Effect of heat treatment on changes in softening, pectic substances and activities of polygalacturonase, pectinesterase and ?-galactosidase of ripening mango.
Ketsa S., Chidtragool S., Klein J. D., Lurie S.
Author Affiliation: Department of Horticulture, Faculty of Agriculture, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
Journal of Plant Physiology 153 : 457-461
Abstract : The relationship between softening, pectic substances, polygalacturonase (EC 3.2.1.15), pectinesterase (EC 3.1.1.11) and ?-galactosidase (EC 3.2.1.23) during ripening of heated (38°C) and non-heated (25°C) mango (Mangifera indica) cv. Nam Dokmai fruits was investigated. Fruit softening was accompanied by a progressive increase in water-soluble and ammonium oxalate-soluble pectin and a progressive decrease in alkali-soluble pectin. Polygalacturonase and ?-galactosidase activities increased while pectinesterase activity decreased continuously during softening. Heating fruits for 3 days at 38°C resulted in an increase in softening, ammonium oxalate-soluble pectin and activity of ?-galactosidase, and a decrease in alkali-soluble pectin and activities of polygalacturonase and pectinesterase, while heating had no pronounced effect on water-soluble pectin. Softening of ripening mango fruits was more closely related to changes in ?-galactosidase activity than to polygalacturonase and pectinesterase activities.