How to optimize produce storage with ethylene removal

Ethylene (C₂H₄) is a natural plant hormone that plays a crucial role in the ripening and aging processes of fruits and vegetables. While it is essential for the natural maturation of produce, excessive ethylene can lead to premature ripening, spoilage, and reduced shelf life. 

Effects of ethylene on plants

This article will explore how to optimize produce storage by effectively removing ethylene, using various methods and technologies.

 Understanding Ethylene Production and Sensitivity 

Different fruits and vegetables produce and respond to ethylene in varying degrees. Here is a chart that categorizes common produce based on their ethylene production and sensitivity:

 Ethylene Removal Catalysts 

Ethylene removal catalysts work by oxidizing ethylene gas into harmless byproducts, such as carbon dioxide (CO₂) and water (H₂O). These catalysts often use non-precious metals (e.g., manganese or copper) or precious metals (e.g., palladium, platinum) for efficient ethylene breakdown.

Applications:

Cold storage facilities, controlled atmosphere (CA) storage, and transportation containers.
 Particularly effective for long-term storage of ethylene-sensitive produce, such as apples, pears, and leafy greens.

Advantages:

Advantages:  High efficiency in breaking down ethylene gas.
Operates at low or ambient temperatures, reducing energy consumption.
Suitable for large-scale environments with long operational life.

 Activated Carbon Adsorption 

Activated carbon removes ethylene through physical adsorption. Its porous structure captures ethylene gas, lowering its concentration in the storage environment.

Applications:

Small-scale storage or transport, such as packaging boxes or household refrigerators.

Advantages:

Low cost and easy to use.
Does not require additional energy.

Disadvantages:

Limited adsorption capacity; frequent replacement of activated carbon is required.
Ineffective for environments with high ethylene concentrations.

 Photocatalytic Oxidation 

Using photocatalysts like titanium dioxide (TiO₂), ethylene gas is oxidized into CO₂ and H₂O under ultraviolet (UV) light exposure.

Applications:

Ideal for small cold rooms and food processing areas.

Advantages:

Environmentally friendly and avoids chemical waste.
     Requires no additional chemical materials.

Disadvantages:

Depends on UV light, resulting in higher energy consumption.
     Effectiveness may vary based on light intensity and environmental conditions.

 Potassium Permanganate Absorption 

Potassium permanganate oxidizes ethylene gas into neutral substances, such as ethylene glycol. It is typically coated onto a carrier material like silica gel and used in filters or sachets.

Applications:

Used in shipping containers, cold rooms, and commercial refrigeration units.

Advantages:

Affordable and simple to use.
Effective for removing ethylene in small-scale environments.

Disadvantages:

Requires frequent replacement of materials.
Generates waste products that need proper disposal.

 Ozone Oxidation 

Ozone, a powerful oxidizing agent, reacts with ethylene to produce CO₂ and H₂O. Ozone generators are used to maintain controlled levels of ozone in the storage area.

Applications:

Large cold storage facilities and shipping containers, especially for high-ethylene producers like bananas and apples.

Advantages:

Quick and efficient removal of ethylene gas.
Also kills bacteria and fungi, improving overall produce hygiene.

Disadvantages:

Ozone is harmful to humans at high concentrations, requiring careful monitoring.
Equipment costs and maintenance are relatively high.