How To Freeze Dry Strawberries?
Strawberries are juicy and delicious, and have high nutritional value. They are rich in vitamins and pectin, folic acid, anthocyanins and other substances, and are known as “the queen of fruits”. The strawberry harvest season is April and May, but strawberries are not easy to preserve. How can we eat strawberries that are rich in nutrients and free from preservatives all year round? Vacuum freeze drying can help you solve this problem.
The mechanism of vacuum freeze drying is to freeze the material that needs to be dried below the eutectic point (the temperature when the moisture in the material is completely frozen into ice crystals) so that the moisture in the material becomes solid ice, and then heat it under a suitable vacuum environment. The ice is directly sublimated into water vapor to obtain a dried product.
Vacuum freeze drying used in strawberries can make them quickly frozen and dehydrated in a vacuum ice shape. The color, aroma, taste, shape and nutrition of the strawberries are kept as much as possible. It can be stored for one year without any preservatives. Lightweight and easy to carry.
How to freeze dry strawberries? What is the specific procedure? Fresh fruits are quickly frozen (as low as minus 40°C) after being picked, and then the ice-like ingredients are directly sublimated into a gaseous state through vacuum dehydration technology. The nutrition of the fruit itself is also left in the ice shelf when it is frozen. So the volume does not change after drying. Doing so can make the fruit “beautiful as before and full of nutrients”, retain the original color, fragrance, taste, and shape, and at the same time, it can keep more than 95% of the nutritional ingredients. The dehydration rate of the lyophilized fruit is over 95%, and it can be stored at room temperature for one year or longer without any preservatives.
In the 1960s, the United States used vacuum freeze drying technology to make astronauts’ space food. In space where gravity is lost, eating and drinking water are very difficult. Cutting open fresh fruit to eat is probably a fatal thing. Juice floats in the air, and it may smear one’s face or even damage the instrument. The birth of vacuum freeze drying has fundamentally solved the problems of freshness and nutrition of astronauts’ food, so vacuum freeze drying is also called “aerospace food technology”.
The solid matter after lyophilization has a porous structure, which maintains the volume at the time of freezing, and is easily dissolved and restored by adding water. Soaking in warm water for one minute can restore more than 80% of the freshness of the food. It not only retains the appearance perfectly, but also retains most of the nutrients and flavor. In food processing, the perfect retention of “flesh” and “soul” is fully reflected in the vacuum freeze drying.
At present, vacuum freeze drying technology is not only used in food production but also widely used in the production of serum, plasma, vaccine, enzymes, antibiotics, hormones and other drugs, bringing great convenience to people’s lives.
Vacuum freeze drying and how to freeze dry strawberries are described in detail in this article. If you want to have a qualified industrial scale freeze dryer, welcome to Hawach!