ETHYLENE PRETREATMENT ALLOWS EARLY HARVEST OF CARAMBOLA

Abstract

Carambolas (Averrhoa carambola L., cv. Arkin) ware harvested at colorbreak (CB) and light green (LG) ripeness stages, commercially packed and cooled. The next day the fruit were treated as: Control (ungassed): CB, LG; Ethylene pretreatment (ETH) @100ppm: LC for 1, 2 or 3 days at 20°C or 25°. After pretreatment the fruit were stored at 5°. After 1, 2, 3, 4 weeks, 10 fruit from each treatment ware removed from storage and placed at 20°. Fruit color and decay were rated daily until 80% of the fruit in each treatment reached the yellow ripeness stage, at which time external color, total soluble solids (TSS), pH and total titratable acidity (TTA) were determined. Carambolas harvested at the LG stage can be ripened to good quality with ETH pretreatment. For two weeks storage at 5°, 2 days ETH are necessary at 20° or 25° to initiate ripening. For three weeks storage, 3 days ETH are required at 20°, and 2 or 3 days ETH are required at 25°. Fruit stored four weeks were of fair quality. LG with slower ripening initiation developed chilling injury during storage; the fastest initiation had the best color but the shortest marketing life. Fruit harvested CB had slightly higher TSS than ETH-treated LG but pH and TTA were similar.