In daily life, when we eat instant noodles, there is often a packet of
DEHYDRATED VEGETABLES in it. So, do you know how dehydrated vegetables are made?
Dehydrated vegetables are
Dried Vegetables made by artificial heating to remove most of the water in the vegetables. Common dehydrated vegetables include bacteria and algae, beans, celery, green peppers, cucumbers, etc., which are usually eaten after soaking in hot water for a few minutes. So, what are the ways to make dehydrated vegetables?
Dehydrated vegetables can be divided into natural sun drying, hot air drying and dehydration and freeze-vacuum drying and dehydration according to their dehydration methods.
Natural drying is the use of natural conditions to dehydrate vegetables. In ancient times, people have begun to apply this method. The principle of hot air drying and dehydration technology is to vaporize and diffuse the water on the surface of vegetables into the air by drying hot air, increase the concentration of the contents of the vegetable surface, form the osmotic pressure difference of the connected inner cells, and make the inner water diffuse and flow to the outer layer. , allowing the water to evaporate continuously. The principle of freeze-vacuum drying and dehydration technology is to quickly freeze the drained material, so that the remaining water in the material is converted into ice, and then under vacuum conditions, the water molecules are directly sublimated from solid to gaseous state to complete dehydration.
Natural sun drying and hot air drying and dehydration will lose a lot of water-soluble vitamins and bioactive components during the processing process, and the color of vegetables will also become darker. In contrast, freeze-vacuum drying and dehydration technology can maximize the preservation of the original nutrition of vegetables Therefore, 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. It can not only improve the nutritional content of products, increase the color and flavor of products, but also enrich the variety of products, which greatly improves the food structure of consumers. .
This article is scientifically checked by Li Yanzhi, a senior teacher at Beijing No. 65 Middle School.
