In our daily life, when we eat instant noodles, we often have a bag of dehydrated vegetables. Do you know how to make dehydrated vegetables?

Dehydrated vegetable is a kind of dried vegetable which is made by removing most of the water in the vegetable by artificial heating. The common dehydrated vegetables are fungi and algae, beans, celery, green pepper, cucumber and so on. They can be eaten after soaking in hot water for a few minutes. So, what are the ways to make dehydrated vegetables?

According to the dehydration methods, dehydrated vegetables can be divided into natural drying, hot air drying and freeze vacuum drying.

Natural sun drying is the use of natural conditions for dehydration of vegetables, in ancient times, people have begun to use this method. The principle of hot air drying and dehydration technology is to vaporize and diffuse the moisture on the surface of vegetables into the air through the drying hot air, so as to improve the concentration of the contents on the surface of vegetables, form the osmotic pressure difference of the connected inner cells, so that the water in the inner layer diffuses and flows to the outer layer, so that the water can continuously vaporize. The principle of freeze vacuum drying and dehydration technology is to freeze the drained materials quickly, and convert the remaining water into ice, and then sublimate water molecules directly from solid state to gas state under vacuum condition, so as to complete dehydration.

In the process of natural drying and hot air drying dehydration, a lot of water-soluble vitamins and bioactive components will be lost, and the color of vegetables will also be easy to darken. In contrast, freeze vacuum drying and dehydration technology can maximize the original nutrients, color and flavor of vegetables, so the processing cost of this technology is relatively high, and it is usually used for the processing of high-grade vegetables.

Dehydrated vegetables are widely used in almost all fields of food processing. They can not only be used to improve the nutritional components of products, increase the color and flavor of products, but also enrich the varieties of products and greatly improve the food structure of consumers.