The storage methods of cherries include ice kiln storage, cold storage, controlled atmosphere storage and reduced pressure controlled atmosphere storage.

(1) Ice kiln storage method

This method belongs to a simple storage method. When cooling, a certain amount of ice is needed to cool down and maintain its low temperature state, which has great limitations. The operation method is not very strict, so it has certain influence on the storage time and quality of cherries. The popularization range of ice kiln storage method is also very small, so it is not suitable to promote it.

(2) Cold storage method

Cold storage methods are widely used, including large ammonia cold storage and small fluorine cold storage. Generally speaking, the most suitable and effective storage of cherries is a small constant temperature cold air storage, which is simple to operate, low in investment risk, low in energy consumption and fast in cooling. The small hang-up automatic cold storage developed and popularized in shandong institute of pomology has a good effect in storing cherries. Taking this constant temperature cold storage as an example, the methods and steps of storing cherries in cold storage are described.

① disinfect and cool the constant temperature cold storage, that is, prepare before storage. Check all kinds of supporting facilities in the cold storage about 1 week before storing cherries. Such as the operation of the unit, whether the control system is normal, after the inspection, it is the disinfection work of the cold storage, and the various facilities in the cold storage are strictly and systematically disinfected. Attention should be paid to protect the metallic parts in the warehouse during disinfection, and spray them with 2% ~ 3% Antwermin aqueous solution. There are two disinfection methods for cold storage.

sulfur fumigation

this method uses smoke from sulfur combustion to fumigate the cold storage. No open flame is allowed during operation. When smoked with sulfur smoke, the refrigerator door will be closed for about 1 day. Then, ventilation will be conducted to release residual gas, so that there is no peculiar smell in the warehouse.

liquid medicine spraying

spray all the facilities in the whole cold storage with 1% ~ 2% formalin, 84 disinfectant, bleaching powder and other liquids with a sprayer. After disinfection, all supporting facilities in the warehouse must be dried to avoid affecting the storage quality.

after the whole cold storage is disinfected, the empty storage should be cooled about 2 days before storage, and the whole storage should be cooled thoroughly. The precooling temperature of the empty warehouse is -2℃.

② storage management of cherries. The harvested cherries will be put into the pre-cooling room in time. If there is no pre-cooling condition, they can be directly put into the constant-temperature cold room at-1 ~ ℃ and put into storage by stages, with each storage capacity being 1/1 of the total storage capacity. After the cherries were put into storage, the staff put on cotton-padded clothes to classify the cherries in the cold storage, and picked out the pests and rotten fruits. The cherries are classified according to the requirement of uniform fruit. Strictly eliminate the fruits that are not suitable for storage, such as diseased fruits, damaged fruits, overripe fruits, sessile fruits and deformed fruits. After finishing the above work, it is also very important to bag and package the cherries to be stored immediately, and choose suitable fresh-keeping bags and fresh-keeping chemicals for the storage of cherries. Through experiments, the general fresh-keeping bag for storing cherries should be .3 ~ .5 mm PVC special fresh-keeping bag for cherries, and the effect is ideal when the weight of cherries in each bag is 1 kg. After bagging, tie the bag mouth tightly with a rope, put it into a plastic turnover box and stack it into different types according to the categories or put it on the shelf in turn. The reservoir temperature is stable at-1 ~ ℃. Special attention should be paid to the long-term storage and preservation of cherries. Never put them in paper boxes for long-term preservation. Before leaving the warehouse, they can be sold in boxes or boxes.

during the storage of cherries, the stable storage temperature has a great influence on the storage quality and storage time of cherries. Stable and suitable low temperature can effectively ensure the storage quality. First of all, inhibit the growth of respiration and bacteria, reduce the metabolic rate and delay aging. Secondly, the storage temperature is stable, and the fluctuation of the product temperature is not very large. Generally, the storage temperature is not more than 2℃, and the fluctuation of the product temperature is not more than 1℃. If the storage temperature fluctuates greatly and frequently, the bag will frost, and the rot rate of cherries will increase during storage, which will affect the storage quality and time.

the humidity in the warehouse should be controlled between 85% and 9%.

(3) Modified atmosphere storage

Modified atmosphere storage is a kind of storage method based on cold storage. This storage and preservation method not only requires strict temperature, but also requires strict gas. It uses gas components with high carbon dioxide and low oxygen to store. That is, the controlled atmosphere storage room is carried out under the dual control of high carbon dioxide, low oxygen and temperature. The storage quality and time of cherries are better than those in cold storage, but modified atmosphere storage of cherries also has some limitations. First of all, from the economic point of view, it is more expensive than the constant temperature cold storage, and it is more complicated to build. Secondly, because the controlled atmosphere storage is greatly limited by gas composition, considering the quality and time of cherry storage, it requires stable delivery and large quantity. During storage, the gas ratio can only be adjusted after the whole storage is full, that is, the proportion of oxygen and carbon dioxide (oxygen: 3% ~ 5%, carbon dioxide: 1% ~ 25%) can not be adjusted casually during the whole storage period. If the proportion of gas components is slightly out of balance, the rot rate of cherries will be greatly increased, and the storage life will be greatly affected, so the constant temperature cold storage is relatively simple.

When using modified atmosphere storage to store cherries, special attention should be paid to using small modified atmosphere storage to store some excellent cherries with good quality.

The methods of storing cherries in controlled atmosphere storage are the same as those in constant temperature cold storage, including grading and classification. The only difference is that the last step of cherry storage in controlled atmosphere storage is the adjustment of gas composition. Adjust the gas in the warehouse to 3% ~ 5% oxygen and 1% ~ 25% carbon dioxide. Special attention should be paid to the concentration of carbon dioxide should not be higher than 25%, so as not to cause carbon dioxide poisoning and odor.

(4) Reduced pressure modified atmosphere storage method

Reduced pressure modified atmosphere storage is negative pressure modified atmosphere storage. Compared with modified atmosphere storage, the storage quality and time are better and longer.

Modified atmosphere preservation is based on the ratio of low oxygen and high carbon dioxide in the mixed gas relative to the air, which limits the life activities of fresh products and pathogenic microorganisms. Negative pressure preservation is based on the reduction of the absolute content of each component in the air, the limited supply of oxygen which plays a major role in preservation and the continuous elimination of harmful gases. Negative pressure controlled atmosphere preservation is to complement the two methods of air conditioning and negative pressure and synthesize the two effects. That is, according to the method of modified atmosphere preservation, the gas components (mainly nitrogen, oxygen and carbon dioxide) in the sealed warehouse are maintained within the required range, and then the air pressure in the sealed warehouse is maintained at a certain negative pressure state through a special device.

The storage of cherry fruits in reduced-pressure controlled atmosphere storage is to put the cherry fruits after selection, classification, sorting and bagging into the reduced-pressure controlled atmosphere storage, and adjust the ratio of nitrogen, oxygen and carbon dioxide to make the gas in the storage in a negative pressure state. Keep the fresh quality of cherry fruit.

this method is troublesome to operate, and the technology of reduced pressure modified atmosphere preservation is still in the experimental stage, so it is not commonly used.

To sum up, we should pay special attention to the following points when storing cherries: ① Choose cherries with good quality and strictly grade and classify them. (2) precooling and preservation in time, controlling suitable low temperature, delaying aging and preventing decay. ③ Suitable low temperature (-1 ~ ℃) and suitable humidity (85% ~ 9%). (4) Uniform and stable storage temperature, suitable fresh-keeping bags and small packages and moisturizing devices should be selected to prevent cherry from wilting due to dehydration, reduce dry consumption, and inhibit dead stems and browning. ⑤ Modified atmosphere storage with low oxygen (3% ~ 5%) and high carbon dioxide (1% ~ 25%). ⑥ Regularly check the storage of cherries in the warehouse. ⑦ Put them into storage by stages, and put them out of storage by stages. Outbound sales should first sell short-term storage, then medium-term storage, and then long-term storage.