Influence of ethephon concentration on colour uniformity and postharvest quality of paprika (Capsicum annuum L.) during storage

This study was conducted to gain insights into the impact of ethephon on the ripening and quality of paprika fruits (cv. US 1039). Mature green paprika fruits were immersed in different concentrations of an ethephon aqueous solution (500, 1000 and 1500 ppm) for 5 min, then placed in a plastic tray and stored at room temperature. The fruits' physicochemical properties were assessed from the stage of mature green to the point of senescent maturation. Applying the aqueous ethephon solution at 1500 ppm resulted in the highest percentage of ripening. The percentages of both ripening and rotting increased as with increasing ethephon concentration (500−1500 ppm) and with the duration the fruits were allowed to ripen. Although the titratable acidity (TA) of the fruits gradually decreased, the levels of ascorbic acid and lycopene rose as the ripening process continued, irrespective of the treatment used. Fruits harvested at the green mature stage exhibited red colour development by the 9th day following the ethephon solution; however, the rotting rate exceeded 30–35 % by that time, rendering the fruits unmarketable. In the control group, the ripening, firmness, rotting and quality metrics were significantly lower compared to those treated with the aqueous ethephon solution and the fruits did not achieve red colouration.