Cold Chain

Perishable produce deteriorates fastest when warm, so every interval spent above its ideal temperature shortens its life and can compromise safety. Because these effects accumulate and are not reversed by later cooling, the value of cold storage or refrigerated transport is lost if the product is allowed to warm up in between — for example while waiting on a loading dock or during transfer. Maintaining temperature at each handover, not just within each facility, is what makes the cold chain effective.

The chain usually begins with precooling to remove field heat quickly, because the greatest damage often occurs in the first hours after harvest. From there, cold storage, refrigerated vehicles, and chilled display each hold the temperature that precooling achieved.

Precooling

Rapid removal of field heat soon after harvest, setting the product’s temperature at the start of the chain.

Cold storage

Holding produce at its commodity-specific temperature and humidity between chain stages.

Refrigerated transport

Insulated, refrigerated vehicles and containers that maintain temperature over distance, including sea and land freight.

Chilled handling and retail

Cold rooms, chilled display, and careful transfers at wholesale and retail that keep produce cold to the point of sale.

Monitoring temperature along the chain — with sensors and data loggers — helps identify where warming occurs so that weak links can be fixed. Each commodity has its own target temperature, and chilling-sensitive crops must not be held too cold.

• Reliable refrigeration and power at every stage, which is not available everywhere.
• Careful management of transfers, where produce is most likely to warm.
• Correct, commodity-specific temperatures, avoiding chilling injury in sensitive crops.
• Temperature monitoring to detect and correct breaks in the chain.