Co-Authors:
Pesis, E., Dept. of Postharvest Sci. of F., Agric. Res. Org., the Volcani C., Bet Dagan, 50250, Israel
Faiman, D., Dept. of Postharvest Sci. of F., Agric. Res. Org., the Volcani C., Bet Dagan, 50250, Israel
Dori, S., Dept. of Postharvest Sci. of F., Agric. Res. Org., the Volcani C., Bet Dagan, 50250, Israel
Abstract:
Exogenous application of acetaldehyde (AA) vapour to whole or half-peeled avocado fruits (Persea americana cv. 'Fuerte'), prior to storage, inhibited fruit ripening. This inhibition was characterized by a delay in fruit softening and a reduction in ethylene production. Activities of the cell wall depolymerizing enzymes polygalacturonase (PG), β-galactosidase (β-GAL) and endoglucanase (Cx), and of 1-aminocyclopropane-l-carboxylic acid oxidase (ACC oxidase), were reduced immediately after treatment. AA-treated fruit had reduced ethylene production and ACC oxidase activity, both in vivo and in vitro. Levels of total free sulfhydryl (SH) group compounds increased in AA-treated fruit, but diminished in untreated fruit. AA treatment inhibited fruit pulp oxidation, while untreated control fruits oxidized and became brown. Application of AA to a PG reaction mixture reduced PG activity on sodium polypectate. Pre-incubation of the substrate with AA did not result in reduced activity. Attempts to detect AA-bound proteins in AA-treated fruits were unsuccessful.