Freshly harvested fruits and vegetables are living plant materials that are highly perishable. Their quality and consequently their storage life are reduced by the loss of moisture, decay, and physiological breakdown. It is possible to slow the deterioration process by controlling the environment to which they are exposed. Low temperature, high humidity, and modification of the surrounding gas composition are the most common techniques utilized to keep these commodities in their most usable form for consumers and processing industries.

In conjunction with low temperature and high humidity levels, controlled and modified atmosphere (CA and MA, respectively) imply the addition or removal of gases involved in the metabolism of the stored commodity. The oxygen (O₂) is generally reduced and the carbon dioxide (CO₂) level increased. The difference between CA and MA is in the way the storage atmosphere is achieved and maintained. Controlled atmosphere storage involves the active control of the gas levels, while it is done passively in MA storage.1