A well-designed storage facility enables the user to dry, cool, and store the product by creating the optimal temperature, humidity and CO₂ levels. By creating the optimal storage conditions disease and sprouting is prevented, and the product quality is maintained.
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|
|Table potatoes||4-6 °C||92%||7000 ppm|
|Chips potatoes||7-12 °C||92%||2750 ppm|
|French fires potatoes||5-8 °C||92%||3000 ppm|
|Seed potatoes||2-4 °C||85%||5000 ppm|
In storing potatoes, the period of storage consists of five specific steps which have to be taken
- Wound healing
- Warming to desired processing temperature
The storage period of onions consist of 4 steps:
- Warming to desired processing temperature without condensation
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.