(1) 1. Add 100g of water-based substances (such as paraffin and fat) to 0.05-5g of surfactant (such as sucrose, fatty acid ester), and then add water-soluble polymer compounds (such as gum arabic, dextrin, and animal glue) 0.0 -2g, 50-500g of fresh water is placed in a container and stirred well in a greenhouse, then heated at a temperature of 100-150°C (a domestic autoclave can be reached) and sterilized for 20-30 minutes. After cooling, it can be used. 2. After the preservative prepared according to the above method is evenly applied to the surface of the fruits and vegetables to be preserved (dip coating, spraying can be used), the surface of the fruits and vegetables will be condensed into a thin film. Since the film has barrier and bactericidal effects, it can Play a good anti-corrosion effect. According to the test, fruits and vegetables treated with the above "preservative" can increase the shelf life by 5-7 times. When preparing and using "preservatives", farmers' friends can make "preservatives" according to different recipes according to different storage items. Under normal circumstances, when preparing "fresh-keeping agents" for egg-type foods, macromolecule compounds in their formulations are prepared. The proportion of the dose should be appropriately high and the water dose can be appropriately low, and the dosage can be appropriately increased when used; the water used in the formulation of the “fresh-keeping agent†for fruits and vegetables with relatively thin epidermis such as apples, peaches and tomatoes The dosage can be appropriately increased, and the polymer compound and the aqueous material can be appropriately reduced. 3. The "preservative" produced by the above method is mainly applicable to apples, pears, oranges, peaches and other fruits as well as various eggs, roots, tubers, eggplant fruits (such as radish, raw mustard, tomato, eggplant, etc.) Due to the inconvenience of spraying and cleaning, leafy vegetables are not suitable for the storage and preservation of the above-mentioned "preservatives". (2) 1. Formula: 97% of sodium sulfate or potassium sulfate, 1% of starch (or gelatin), 1% of calcium fosin, and 1% (weight ratio) of stearic acid. 2, the system of law: The above raw materials according to the formula measured by mixing smash, add appropriate amount of water into a paste, re-entry into pieces, each about 0.5g. 3, the use of methods: The preservation of the paper wrap, scattered in the storage of fruit containers. Its use amount is: apples, pears, oranges, etc. 5 pieces/kg grape 8-10 pieces/kg. Citrus fruits are stored under normal conditions for 4 months. The loss rate is only 2%, and the cost for storing 50kg oranges is only 3 yuan. However, the surrounding environment should be kept at a certain humidity. (3) 1. Formula: 25% sodium chlorite, 15% ferrous sulfate, 10% zinc oxide and 50% activated carbon. 2. Method: Sodium chlorite, ferrous sulfate, zinc oxide and activated carbon are mixed together, added with a small amount of water and thoroughly stirred, dried at 110° C., and dried to form particles having a diameter of about 2.5 mm. Among them, sodium chlorite is the main agent, and sodium chlorate can also be used instead; ferrous sulfate and zinc oxide are active components, which can not only improve the effect of preservatives, but also extend the use and shelf life of preservatives; activated carbon is a carrier. Silica, alumina, diatomaceous earth, zeolite, etc. can also be used as a carrier. This preservative can not only effectively decompose and remove ethylene gas, but also can decompose and remove other harmful gases such as ethanol and aldehydes, inhibit the occurrence of mould, prevent rot, and is suitable for fruits, vegetables and flowers, and has a long duration of action. 3. Usage: In order to facilitate the use and give full play to the effect of preservatives, the preservatives should be packed into small bags, packed with breathable materials such as paper and cloth, or enclosed in polyethylene, polypropylene plastic film pouches. When using, use a small hole in the needle to breathe. Each pouch can be filled with 5-10g, and the amount used varies depending on the type of fruit and vegetable. By weight, apples, pears, peaches, melons with 2-3%, Chinese kiwi, cherry, mushrooms with 3-5%, can achieve good results. When used, seal the preservative with the fruits and vegetables in the packaging container.