The primary gasses used in controlled atmosphere storage are oxygen, carbon dioxide, and nitrogen.
Controlled atmosphere (CA) storage is a technique used in agriculture to extend the shelf life of stored products, such as fresh fruits, vegetables, and dry commodities. It involves regulating the concentrations of several atmospheric gasses within a storage room, alongside controlling temperature and humidity. This creates an environment that slows down the natural ripening and decay processes.
Here's a breakdown of the roles of these gasses:
- Oxygen (O2): The concentration of oxygen is reduced below normal atmospheric levels. Lowering oxygen levels slows down respiration, which is a major factor in the ripening and aging of produce.
- Carbon Dioxide (CO2): The concentration of carbon dioxide is increased above normal atmospheric levels. Elevated carbon dioxide levels further suppress respiration and inhibit the growth of spoilage microorganisms.
- Nitrogen (N2): Nitrogen is an inert gas, and it is used to displace oxygen in the storage environment. By increasing the nitrogen concentration, the oxygen level can be lowered without introducing other reactive gasses.
The precise concentrations of these gasses are carefully controlled based on the specific needs of the product being stored. For instance, some fruits and vegetables tolerate higher CO2 levels than others. Therefore, specific combinations of these gasses create the most optimal environment for particular commodities.
In summary, controlled atmosphere storage involves carefully balancing the levels of oxygen, carbon dioxide, and nitrogen to help maintain the quality of stored agricultural products.
