Storage and Fresh-keeping Technology of Chili Treated with "1-MCP" Preservative

"1-MCP" fruit and vegetable preservative is to absorb and fix the active 1-MCP gas that inhibits the production of ethylene in the carrier. When using it, dissolve the preservative in water according to the type of horticultural product being treated and the volume of the closed container. The gas is released and comes into play. Therefore, 1-MCP preservatives can be used to preserve chili peppers in cold storage, air-conditioned warehouses, simple warehouses, earthen caves or well sealed plastic tents that can be sealed.

The key points of chili storage and preservation:

1. Temperature: Pepper fruits are very sensitive to low temperature. When the temperature is lower than 9℃, they are susceptible to cold damage. When the temperature is higher than 13℃, they will age and rot. The storage temperature is 9℃-12℃. Generally, the suitable storage temperature for hot peppers in summer is 10℃–12℃, and the cold damage temperature is 9℃; in autumn, the storage temperature is 9℃–11℃, and the cold damage temperature is 8℃. The use of dual temperature (two-stage temperature) storage will greatly extend the storage period of pepper.

2. Humidity: The appropriate relative humidity for pepper storage is 90%–95%. Peppers are extremely susceptible to dehydration. If the humidity is too low, the fruits will dehydrate and wilt. The use of plastic sealed packaging bags can prevent water loss. But on the other hand, peppers are very sensitive to moisture. If the humidity in the sealed packaging is too high, condensation will occur, which will accelerate the activity of pathogens and the development of diseases. Therefore, it is necessary to pre-cool thoroughly before bagging to keep the humidity stable. The use of non-drip film and a film with high moisture permeability, plus a humidity control film, can control condensation and excessive humidity.

3. Time: when treated with the preservative 1-MCP, the processing effect is generally best after the pepper is harvested in time, preferably not more than three days, so as not to affect the treatment and preservation effect.
Treatment time: The length of time for processing peppers with 1-MCP should be determined according to the temperature and the facilities that store the peppers (such as whether to use a plastic large account or a cold storage, and how to seal the conditions). Generally, it is suitable to treat for 8-12 hours at 20℃. As the temperature decreases, the time is appropriately increased, and the temperature increase shortens the time.

4. Concentration of use: Generally, 1g of 1-MCP can handle peppers with a space volume of 15m³.

5. Treatment method: "1-MCP" preservative is a solid powder, the active ingredient is 1-methylcyclopropene (1-MCP) gas, and the use concentration is low, so the treatment place must be an enclosed space. The specific operation is as follows: ① Calculate the volume (M³) of the treatment site. ② Calculate the most suitable dosage of medicine according to the volume of the body, airtightness, ambient temperature, and scheduled processing time. ③ Pour the medicine into the cup, then add a certain amount of solution, and quickly seal the door for fumigation. ④ After the fumigation is finished, open the scavenge port for ventilation.

6. Storage management

(1) Temperature, humidity and gas control

The temperature fluctuation range in the storage should be less than ±1℃. If the fluctuation is too large, it may cause the pepper to lose water. Try to balance the temperature in each part of the storage. If the temperature of the peppers in the vegetable basket is higher than the storage temperature, the plastic film should be opened for ventilation. Check the pepper every 4-5 days, and find the problem and deal with it in time.
Although the humidity is too high, it can control the loss of pepper, but it will also bring about the growth of microorganisms. In general, when the outside is dry and the warehouse humidity is low, you can spray some water on the ground, and when it is rainy and the outside air is wet, you can sprinkle some dry lime in the warehouse to help absorb moisture.

(2) Antiseptic and sterilization
It should be sterilized regularly during storage, preferably every 10 days. The  fungicides are used alternately, which has a better effect and reduces the occurrence of mildew in the later period of storage.

(3) Regular ventilation
Pepper is more sensitive to carbon dioxide. During storage, it is usually changed every 10 days or so. It should be selected when the weather is sunny and the temperature difference between the outside temperature and the storage temperature is not large.

7. Other considerations:
(1) Pepper is very susceptible to dehydration and wilting.
(2) Pepper is very sensitive to moisture.
(3) Pepper is very sensitive to low temperature.
(4) Pepper is very sensitive to carbon dioxide.
(5) Chili is perishable.

Maintaining proper temperature, preventing water loss, controlling disease, and avoiding carbon dioxide damage are the key to chilli storage technology.