Banana is a tropical and subtropical fruit, which belongs to typical respiratory climacteric fruit. After fruit harvest, respiratory jump occurred rapidly at normal temperature; During post ripening, the ethylene release peak of banana appears before the respiratory peak, thus accelerating the arrival of the respiratory peak and the release of ethylene, promoting the fruit to turn yellow, sweet, soft and astringent. Pathogenic bacteria and mechanical damage will promote physiological post ripening and shorten the storage life of fruit. Therefore, delaying the late ripening of fruit is to delay the emergence of respiratory peak, reduce the stimulation of ethylene and eliminate the diseased fruit. At the same time, bananas are very sensitive to low temperature and are very prone to freezing damage.

（1） Refrigerate

The harvested bananas mature due to their own ethylene production and self catalysis. During the ripening process, more ethylene is produced to stimulate the ripening of the surrounding bananas. This chain reaction leads to a large number of mature bananas, which can not be stored for a long time. The cold storage of green and hard (immature) bananas can reduce the arrival of respiratory peak and delay the production of ethylene, so as to prolong the storage life. According to the experiment, the banana with 75% ~ 80% plumpness can be stored at 11 ~ 12 ℃ with good effect. If the temperature is lower than 10 ℃, cold damage will occur. The cold injury symptoms of banana are: first, the peel turns dark gray, and in serious cases, it turns gray black. When most of the peel has turned gray black, the skin color becomes darker after ripening, and white mold appears quickly. The skin feels sticky and slippery when touched by the finger, and the flesh is difficult to separate. The flesh is still solid. Sometimes, part of the flesh in a fruit finger becomes soft, and the food is light and tasteless, and it feels like eating raw starch. Another key measure during banana cold storage is ventilation, because only a very small amount of ethylene is enough to make the stored bananas ripen in a short time. Therefore, it is necessary to pay attention to frequent ventilation to reduce the ethylene concentration. When the cold storage is dry, the humidity can be increased by wetting, spray and other methods. When the banana is released from the cold storage, the fruit temperature should be gradually raised to room temperature before the banana is released, otherwise the fruit surface will sweat, the respiration will increase greatly, and it is easy to be soft and rotten.

（2） Controlled atmosphere storage

1. Spontaneous regulated gas storage: bananas are packed in polyethylene film bags, and the storage life is prolonged by changing the gas composition in the bags. This technology has good effect. Under normal temperature, the content of CO2 and O2 in the polyethylene bag varies from 0.5% to 7.0% and 0.5% to 10.0%, respectively. The specific method is as follows: the thickness of plastic film is 0.04-0.06 mm, each bag is filled with 10 kg of banana dipped in 1000-2000 times of methyl tobuzin, and 200 g of bricks or vermiculite soaked in saturated potassium permanganate aqueous solution and 100 g of slaked lime are put into it. The initial half bag is sealed, and the middle and later full bags are sealed to ensure that the CO2 content is stable at 1% ~ 7%. During the storage period, the temperature was kept at 11 ~ 13 ℃, the relative humidity was 90% ~ 95%, and the peel was still green after about 100 days of storage.

2. Regulated gas storage: according to the test report, the regulated gas storage is used to regulate the gas composition to ensure that 5% CO2 and 3% O2 are stored at the temperature of 20 ° C. the single fruit is stored for 182 days and still does not mature until it is transferred to the natural air. If appropriate storage temperature is adopted, it can be expected that the storage period can be extended. During the CA process, the ethylene production increases with the increase of oxygen content and decreases with the increase of CO2 content. Therefore, ventilation must be done well to reduce ethylene concentration.

Home common save:

It is suitable for storage at about 12 ℃. If stored in an environment below 12 ℃, it will turn black and rot. It can be placed in a cool place at room temperature. If it is placed in the refrigerator, they will be damaged by cold and deteriorate in advance.

You buy a bunch of bananas, then separate them, and then wrap a small part of plastic wrap around the stem of each banana. The fresh-keeping film helps to suppress the ethylene gas produced when the banana is ripe. If there is no plastic film, the ethylene gas will be diffused to other parts during the ripening process of bananas, and the whole ripens quickly.