Methods of preserving fruits and vegetables, and what are the methods of preserving fruits and veget

It is better to put fruits and vegetables in the refrigerator or put edible preservatives. Putting lettuce in the refrigerator can effectively prevent the spoilage of raw fruits and vegetables, which can keep fruits and vegetables fresher for a longer period of time. You can also use the air exhaust method to vacuum the plastic bags containing fruits and vegetables without contact with the air to keep the fruits fresh.

The specific operation method is to put the fruits and vegetables into a plastic bag, and then put the bag into the water, do not let the bag enter the water, and tie it into the refrigerator after draining the air in the bag, so as to keep the vegetables and fruits fresh for a longer time. You can buy some edible preservatives to keep vegetables fresh, and the right amount of edible preservatives will not harm health.

1. Bananas are the most susceptible fruits to lose freshness, as long as the banana stem part is damaged a little, it is easy to turn black. Wrap a piece of wax paper or plastic film around the banana stem and secure it with an elastic band. Then the lifespan of the banana will be extended by about a week.

2. Asparagus is bought back and, because the root of his stem is in contact with the air, it is easy to harden. At this time, the stem and root of the asparagus can be soaked in water. (Change the water once a day) the lifespan of asparagus will be extended by about a week.

3. Fruits such as strawberries and grapes are perishable, and berries should not be soaked in water or stored in an airtight container before being stored in the refrigerator. The correct way is to wash the berries with a mixture of water and white vinegar in a ratio of 8:1, and then store them in a plastic container below where there is time to drain the fruit, and store them in the refrigerator, so that the circulating air in the refrigerator can help them stay fresh for about 1 week.

4. Celery is easy to rot and shrivel, you can cut the celery neatly first, leaving only the stems, remove the leaves, and then wrap it in aluminum foil, which can keep your celery fresh and crisp for up to a week and a half.

How to preserve fresh vegetables and fruits, you must learn this method, it is recommended to collect them.

1.Use natural cold source for storage. It is a method of low-temperature storage, that is, the method of using nature and regulating natural low temperature to maintain a lower temperature in the storage place, including stacking, trenching, cellaring, ventilation storage, frozen storage, etc.

2.Artificially cooled storage. In the warehouse with good thermal insulation performance, mechanical refrigeration equipment is installed to control the temperature and humidity in the warehouse through the role of the mechanical refrigeration system, so as to maintain a suitable storage environment and achieve the purpose of long-term storage of fruit and vegetable products.

3.Controlled atmosphere storage. It is divided into Changsong group artificial controlled atmosphere storage and spontaneous controlled atmosphere storage.

Artificial controlled atmosphere storage. It refers to a modified atmosphere storage method that adopts mechanical modified atmosphere equipment to manually adjust the concentration of gas components in the storage environment and maintain stability on the basis of relatively closed environment (modified atmosphere warehouse) and refrigeration, according to the needs of fruit and vegetable products, and its advantages are; The proportion of oxygen and carbon dioxide can be strictly controlled, and it can be closely coordinated with the storage temperature, so the storage time is long and the storage effect is good, but the construction investment of the controlled atmosphere reservoir is large and the operating cost is high.

Spontaneous controlled atmosphere storage. Also known as simple modified atmosphere or limited gas storage, it is a modified atmosphere storage method that spontaneously adjusts the concentration of oxygen and carbon dioxide in the storage environment in a relatively closed environment (such as plastic film bags, tents, etc.), relying on the respiration of the storage product itself and a certain degree of air permeability of the plastic film. This method uses Fang Nai orange stool, the cost is low, can be set up in the ordinary cold storage or room temperature storage warehouse, can also be used in transportation, is a simple form of controlled atmosphere storage cherry shed.

1. Dry the water on the surface of green leafy vegetables and then store them. For the green leafy vegetables in the general supermarket, the merchant may spray some water on the surface of the green leafy vegetables in order to keep them fresh. Note that in this case, it should be placed in a cool, dry and ventilated place to dry the surface moisture, and the water-stained vegetables are easy to freeze in the refrigerator, especially green leafy vegetables.

The key to the preservation of leafy vegetables is to lock in water, and most of the leafy vegetables are cool-loving vegetables, which are suitable for storage at 0-4 °C, that is, the temperature of the refrigerator preservation layer.

2. Before putting it in the refrigerator, remove the rotten and yellowed leaves, then wrap the roots of the dish with kitchen paper, then wrap the dish with plastic wrap or a plastic bag, and finally put it in the refrigerator. However, it should be noted that it should not be stored close to the inner wall of the refrigerator to avoid frostbite of vegetables.

3. Rhizomes generally do not need to be put in the refrigerator. Sweet potatoes, potatoes, radish, lotus roots, yams and other root vegetables, generally do not need to be put in the refrigerator, as long as the surface moisture is dried and put into a fresh-keeping bag or paper bag, and then stored in a cool and dry place, you can also wrap them with a layer of newspaper and store them in a balcony away from light, do not get direct sunlight, resulting in potatoes and other green and long sprouts.

4. Wrap the seasoning ingredients in kitchen paper and store them in the refrigerator. Condiments such as coriander, green onions, ginger, and garlic can be wrapped in kitchen paper like vegetables. Those with less water, such as shallots, minced garlic, and millet spicy, can be directly chopped and frozen, and can be taken at any time.

5. For mushrooms, put a sealed bag with the umbrella handle facing upwards for preservation. Fresh mushrooms have a short shelf life, so use kitchen paper towels to absorb excess moisture on the surface, put the whole unwashed mushrooms into a sealed bag (note that the umbrella handle is facing up, otherwise it may be crushed and collapsed), and close it and put it in the refrigerator. If the dried mushrooms have been dehydrated, they can be stored for 3-6 months as long as they are placed in a cool, dry and ventilated place.

6. Fruits, whether they are durable determines the storage method. According to the classification to decide whether the fruit should be put in the refrigerator, tropical fruits, such as mangoes, bananas, etc., should not be put in the refrigerator, otherwise it is easy to frostbite, and it can be stored at room temperature. Fruits such as grapes, strawberries, and blueberries need to be refrigerated separately and eaten within 2-3 days.

More durable fruits, such as apples, pears, oranges, oranges and other fruits, can be placed in a cool and ventilated place without putting in the refrigerator, but should not be stored for a long time, easy to air dry, volatile moisture, affecting the taste.

Vegetables and fruits are fresh food, perishable after harvesting, in order to extend the shelf life, scientific researchers from various countries have invented a variety of new preservation technologies, which are introduced as follows:

1. Plastic cartons:

This is a new type of carton developed by the Japan Food Distribution System Association in recent years. The researchers used a "Ristoval stone" (a type of silicate) as an additive for pulp. Because this kind of stone powder has a good adsorption effect on various gases, and the amount of fresh vegetables and fruits will not be reduced, so merchants love to use it, and it is unique for long-distance storage and transportation.

2. Microwave preservation:

This is a low-temperature sterilization of fruits, vegetables and fish by a Dutch company. It is the use of microwave in a very short time (120s) to heat it to 72, and then the processed food in 0-4 environmental conditions on the market, can be stored for 42-45 days, will not deteriorate, very suitable for the off-season ** "seasonal vegetables and fruits", favored by people.

3. Edible preservatives for vegetables and fruits:

This is an edible preservative for fruits and vegetables developed by a British food association. It is a kind of "translucent emulsion" made of sucrose, starch, fatty acids and polylipids, which can be sprayed and brushed, and can also be impregnated and covered on the surface of watermelon, tomatoes, bell peppers, eggplants, cucumbers, apples, bananas, etc., and its shelf life can be as long as more than 200 days. This is due to the fact that this preservative forms a "sealing film" on the surface of vegetables and fruits, which completely prevents oxygen from entering the inside of vegetables and fruits, so as to prolong the ripening process of vegetables and fruits and enhance the preservation effect.

Fourth, the new film preservation:

It is composed of two translucent nylon membranes with strong water permeability, and between the membranes are filled with natural paste and sugar syrup with high osmotic pressure, which can slowly absorb the water exuding from the surface of vegetables, fruits and flesh to achieve freshness.

5. Pressurized preservation:

It is successfully developed by the Institute of Food Science of Kyoto University in Japan, the method of making food under pressure, the preservation time of vegetables can be extended after pressure sterilization, and the fresh taste can be improved, but the acid cannot play a role in the pressurized state, so it is ideal to preserve pickles and fruits in the best state.

Fruit preservation. 1. Do not wash refrigerated fruits.

It is best to wrap it in a paper bag to prevent water evaporation, if there is no paper bag, you can use plastic tape, but you need to prick some small holes in the plastic belt to have the effect of aeration, so as to avoid the water evaporating in the fruit becoming the source of microbial breeding.

2. Pay attention to the storage temperature.

The optimal storage temperature and shelf life of each fruit are different, and the general refrigerator storage temperature is 3-6°C, if this temperature is not the optimal temperature, their shelf life will be shortened. Therefore, it is best to eat the fruits as soon as possible, generally within a week.

3. For some tropical fruits, such as bananas, pineapples, papayas, mangoes, etc., their optimal storage temperature is relatively high, so there is no need to put them in the refrigerator. As long as it is stored in the shade at room temperature, it is fine. If the temperature is too low, it can cause the peel to become dented or spotted or browned, for example, the skin of a banana will turn black quickly when left in the refrigerator.

4. Some fruits will produce ethylene during storage, which has the effect of ripening. For example, apples, pears, bananas, etc., it is best to store them separately from other fruits, so as not to accelerate the ripening and aging of the fruits, affecting the quality.

5. After peeling the fruit, if you don't eat it immediately, the air will oxidize the fruit after a period of time, making its surface turn light brown and very ugly. If the peeled fruit is soaked in cool boiled water, it can not only prevent oxidation and maintain the original color, but also make the fruit crisp and sweet.

Vegetables are preserved. 1. The most important thing to preserve leafy vegetables is to retain water and avoid leaf rot. The easiest way is to use old newspapers, spray some water on the leaves, and then wrap them in newspaper and put them in the refrigerator with the roots facing down, which can effectively extend the storage time and retain the freshness.

2. If you can't eat leeks, garlic and other green vegetables purchased in winter, you can wrap them in fresh Chinese cabbage leaves and put them in a cool place to keep them fresh for several days.

3. As long as the lettuce is left for a period of time, it will gradually become soft and discolored, you can remove the cabbage sum, then stuff the moist paper towel into the cabbage sum to let the lettuce absorb water, wait until the paper towel is dry, take it out, and then put the lettuce into a fresh-keeping bag for refrigeration.

4. Garlic, green onions, ginger, and chili peppers are mostly condiments, and it is best to keep them in their original appearance when preserved. Garlic can be stored in a similar way to onions, by placing it in a mesh bag and hanging it in a cool, ventilated place indoors or in a special ceramic jar with air holes. The ginger is divided into old ginger and young ginger, old ginger is not suitable for refrigeration preservation, can be placed in a ventilated place and sandy soil, and the tender ginger should be wrapped in plastic wrap and placed in the refrigerator for preservation.

1. Green leafy vegetables.

The green leafy vegetables bought from the market are first placed in a ventilated place to dry the moisture on the surface of the leaves, then wrapped in kitchen paper and packed into a plastic bag, and finally tied up in the refrigerator for preservation. Since the kitchen paper absorbs water vapor, the vegetables will not be soaked in water vapor and cause them to rot. This method is suitable for most green leafy vegetables, such as raw and sleepy cabbage, cabbage, cabbage, spinach, water spinach, Shanghai greens, celery, etc.

2. Carrots.

Wipe off the moisture on the surface of the carrot with paper or air dry, cut off the green part of the long leaves on the top of the carrot, and then put it in a plastic bag and store it in the refrigerator.

3. Eggplant. When storing the eggplant in the refrigerator, it is important not to let the eggplant get contaminated with water, and there are no cracks on the surface, because the skin of the eggplant will be covered with a layer of wax, which can not only ensure the gloss of the eggplant, but also effectively prevent microorganisms from attacking the eggplant. Therefore, do not rinse with water when storing, keep the skin of the eggplant dry and put it directly into a plastic bag.

4. Corn. Remove the outermost thick husk of the corn that needs to be stored, leave 3 layers of corn inner husk, do not need to clean, remember not to peel off all the lint on the corn husk and the corn head, and then put the corn into a fresh-keeping bag, squeeze out the excess air and tie it tightly, and finally put the corn in the freezer of the refrigerator for storage.

5. Mushrooms. When storing mushroom food, it is best to put the mushroom food into a kraft paper bag and then put it in the refrigerator for preservation, because the kraft paper bag is more breathable than the plastic bag, and the paper bag will not accumulate moisture and moisture inside, and it can be reused many times.

6. Fruits. Most fruits are stored in the refrigerator at low temperatures, but it is important not to wash the fruit before putting it in the refrigerator, because the surface of the fruit has natural pectin, which can resist microorganisms and prevent the loss of moisture from the fruit. Thick-skinned fruits such as watermelon and cantaloupe can be stored directly in the refrigerator.

Apples, grapes, lychees, longans, peaches, plums, lotus mist, cherries, strawberries, blueberries and other fruits are packed in paper bags or plastic bags when they are put in the refrigerator to prevent the water from evaporating too quickly, and at the same time prick a few small holes in the plastic bag so that the fruits can breathe and prevent rotting.