Scientists found that the red romaine lettuce grown in International Space Station (ISS) is as nutritious as those grown on earth. This is a great development that would enable astronauts to grow fresh and safe food during space missions.
The study published in the journal Frontiers in Plant Science claims that the lettuce grown in space is free of microbes and is safe to eat.
Despite grown under low gravity and intense radiation, the space-grown lettuce is as nutritious as those grown on earth, said Christina Khodadad from NASA’s Kennedy Space Center in the US.
Until now, pre-packaged and processed space rations like peanut butter, shrimp cocktails, nuts, fruits, chocolate, beef, and chicken were the source of food for astronauts in space.
Nutrients and Vitamins like K, B1, and C that are less abundant in pre-packaged rations can be made available to the astronauts through the freshly produced vegetables. There is also a possibility for the packaged foods to degrade during long term storage.
The research team believes that growing crops on board will be useful during long-distance space missions like the upcoming Artemis-III missions to land humans on lunar south pole by 2024 and the NASA’s mission to Mars
in 2020.Lettuce was grown on the space station between 2014 and 2016 from surface-sterilized seeds within Vegetable Production Systems. Vegetable Production Systems, also known as “Veggie” is growth chambers designed to grow crops in space, equipped with watering systems and LED lighting.
For 33 to 56 days, the crops grew undisturbed after which the crew members ate the mature leaves without any side effects.
Researchers deep froze the crop remainings and transported back to earth for biological and chemical analysis.
Researchers grew plants under the same conditions (temperature, carbon dioxide, and humidity) as ISS on earth as a control. They found that the ISS grown lettuce had the same composition as the Earth grown ones. Surprisingly, the space-grown plants seemed to be richer in sulfur, phosphorous, potassium, sodium, zinc and some anticancer, antiviral, and anti-inflammatory molecules.
The levels of anthocyanin and other oxidants that protect cells from highly reactive natural chemicals present in the body were similar in both the varieties.
Researchers also found that the typical microbes present on Earth grown plants that affect the health of plants and suitability as food were present in space-grown plants too. Using DNA sequencing technology, they identified the 15 most abundant microbial genera on the leaves and 20 in the roots in both Earth grown and space-grown plants and discovered that the diversity and identity of these microbes were similar in both cases. And none of the microbes were pathogenic to humans.
Lettuce grown in Veggie units opens the door for experiments that could enable growing tasty and nutritious crops on board the space station, which in turn will help astronauts journey further into space.
The scientists are planning to study other types of crops like tomatoes and pepper on board to help provide fresh food for astronauts in space.