Changes in some enzyme activity of ‘Irwin’ mango fruit during maturation

Mango fruit ‘Irwin’ produced on 13-year-old trees cultivated in a plastic greenhouse were used for this study. Fruit were harvested approximately 10（ color stage: green）, 12（ color stage: purple）, 14（ color stage: purplish red） and 16（ color stage: red） weeks after flowering. Variations in the activities of some enzymes related to the degradation of starch and pectins were also examined.Respiratory rate, pectin esterase activities, polygalacturonase activities and α-β amylase activities increased during maturation of ‘Irwin’ mango fruit. These values increased markedly when the fruit turned purplish red.Changes in the activities of polygalacturonase, β-D-galactosidase and α-amylase during maturation appeared to correlate with a marked decrease in the firmness of ‘Irwin’ mango fruit