I want to open a fruit shop near the school. what do you think?

First of all, it is not good to be near the school, but it is better to be around the hospital. Let's talk about preservation first.

Fruit preservation technology

Fresh-keeping storage of fruits can avoid the problems of tight transportation and low price of concentrated fruits, that is, it can prolong the time of fruit market, meet the needs of consumers after New Year's Day and Spring Festival, and increase added value, which is a good way for fruit farmers to increase their income. In order to keep the fruit from rotting when selling, and keep the golden skin wrinkle-free and unique sweetness, a series of measures should be taken to open the mushrooms at harvest.

First, harvest. Before picking 15 days, a large amount of water should not be poured or drenched, and fruit trees should be picked at least 7 days after heavy rain, so as to prevent the fruits from being stored or rotted due to excessive water content, and should not be picked in rainy days or when the fog is still wet. You should choose sunny or cloudy days to pick fruits. When harvesting Shatian pomelo, you should "cut two fruits at a time". First cut the fruit with a fruit scissors, then cut the fruit flat with the fruit shoulder, hold the bottom of the fruit with your left hand and cut it with your right hand. Gently put the fruit into the basket. Don't pull the fruit hard when picking, and don't throw the fruit down into the laundry basket from a height to prevent the fruit from being damaged and rotted due to the invasion of germs during storage.

Second, keep fresh. Fruit should be transported to the house or warehouse immediately after harvesting to avoid rain and sun exposure. When the fruit is stacked, the height shall not exceed 1 m to prevent the fruit from deformation or internal injury. After sweating for 7 days, it can be diluted by 600- 1000 times with Zhuhai true green orange preservative, and washed with 1 g 2,4-d 1-2 minutes. The advantage of this method is that the storage time is as long as 4-6 months, and the peel is bright in color. 2. Soak in Jing 2-B preservative 15-20 solution for 30 seconds, then take it out and put it in a special fresh-keeping bag, which can be stored for 4-6 months at room temperature.

3.70% of the imported thiophanate methyl or carbendazim (4 kg per 4-6 g of water) is washed with 1 g of 2,4- drops powder, scattered and dried, immediately packed into special fresh-keeping bags, and then put into storage. After entering the warehouse, always check whether there is any water leakage in the house and whether it has been bitten by rats. If it is found to be rotten, pick it up immediately. Open the window for ventilation when the indoor temperature is too high, and close the window when the temperature is too low. Don't touch alcohol from harvest to storage, and don't store alcohol in the warehouse, because many fruits will rot when they touch alcohol.

Excerpt from: Hubei Science and Technology News 2006. 1.3.B 1 edition.

Responder: Ziggy-Magic Apprentice Level 1 3- 18 10:45

See: Fruit Preservation Network /store/b4/

Interviewee: 55ss 22 ZZ 88 cc- Vice President 10 Level 3- 18 10:45

New method of fresh-keeping packaging for vegetables and fruits

-

With the development of economy and the improvement of living standards, people's diet has changed from simple food and clothing to diversified nutrition. The demand for vegetables and fruits is increasing, and the requirements for their freshness are getting higher and higher. At present, a variety of preservation technologies and materials have been developed.

Unlike other foods, vegetables and fruits do not die after being picked, but remain? Life. Traditional fruit and vegetable packaging, whether corrugated boxes or net bags, woven bags, plastic wrap, can not achieve the function of preservation. At present, a variety of functional preservative films, new corrugated boxes and functional preservatives have been developed, and some technologies and materials have been applied. Because these fresh-keeping materials and technologies often have a single function, in order to achieve the best fresh-keeping effect, it is sometimes necessary to use a variety of fresh-keeping technologies and materials at the same time.

Functional plastic wrap.

Although the traditional film can play the role of packaging and has a certain fresh-keeping effect, it obviously can not meet the fresh-keeping needs of the modern market. Therefore, a large number of new plastic wrap films have been developed. These functional cling films not only have the functions of preventing water evaporation and simply controlling gas, but also can further improve the freshness of vegetables and fruits.

Ethylene adsorption membrane

In order to remove the harmful ethylene gas, the ethylene adsorption membrane is a plastic film (especially LDPE) mixed with gas to adsorb porous substances, such as tuff, zeolite, clay minerals, stone powder and other micro-powders. Most of them can absorb ethylene or block far infrared radiation. The mechanism of ethylene adsorption is that the pores on the surface of porous inorganic substances can capture ethylene, and even in the case of high moisture, water molecules in the pores can replace ethylene. However, the addition of gas adsorbent is 3%-5%, because the adsorption capacity of ethylene gas is limited.

Anti-condensation film

Fresh-keeping film for vegetables and fruits is generally made of high-permeability resins such as low-density polyethylene, polypropylene, polybutadiene, polystyrene, ethylene-vinyl acetate polymer and polyvinyl chloride. However, when the water vapor generated by the vegetables and fruits packed with these films condenses on the inner surface of the film, it not only makes its transparency worse, but also makes water droplets gather, which makes bacteria multiply rapidly and leads to the decay of vegetables and fruits. What can solve this problem is the dew-proof film. Dew-proof film uses surfactants to treat the inner surfaces of the above-mentioned polyethylene, polypropylene, polystyrene and other materials, which can absorb excess water, moderately maintain the humidity in the package, and achieve the purpose of preservation.

Antibacterial film

The antibacterial membrane is a mixture of antibacterial silver zeolite mixed into the membrane. Silver zeolite is a mixture of antibacterial silver and sodium ions in the zeolite crystal structure, or a mixture of silver ions and loose zeolite synthesized from aluminum and silicon. PE, PP and PS are mainly used as substrates. This kind of membrane can inhibit the reproduction of bacteria to a certain extent and play a fresh-keeping role.

Selective permeable membrane

If there is no oxygen in the package, the respiration of fruits and vegetables will stop and the fruits and vegetables will rot and deteriorate; Too much oxygen will accelerate the breathing of fruits and vegetables, and will also accelerate the withering of fruits and vegetables. Therefore, controlling the permeability of oxygen and carbon dioxide in packaging is a very effective technology, which can be combined with modified atmosphere technology. In the past, silicon windows were mostly added to ordinary packaging bags to achieve the purpose. At present, the more advanced way is to directly produce breathable film products by adding silicone material into synthetic resin.

Fresh-keeping corrugated box

Corrugated box is a packaging container for commodity transportation between consumption and production at present. Some functional corrugated boxes can be used to keep vegetables and fruits fresh, which has aroused great concern.

Corrugated paper box with heat insulation function

At low temperature, not only the respiration of vegetables and fruits is weakened, but also the activity of bacteria is greatly reduced. Therefore, low-temperature storage is the most effective means and development direction to maintain food freshness.

Corrugated box with heat insulation function has good fresh-keeping function. This kind of corrugated box is lined with composite resin and aluminum evaporation film in the inner and outer packaging of traditional carton, or foamed resin is added in the paper core. This corrugated box has excellent heat insulation performance, which can prevent the temperature of vegetables and fruits from rising during circulation.

Corrugated paper box with gas control function

Adjusting the storage gas composition, humidity and other conditions will also achieve a certain preservation effect, which is an important aspect of preservation technology. Corrugated paper box with gas control function is to sandwich preservative film in the inner lining and outer lining of the carton or mix porous powder that can absorb ethylene gas in the papermaking stage. This kind of corrugated box has gas barrier, which can prevent the moisture evaporation of vegetables and fruits, achieve the effect of controlling gas content, and thus maintain the freshness of vegetables and fruits.

Plastic wrap, preservative and cold storage agent

In order to enhance the fresh-keeping effect of vegetables and fruits, substances with specific functions can be added while using the above packaging materials, such as fresh-keeping tablets, preservatives, cold storage agents, etc.

Save sheet

The single package of vegetables and fruits is mostly a composite product of plastic tray and film, so the functional tablets placed on or above the tray body have a fresh-keeping function. Most of these sheets have one or more functions, such as humidity control, dew prevention, ethylene gas absorption and antibacterial. Among them, humidity control and water absorption is a multi-layer structure composed of super absorbent resin, non-woven fabric, cotton paper and water absorbent polymer; The absorption of ethylene gas is mostly based on the porosity of activated carbon; Antibacterial properties are due to the addition of inorganic substances with antibacterial properties such as silver zeolite or antibacterial components extracted from plants.

antistaling agent

Because the absorption effect of functional membranes for absorbing ethylene gas is limited by the dosage, preservatives for absorbing ethylene gas are widely used. Packaging vegetables and fruits together with preservatives can achieve a certain purpose of inhibiting ethylene gas. At present, antioxidants such as potassium permanganate, gas adsorbents such as activated carbon and mineral powder, and palladium catalysts are commonly used as preservatives.

Cold storage agent

Because the low-temperature preservation of vegetables and fruits is conducive to maintaining their freshness, the use of refrigerated materials has become an important means of preservation technology. An elastic gel-like material with ultra-high molecular weight sodium polyacrylate or its graft polymer as the main component is a high-performance cold storage material. After freezing, energy can be released slowly, and if it is used with an insulation box, a good cooling effect can be obtained.

Other preservation methods and techniques

Novel fresh-keeping tray

The fresh-keeping tray is made of thermoplastic plate through vacuum forming and stamping forming. The use of tray can not only prevent fresh food from being destroyed, but also has certain heat insulation. The so-called new pallet is to add functional film or long fiber non-woven fabric to the thermoplastic plate with the same weight? And molded products. On the basis of the original function, this tray also has the functions of adjusting humidity, controlling gas content and preventing mold propagation, so it can keep the freshness of vegetables and fruits.

Radioactive sterilization

In order to reduce the influence of pathogenic microorganisms on the freshness of fruits and vegetables during storage and transportation, the fruits and vegetables can be sterilized by radiation after picking and then packaged and transported. At present, the United States, South Africa and other countries all adopt irradiation treatment of certain varieties of vegetables and fruits under certain radiation intensity.

Usage and dosage:

1. When washing 10 kg of fruits and vegetables, respectively take 5ml of Agent A and Agent B (which can be measured in a small measuring cup), pour them into a porcelain enamel basin or a plastic basin or a plastic bucket, shake them evenly and let them stand for 5- 10 minutes to fully activate them.

2. add 200 times of the total amount of agent a and agent b, about 2 kg.

3. If you eat directly, you can wash the fruits and vegetables and soak them in this disinfectant for 5 minutes, preferably by soaking. After taking it out, rinse it with water again.

If it is fresh, there is no need to clean it. Just soak it in sterile water for 5 minutes, take it out, dry it naturally and store it in the open air. It can also be dried and put into a clean food bag for sealed storage. Generally, the shelf life can be extended by 1- 10 days.

Precautions:

1, ready to use and used up within 24 hours.

2, can not be mixed with other disinfectants.

3. If it accidentally spills into your eyes, rinse it with water immediately.

4. Tighten the bottle cap after use and put it in a cool and ventilated place, out of reach of children.

1, the most important thing to keep leafy vegetables fresh is to keep water and avoid leaf rot. The easiest way is to use old newspapers, spray some water on the leaves, then wrap them in newspapers and put them in the refrigerator with their roots down, which can effectively prolong the storage time and keep them fresh.

2. Vegetables such as leeks and garlic yellow bought in winter can be wrapped in fresh Chinese cabbage leaves and stored in a cool place for a few days if they can't be eaten at one time.

Lettuce will gradually become soft and discolored as long as it is left for a period of time. You can remove the cabbage heart, then put a wet tissue in the cabbage heart to make the lettuce absorb water, take it out when the tissue is dry, and then put the lettuce in a fresh-keeping bag for refrigeration.

4, garlic, onions, ginger, peppers are mostly condiments, and it is best to keep the original appearance when preserved. Garlic is preserved in a similar way to onion. It can be placed in a net bag and hung in a cool and ventilated place indoors, or it can be placed in a special ceramic cylinder with air holes. Ginger is divided into old ginger and young ginger. Ginger is not suitable for cold storage, so it can be placed in ventilated places and sand. Young ginger should be wrapped in plastic wrap and kept in the refrigerator.

If you don't eat the fruit immediately after peeling, the air will oxidize the fruit after a while, making its surface light brown, which is very ugly. If the peeled fruit is soaked in cold boiled water, it can not only prevent oxidation, maintain the original color, but also make the fruit brittle and fragrant.