ENSURING BANANAS ARE READY FOR THE STORE
How do you like your bananas? It probably depends on where you live. In Japan, consumers prefer a very ripe bright yellow banana and flecked with brown. In Northern Europe, on the other hand, a less ripe, green-tipped fruit is preferred. But whichever way we like them, we buy them in large quantities—more than 125 million metric tons are produced each year around the world. They’re good for us, too. Bananas are nutritional powerhouses packed full of energy-boosting carbohydrates and heart-regulating potassium.
However, getting bananas to stores at just the right level of ripeness is a challenging process. They are grown in more than 150 countries in tropical regions across the globe and harvested while still green. Then their journey begins. First, they are transported in refrigerated containers to their destination country at an optimal temperature of 55.9°F, which “puts them to sleep.” If the temperature drops any lower, it can damage the fruit.
Once arrived, and before they can continue to stores, the ripening must begin. This is done in special “ripening chambers,” where ethylene—a harmless natural plant hormone—is used to stimulate the process until the bananas start producing their own ethylene in large quantities. The chambers need to be airtight to avoid ethylene leakage, and the temperature needs to be tightly controlled between 57.2°F and 64.4°F, depending on the level of ripeness required. The ripening process lasts between four and eight days.
Banana ripening is a highly specialized business, and Güntner has many decades of experience in the field. Its cooling systems can be found in ripening chambers around the world: for example, for more than two decades, Güntner has worked with the Chiquita banana brand in the US and Mexico.
In China, Güntner’s technology can be found in many projects across the country. A typical example is a project for 15 ripening chambers in Dongguan, a city in Guangdong province, on behalf of Sumifru, a multinational fruit exporter. The company owns a large banana plantation in Malaysia, and its investment in a large new ripening facility in Dongguan was part of its strategy to target consumers in China.
Sumifru chose to work with Güntner because it was impressed by the company’s previous experience in banana ripening, and it was able to draw on Güntner’s expertise from the very beginning of the project. Güntner’s engineers made many contributions during the design phase, including recommendations for the size of the chambers, load calculations, comparisons between solutions with one or two air outlets, and many other details.
The project utilized powerful Güntner Dual VARIO Air Coolers. They were positioned above the central aisle of each double-floored, 21-foot-tall chamber, where the banana pallets are positioned in rows on each side. These are comparatively large chambers, but the Güntner Air Coolers have the capacity to achieve uniform ventilation across all the pallets while also maintaining a relative humidity of between 90% and 95%.
Guiding sheets mounted on the Air Coolers allow the air to be pushed to the sides of the chamber and downwards. It then flows through the pallets before being pulled back to the coolers. This ensures the bananas are uniformly ventilated during the ripening process.
Other banana ripening solutions tend to use smaller air coolers positioned at the sides of a chamber, a setup that uses more energy and results in less even air distribution. Because Güntner’s Air Coolers are situated above the center aisle, they are also easy to access for cleaning and maintenance. And thanks to their intelligent design, the units can be opened effortlessly and are easily cleaned.
The 15 ripening chambers in Dongguan have the capacity to store a total of more than 25,000 boxes of bananas, adding up to nearly 750,000lb of fruit. They began operating in 2018 and are still running perfectly, providing exquisitely ripened bananas for the Chinese market.