Process method of hot air drying dehydrated vegetables and frozen vacuum drying dehydrated vegetables

Process method of hot air drying dehydrated vegetables and frozen vacuum drying dehydrated vegetables

There are two kinds of dehydration drying methods: natural drying and artificial dehydration. Artificial dehydration includes hot air drying, microwave drying, expanded drying, infrared and far infrared drying, vacuum drying and so on. At present, the application of vegetable dehydration and drying is more hot air drying and freezing vacuum drying. Freezing vacuum dehydration is an advanced method of vegetable dehydration and drying. The product can not only retain the original color, aroma, taste and shape of fresh vegetables, but also has an ideal rapid rehydration. The processes and methods of hot air drying dehydrated vegetables and frozen vacuum drying dehydrated vegetables are described as follows.

Hot air drying varieties processing process and method

1, the selection of raw materials to choose vegetable varieties with rich meat, before dehydration should be strictly selected to remove the bad, disease, rot, shrivelled parts. 80% maturity is appropriate, too ripe or immature should also be picked out, except melons seeds, other types of vegetables can be washed with water, and then put in a cool place to dry, but should not be exposed to the sun.

2, cutting, blanching will be washed raw materials according to product requirements respectively cut into pieces, silk, strip and other shapes. Pre-cooking, due to different raw materials, easy to boil through the boiling water blanched, not easy to boil through the boiling water (water temperature is generally above 150 ° C) in a little cooking time, the general blanching time is 2 to 4 minutes. Leaf vegetables are best not blanched.

3, cooling, pre-cooking vegetables should be cooled immediately (generally using cold water flushing), so that it quickly dropped to normal temperature. After cooling, in order to shorten the drying time, the centrifuge can be used to throw water, or the simple manual method can be pressed to drain, after the water is drained, it can be spread out a little cool sun, ready for the plate baking.

4, drying should be determined according to different varieties of different temperature, time, color and moisture content during drying. Drying is generally carried out in the drying room. There are roughly three kinds of drying rooms: the first kind of simple drying room, using counter-current blast drying; The second kind is the drying room with two-storey double tunnel and the combination of upstream and downstream; The third is the van type stainless steel hot air dryer, the drying temperature range is 65℃ -85 ℃, dry at different temperatures, and gradually cool down. When the first and second drying rooms are used, the vegetables are evenly spread on the tray, and then placed on the pre-set drying rack, maintaining the room temperature of about 50 ° C, and constantly turning to speed up the drying time, the general drying time is about 5 hours.

5, classification, packaging dehydrated vegetables after inspection to meet the requirements of the food hygiene law, you can be divided into plastic bags, and sealed, packed, transported.