The effect of postharvest
dips in a 1-methylcyclopropene-generating
solution of the formulation AFxRD-038 (Rohm & Haas) on plum fruit (Prunus salicina Lindell cv. 'Harrow Sun') quality and ripening during storage was determined. Fruit
weight loss, tissue firmness, soluble solids content (SSC), titratable acidity (TA),
ethylene production, respiration, and the activities of the cell wall modifying
enzymes polygalacturonase (PG), 1,4-beta-D-glucanase/
glucosidase (EGase),
beta-galactosidase (beta-gal), and
pectin methylesterase (PME) were measured. Fruit reddening,
anthocyanin content, and
phenylalanine ammonia-lyase (PAL) activity were also analyzed. The 1-MCP-treated fruit showed reduced
ethylene production and respiration rate and delayed softening, which was associated with the reduction in the activity of PG, EGase, and beta-gal. The immersion in 1-MCP-generating solutions also decreased weight and acidity loss without modifying the fruit SSC. The immersion treatment was particularly effective in the fruit stored at 5 degrees C, keeping higher overall quality, maintaining lower levels of
anthocyanins and PAL activity, and preventing flesh reddening. The present data show that beneficial effects in delaying plum fruit ripening and controlling chilling injury can be obtained by dipping the fruits in a
solution of this novel 1-MCP-generating formulation.