Starch mobilization and sucrose accumulation in the pulp of Keitt mangoes during postharvest ripening.
Silva A. P. F. B., 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, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Avenida Lineu Prestes 580, Bloco 14, CEP 05508-900
Journal of Food Biochemistry 32 : 384-395
Abstract : Sugar is a determinant for the quality of mangoes, but information about its accumulation is scarce. Although starch can contribute to sugar production during ripening, not much is known about the enzymes involved. This work presents the changes in carbohydrate and enzymes during the development and ripening of Keitt mangoes. Starch disappearance was concomitant to a fivefold increase of sucrose, the most abundant sugar of the ripe fruits. The activities of ?-amylase, ?-amylase, phosphorylase and isoamylase were detected in the pulp, and while ?-amylase increased parallel to the starch content, ?-amylase presented a 20-fold increase during ripening. On the other hand, high phosphorylase activity was observed when fruits were still accumulating starch, and lowered during ripening. Isoamylase was detected during development and increased slightly during ripening, which would be in agreement to the expected role for isoamylases as acting on both subproduct of starch synthesis and degradation.