Ethylene can cause fruits and vegetables to ripen, soften, or yellow too early.
Even with the right cold room temperature, produce can still lose quality. Proper ethylene control helps extend shelf life and reduce waste.
What is Ethylene Gas?
Ethylene is a natural gas produced by plants. Many fruits release it as they ripen. Apples, bananas, pears, avocados, tomatoes, and mangoes are common examples.
The gas helps control ripening, color change, softening, and aging. Some products produce very little ethylene but are highly sensitive to it. Broccoli may turn yellow faster. Kiwifruit may soften sooner.
You must consider both ethylene production and sensitivity before storing products together.
Is Ethylene Causing the Problem?
Not every storage problem is caused by ethylene. Soft fruit may already be too mature. Yellow vegetables may have been stored too warm. Decay may begin because of bruising, moisture, or disease.
Before you invest in an ethylene-control system, check the product condition first.
Look at the temperature, maturity, storage time, humidity, airflow, packaging, and signs of damage. You should also confirm that the temperature is right for the product. Cucumbers, for example, can suffer chilling injury when stored below their recommended temperature range.
The damage may only appear after they leave the cold room. Find the real cause before choosing a solution.
Safe Ethylene Level in Cold Storage
There is no single safe level for all fruits or vegetables. The correct limit depends on the product, variety, maturity, temperature, packaging, and storage period. Sensitive produce may react to levels that have little effect on other products. Exposure time also matters.
A short increase during loading is not the same as continuous exposure over several days. Record the concentration and how long it remains high.
Use product-specific guidance when setting your target. Do not treat a general figure such as 0.1 parts per million as a fixed limit for every cold room.
UC Davis also advises checking temperature, humidity, and ethylene compatibility before storing different products together.
How to Measure Ethylene
Use a sensor that can detect the low ethylene levels found in cold storage. Check its measurement range, accuracy, response time, and calibration needs. It should also work reliably at your room’s temperature and humidity.
Do not rely on one reading. Test near the return air, inside selected pallets, and around sensitive produce. You can also compare readings before and after an ethylene removal unit.
Let portable sensors adjust to the cold room before use.
How to Reduce Ethylene in a Cold Room
Start with the basic storage practices. Add special equipment only when the measured ethylene level shows a clear need.
Keep Produce at the Right Temperature
Fast cooling slows respiration and ripening. Follow the recommended temperature for each product. Measure the produce itself instead of relying only on the room controller.
The air may be cold while the center of a tightly packed pallet remains warm. Leave enough space for air to move through cartons and around the load. Keep vents clear.
Separate Incompatible Products
Store high ethylene producers away from sensitive produce when possible.
Keep ripe fruit separate from unripe fruit. Do not place damaged stock beside healthy products.
Ripening rooms should not share return air with long-term storage areas. Temperature and humidity must also match. Two products may be compatible in terms of ethylene but still require different temperatures or humidity levels.
Remove Damaged Produce
Overripe, bruised, and decaying products can increase the ethylene load. Remove them as soon as possible. Clean bins, drains, waste areas, and loading zones.
Use a first-in, first-out stock system. This reduces the chance of older products remaining in the room too long.
Removing the source is often easier than treating the gas later.
Use Clean Ventilation Air
Fresh air can dilute ethylene. However, the intake must be located away from truck exhaust, generators, boilers, waste areas, and ripening-room outlets.
More ventilation is not always better. It may increase refrigeration demand and affect humidity. Set the airflow according to the room size, product load, door activity, and measured ethylene level.
Install Ethylene-Removal Equipment When Needed
Use a scrubber or filter when ventilation and product separation are not enough.
Choose equipment that suits your room size, product load, airflow, temperature, and humidity. Check the system regularly, since filters and treatment media lose performance over time.
Use 1-MCP Only for Approved Products
1-methylcyclopropene, or 1-MCP, reduces the way plant tissue responds to ethylene. Approved uses vary by product, crop, and country. Follow the registered product label, treatment time, ventilation instructions, and worker entry rules.
The US Environmental Protection Agency identifies 1-MCP as a postharvest tool used to counter some effects of ethylene on approved fruits and vegetables.
Use it as part of a storage plan. It does not replace correct cooling or monitoring.
How to Choose Ethylene-Control Equipment
Choose equipment that matches your cold room and stored products. Common options include ethylene scrubbers, air filters, catalytic units, and fixed monitoring systems.
Before buying, check:
- Room size
- Type and amount of produce
- Airflow
- Temperature
- Humidity
- Target ethylene level
Different products release different amounts of ethylene. Ask the supplier how the equipment was tested. The test conditions should be close to your own storage conditions.
You should also check the maintenance needs. Confirm how often the filters, sensors, or treatment media must be inspected and replaced.
How to Know the System Is Working
Measure the ethylene level before and after installing the system. Take readings from the same locations and under similar storage conditions. This gives you a fair comparison.
Also check the produce itself. Look at firmness, color, yellowing, decay, and remaining shelf life.
A lower ethylene reading is helpful, but better product quality is the real result.
Safety Considerations
Ethylene is flammable. Keep concentrated ethylene sources away from flames, sparks, hot surfaces, and unsuitable electrical equipment.
Controlled-atmosphere rooms may contain dangerously low oxygen levels. Use proper gas testing, alarms, warning signs, and access controls.
Follow the equipment manual, safety data sheets, product labels, and local regulations.
Conclusion
Good ethylene control starts with the right storage conditions. Keep produce at the correct temperature. Maintain proper airflow. Separate incompatible products. Remove damaged stock and monitor ethylene when needed.
Use ethylene removal equipment only when your storage conditions require it.
Sunnyda Cold Room provides customized cold storage solutions based on your products, room size, temperature, airflow, and daily operation. A Sunnyda cold room tailored to your storage needs helps maintain product quality and support a longer shelf life.
Frequently Asked Questions
1. Can refrigeration remove ethylene?
No. Low temperatures can slow ethylene production and its effect, but they do not remove the gas from the room.
2. How can you lower ethylene levels?
You can separate incompatible products, remove damaged produce, use clean ventilation air, and install an ethylene scrubber or filter when needed.
3. Do all cold rooms need ethylene-removal equipment?
No. Equipment is most useful when measurements show that ethylene is affecting product quality and basic storage controls are not enough.
4. Does damaged produce release more ethylene?
Yes. Damaged, overripe, or decaying produce may release more ethylene. Remove it quickly to protect nearby stock.
5. Should ripe and unripe fruit be stored together?
It is better to separate them. Ripe fruit may release more ethylene and cause unripe fruit to mature faster.
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