Activity of the enzyme polyphenol oxidase and susceptibility to damage from latex in 'Haden' and 'Tommy Atkins' mangoes.
León-Sánchez F. D. de, Rivera-Cabrera F., Bosquez-Molina E., Domínguez-Soberanes J., Álvarez-Hoppe Y., Pérez-Flores L. J.
Author Affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco Núm. 186, Col. Vicentina, Iztapalapa, D.F. México, C.P. 09340, Mexico.
Revista Chapingo. Serie Horticultura 11 : 39-42
Abstract : Damage from latex (DPL) represents a problem in Mexican mango, causing up to 10% of annual losses. DPL begins when exuded latex touches the fruit's skin, producing a superficial darkness that diminishes mango quality and commercial value. Previous studies in mango suggest that terpens favour damage from latex through the activation of polyphenol oxidases [catechol oxidase] (PPO's). An experiment was conducted to determine the correlation between damage from latex and the activity of total PPO's of the exocarp and latex in 'Haden' and 'Tommy Atkins' mangoes harvested in April, May, and June in Lázaro Cárdenas, Michoacán, México. Enzyme activity was measured with a spectrophotometer and susceptibility to DPL was evaluated as the percentage of damaged area. Activity of exocarp total PPO's was similar for 'Tommy Atkins' and 'Haden' during the first 2 harvest seasons, and it only increased for 'Tommy Atkins' in the last harvest season. Susceptibility to DPL showed contrasting performance between both cultivars. In 'Haden' it increased throughout the 3 seasons while it decreased in 'Tommy Atkins'. Therefore, total activity of exocarp PPO's and damage from latex do not explain susceptibility to DPL in Mexican mango. We suggest including the analysis of other components and latex enzymes in future experiments on susceptibility to DPL.