Potatoes are important vegetable crops in our life. The harvested fresh potatoes can also be kept fresh in the cold storage room, it can be stored as long as 8 months in the cold room.
Potato cold storage preservation technology mainly includes three points: potato harvesting, cold storage room period and delivery management.
I Potato harvesting
1,The potato harvest time is selected on a sunny day. Watering should be stopped 7-10 days before harvest, which can promote the aging of potato skins and reduce the moisture content in the tubers.
At this time, the land is dry, and the potato pieces that are excavated are less muddy, and part of the water is distributed, making the skins dry and conducive to storage.
2, After the potatoes are harvested, the next step is to grade the potatoes to eliminate the potatoes with diseases and insect pests.
We will choose good quality potatoes that are moderate in size (usually medium), harmless, and disease-free for storage.
II Potatoes pre-cooling
After the potatoes are graded, they are pre-cooled. There are three pre-cooling methods: natural pre-cooling, cold storage pre-cooling, vacuum pre-cooling.
The pre-cooling time of the cold storage room is not more than 48 hours, and the pre-cooling is stopped when the temperature reaches five degrees higher than the storage room temperature. The pre-cooling time is scheduled within 12 hours after harvest.
III Potato cold storage room
Temperature cooling down in advance is to help the potatoes better adapt to the low temperature environment of the cold storage. Generally, they are turned on and cooled 3 to 5 days before the potatos put in, and the temperature is controlled at about 1 to 4°C.
(1) Cold storage room temperature
AC potato cold storage room temperature is 3℃~5℃.
The room temperature is required to reach the specified storage temperature within 48 hours. The storage room temperature is required to be stable during the entire storage period, and the fluctuation does not exceed ±1℃.
(2) Relative humidity
The relative humidity of the potato cold storage room is kept at 80%～90%.
If the humidity is higher than this, the potatos are easy to rot and germinate early; if the degree is too low, the potatoss are easy to lose water, lose weight, become soft and shrink, and lose their edible and seed value.
(3) Gas management of potato controlled atmosphere storage room
It is recommended to be controlled as: oxygen concentration 3%~5%, carbon dioxide concentration 2%~3%.
The respiration of potatoes is still going on after harvesting. Potatoes with too low oxygen content will be hypoxic. In some cases, they will lose their germination ability, and in severe cases, they will cause suffocating rot.
The appropriate concentration of carbon dioxide concentration can also slow down the respiration of fresh potatoes, and can effectively delay the initiation of the respiratory jump.
But the carbon dioxide concentration can not be too high, too high carbon dioxide will cause potatoes to be forced to undergo “anaerobic respiration”.
refers to the process in which the respiratory substrate of potatoes cannot be completely oxidized under hypoxic conditions to produce alcohol, aldehyde, lactic acid and other products, and at the same time release a small amount of energy. The reaction equation is as follows:
Anaerobic respiration is not good for potato storage, it will consume more nutrients stored in potatoes and accelerate the aging of fruits and vegetables.
In addition to controlling the carbon dioxide and oxygen components, the cold room also controls the concentration of ethylene. Ethylene can quickly increase the respiratory intensity of potatoes and accelerate the ripening of potatoes. The ethylene removal machine of the air conditioning warehouse can control and reduce the concentration of ethylene.
IV Potatos taken out from cold storage room
1, The taken out potatoes should be warmed up slowly to prevent the dew and deterioration of the potatoes caused by the excessive temperature difference;
2, Pay attention to the handling process: handle, put, and move gently to avoid mechanical damage;
3,Cold chain transportation should be implemented for medium and long-distance transportation, and room temperature transportation can be selected for medium- and short-distance transportation.