to a cotton ball, which was then placed in a sealed container that was then given to the participants to smell. The vapors emitted from the container contained several volatile chemicals such as limonene, camphene, 3-carene, and monoterpene alcohols such as linalool and carveol, among others.

The almond flavors had similar chemicals, but there was a notable difference: Almond and vanilla flavors contained benzaldehyde, while lemon flavors did not. “Benzaldehyde naturally smells sweet, while lemon, which does not contain it, has a more fruity and citrusy odor. We think the sweet properties of odors may lead to a more intense perception of [simulated] “Space,” Luke said.