CA Applications
UDO, Dynamic CA, Pallet CAP, CO2 Ripening and Laboratory Systems
Pallet CAP
Laboratory Systems
CO2 Ripening
Other sections
Controlled Atmosphere, Ultra Low Oxygen, Dynamic CA
Controlled Atmosphere Applications in Fruit Storage:
Ultra low oxygen (ULO) is a type of controlled atmosphere that is adjusted dynamically. This technique has different names depending on the refrigeration and various industries that use it. Some of them are:
- Controlled Atmosphere (CA),
- Advanced Control of Respiration (ACR),
- Dynamic Controlled Atmosphere (DCA),
- Ultra Low Oxygen (ULO)
These names are actually based on the protocols that are applied, however the main machine groups are usually similar or the same. The key point here is the desired level of O2 in the storage environment. For this, different protocols must be used and the room where the products are kept under CA conditions needs to be properly sealed.
Ultra Low Oxygen (ULO)
Some fruits, like pears for example, are usually stored with oxygen levels between 1-3%. For most kinds of apples, on the other hand, the oxygen levels should be 1.5% or lower. The condition when the O2 level is at 1.5% or lower is called ULO – Ultra Low Oxygen storage. It is a controlled atmosphere technique that keeps fruits with climacteric characteristics like apples, pears, pomegranates and kiwis fresh for a long time in special gas-tight cold rooms.
Dynamically Controlled Atmosphere
The commercially available Dynamically Controlled Atmosphere (DCA) uses various methods (fluorescence or gas measurement) to measure ethanol production at the moment of fruit crisis. ACR – Advanced Control of Respiration is implemented with various techniques based on measuring the respiration rate throughout the store without waiting for the fruit to extract ethanol.
A dynamic control system should be able to perform precise measurements regularly, intervene in the system and communicate with the operator in a synchronized manner via alarm when necessary.
The Dynamic CA Storage Control system operates in cold storage according to the physiological state of the fruit. Storage protocols must be adjusted and programmed depending on the respiratory response of the fruit. The O2 concentration must be adjusted by the system according to the response of the fruit to avoid the danger of too low oxygen. Therefore, using a reliable control system and integrated measuring devices, even oxygen levels below 1% pose no danger to the fruit.
Controlled Atmosphere Pallet – PalletCAP
Each type of fruit requires different storage protocols. With a controlled atmosphere system, each room can be conditioned individually. However, this is slightly different when it comes to berries. Due to the different dynamics of storage, harvesting or sale to market, OXYCAT has developed PalletCAP, controlled atmosphere storage pallet units for berries.
Separate gas-tight covers on the pallets and a special pallet system prevent odor or aroma from contaminating/ mixing from one product to the others during the storage, especially of valuable types of grapes. It is possible to sell the product on pallet basis at the end of the storage. In this case, it allows other pallets to continue storage without deteriorating the controlled atmosphere conditions. Keeping different types of fruit in the same room under controlled atmosphere is only possible with PalletCAP as it provides a possibility for different gas levels to be applied to each and every pallet.
The PalletCAP unit consists of a cover and a special plastic pallet on which crates or boxes with products are placed. A 1.0 m x 1.2 m, gas-tight and transparent cover with a maximum height of 5 meters is placed over the pallet; therefore, up to 1 ton of fruit can be stored per pallet on average, depending on the product. The system measures the gas conditions inside the cover at the required intervals and adjusts the gas values if necessary. For products requiring in-pallet carbon dioxide application, the controlled atmosphere system utilizes special injection stations and gas cylinders. When necessary, oxygen reduction – pulldown work is done by a properly selected nitrogen generator.
Controlled Atmosphere Laboratory Systems
In controlled atmosphere laboratories, researchers can do different protocol research on existing fruits or new types. These laboratories are generally located in private/ state research institutes/ universities. There are various ways to construct controlled atmosphere laboratories with unique designs that suit the needs of the researchers and the kind of research they intend to do.
In general, testing different gas combinations at the same time with different temperatures in research enables large-scale testing. Since the fruits harvested in different seasons will have different properties, it is very important to test the products harvested in the same year by storing them with different combinations at the same time.
The results of laboratory systems are generally based on tests performed on products in quantities of 20 kg – 50 kg or 100-200 kg.. However, when the results are applied to commercial storage, it can often lead to different storage scenarios because the quantity of products used is much less. Therefore, the results from small units can be used as a reference for commercial mini testing cold stores that offer conditions for quantity close to 3-5-10 tons, which are still regarded as laboratory size.
Controlled atmosphere rooms with test units, cabinets or mini pallet system can be made in the size of a mini laboratory with cooling. Cooling is provided from outside the unit and different gas values can be applied in 1 room by the number of units. If different temperatures are desired, the same systems should be installed in 2 or 3 rooms. In other applications, techniques such as dynamic controlled atmosphere, the conditions can be studied using cabins made of special inflexible materials. These cabinets, depending on the need, each can be cooled separately or placed in the same room with the cooling provided from the room. Humidity loss control etc. is important here to choose which one to use.
OXYCAT Controlled Atmosphere Laboratory Systems – our team, with over a decade of experience in the field, is pleased to offer turnkey Controlled Atmosphere Laboratory Systems. We will help to develop the design of rooms / cabinets/ pallets with Controlled Atmosphere, tailored to your needs and your budget. We also provide after-sales support and user training for this system.
CO2 Ripening Systems
These are controlled atmosphere chambers used for flavoring the Rojo Brilliante variety of persimmon. The process can take for about a day. The fruit is taken into the room after storage and fumigation with special protocols of CO2 is applied . Here, it is also important to make accurate measurements with the special injection system and to take the measurements with analyzers other than the devices integrated into the automation.
This application uses CO2 gas. Since CO2 is a toxic gas, good sealing of the rooms both prevents CO2 from being wasted and prevents leaks around the room during the fumigation process, making the application safe for life safety.
CO2 Fumigation Ripening system is not suitable for every persimmon type. The type of persimmon it can be applied to is a hard type. With this application, sweetening is done after storage, that is, after sales, before shipment .