The object of temperature management is to control the respiration rate of the crop. Fresh produce (harvested crops) continue to breath, taking in oxygen and giving off carbon dioxide, water and heat. These components are the result of breakdown and oxidation of the organic components in the composition of the plant. They are the food reserves of the plant, and include sugars, fats, and proteins, the same constituents that the consumer seeks in consuming the crop.

One of the most important functions of refrigeration is to control the crop's respiration rate. The loss of the stored food reserves of the plant through respiration means decreased food value, loss of flavor, loss of salable weight, and more rapid deterioration. The ability of the producer to ship crops to distant markets is directly tied to the respiration rate of the crop. The greater the rate of respiration, the shorter will be the shelf-life.

Different crops have different respiration rates. The greater the rate of respiration, the more important it is to reduce the temperature of the crop to the lowest temperature it can hold without incurring damage.

Another important factor for many crops is the production or presence of ethylene gas. Ethylene is a small organic molecule (C2H4). It is also an important plant hormone, involved in the maturation and senescence (decay) of most fresh crops. Some crops are low producers of ethylene, but may be highly sensitive to it, while others may produce large quantities but not be too sensitive. No matter which situation may exist it is best if ethylene concentrations are controlled. This is possible with the use of ethylene absorbing or destruction apparatus, and also with temperature management.

Proper post-harvest pre-cooling can:
●　Suppress enzymatic degradation and respiratory activity (softening)
●　Maintain crop weight by slowing or inhibiting water loss which will result in wilting a
　　shriveling
●　Slow or inhibit the growth of decay-producing microorganisms (molds and bacteria)
●　Reduce production of ethylene (a ripening agent) or reduce the rate of the product's reaction
　    to ethylene

THERE ARE NO SHORTCUTS TO PROPER POST-HARVEST PRE-COOLING!

IT IS AN ESSENTIAL STEP IN PRESERVING NUTRITION AND QUALITY …
AND ECONOMIC VALUE!