Una variedad de caramelos liofilizados, incluidos caramelos arcoíris liofilizados, malvaviscos liofilizados, gomitas liofilizadas, etc.

When it comes to space food, some people may still think of it as a paste extruded from an aluminum toothpaste shell. We can try to imagine that squeezing something like this into your mouth, no matter what it tastes like, is not an enjoyable process.

In fact, it was a stopgap measure at the start of the space industry, where food was gradually improving, and by the 1980s astronauts were eating almost as much as they did on earth. However, space food from the initial “food” to the later “well-off level”, there is a sense of science and technology of food, has been playing an important role, that is, today we will talk about freeze-dried food.

So, what is freeze-dried food?

Freeze Dried food is an abbreviation for vacuum Freeze Dried food. It is also called FD (Freeze Dried food). As the name suggests, freeze-dried food is a food that is quickly frozen into ice and then heated to sublimate directly into air. The food is then dehydrated and dried into freeze-dried food.

Maybe the concept is too general, we can combine the knowledge from the textbook to explain it briefly. The main technology used in freeze-drying food is vacuum freeze-drying, which is a kind of physical dehydration technology. Water has three phases: solid, liquid and gas. When the temperature is 0.01℃ and the pressure is 610Pa, water is the coexistence of three phases. O in the figure is the three-phase equilibrium point. It can be seen from the figure that when the pressure is lower than 610Pa, if the ice is heated, it can only sublimate directly from the liquid to the gas. Vacuum freeze drying is based on this principle, which is the theoretical basis of freeze-dried food.

 

Lyophilization technology emerged in the early 19th century, but was limited by refrigeration technology and vacuum technology. It was not used to dry biological products until the early 20th century. At that time, during world war ii, a large amount of human plasma was urgently needed, so the lyophilization technology was rapidly developed. After the war, people began to apply this advanced technology to other fields. In 1930, researchers conducted the first food freeze-drying experiment. In 1940, British scholars proposed the treatment technology of freeze-dried food. In 1943, the most primitive food freeze-drying equipment appeared in Denmark. Later, freeze-drying technology was widely used in the space industry of the Soviet union, the United States and other countries, which was also known as space freeze-drying technology at that time.

 

By luck, more by skill

From the sources of freeze-dried food, it can be seen that its application in aerospace food is accidental under certain historical background. But if we analyze the characteristics of freeze-dried foods, there is an inevitable side to this application.

 

Feature 1: freeze-dried food can maximize the preservation of food color, aroma, taste and shape.

The reason why the color, aroma, taste and appearance of food are mentioned in front of its nutritional value is that we often regard these qualities as the “soul” of food. This is a precedent. In the 1970s, astronauts rejected toothpaste-like food, which led to the development of space food. The unique processing technology of freeze-dried food can not only retain the “body” of food, but also retain its “soul”.

Feature 2: can preserve all levels of nutrients in food, especially heat sensitive substances.

Space food is essentially the same as ordinary food on the ground, which provides energy and nutrition for the human body, and is a guarantee for astronauts to successfully complete their missions. Therefore, the nutritional value of freeze-dried food is of vital importance. Take spinach for example, after freeze drying, vitamin C can be retained 93%, while hot air drying can only retain 59%, dry only 7%, sun drying is less, only 4%.

Feature 3: long shelf life.

Freeze-dried foods are often up to 95% dehydrated and can be packed for storage and transportation at room temperature. It can be stored at room temperature for 3~5 years without adding any antioxidant after sealed packaging, and even up to 10 years at room temperature with protective gas. And because of its light weight and small size after dehydration, it is very convenient for transportation.

It is because of the unique nature of freeze-dried food that it is closely integrated with the aerospace field and gradually developed. It can be said that the development of space industry cannot be separated from freeze-dried food, which has made great contributions to the development and progress of space industry.

 

Star product – space ice cream

There are many kinds of freeze-dried foods, and they are widely used. I don’t want to introduce any of them here, but there is one star product that has to be sold by amway. Had eaten ice cream, but, specially serves the astronaut to eat the space ice cream to have not eaten? Space ice cream is a freeze-dried food made by the above mentioned freeze-drying technology. The earliest aerospace ice cream was developed by Whirlpool corporation in accordance with the Apollo mission signed by NASA. China’s aerospace ice cream is based on our own patented technology, providing special leisure food for astronauts.

Spaceflight ice cream is made of whey protein and other functional factors through freeze-drying. The freeze-drying process can dehydrate the ice cream in vacuum, retain its nutritional value to the greatest extent, and give the ice cream unique taste and flavor. High expansion rate is adopted in the preparation process to make the raw material softer and smoother after freeze-drying. Due to the current space flight does not have low temperature storage conditions, space ice cream can be stored at room temperature, can enter the flight diet; At the same time, the space overcomes the traditional cold drink ice cream temperature is too low, not suitable for the shortcoming of intestines and stomach bad people eating, small space ice cream flavor changes during the storage period, long shelf life, anytime, anywhere can enjoy, appropriate crowd is extensive, can also by adding all kinds of fruit and vegetable producing/particles, etc., make varieties of color, flavor, functional diversification, and sustained development.