Postharvest fruit detachment in oil palm bunches with ethephon and ethylene gas application

Abstract

The processing of oil palm fresh fruit bunches (FFB), together with loose fruits, in the current mill operation contributes to oil loss and high free fatty acids (FFA), affecting crude palm oil quality. Fruit detachment induced by ethephon and ethylene may mitigate the current processing issues. This study shows that a 0.50% (v/v) ethephon application by the evaporation method induced the highest fruit detachment of 30.8 ± 1.1% after 24 h at room temperature, with the FFA content in the extracted crude palm oil at 0.34 ± 0.09%. Ethephon application was effective on bunches between 14 and 28 kg, and fruit detachment was higher in ripe and underripe bunches at 24.1 ± 0.9% and 23.2 ± 0.1%, respectively. A significant fruit detachment of 47.2 ± 2.4% was achieved when the bunches were also stripped mechanically, but the FFA content increased almost 4-fold, from 1.0 ± 0.2% to 3.8 ± 1.2%. The application of ethylene gas at 750 ppm yielded 29.4 ± 1.9% fruit detachment. The findings present the possibility of using ethylene as an indirect method for minimizing oil loss without increasing the FFA content in future crude palm oil production systems.