ULO preservation
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What is ULO preservation?
When storing fresh fruits and vegetables, it is important to create the right conditions to prevent spoilage and maintain quality for as long as possible. A commonly used method in the agricultural sector is ULO preservation. But what exactly is ULO preservation, and why is it so commonly used?
ULO: Ultra Low Oxygen
ULO stands for Ultra Low Oxygen, or in other words, an environment with very low oxygen levels. In ULO preservation, products such as apples, pears, blueberries are stored in gas-tight cells in which the oxygen concentration is artificially reduced. At the same time, carbon dioxide levels and temperature are also carefully regulated.
ULO cells
By reducing the oxygen concentration to about 0.8 – 2%, the fruit’s respiration process slows down. As a result, the product ages more slowly and stays fresh longer. Most ULO cells are also fitted with nitrogen generators to expel oxygen gas from the air to achieve the desired composition. This respiration delay effect causes the natural ripening process to slow down.
Why choose ULO custody?
ULO preservation offers several advantages:
- Longer shelf life without the use of chemicals
- Preservation of fruit quality, flavor and structure
- Less weight loss due to evaporation
- Flexible in delivery times, which is important when exporting or seasonal storage
Therefore, for growers, fruit traders and storage companies, ULO preservation is an efficient way to keep their produce in top condition until the time of sale. In such a cell, fruit keeps for a long time without significant loss of quality or stuffiness.
What products is ULO suitable for?
ULO preservation is mainly applied for:
- Apples
- Pears
- Blueberries
- Kiwis
- Some types of vegetables, such as cabbage
Not every product is suitable for ULO because some crops are sensitive to low oxygen levels. Therefore, it is important to determine on a product-by-product basis whether ULO is the right storage method. In some cases, such cell trying may actually result in damage to the product.
Technology behind ULO
A reliable ULO installation requires more than just an airtight cell. Equipment is needed to:
- Measure and regulate oxygen and CO₂
- Nitrogen generation
- Keep the temperature and humidity stable
- Provide alarms in the event of deviations
Increasingly, smart, automated systems are also being chosen to monitor and adjust storage quality. Additional interlocks and accurate sensors ensure that gas-tight storage cells function optimally. This also prevents oxygen gas from being consumed at undesirable times.
ULO preservation and sustainability
Because ULO preservation eliminates the use of chemical preservatives, it fits well with the trend toward more sustainable growing and storage. It also helps to reduce waste, as more products reach the end user in good condition. Regular incidents with spoiled fruit are therefore preventable.
ULO custody for pest control
The technique behind ULO preservation – lowering oxygen levels to extremely low levels – offers advantages not only for preserving fruits and vegetables. The same principle also proves particularly effective for pest control.
Many insects and other pests cannot survive in an environment with little oxygen. By temporarily creating a kind of ULO environment in, for example, a locked storage room or container, an infestation is controlled without chemical pesticides. This makes it a safe, sustainable and residue-free solution,
At Presscon, we have translated this application into an innovative solution: the BPC generator. This system works almost entirely on the same principle as a traditional ULO setup, but is designed specifically for pest control in enclosed spaces. With the BPC generator, users can create a low oxygen environment in a controlled and efficient manner, tailored to the specific pest and space.
Conclusion
What is ULO preservation? It is a smart and sustainable method of preserving fresh fruit for a long time by minimizing oxygen in the storage environment. For many growers and storage companies, it has now become indispensable. But in the future, this method is going to become even more important for pest control, for example. A long storage life will kick in, while the risk of quality loss will decrease. So don’t let your fruit age unnecessarily: with ULO preservation, you extend shelf life considerably.
