Views: 5 Author: Golden Horizon (Chengdu) Technology Co., Ltd. Publish Time: 2022-04-29 Origin: Golden Horizon (Chengdu) Technology Co., Ltd.
In recent years, all kinds of freeze-dried foods can be described as the new favorites in the snack world. Various kinds of freeze-dried fruits such as dried winter dates, dried strawberries, dried durians, and even "the same type of vegetables"-dried okra have appeared. So, what is the nutritional value of freeze-dried food?
What Is The Principle Of Freeze-Drying?
Freeze-drying stands for freeze-drying. After freezing the raw materials at -40°C, the air in the drying box is pumped out to become a vacuum environment. The solid ice in the fruit can be directly sublimated into gaseous water vapor, so as to achieve the purpose of freeze-drying.
Freeze-drying can remove more than 95% of the water in fruits, and the appearance and volume of freeze-dried fruits and vegetables are almost the same as fresh fruits.
Freeze-drying Can Preserve the Nutrients in Food to A Great Extent
Someone has done experiments with purple mulberry fruit, comparing freeze-drying with other ordinary drying methods, and measuring the content of its main biologically active ingredient-anthocyanin after drying.
Through comparison, it is found that the freeze-dried purple mulberry has the least loss of anthocyanin content (about 5% loss), and is very close to the fresh purple mulberry, while other drying methods lose up to 80%.
Therefore, compared with the common drying methods on the market, the freeze-drying process can greatly retain the nutrients in the raw materials. But at the same time, it can be seen that freeze-drying still cannot completely retain all the nutrients.
Like all drying methods, freeze-drying is to extend the shelf life of food by removing most of the water in the food, but while removing the water, it will cause the loss of many water-soluble vitamins (such as vitamin C).
In addition, some alkaloids and flavonoids with high chemical reaction activity in food will also cause certain damage during the process of water loss.
Freeze-Dried Fruit Cannot Completely Replace Fresh Fruit
Since freeze-drying technology will still cause a certain loss of nutrients in raw materials, freeze-dried foods cannot completely replace fresh fruits and vegetables.
In addition, since the freeze-dried fruits and vegetables have removed most of the water they contained, their sugars have been enriched, that is, the heat has been increased several times. In addition, dried fruits and vegetables lose their moisture and feel less full, making them easy to overeat. Therefore, freeze-dried fruits are not as healthy as fresh fruits.