Temperature and humidity
In general, the following conditions are used for long-term storage.
| Product | Storage Temperature ˚C | Storage Humidity Relative % | Max CO₂ – Levels Parts Per Million (PPM) |
|---|---|---|---|
| Carrots | 0-1 C | 95-98% | < 10.000 ppm |
| Onions | 1-2 C | 65-75% | < 10.000 ppm |
| Cabbage | 0-1 C | 90-95% | < 10.000 ppm |
| Red beets | 3-4 C | 85-90% | < 10.000 ppm |
| Consumption potatoes | 4-6 C | 92% | 7.000 ppm |
| French fries | 5-8 C | 92% | 3.000 ppm |
| Chips potatoes | 7-12 C | 92% | 2.750 ppm |
| Seed potatoes | 2-4 C | 85% | 5.000 ppm |
Potatoes
In storing potatoes, the period of storage consists of five specific steps which have to be taken
- Drying
- Wound healing
- Cooling
- Conditioning
- Warming to desired processing temperature
Additional important information
- It is very important that the product that comes into the storage is healthy. Bad product cannot be stored
- Preventing damages during harvest and transport will repay itself during storage
- Take care that product is not coming in either too hot or too cold
- For a healthy batch of potatoes the product is to be stored with some soil which is evenly spread through the batch. This is a moisture buffer
Onions
The storage period of onions consist of 4 steps:
- Drying
- Cooling
- Storage
- Warming to desired processing temperature without condensation
For long term storage of onions it is needed to dry the onions in a correct way, so that the neck is completely closed. The way of drying depends on climate and harvest conditions.
Carrots
Healthy carrots must be cooled upon arrival in the storage to a wound healing temperature of approximately 10 to 12 °C. after a period of three days the product can be gradually cooled to a desired temperature of approximately 0 – 1 °C. Unhealthy product must be cooled as quickly as possible to the desires storage temperature to prevent mold and bacteria diseases. In the storage facility it is vital to have proper air circulation to prevent differences in product temperature. During storage respiration of the product continues which emits CO₂. With a CO₂ percentage of over 3% visible damage may occur.