How to use cold storage for preservation of fresh fruits and vegetables?
With the continuous development of market economy, fruit, vegetable and other agricultural products have an increasing need of cold storage preservation in production, transportation, sales and storage process. If the operation of the cold storage preservation is not in right place, it will certainly affect the fruit and vegetable preservation, so that fruits and vegetables may be deteriorated during storage, affecting the seller's benefits.
The following is the operation steps of cold storage preservation for fruits and vegetables:
First of all, you must have a qualified, well-designed cold storage (adding air conditioning equipment to the ordinary cold storage can improve the preservation effect). Before operation, a thorough cleaning and sterilization is needed. The dust, garbage, stains, sewage, dirt on the surface of equipment are need to be removed, and then use sodium hypochlorite solution or ozone for sterilization. The final requirements of the cold storage (including the house and equipment) is that there is no garbage, no mold, no smell, no dirt, no pests. Cold storage should also be ventilated, the air inside to be fresh.
Fresh fruits and vegetables need properly pretreatment. Fruits and vegetables have more heat after harvest, before we put them to storage, we should use cold water or cool air blower to cool them down. Fruits and vegetables need to be selected, those sick and damaged ones need to be removed. Fruits and vegetables are cleaned, it is best to remove the leaves (foliage will be with insect eggs and dirt).
Well-cleaned fruits and vegetables, according to the requirement of transportation, need to be put into net bags, bamboo baskets, cartons, wooden boxes or other containers with proper ventilation. After packing into the cold storage stacking, we should remember to leave some gaps, so that cold air may get in touch with the goods, speeding up the cooling of fruits and vegetables.
Before packing, if fruits and vegetables are vacuum sealed by impermeable plastic film, drying loss can be avoided in the storage so as to the decline of quality; if fruits and vegetables are not packed, then pay attention to the humidity, which will be described in detail below.
The temperature inside cold storage need to be adjusted, fruits and vegetables need a temperature of zero degrees or a bit above zero degrees, the specific temperature depends on the kind, origin, harvest season and maturity level. During storage, the relative humidity of the cold storage need to be controlled. As the fruits and vegetables will lose water during the preservation, which may cause shrink, so we need vacuum packaging or control the humidity around 80% to 90%. The humidification of the cold storage can be done by manually sprinkling water or using a humidifier.
Fruits and vegetables will also release carbon dioxide, ethylene and other detrimental gas which are bad for the preservation, so regular ventilation is needed. The best time for ventilation is at night when the temperature difference is smaller. Or we may use air cleaners, deaerator, nitrogen generator, carbon dioxide adsorber, ethylene adsorber and other air conditioning equipment to remove harmful gas, manufacturing the beneficial gas.
While the delivery of the fruits and vegetables, due to the temperature difference, there will be dew on the surface of fruits and vegetables, which may affect the quality of fruits and vegetables. In order to avoid this situation, fruits and vegetables can be moved into the heating room first, and slowly raise the temperature inside the room, so that the temperature of fruits and vegetables slowly rise to the outdoor temperature.