In order to keep fruitage as long as possible without losing its nutritional properties and appearance, it is essential to create special conditions for reducing the fruit respiration intensity. For this purpose special controlled atmosphere fruit storage facilities are created: due to reduced concentration of oxygen, natural decomposition of fruit tissues slows down, which allows for preservation of the fruit flavor characteristics. 

Storage of apples in controlled atmosphere (CA) 

CA technology implicates the storage of apples in an environment with specific concentration of oxygen and carbon dioxide (СО2). In normal air the concentration of nitrogen amounts to 78%, oxygen to 21% and СО2 to 0.03%

The following technologies are applied to create the required gaseous atmosphere:

• ILOS (Initial Low Oxygen Stress) – superfast reduction of oxygen content in a chamber within a short span of time.

• RCA (Rapid Controlled Atmosphere) – rapid reduction of oxygen concentration technology.

• CO2 shock treatment – shock treatment technology whereby СО₂ concentration is increased up to 30%.

• LECA (Low Ethylene Controlled Atmosphere) – reduction of ethylene content in a chamber technology.

• DCA (Dynamic Controlled Atmosphere) – dynamic controlled atmosphere.

Taking into account specific features of the kind of apples, you intend to store, the humidity in the chamber is set to 90% and the temperature - to -2...-7 °С. The key point: natural air in the storage room must be replaced with a different atmosphere, in which oxygen content amounts to only 5%, while all the rest is mainly carbon dioxide and nitrogen. This is done in order to slow down the apple after-ripening process and extend their storage life. 

Controlled atmosphere is maintained with the help of special equipment: 

• Nitrogen generator. Nitrogen generator is designed for producing gaseous nitrogen. It operates on the basis of adsorption technology. The process is fully automatic and does not require any additional attendance. 

• Carbon dioxide scrubber. This equipment is in charge of maintaining the level of carbon dioxide, released in the course of fruit respiration. The scrubber includes a tank with adsorbing agent, used to reduce CO2 concentration in the air. 

• Ethylene converters, which reduce ethylene concentration in the chamber.

• Automatic control system. This system is designed to simplify the equipment control procedure: you only need to set the required parameters, and the system will take care of their stability. The automatic control system includes a gas concentration analyzer and a software for nitrogen generator and scrubber control; apart from that, there is a possibility of remote control and data monitoring for maximum process management.

• Sealed doors. Air-tightness is not the least of the factors, ensuring preservation of controlled indoor climate and complete gas-tightness.

Why CA?

• Controlled atmosphere allows for removing of volatile organic compounds (VOC) from the air, such as ethylene, which intensifies the ripening process and consequently accelerates spoilage of the product. 

• Controlled atmosphere inhibits biochemical reactions, nearly stops them and reduces the fruit respiration intensity. This allows for long-term preservation of the product quality: color, taste, texture, nutrients, juiciness, etc. Besides, in controlled atmosphere you save the crop with the least losses.

• The indoor air is cleaned of bacteria, harmful microorganisms and fine dust.  

As a result of all these efforts, the shelf life of the product increases, while its nutritional properties and marketable appearance are preserved.