Introduction to Modified Atmosphere Freshness Storage
Modified atmosphere storage and preservation is a modern preservation technology developed on the basis of traditional refrigeration preservation, and is considered to be a storage method for water in the world today
The most effective storage method for fruits. Commercial controlled atmosphere storage has a history of over 80 years in foreign countries, and various products from developed countries, especially apples
The long-term storage of fruits and vegetables such as pears, kiwis, citrus fruits, grapes, and jujubes mostly uses controlled atmosphere storage for preservation. In normal air, it generally contains oxygen
Gas 21%, carbon dioxide 0.03%, the rest is nitrogen and some trace gases. Fruits are living organisms that undergo internal processes before and after harvesting
Metabolic activity dominated by respiration. The characteristics of aerobic respiration after fruit harvesting are: breaking down sugars stored in fruit tissue cells
Carbohydrates such as fruit acids produce carbon dioxide, water vapor, heat, and some aromatic compounds, which consume the fruit body during this process.
The stronger the respiratory function, the faster the consumption, the earlier the ripening period comes, and the shorter the storage time. Oxygen, carbon dioxide, and temperature affect respiratory intensity.
The oxygen content in the storage space is high, the respiratory intensity is high, and vice versa is low. High carbon dioxide gas content in storage space can inhibit respiration and delay
Pectin substances decompose and chlorophyll degrades, and can inhibit microorganisms. The temperature in the storage space decreases, resulting in a decrease in respiratory intensity, and vice versa, an increase.
In addition, a certain concentration of low oxygen and high carbon dioxide in the environment has the effect of inhibiting the growth and expansion of fungal diseases.
The basic principle of controlled atmosphere preservation technology is:
On the basis of sealed storage and refrigeration, air conditioning parameters are set according to the physiological characteristics of different fruits. Through specialized testing and control equipment, the oxygen concentration in the storage space is manually reduced and the carbon dioxide gas concentration is increased to the set air conditioning parameters, and this parameter is accurately maintained throughout the storage period, thereby inhibiting the respiration of fruits and keeping them in a normal and low consumption metabolic state, achieving the purpose of fruit preservation.
Advantages of Modified Atmosphere Storage：
1- The preservation effect is good. After long-term storage, most fruits such as mid to late maturing apples and pears still have bright colors, green stems, pure flavors, and full appearances, which are almost the same as when they were first harvested. Taking apples as an example, after controlled atmosphere storage, the hardness and titratable acidity of the fruit flesh are significantly higher than those of fruits refrigerated at the same time.
2- Long storage time controlled atmosphere storage combines the techniques of low temperature (refrigeration) and regulating the gas composition of the storage environment, greatly inhibiting the respiration of fruits, delaying the rate of fruit metabolism, and extending the storage period of fruits to a large extent.
3-. Low storage loss. Modified atmosphere storage, especially in controlled atmosphere warehouses, strictly controls the temperature, humidity, and gas components such as oxygen and carbon dioxide inside the warehouse, effectively suppressing the respiration, transpiration, and microbial hazards of fruits. During storage, losses caused by water loss, decay, and other factors are greatly reduced.
4- After a long shelf life and controlled atmosphere storage, fruits that have been exposed to low oxygen and high carbon dioxide for a long time still have a long period of "lag effect" after being released from the controlled atmosphere state. According to experiments conducted on apples in Shaanxi, it is generally believed that the shelf life of modified atmosphere storage is 2-3 times longer than that of regular refrigeration, while maintaining the same quality. In addition, under the same storage time conditions, fruits stored under controlled atmosphere have a longer "lifespan" after being released from storage than those stored under refrigeration, making it easier for fruits to be transported and exported over long distances.
Green "storage during fruit controlled atmosphere storage can effectively inhibit the occurrence of infectious diseases due to the interaction of low temperature, low oxygen, and relatively high carbon dioxide. Chemical preservatives are not required during storage.
