Blog

Home

Process and method of hot-air drying for dehydrated vegetables

Jan 12,2026

Dehydrated vegetables are made from plant seeds, buds, leaves, stems, roots, or their extracts, and they possess a stimulating aroma that enhances the flavor of food, stimulates appetite, and aids digestion and absorption. Today, let's take a look at the process and method of hot-air drying for dehydrated vegetables:
1. Selection of raw materials: Choose vegetable varieties with rich texture. Before dehydration, strictly select the best and remove the inferior, discarding any parts that are diseased, decayed, or wilted. It is advisable to use vegetables at 80% maturity. Overripe or unripe vegetables should also be removed. Except for melons, which need to have their seeds and pulp removed, other types of vegetables can be rinsed clean with water and then placed in a shady place to dry, but should not be exposed to direct sunlight.
2. Cutting and blanching: Cut the cleaned raw materials into slices, shreds, strips, or other shapes according to product requirements. During pre-cooking, the process varies depending on the raw materials. For those that are easy to cook through, blanch them in boiling water until cooked. For those that are not easy to cook through, briefly cook them in boiling water for a short period of time. The general blanching time is 2 to 4 minutes. Leafy vegetables do not require blanching.
After cooling and draining for pre-cooking, the vegetables should be immediately cooled to bring their temperature down to room temperature quickly. After cooling, to shorten the drying time, the water can be spun off using a centrifuge, or a simple manual method of pressing and draining can be used. Once the water is completely drained, the vegetables can be spread out and slightly cooled and dried for later use in baking.
4. Different temperatures, durations, colors, and moisture contents during drying should be determined based on different varieties. Drying is generally carried out in drying rooms. There are roughly three types of drying rooms: one is a simple drying room using counterflow blast drying; the second is a drying room with two layers of double tunnels, combining both parallel and counterflow drying; and the third is a van-type stainless steel hot-air dryer, with a drying temperature range of 65°C to 85°C, drying at different temperatures and gradually reducing the temperature. When using the first two types of drying rooms, vegetables should be evenly spread out in trays and then placed on pre-set drying racks, maintaining a room temperature of around 50°C, while constantly turning them to accelerate drying. The general drying time is about 5 hours.
After the inspected and tested dehydrated vegetables meet the requirements of the Food Hygiene Law, they can be repackaged in plastic bags, sealed, and packed into boxes before being marketed.

None

Will the nutrients of quick-frozen fruits and vegetables be lost?