Controlled ripening of bananas
In order to deliver bananas at the desired stage of ripeness to retailers and ultimately to the consumers, controlled ripening takes place. Controlled ripening takes place in so-called “ripening rooms” or “banana rooms” in special ripening facilities or in the distribution centre. In these rooms, ethylene is released at a controlled temperature and humidity. Experts adjust the details of the ripening program to the maturity of the batch and the planned delivery to retail
Controlled ripening close to the market
Bananas are harvested in tropical regions in the green stage. After overseas transport, the bananas need to undergo a ripening process to become ready for consumption. This ripening towards a ready to eat banana takes place close to the market in the countries of destination. The application of ethylene in sealed ripening rooms initiates the ripening. This artificial ripening process is well controlled with to aim to providing uniform ripening bananas with a bright yellow colour and a good flavour when reaching the consumer.
Ripening of bananas
Quality inspection of bananas. These bananas show premature ripening. Photo by WUR.
Quality inspectionUpon arrival in the ripening facility, the grade (diameter) and ripening stage of the bananas is inspected. Full grade fruit ripens faster. So determining the grade helps in setting the right ripening program. Other indicators are: skin colour, skin crispness, flow of latex from a cut, colour and firmness of the pulp, and the aroma (smell).
Ripening room with bananas. Photo by WUR.
Ripening roomRipening takes place in the ripening rooms. Proper loading of the rooms is a prerequisite for a good air flow. Forced air systems are used to force air through the boxes to control the temperature and ethylene concentration uniformly throughout the room. For the ethylene to reach the bananas, the box and linerbag must be sufficient permeable. For Banavac bags, this means these must be torn open.
Ethylene gas bottle, used to initiate ripening. Photo by WUR.
Ripening programThe temperature is adjusted according to the maturity of the bananas and to program the speed of ripening. The temperature is in the range 14.5 – 20 °C. The process of ripening involves the use of ethylene gas, during a period of 24-48 hours. During this treatment, the CO2 is kept low to prevent the adverse effect on ethylene action. Experts determine the exact details of the ripening program.
Ripe bananas at retail. Photo by WUR
Delivery to retailProviding ready to eat bananas to consumers requires careful timing. About 2 days after the ripening program, bananas start to break colour. Many details depend on the exact ripening program. Colour stages 3 (more green than yellow, or half green half yellow) and 4 (more yellow than green) are suitable stages to deliver to retailers. Bananas may be repacked in consumer bags before being delivered to stores.