Storage in this way using a container / container composition of the air (nitrogen gas, carbon dioxide, and oxygen) are arranged so that can increase the shelf life of agricultural commodities. The way it works is gas unused / exaggeration in the container is reduced. Containers can be filled with gas N2, O2, and CO2 as needed. Replacement of gas causes the gas composition in the container be below 8% O2, CO2 more than 2%, and 90% N2.
This is in contrast to the free air composition comprising 78.03% N2, O2 20.99%, and 0.09% CO2. The air humidity is maintained around 85% so that the metabolic activity of the vegetables will be reduced and the damage can be inhibited. Santoso (2006) revealed that agricultural produce after harvest still continues to carry out respiration and metabolism, so it is considered still alive. During the process of respiration takes oxygen contained in the surrounding environment.
Results metabolic process of respiration in the form of CO2 and water as well as ethylene. The content of oxygen, carbon dioxide and ethylene, each influencing the metabolism of commodities. Based on the theory it is known that the composition of the air in the storage room has a great influence on the properties of the fresh ingredients are stored. The air composition normally consists of O2 (20%), CO2 (of 0.03%), N2 (78.8%). By modifying atmosphere around commodities can generate some gains against the commodity.
Modification of the air composition is done by reducing or increasing the oxygen and carbon dioxide (CO2). Sometimes they are also necessary to prevent the ethylene gas produced does not accumulate in the air space. In general, the air is depleting oxygen content and increasing carbon dioxide will lead to reduction in the rate of respiratory activity of the fresh commodity.
Ethylene is a plant hormone, which with very small doses can be a big influence on the stages of metabolism, including the initial process of maturation, wilting and maturity as well as the process of formation of phenolic compounds. Ethylene gas accumulated in the storage space will result carrots a bitter taste due to the accumulation of substances as phenol, so too can cause asparagus to be hard, since ethylene stimulates the process of making lignin.
Ethylene (C2H4) can lead to a hardening of sweet potato or decay inside. Modification of the composition of air, also known as an example of the storage atmosphere serves to determine or set the system noymonal by ethylenene. Sinthesis ethylene sufficient to stimulate the maturation process will not occur when oxygen levels below 7% (Mapson and Robinson, 1966). Commodity sensitivity to ethylene also be lower at low oxygen concentrations.
Before ethylene can affect something commodities should be bound oxygen molecules or react to the part where ethylene is attached. When the high oxygen content of 3%, the bound ethylene fell as much as 50% (Burg and Burg 1967). Carbon dioxide (CO2) does not directly affect sinthesis ethylene, but rather antogonistis to ethylene. CO2 is structurally analogous to the ethylene thus competing against places that should be occupied by ethylene.