Ethephon as an Alternative Ripening Agent for ‘Cardaba’ Banana (Musa acuminata x M. balbisiana)
Ethephon and bioethylene from Gliricidia sepium were evaluated as potential alternatives to the unsafe calcium carbide (CaC2) in ripening ‘Cardaba’ banana. In Experiment 1, bananas were treated with CaC2 (1 and 2 g kg-1), G. sepium leaves (30% and 40% w/w), or ethephon (200 and 500 μL L-1). In Experiment 2, fruit were applied with CaC2 (2.5 or 5 g kg-1) or ethephon (200 or 500 μL L-1). Results showed that the use of low CaC2 concentration (1 or 2 g kg-1) or G. sepium leaves for 48 h was not sufficient to effectively ripen banana fruit (Experiment 1). The fruit dipped in 500 μL L-1 ethephon for 3 min exhibited similar effect as the 5 g kg-1 CaC2 for 72 h, which allowed the fruit to ripen faster than the lower concentrations of CaC2 (2.5 g kg-1) and ethephon (200 μL L-1), and the control (Experiment 2). The higher concentrations of ethephon and CaC2 resulted in bananas with higher total soluble solids, least firmness, most advanced peel color after 2-3 days and least green (a*) color that was towards the yellow hue angle. Ethephon-treated fruit had better visual quality than those treated with CaC2 and reached the full yellow stage the earliest (4.5 to 5.8 days) compared with the other treatments (7 to 11 days). As ripening took place earlier, fruit dipped in 500 μL L-1 ethephon solution had the least visual quality rating after seven days resulting in shorter shelf life of eight days compared with the control at 11 days.