There’s something extraordinary about the cosmic environment that remarkably alters the flavor of miso.
Researchers conducted an experiment to prepare the famous Japanese paste simultaneously on Earth and aboard the International Space Station (ISS). The results revealed that the flavors of Earth-made and space-made miso differ significantly.
Unlike the paste produced under earthly conditions by scientists from the U.S. and Denmark, the space miso had a nutty and roasted flavor.
Miso is a delicious, salty fermented paste widely used in traditional Japanese cuisine. It is made from steamed soybeans, salt, grains like rice or barley, and the mold Aspergillus oryzae, which is responsible for the fermentation process.
How Were the Experiments Conducted?
The researchers prepared three batches of miso starter and sent them to laboratories in Cambridge, Massachusetts, Copenhagen, and aboard the ISS.
In the high-radiation and microgravity conditions of the ISS, the experimental batch fermented for 30 days. It was housed in a specially designed sensory box that monitored temperature, humidity, pressure, light, and radiation.
Meanwhile, the batch for Cambridge was placed in an identical box. The Copenhagen batch was prepared using traditional methods, allowing scientists to assess whether the sensory box altered the fermentation process.
After the 30-day fermentation process was completed, the miso from the ISS was brought back to Earth for analysis and comparison with the two control batches from the U.S. and Europe.
The analysis involved genome sequencing to study the microbial populations in the miso, evaluating the physical properties of the paste, such as texture and color, as well as assessing the flavor profiles.
The space paste fermented successfully, but it differed noticeably from its Earth counterparts in various aspects, according to Science Alert.
For instance, the microbial communities in the space miso contained more Staphylococcus epidermidis and Staphylococcus warneri bacteria—possibly due to the higher temperatures aboard the space station. Additionally, the bacterium Bacillus velezensis was identified only in the space miso.
It’s worth noting that all three finished pastes had similar aromatic compounds and amino acids, along with the expected characteristic salty taste. However, as researchers discovered, the space miso had a more pronounced nutty and roasted flavor.
This is likely linked to the organic compound pyrazine, which may have also formed due to the high temperatures on the station and could have accelerated the fermentation process.
“By combining microbiology, flavor chemistry, sensory science, and broad social and cultural aspects, our research opens new avenues for exploring how life changes when it moves into new environments like space,” said food scientist Joshua Evans from the Technical University of Denmark.
The findings of the study were published in the journal iScience.