Production process and production process of dehydrated vegetable market definition Dehydrated vegetables, also known as rehydrated vegetables, are dried vegetables made by washing and drying fresh vegetables to remove most of the water in the vegetables. The original color and nutrient composition of vegetables remain unchanged. It is not only convenient for storage and transportation but also can effectively adjust the vegetable production season. When eating, it can be restored by soaking in water, and the original color, nutrition, and flavor of vegetables are preserved. Types of dehydrated vegetable AD vegetables, also known as dried vegetables. Dehydrated vegetables made by drying and dehydration mechanisms are collectively referred to as AD vegetables. FD vegetables, aka frozen vegetables. Dehydrated vegetables made from freeze dehydration are collectively referred to as FD vegetables. The characteristics of dehydrated vegetables are not only delicious and delicious but also maintain their original nutritional value. In addition, they are smaller than fresh vegetables, light in weight, recoverable after entering the water, easy to transport and eat, and are favored by people. Dehydrated vegetable processing technology Dehydration and drying methods include natural drying and artificial dehydration. Artificial dehydration includes hot air drying, microwave drying, puffing drying, infrared and far-infrared drying, and vacuum drying. At present, the most common applications of vegetable dehydration and drying are hot air drying and dehydration and freeze-vacuum drying and dehydration. The freeze vacuum dehydration method is an advanced vegetable dehydration drying method. shape and ideal for quick rehydration. The technological process and method of hot air drying dehydrated vegetables and freeze-vacuum drying dehydrated vegetables are now introduced as follows. 1. Hot air drying and dehydration vegetable processing process and method: 1. Raw material selection Choose vegetable varieties with rich meat quality. Before dehydration, the pros and cons should be strictly selected, and the parts with pests, rot, and wither should be removed.
Suitable for 80% ripeness, pick out over-ripe or under-ripe. In addition to melons, other types of vegetables can be washed with water and then placed in a cool place to dry, but do not expose to the sun. 2. Cutting and blanching Cut the cleaned raw materials into slices, wires, strips, and other shapes according to product requirements. When pre-cooking, it varies according to the ingredients. If it is easy to cook, put it in boiling water, and if it is not easy to cook, put it in boiling water (the water temperature is generally above 150 ℃) and cook for a while. The general blanching time is 2 to 4 minutes. It is best not to blanch green leafy vegetables. 3. Cooling and Draining Precooked vegetables should be cooled immediately (usually with cold water) to bring them back to room temperature quickly. After cooling, to shorten the drying time, the water can be removed by a centrifuge, or it can be squeezed by a simple manual method. 4. Drying The drying temperature, time, color and water content should be determined according to different varieties. Drying is generally carried out in a drying chamber. The drying room is roughly divided into three types: one is a simple drying room, which adopts countercurrent blast drying; the other is a drying room with a combination of forward and reverse currents with two layers and double tunnels; the third is a box-type stainless steel hot air dryer with a drying temperature range of 65 ℃-85℃, dry at different temperatures, and gradually cool down. When using the second type of drying room, spread the vegetables evenly on the tray, then put them on the pre-set baking rack, keep the room temperature at about 50°C, and keep rotating to speed up the drying speed. The general drying time is about 5 hours. 5. Sorting and packaging Dehydrated vegetables can be put into plastic bags after being inspected to meet the requirements of the Food Sanitation Law and put on the market after being sealed and boxed.
2. The technological process and method of freezing and vacuum drying dehydrated vegetables: 1. The selection of raw materials does not exceed 24 hours from harvesting to processing, and the yellow and rotten parts are manually selected; root vegetables are selected by hand, and the rotten parts are then graded. 2. Cleaning Remove dirt and other impurities from the surface of vegetables. To remove pesticide residues, it is generally necessary to soak in 1.55%-1% hydrochloric acid solution or 0.05%-0.1% potassium permanganate or 600 mg/kg bleaching powder for a few minutes. Disinfect and rinse with clean water. 3, peeled root vegetables should be peeled. Chemical lye peeling raw material loss rate is low, but export products generally need manual peeling or mechanical peeling. After peeling, it must be placed in water or color protectant immediately to prevent browning. 4. Slicing and shaping Cut the vegetables into a certain shape (granular, flake), and the vegetables that are easy to brown after cutting should be soaked in the color protection solution. 5, blanching generally uses hot water blanching. The water temperature varies with vegetable varieties, but is generally above 100°C; the time varies from a few seconds to a few minutes. When blanching, you can add some salt, sugar, organic acid, and other substances to the water to make the vegetables change color and increase the hardness. 6. It should be cooled immediately after blanching (water cooling or ice water cooling), the shorter the cooling time, the better. 7. Drainage After cooling, some water droplets will remain on the surface of vegetables, which is not conducive to freezing, and it is easy to make frozen vegetable agglomerate, which is not conducive to the next vacuum drying. This method generally adopts centrifugal drying. 8. Freezing The discharged materials are quickly frozen, and the freezing temperature is generally below -30 °C to prepare for the next vacuum drying.
9. Put the vacuum-dried and pre-frozen vegetables into a vacuum container, reduce the pressure in the window below the triple point through the vacuum system, supply heat to the material through the heating system, and gradually evaporate the moisture in the material until it is dried to a Moisture ends. 10. Separation and measurement Freeze-dried products should be sorted immediately to remove impurities and other foreign matter accurately weighed according to packaging requirements, and sealed in bags. 11. Packaging Double-layer plastic bag vacuum packaging. Due to the oxidative browning of the product, it can be packed with nitrogen, and then put into the outer carton for storage. The production process of vegetable dehydrator [Graphic and text display] (1) Use a vegetable washing machine or manual washing to ensure that the dehydrated vegetables are free of soil and impurities. (2) It is necessary to use a professional vegetable cutter to cut vegetables according to the required specifications (3) Dehydrated vegetables are divided into dry dehydration (AD vegetables), freeze dehydration (FD vegetables) (4) Vegetables are packaged and dehydrated and then packaged into 2 Layers to keep fresh, and then put in a woven bag. (5) Store dehydrated vegetables in a zero-temperature freezer to store dehydrated vegetables, which can be stored for about half a year.
