Effects of Vapor Gard on polygalacturonase, malic enzyme and ripening of Harumanis mango.
Lazan H., Ali Z. M., Sani H. A.
Author Affiliation: Department of Botany, Faculty of Life Sciences, Universiti Kebangsaan, Malaysia, 43600 Bangi, Selangor, Malaysia.
: 359-366
Abstract : Mature mango fruits were coated twice with the antitranspirant Vapor Gard (VG) (1.3% v/v) prior to ripening at ambient temperature (24-28°C). Control fruits were untreated. Polygalacturonase (PG) activity increased during ripening of treated and control fruits and was higher in the inner than in the outer mesocarp. Throughout ripening, the inner tissue was softer and more acid and had higher malic enzyme activity, but contained less ascorbic acid, than the outer tissue. Surface coating with VG reduced water loss, retarded softening and inhibited the increase in PG activity in both tissues during ripening. VG treatment also inhibited malic enzyme activity and reduced the decrease in ascorbic acid, which accounted for the observed delay in the decline in titratable acid levels in both tissues during ripening of treated fruits. VG treatment had only a slight effect on the increase in total soluble solids during ripening. It appears that VG affected not only ripening but also flavour development (the sugar/acid balance) in the fruits.