A shipment of Taiwanese custard apples was completed successfully earlier this year from Taiwan to Malaysia with the help of controlled atmosphere (CA) technology from Daikin Reefer, a leading supplier of refrigeration and climate control solutions for freight containers. Headquartered in Japan, Daikin Reefer is the refrigeration business division of global refrigeration, air conditioning and climate control provider Daikin Industries, Ltd.
The container-load of custard apples was shipped from Kaohsiung, Taiwan to Port Kelang in Malaysia, arriving on 7th February, after 12 days in total from harvest through loading to ship and subsequent offloading in port.
Taiwan is one of the leading sources of custard apples and growers and shippers have been frustrated over the years by the difficulty of finding new markets with their produce. The custard apple, known by a number of different names such as the atemoya fruit, is a tree of the family Annonaceae. It has a taste similar to that of custard. Popular with the health conscious, it has low GI (Glycemic index), is naturally sweet and an excellent source of vitamins C and B6, as well as being rich in potassium.
The fruit is particularly popular in China which typically accounts for over 90% of Taiwanese exports each year. The initial impact of the COVID-19 pandemic on fruit imports due to blockages at Chinese ports under lockdown provided an opportunity for the custard apples to be shipped using Daikin Active CA. Previous reefer shipments of custard apples made without Daikin Active CA on this route saw anywhere from 30% to 80% of the fruit arriving spoiled, due to either chilling injuries or overripening which results in brown spots to the fruit’s skin. Once offloaded, such spoiled fruit typically only has a shelf life of 2 days.
When shipped with Daikin Active CA, the custard apples arrived in optimum condition with an extended shelf life of between 5 and 7 days.
Taiwan custard apples vary in shape, size and colour and it is particularly challenging to ship them over longer distances because of the speed at which they can spoil and discolour when transported in normal reefers that rely on natural respiration.
The Daikin Active CA system reduces oxygen and manages carbon dioxide levels, as well as boosting nitrogen levels to quickly put fresh produce into a state of hibernation inside the reefer. This helps to maintain the quality of the fruit and extend both the shelf life (i.e. the selling days on shelf in stores) and the overall storage life of a wide range of fresh produce, even on the longest of journeys.
This means perishable cargoes with low respiration rates can be transported under optimum conditions – unlike when more passive systems are used.
In 2019, Daikin Reefer led a research project together with the National Taiwan University (NTU) and Taitung District Agricultural Research and Extension Station to test whether custard apples could be transported over long distances using its Active CA. The research team at NTU was funded by Taiwan’s Ministry of Science and Technology. NTU conducted extensive tests to simulate the same transit days using custard apples of varying maturity, all of which were stored using the Active CA optimal atmospheric conditions. The project successfully demonstrated the effectiveness of CA technology: custard apples stayed firm after five weeks, with samples taken at intermittent stages to assess progress.