Mango starch degradation. II. The binding of ?-amylase and ?-amylase to the starch granule.
Peroni F. H. G., Koike C., Louro R. P., Purgatto E., Nascimento J. R. O. do, Lajolo F. M., Cordenunsi B. R.
Author Affiliation: Laboratório de Química, Bioquímica e Biologia Molecular de Alimentos, Departamento de Alimentos e Nutrição Experimental, FCF, Universidade de São Paulo, Avenida Lineu Prestes 580, Bloco 14, CEP 05508-900, São Paulo, SP, Brazil.
Journal of Agricultural and Food Chemistry 56 : 7416-7421
Abstract : During mango ripening, soluble sugars that account for mango sweetening are accumulated through carbon supplied by both photosynthesis and starch degradation. The cultivar Keitt has a characteristic dependence on sugar accumulation during starch degradation, which takes place during ripening, only a few days after detachment from the tree. Most knowledge about starch degradation is based on seeds and leaves currently used as models. However, information about the mango fruit is scarce. This work presents the evaluation of ?- and ?-amylases in the starch granule surface during fruit development and ripening. Extractable proteins were assayed for amylase activity and detected by immunofluorescence microscopy and correlated to gene expression. The results suggest that both amylases are involved in starch degradation during mango ripening, probably under the dependence of another signal triggered by the detachment from the mother-plant.