Food preservations are not something unfamiliar to us. People preserve foods for many reasons. Some of the reasons are mostly to keep the foods to last longer. For example, we are all in the middle of the global pandemic where people would want to store foods that is easy to be kept, so they do not have to go grocery shopping many times. There are many ways you could preserve your foods, including refrigerating, fermentation, drying in the oldest method. Meanwhile, in a modern way of preserving your food are freezing, irradiation, maybe you also add a few chemicals and canning. If you are taking or learning culinary-based subjects or “bidang kulinari”, “seni kulinari”, this can give you extra points to have this knowledge. But have you tried to imagine how astronauts have their food preserved? How can they live that long in outer space without having normal food, and how can they store their food that long? In this article, I will share with you guys how astronauts got their food preserved.
Food preservations for outer space are a bit different than normal food preservations. This is to maintain food quality and safety in the space ship. Normally, they would minimally process the fresh fruits and vegetables and sanitized with a chlorine rinse, air-dried and they will put in on the food tray, meaning that it is ready to be stored with the fresh foods locker. But not everything is preserved in the same way. Some of the other vegetables like carrots and celery will be packaged in sealable bags. Typically, most of the fresh foods need to be eaten quickly, or else, they will spoil quickly.
Typically, NASA scientist would preserve the foods and using processing techniques to make the food safe to store at room temperature or make the food shelf stables. If the foods are thermo-stabilization, or in other words, heat processing, is to extend the shelf life to 3 years. Meanwhile, irradiated foods are considered shelf-stable because they have sterilized with a dose of ionizing radiation. Moreover, reducing the pH and water activity of foods can also stabilize them. Getting rid of water from the food or in different words, freeze-drying inhibits microbial growth, and allow mold growth, when it can be prevented by sucking all the oxygen from the packaging. Observations on the changes in the product quality determine the shelf life. Normally, if the foods are for shuttle flights, the foods must at least 9 months of shelf life. While the foods that are going to the International Space Station must have 1 year of shelf life, and the foods that are made for upcoming planetary expeditions or outposts must have 5 of shelf life.
Sensory evaluations are normally the first thing they begin with at Space Food Systems Laboratory. How the astronauts will rate the food are by their colors, taste, appearance, odor, flavor, and palatability overall. Then, they will expose the food to time and temperature changes, and the sensory evaluations will be repeated to observe how the food holds up. Chemical analysis will be performed by the scientists to test the food’s moisture, water activity, pH, texture, color, and nutrients, including considering the time and temperature changes as well. We learned that to reduces contamination, it is best to consider packaging materials and methods. During the process, the material’s shape, weight, and waste will be considered as well. What the scientists will do, is they will take advantage of the materials to invent flexible containers and pouches like the old standard such as foil poachers and cans aluminum.
Food preservations are not as simple as it seems, especially when for the manufacturers for people, as well as for the scientist developing food preservations for astronauts. If it is just common people trying to store opened food from wasting it, we would just put it in a container or sealable bags and keep it in the refrigerator. Normally it would last to 3 days. But for manufacturers and scientists have to make sure that the food they store will still be okay, healthy, and have enough nutrients for people to consume. For normal people, if they find the food is already bad, they would probably throw it away and buy a new one, and most probably they would make a complaint about it. But astronauts depend on those foods stored by the scientists to live in outer space. Therefore, it is still important to make sure the food preservations are correct and nicely put. For a good University to study food, maybe you can check Widad for more information.