What is freeze drying
Drying is one of the ways to keep things from spoiling.
There are many drying methods, such as drying, boiling, drying, spray drying and vacuum drying. But these drying methods are all carried out at a temperature above 0°C or higher.
Freeze-drying technology is the abbreviation of freeze-drying technology. It first quickly freezes the moisture in the food into ice, and then uses high temperature heating to sublimate it into gas, so the food is dehydrated and dry.
Definition of freeze-dried fruit
Freeze-dried fruit uses the vacuum freeze-drying method of a freeze dryer to freeze the water in the fruit in advance, and then sublimates the frozen water in the fruit in a vacuum environment to obtain freeze-dried fruit. In short, the water in the fruit is extracted in a low temperature environment to retain its original nutrition.
Freeze-dried fruit is fast-frozen, dehydrated in vacuum ice, retains the original color, aroma, taste, nutrients and the appearance of the original material, and has good rehydration, and does not contain any additives. It is an ideal natural Hygienic food.
one. Freeze-drying is performed at low temperatures and is therefore particularly suitable for many heat-sensitive substances. Such as or loss of biological vitality.
two. When drying at low temperature, the loss of some volatile components in the material is very small, and the original nutrient content is maintained.
three. During the freeze-drying process, the growth of microorganisms and the action of enzymes cannot be carried out, so the original shape can be maintained.
Four. Since it is dried in a frozen state, the volume is almost unchanged, the original structure is maintained, and no condensation occurs.
five. The dried substance is loose, porous and spongy, and when water is added, it dissolves quickly and completely, returning to its original shape almost immediately.
six. Since drying is carried out under vacuum with very little oxygen, some easily oxidizable substances are protected.
seven. Drying can remove more than 95-99% of water, so that the dried product can be stored for a long time without deterioration.
Features of freeze-dried products
- It can restore the delicious taste at the beginning of production to the maximum extent. Freeze-dried fruit is quickly frozen and dehydrated in vacuum ice, which preserves the original color, aroma, taste, nutrients and appearance of the original material, and has good rehydration properties.
- Nutrients such as vitamins are not easily destroyed.
- The ingredients are clean, suitable for all ages, ready to eat, simple and convenient. Fresh fruit directly from the farm is used, and the ingredients are clean, without artificial colors, preservatives and sugar products.
- It can be stored for a long time at room temperature and is light in weight and easy to carry. Because the drying technology is carried out under vacuum, there is very little oxygen, and some easily oxidized substances are protected. Therefore, freeze-dried fruit products can be stored at room temperature for a long time without preservatives, and are light in weight, easy to carry, transport and store.
①Food is vacuum freeze-dried, which avoids heat-sensitive reaction and oxidation, and can retain the color, fragrance and nutritional content of food to the greatest extent. Taking spinach as an example, after being processed by freeze-drying technology, 93% of the vitamin C in spinach can be retained, only 7% is retained when dried in the shade, and even less is only 4% when dried in the sun.
② Freeze-dried food can better maintain the appearance and shape of raw materials, and has excellent rehydration properties. The food is vacuum freeze-dried, which maintains the volume, shape and porous structure of the food. After being immersed in water, it can quickly absorb water and restore it to its original fresh state to the greatest extent.
③ Freeze-dried food does not contain preservatives, and the vacuum low-temperature dehydration process inhibits the oxidative deterioration of food and the reproduction of bacteria. Therefore, under the condition of controlling the relative humidity, it can be stored at room temperature for one year or even more than several years.
What are the ways to eat freeze-dried fruit
Freeze-dried fruit is rich in fruity aroma, and retains 99% of fresh fruit color, fragrance, and nutrition. It can be eaten in a variety of ways: it can be eaten directly, and the taste is crispy; it can be put into water to restore it to fresh fruit; it can be soaked in milk for more delicious nutrition; Pair it with salads, yogurt, etc. to create different delicacies.
The difference between freeze-dried fruits and vegetables and crisp fruits and vegetables
In supermarkets, you can often see dried fruits and vegetables. Freeze-dried fruits and vegetables and crispy fruits and vegetables are all dried fruits and vegetables. However, freeze-dried fruits and vegetables adopt vacuum freeze-drying technology, while crisp fruits and vegetables adopt vacuum low-temperature oil bath drying technology. Fragrant and crunchy fruit and vegetable crisps are fried foods with high fat content, so eating too much fruit and vegetable crisps will increase the risk of obesity; while the fat content of freeze-dried fruits and vegetables is usually only about 1%. This can be easily read from the nutrient composition list of dried fruits and vegetables.