Question
Is there a lower limit in temperature when there is no response in green bananas to ethylene? Many years ago I heard that bananas do not respond to ethylene below 16 deg C since the stomata are closed. Is this correct? (R.M.)
Answer
Mature-green bananas respond to ethylene (ripen as indicated by color changes from green to yellow, pulp softening, skin thinning and ease of peeling, higher respiration and ethylene production rates, starch to sugar conversion, loss of acidity, and increased aroma intensity) at temperatures between 12C(54F)and 30C(86F). Within this temperature range, the higher the temperature the faster the ripening rate. At temperatures below 12C (54F), chilling injury prevents ripening and at temperatures above 30C (86F), responses to ethylene and associated ripening changes are inhibited. Between 20C (68F) and 30C (86F) excessive pulp softening occurs and that is why 14 to 18C (58 to 65F) is the recommended range for ripening mature-green bananas to assure a longer yellow-life of ripe bananas. It is important to note that all temperatures above refer to fruit temperature and not air temperature.
-Adel Kader