The production of suitable food for astronauts in space is a major challenge, given the complexity of their special nutritional needs and the difficulty of cultivating food in microgravity conditions. Researchers have developed the "perfect meal" for male astronauts: a vegetarian salad that includes ingredients that can be efficiently grown in space and that meet their nutritional needs.

Long-term space travel has different nutritional requirements compared to Earth dwellers. They burn more calories and need additional micronutrients, such as calcium, due to prolonged exposure to microgravity.

Food production also has different requirements in the context of space travel. For future long-term missions, it needs to be circular.

Now, researchers have developed a meal that fits both the nutritional requirements of an astronaut and the production requirements of future space missions, such as potential missions to Mars.

Nutrition is important in space. It especially needs calcium, as Volker Hassel, one of the researchers, told FoodNavigator. "The circulatory system expands and the heart may need to pump more. In the medium term, bone loss occurs; up to 20% of weight in a few months. Calcium forms bones, like calcium apatite. Calcium intake can help reduce bone loss in space."

To develop an optimal meal for male astronauts, researchers used a model called linear programming to computationally determine how well different combinations of foods could meet astronauts' nutritional requirements while using as little water as possible.

They also looked at the sustainability of different ingredients and tried to choose those that require little time, space, and fertilizer to grow. Ten scenarios were tested - six omnivorous (combining meat and crops) and four vegetarian (only crops). The crops were evaluated based on their circularity, using parameters such as waste generation and recycling rate.

The researchers came up with a meal that balanced agricultural needs and nutritional needs: a salad made from soybeans, poppy seeds, barley, kale, peanuts, sweet potatoes, and/or sunflower seeds.

Although the meal did not necessarily meet all the micronutrient needs of a male astronaut - supplements may be needed - it was the best product produced from the research.

"We have developed models that can identify the best crop mix under given nutritional constraints. Our constraints were

1. sufficient nutrition supply, i.e., fats/proteins/carbohydrates plus vitamins etc.;
2. calorie limit (no overweight);
3. food weight limit (no one can eat 5 kg per day).
4. water needed for plant growth;
5. fertilizers; etc."

To ensure that astronauts will be happy to eat the meal, researchers tasted it together with people here on Earth. Many went back for seconds, and one gave it an extraordinary review.

Food for female astronauts

The food created here was developed specifically with male astronauts in mind. Researchers say that in the future, they will use a similar method to develop one for female astronauts.

"We used data about male astronauts because it was available. I'm sure this is also true for female astronauts. It would be easy for us to model the best food for female astronauts; a question for another day," Hassel told us.

Source: ACS Food Science & Technology 'Modeling of Space Crop-Based Dishes for Optimal Nutrient Delivery to Astronauts and Beyond on Earth'