Banana ripening room
Also known as: banana ripening chamber
Short definitionA special room that brings green bananas to the same yellow across the whole batch in a few days. It works with an ethylene dose, high humidity and a system that can both cool and heat.
The wholesaler buys bananas green; the fruit has been kept at 13–14 °C on the way. Ripening is a programme: first the pulp temperature is raised to 16–18 °C, then 100–150 ppm ethylene is applied for one day. After that the room is ventilated and the temperature is lowered step by step to 14–15 °C. The length is chosen between 4 and 8 days to suit the day of sale. Shops mostly want bananas at stage 3 or 4 of the seven-stage colour scale.
In this room the source of the load is the banana itself. Fruit that starts to turn respires much faster and warms up; the unit removes this heat and also heats when needed. The controller follows a probe pushed into the fruit, not the air temperature. Humidity has to be 90–95%, so a humidifier is fitted. If air does not pass through the holes in the boxes, bananas in the front and back rows come out in different colours. Supply air colder than 13 °C turns the peel grey. Room size is discussed in pallets.