Passive CA can be used for products like avocados and bananas, but what about shipping grapes or berries? According to Mr Ah Huat Goh, General Manager, Global Marketing and Service, Reefer Container Department at Daikin their new Active CA system works very well for all kinds of fruit and even the low respiration ones.
Adapted from technology used in hospitals for supplying oxygen, Daikin’s Active CA technology is based on vacuum pressure swing adsorption (VPSA), an active atmosphere separation technology that can create the optimal controlled atmosphere very quickly. "VPSA uses the mineral adsorbent zeolite to capture a large quantity of nitrogen from the air and transfer it into the reefer container, allowing oxygen levels to be quickly reduced, without the need for additional nitrogen gas injection," explains Mr Goh.
"Unlike passive CA, which relies on produce respiration, Daikin’s Active CA produces nitrogen rich gas to the reefer container with inbuilt equipment, reducing oxygen density rapidly. This puts the fresh produce to “sleep” in a matter of a day or so, leading to longer shelf-life at the destination. In addition, produce loses its water content from respiring. Active CA’s ability to put the produce to sleep quickly minimises loss of water content."
In emerging markets such as Asia and Africa, the cold chains have improved in the last 5/10 years, China, Philippines, Thailand and Vietnam have improved their cold storage tremendously, according to Mr Goh. "The avocados and bananas coming from Africa are already using CA, both active and passive."
"In my opinion, active CA technology has clear benefits over passive solutions, and I’m excited about the potential of Daikin’s Active CA, as you can keep the atmosphere stable by continuously injecting nitrogen," explains Mr Goh.
"This technology will be even more reliable when used on trains where there is a lot of vibration, which may cause leaks and allow gas to escape causing damage to produce under passive CA, but with an Active CA system you would always maintain a precise optimal level. When used together with a data logger, as well as seeing the temperature information, you can also see the oxygen and carbon dioxide levels."
"During my many years in the trade I have been asked by shippers for Active CA, so I think this is a very important breakthrough for them," concludes Mr. Goh.