How long can a cold storage preserve vegetables and fruits? As is well-known, the installation of quick-freezing and refrigerated cold storage is primarily for storing fresh produce like vegetables and fruits. Due to the variety of stored items, the temperature inside the preservation room also varies, as does the required humidity. The shelf life also differs accordingly. The editor will share with you the preservation time for different types of vegetables and fruits.
Fruits:
Pomelos have a storage duration of 3-12 months in a food refrigerated cold storage at temperatures between 0-10 degrees Celsius and humidity levels of 85-90%.
2. Oranges have a storage period of 8-10 weeks when stored at 0-1.2°C with humidity ranging from 85-90%.
3. Apples can be stored for 2-7 months when the relative humidity is between 85-90% and the temperature is -1 to +1 degrees.
4. Pears can be stored for 1-6 months at a temperature of +1.5 to -0.5 degrees Celsius and a relative humidity of 85-90%.
Section 1: Vegetables
Potatoes can be stored at +2 to +4°C with humidity between 85-90%, and they can last for about 90 days.
2. Fresh storage temperatures for vegetables like beans, cucumbers, and tomatoes are +7 to +13°C, with humidity between 85-95%; shelf life is approximately 60 days.
3. Cabbage and green garlic, among other vegetables, are best stored at temperatures between -1 to +1°C, with a relative humidity of 90-95%, and have a storage period of 30-90 days.
Fruit and Vegetable Cold Storage
1. Refrigerated warehouse envelope structure
The cooling capacity of the cold storage is proportional to the unit heat flux of the insulation structure of the refrigerated warehouse. Therefore, efforts should be focused on reducing the unit heat flux of the insulation structure. To lower the unit heat flux of the insulation structure, one must ensure that the thermal conductivity of the insulation material is low and the insulation layers are thick. However, the thickness should not be excessive, as it may increase construction costs and waste space. Therefore, it is important to select insulation materials within an appropriate thickness range. Generally, the requirements include low thermal conductivity, low water absorption, good low-temperature performance, and reasonable costs.
Common cold storage thermal insulation materials include rice hulls, foam plastics, and polyurethane rigid foam plastics. Rice hulls are convenient to source, but have low thermal resistance. They are prone to moisture absorption, require a large amount of material, and the construction is labor-intensive, making the actual cost relatively high. There are many foam plastic manufacturers, making it easy to purchase. Foam plastics have higher thermal resistance and moderate prices, with convenient construction and installation. Polyurethane rigid foam plastics offer high thermal resistance and good insulation properties, but are more expensive.
2. Methods to Eliminate Odors in Cold Storage
(1) Causes of odor in cold storage
Offensive odors refer to the abnormal smell that develops in cold storage due to physical and chemical changes in cooking ingredients and food, influenced by external factors over time. This smell eventually adheres to the walls, ceiling, and equipment and tools within the cold storage. There are several reasons why offensive odors may arise in cold storage: The cold storage already has an offensive odor before any food is introduced. The food has already started to spoil before entering the cold storage, such as rotten eggs, meat, or fish. Cold storage used for fish, refrigeration plants, and storage of meat, eggs, or fruits and vegetables without prior cleaning leads to odor contamination. Poor ventilation in the cold storage, with excessive temperature and humidity, fosters the growth of mold, resulting in a musty smell. Leaks in the refrigeration pipes allow refrigerants (ammonia) to contaminate the food, causing the offensive odor. Failure to lower the temperature in the cold storage leads to meat spoilage and decay, producing a rancid smell, often occurring when fresh meat is not properly frozen or thawed before storage. Different-smelling foods stored in the same cold storage room can cause cross-contamination and flavor transfer.
