Dehydrated spinach processing technology

Dehydrated spinach uses natural or artificial drying methods to reduce the water content in spinach and increase the concentration of soluble substances to prevent the activity of microorganisms. It can also inhibit the activity of the enzymes contained in spinach itself so that the product can be stored for a long time. .
Dehydrated spinach not only has a long shelf life, but also has a small size, light weight, easy to carry and transport, and is convenient to eat. It is one of the most important vegetables in military food and travel convenience foods, and it also plays a role in regulating the season of spinach supply. Can also be used as foreign trade export goods.
Dehydrated spinach production technology:
1. Raw material selection Spinach varieties with leaf hypertrophy, shorter petiole, higher dry matter content, lighter odor, less crude fiber, and soft and golden color should be selected for dehydrated spinach. The high yield of autumn spinach, which is used as raw material for the production of dehydrated spinach, can reduce the production cost, and the growing season is in a cool climate of September-October (the average daily temperature is about 9°C), which is beneficial to the vegetative growth of plants, and flower buds. The elongation is inhibited. Therefore, the harvesting period is relatively flexible and can be sown in stages, harvested in batches, and dried in batches. Harvested spinach should be framed in time to keep it fresh.
2. Pre-treatment Selection of spinach with moderate size and no calyx, removal of old yellow leaves, diseased leaves and worm leaves, cutting of roots from rhizomes, washing after use.
3. Hot water in the boiling pot. After the opening, a few strains of the spinach will be prepared as a handful. From one side of the pan, the ground shall be dispersed and thrown into the pot so that all parts of the spinach will be evenly heated. After 40 to 50 seconds, the fish will be removed and immediately put into the equipment. There is a cooling water cooling pool, so the cycle is blanched. The water in the pot must keep boiling and the water in the cooling tank must keep flowing. Continuously drain warm water and add cold water.
The amino acids and tannic acid contained in spinach can be browned by the action of related enzymes and make the color of dehydrated vegetables brown. The purpose of blanching is to suppress or destroy the activity of enzymes in raw materials, prevent browning of dehydrated vegetables, and reduce microbial contamination. In addition, after blanching, heat is used to eliminate the air inside the raw material, making The increase in permeability facilitates the evaporation of moisture during the drying process and shortens the manufacturing time. However, the time for blanching must be strictly controlled. When the blanching time is too long, the nutrients in the raw material dissolve in the water, and the color becomes dark, the tissue becomes soft, and the quality of the dehydrated food is reduced. Cooling immediately after blanching is to prevent microbial activity and maintain the raw green color of the ingredients.
4. Drying According to the different heat sources, it can be divided into natural dry and artificial dry.
(1) Natural drying uses natural conditions such as sunlight and hot air to dry spinach. The method of operation is that the blanched spinach is dried directly on the cement roof or on the ground. Or set up bamboo mats on the ground and spread the raw materials to dry on the ground. This method has good ventilation and can dry quickly. At night or when it rains, it can be rolled up and moved into the air to continue drying.
The natural way of doing it is low investment and low cost. However, the drying effect is affected by the climatic conditions. In case of continuous rainy weather, it often causes mild deterioration.
(2) The artificial dried stem drying equipment has a traditional simple drying room and a modern artificial drying machine. The drying room has lower equipment costs and easier operation and management. It is suitable for mass production of dehydrated spinach in rural areas. However, the temperature, humidity, and ventilation in the drying room are difficult to control in accordance with the required standards. The management personnel are labor intensive and sometimes lose money due to lack of management.
Modern laboratories include tunnel dryers, drum dryers, conveyor dryers, etc., which are suitable for large-scale production of dehydrated spinach plants. The advantage is that the use of special equipment can automatically regulate or manually regulate the air temperature and flow rate, drying time is short, high efficiency, high quality dehydrated vegetables can be obtained.
When the spinach is used to produce dehydrated spinach, the blanched spinach is drained of excess moisture, placed in a baking tray, and placed on a drying rack. The amount of food on each baking tray does not affect the air circulation between baking trays. Keeping a constant temperature of 75-80°C in the drying room, drying can be completed in 3-4 hours. Near the time of drying, the temperature is lowered to 50-60°C to soften slightly to facilitate packing. Eight kilograms of dehydrated spinach can be made per 100 kilograms of fresh spinach. The moisture content of dehydrated vegetables has a great influence on the storage effect. The lower the water content is, the better the storage effect is without damaging the product quality.
5. After the packaged spinach is allowed to cool, it should be packaged in time. Packaging requirements are sealed, insect-proof and moisture-proof. In order to meet the needs of the tourism industry, a small moisture-proof paper bag or plastic bag can be made, and the dehydrated spinach can be loaded into the briquettes according to the prescribed weight, and then sealed with a small electric sealer. When packing, put a big plastic bag inside the box, then put a small plastic bag, and finally seal the big plastic bag.
6. Storage and storage sites should be kept cool and dry. Storage temperature is preferably 0-2 °C, not more than 10-14 °C; air relative humidity should be below 65%. In addition, light can make dehydrated vegetables discolor, reduce the aroma, so the store should be shading.
7. Rehydration and rehydration is to soak the dehydrated vegetables in the water, after a period of time, to restore it to the dry state as much as possible. The method of rehydration is to soak the dehydrated broth in cold water weighing approximately 14 times the weight of the dish before eating. After the fresh state is restored, it can be cooked. The rehydration rate of spinach is 1 to 6.5-7.5, ie 1 kg of dehydrated spinach. After soaking in water, 6.5-7.5 kg of spinach can be obtained.