Storage Systems: Controlled and Modified Atmosphere Storage

The storage life of a crop plays an important role in the financial support it will provide to the farmer. In earlier times, the storage system was an issue in managing the crop storage life. Nowadays, practices like controlling and modifying the temperature of the storage systems are helping agriculture by increasing the storage life significantly. This article will deal with the concept of storage systems, their types, and the advantages of modified and controlled atmosphere storage.

Define Storage Systems

Storage systems can be defined as storing crops in their final stages after harvesting. It ensures that the crop is kept under maintenance to guarantee food security and safety. Apart from storage in the post-harvest phase, storage also offers great help in maintaining the proper balance in demand and supplies in the market. This eventually results in stabilising the market prices of agricultural products.

Types of storage systems

Storage systems are generally categorised into two divisions:

• Modified Atmosphere Storage 

• Controlled Atmosphere Storage

Now that you have understood the concept and function of storage systems. Let’s move on to the detailed discussion on modified and controlled atmosphere storage and its features.

Introduction to Controlled Atmosphere Storage 

Controlled storage can be defined as the process of constant monitoring and adjustments in the oxygen and carbon dioxide levels in air-tight containers and storage. Controlled atmosphere storage is a vital innovation that helps in reducing the adverse effects of storage on the shelf life of vegetables and fruits. This is done by controlling the gas composition in the storage facilities that eventually control the storage life.

Controlled atmosphere storage consists of reducing the oxygen and increasing the carbon dioxide levels according to the ambient atmospheric conditions. However, sometimes it also deals with removing ethylene and adding carbon monoxide.

Controlled atmospheric storage refers to the continuous monitoring and adjustments in the gases of the storage containers accordingly.

Whereas the modified atmospheric storage does not deal with the active control of gas, it only deals with the packaged atmosphere created by the respiration in the freshly produced items.

Various processed fruits and veggies are stored in modified atmosphere packages to control aging and increase the shelf life. In the early twentieth century, Kidd and West developed the technology to control and monitor the atmospheric system.

The world has seen the global use of this technology in the short and long term to manage and meet market demands.  

Introduction to Modified Atmosphere Storage 

Modified atmosphere storage refers to modifying atmospheric conditions, generally temperature and humidity, to enhance the storage life of several perishable crops like atemoya.

The storage system is crucial for any crop as it controls the life cycle of the yield, and an improper temperature and storage environment can result in damaged stored crops.

Modifying the atmosphere, packing the fruits in PVC film, and storing the fruit in polyester trays wrapped in PVC film do not influence the fruit’s skin colour. However, it significantly reduces weight loss compared to a non-packet fruit and preserves the pulp brightness. Various studies and research has been done on comparison of the weight loss in the packet fruit and unpacked fruit, and they show a significant lowering in weight loss of the packet fruit.

Fruits sealed in LDPE remain raw and do not ripen as the packing develops an injurious atmosphere inside.

Research shows that atemoya fruit, when packaged in PD-955 film and stored in storage at 15 degrees, offers a shelf life of 17 days which is far better than the 13 days shelf life of control fruit. 

Effects of Modified Oxygen and Carbon-dioxide Levels on Crops

• Modified O2 levels 
• Reduced rate of respiration
• Less oxidation of the substrate 
• Delay in the ripening of climacteric fruit 
• Reduced ethylene production rate
• Development of several physiological disorders 

Modified CO2 Levels

• Reduced distortion 
• Reduced fungal growth
• Often results in the production of off-flavours
• Inhibits some enzymatic reactions

Conclusion

Agriculture is vital to meet the demands and supply of food items like fruits and vegetables. Techniques like modified atmospheric storage systems and controlled atmospheric storage systems offer a greater shelf life to freshly grown products. This article discussed the concept of modification and controlling of atmospheric storage and their advantages and concepts of continuous monitoring and controlling.