Controlled Ripening of Some Fruits

Controlled ripening of fruits can be used for bananas. It can also be used for tomatoes, melons, avocados, mangoes and other fruits.

Maturity at harvest is the key factor for quality and postharvest life. When shipped to distant markets, fruits must be harvested when slightly immature (particularly climacteric fruits) to reduce bruising and losses during transport. However, prior to distribution and retail sales it is necessary to speed up and achieve uniform ripening so that produce reaches consumers at the right stage of maturity. As with degreening, ethylene is used but at higher concentrations.

Controlled ripening is carried out in purpose-built rooms where temperature and relative humidity can be controlled and ethylene removed when the process has been completed.

The process involves initial heating to reach the desired pulp temperature.
Followed by an injection of ethylene at the desired concentration.
The product is maintained under these conditions for a certain amount of time followed by ventilation in order to remove accumulated gases.
On completion of the process, the temperature is reduced to the desired level for transportation and/or storage. Ethylene concentration and exposure time are functions of temperature, which accelerates the process.

Conditions for controlled ripening of some fruits

	Ethylene concentration (ppm)	Ripeningtemperature °C	Exposure time tothese conditions (hr.)
Avocado	10-100	15-18	12-48
Banana	100-150	15-18	24
Honeydew melon	100-150	20-25	18-24
Kiwifruit	10-100	0-20	12-24
Mango	100-150	20-22	12-24
Stone fruits	10-100	13-25	12-72
Tomato	100-150	20-25	24-48