The watermelon is native to the tropical arid regions of the Sahara Desert in Africa. It is a kind of popular fruit, containing a lot of water, sugar, cellulose, vitamins, pectin and calcium, phosphorus, iron and other mineral elements. It can quench thirst, relieve heat, diuresis, eliminate irritability and other effects, often Eating watermelon is wholesome. However, watermelon is hot and hot, extremely cold-resistant, with large bodies and thick skin, but it is not resistant to storage. Watermelon is sensitive to low temperature, and it has cold damage symptoms when it is stored below 9.5°C, but it decreases when it is stored under high temperature. Therefore, understanding and mastering watermelon preservation technology plays a decisive role in the economic benefits of melon farmers. The best black wolfberry generally refers to more than 0.8 centimeters of Chaidamu black wolfberry, scarce resources, high nutritional value.
The black Chinese wolfberry, which is rich in anthocyanins, has naturally become one of the choices of people's health preservation. In many planting areas, the quality of Qaidam black wolfberry in Qaidam area is good, and the Chaidamu black wolfberry is selected. In the Qaidam Qaidam black wolfberry, the quality and product are all the best. After the fine work process of the Seiko, every wood black wolfberry arrived in the hands of the customer. All of them are of high quality.
Black Wolfberry 0.8 Specifications Black Wolfberry 0.8 Specifications,Super Grade Black Wolfberry 0.8 Specifications,AAAA Grade Black Wolfberry 0.8 Specifications,Best Qinghai Chaidamu Black Wolfberry Ningxia Hongqiaozhigu Technology&Development Co.,Ltd , http://www.guofuhui-ec.com
I. Precautions before storage and preservation of watermelon
1. Selection of storable varieties Different varieties of watermelon have a great difference in storability, which is mainly related to the disease resistance, susceptibility to chilling injury and their own nutrient content. According to experiments, Zhongyu No. 10, Fengshou No. 2, Xincheng, honey orange and Zhejiang honey are relatively easy to store, while Zahua, Shihong No. 1, Su Mi, Zhongyu No. 1, Qionglu and other varieties have good storage. Poor. Xinhongbao is sensitive to cold and affects the storage effect. The symptoms of chilling injury are pits on the surface of melons. The small round pits with an initial length of about 2 mm gradually spread out into irregular shapes with a relatively flat bottom and sharp edges. They moved to temperatures above 20° C. Severe odor.
2. Strengthen field management The main diseases during the storage of watermelon such as anthrax, blight, and brown spoilage disease are infected with germs in the field. Therefore, disease prevention and control should be strengthened, field diseases should be reduced, and diseased leaves in the fields should be cleared at any time, flood prevention should be conducted during the rainy season, and water accumulation in the fields should be eliminated in time. About a week before watermelon harvest, 50% carbendazim 800 times, 70% thiophanate 800 to 1000 times, 75% chlorothalonil wettable powder 600 times, spraying or rooting at the beginning of the disease, 7 to 10 days spray 1, spray the leaves of melon and watermelon evenly. More than three years of rotation should be implemented for non-melon crops on severely affected plots.
3. Earl harvesting in advance to prevent injury watermelon early harvest poor quality, over-ripe melon easy to change, are not resistant to storage. Generally, melons are best harvested when they are seven or eight mature. About 40 days after flowering of the late-maturing variety, several tendrils around the fruit withered, fruit fluff off, fruit peel smooth and shiny, and the voiced sound of melons from the hand, the melon has been very mature and ready to eat. Choose sunny morning harvest, do not pick in the hot sun. Each watermelon leaves 10 to 15 centimeters long dendrite. The end of the dendrite is smashed with straw or slaked lime powder to eliminate the germs and prevent infection. Be careful when picking, not only to prevent trauma but more importantly to prevent internal injuries. During picking and transport, prevent bumps, vibrations, and squeezing to prevent internal injury and rot.
4 to avoid mechanical damage in the harvesting, loading and unloading and transport of watermelon in the process of strong vibration, extrusion and other easy to cause damage, easily corrupted into storage. Mechanical wounds on the peel provide access to pathogens. Therefore, storage of watermelon must avoid skin damage, but also to prevent the squeeze, pressure, falling and strong vibration, it is best stored in the place of origin to avoid excessive transport and long-distance transport.
5. After preserving and picking it back, after the dew is dried, the watermelon is fumigated with Kemoding, RQA and other drugs, which can prevent diseases during the storage period. The method is to Keluling drug solution containing 0.1 to 0.2 ml per kilogram of adsorbed on the ball or absorbent paper, scattered and placed around the melon, and then sealed with a plastic film fumigation 24 hours, or pharmaceutical disinfection. Put in 15% salt water and soak for 3 minutes. After slightly drying, wipe the surface of the watermelon with 0.5% to 1% potassium sorbate and seal it in a polyethylene plastic bag.
6. Storage temperature The appropriate temperature for storage of watermelon should be selected according to the cultivation area and length of storage. Under the premise of not generating odor, the lower the storage temperature is, the better the meat flavor is, but the low temperature is prone to cold injury, which affects the appearance of the melon and reduces the value of the product. The longer the storage time at low temperatures, the more likely it is cold damage. Temperature: The suitable temperature for short-term storage is 7 to 10°C, and the suitable temperature for long-term storage is 12 to 14°C. When the temperature is lower than 7°C, it is prone to cold damage. The symptoms of chilling injury are: irregular and shallow depressions on the surface of the fruit; when the chilling injury is severe, the color of the pulp is light, the fibers increase, and the flavor deteriorates. Therefore, when the storage period is short, a lower storage temperature can be used to better maintain the quality. When the storage period is within 20 days, it should be kept above the cold injury threshold.
Second, the specific storage and preservation methods
1. Select the sand-and-water method to select air-ventilated houses, clean them, use the fine river sand bottom to 70 centimeters, grab the fine evening or cloudy days to harvest seven ripe watermelons, and request melons to be positive, non-injury, and free of pests and diseases. The watermelons were left with 3 vines, cut at 33 cm from the nodes at the ends of the vines, and the cuts were immediately stained with hay ash to prevent bacterial invasion. Each vine leaves a green leaf, the watermelon is discharged on the sand bed, and then covered with fine river sand, covered with watermelon 5 centimeters thick, three pieces of melon leaves exposed outside the sand. Should pay attention to a few issues: 1. Handle the watermelon gently, lightly, gently, to prevent damage to the watermelon rind. 2. The sand bed stores only one layer of watermelon to prevent crushing. 3. Apply foliar fertilizer to 50 kg of monobasic potassium phosphate 50 g every 10 days to keep the leaves green. 4. The surface of the sand is dry when it is white, spray water to increase the humidity. 5. Sand beds are made on that day, harvested, transported, and stored on that day.
2. Ozone Preservation Method Select guarantee robust, melon shape is correct, no spots, sixty-seven mature watermelon, cut melon vine, Daiguatao set to take, to avoid vibration or bump, shipped to the storage pit. The cellar is disinfected first, watermelon is stored in grades, and it is padded with a soft straw mat. Do not touch the ground or the plastic film directly. Cover the soft and soft straw bag to prevent dust and water droplets from falling onto the melon. It is better to keep it at 4°C during storage. Breathing is stronger than 5°C, and frozen below 3°C. With the change of day and night temperature changes in time to increase the thermal layer, the humidity remained at 85%. Appropriate oxygen release, regular reshipment. Ozone can be applied to seal and kill bacteria. 150 kg of watermelon need 20 grams of ozone every day and night, and every 12 hours, once every 15 minutes, 10 grams. Every 5 days wear clean gloves gently turn the melon once and find that the diseased melons were picked out in time. Storage of watermelon can not store other fruits or vegetables at the same time in the cellar.
3. Unoccupied storage Select empty, shaded and ventilated houses and disinfect with 40% formalin 150-200 dilutions. At the same time, the stalks and skins of the stored watermelon should be smeared, and then a 6% copper sulphate solution should be sprayed to prevent bacteria and other diseases from invading the vascular bundle to the inside of the fruit. The ground is first covered with a layer of sterile reeds. Then the watermelon is placed in a single layer in a long position. The doors and windows of the room are closed during the day and opened at night. The room temperature is maintained at 15 to 16°C and the relative humidity is about 80%. When the ground is dry, it can be sprayed properly. This method can be stored for 1 month and its color and quality are similar to those of freshly harvested watermelons.
4. Cellar storage Choose a place with high dryness and high soil structure, dig a cellar with a small mouthful, a large mouth, and a shape resembling a gourd. The depth is about 3 meters. The bottom is flat and the sand is 1 centimeter thick. 200-fold omethoate and 150-200-fold formalin solution were sterilized and sealed for two days. After ventilation, the watermelons were allowed to enter the pit. Then cool and put the melons into storage. Around the cellar, the original position of the watermelon growth was layered and placed in the middle to allow space for inspection and handling. The cellar mouth stays 1 meter square and slightly higher than the ground, and supports shades and rains with shading. The cellar temperature is maintained at about 15°C and the carbon dioxide concentration is between 2% and 4%. Stored in this way, fresh up to 3 months. The cellar should have “vital eyes†and skylights, be careful of ventilation and heat dissipation during storage, the cellar temperature should be controlled between 5°C and 15°C, and the relative humidity should be kept between 60% and 80%. Ventilation and cooling can be used in the cellar when nighttime temperatures are low. Check every 10 days to remove the watermelon that should not be stored.
5. Silicone rubber film container bags It is a closed bag made of 0.15~0.18 mm thick polyethylene plastic film. It has a certain area of ​​silicone rubber gas exchange window, and has a higher choice for carbon dioxide, oxygen, etc. Transparency allows the container to maintain a certain concentration of oxygen and carbon dioxide, and play a role in automatic regulation. For different varieties and ripeness of watermelon, as long as the adjustment of the silicon window, you can achieve the purpose of safe storage. Saving watermelons in this way simplifies management, increases storage, and costs less.
6. Saline fresh-keeping Select mature medium-sized watermelon, soak it in 15% salt water for about 10 hours, then dry it up, then seal it in a polyethylene bag, and hide it in a cellar. You can also set the wood in the cellar. In a container, put the watermelon in the box. Using this method to store fresh watermelon, the skin of the watermelon is still fresh and tender as it was taken out in a year. It is sweet and delicious, and its taste is not changed. This method can also be used for preservation of grapes, cucumbers, apples, etc.
Third, the watermelon preservation notes Watermelon in the premise of no odor, the lower the storage temperature, the better the meat flavor, but it is easy to appear cold damage, affect the appearance and reduce the value of the goods. The longer the storage time at low temperature, the more likely it is cold injury. When the chilling injury is severe, the color of the pulp becomes lighter, the fibers increase, and the flavor deteriorates. The symptoms of cold damage often become more pronounced after warming out. The threshold (limit) temperature of cold damage in watermelon is 10°C in Shanghai, 12.5°C in Beijing, and 11°C in Heilongjiang. Stored at this temperature, does not produce cold damage. Therefore, when the storage period is short, it can be stored at a lower temperature. When the storage period is more than 20 days, the storage temperature should be above the threshold value to avoid cold damage, or the pre-storage at high temperature (26°C, 4 days) before storage is also used. Cold damage can be avoided. When the storage period is about 1 month, 14 to 16°C is a safe temperature, but anti-corrosion measures must be taken.
Methods as below:
1. The layer of watermelon should be left from the cold storage wall to prevent cold damage to the watermelon.
2. If any rotten fruit is found in the inspection, it should be picked up promptly to prevent infestation of other watermelons.
3. If there is a dampness, turn the watermelon and drain it.
4. Strictly prevent rat damage.
Author: College of Food Science and Technology, Fujian Agriculture and Forestry University
Chaidamu black wolfberry has become an essential natural plant product in the health community. It has the title of "the king of anthocyanins", and anthocyanin has antioxidant, anti mutation, prevention of cardiovascular and cerebrovascular diseases, protection of the liver and so on. It has been widely loved by everyone.
