SOFTENING AND BIOCHEMICAL CHANGES OF SAPOTE MAMEY FRUIT (POUTERIA SAPOTA) AT DIFFERENT DEVELOPMENT AND RIPENING STAGES

Abstract

We investigated some of the physicochemical and biochemical factors associated with flesh softening of sapote mamey fruit during development and ripening. The activities of pectinmethylesterase (PME), polygalacturonase (PG) and β-galactosidase (β-GAL) enzymes were measured in fruits harvested at different development stages, and postharvest in two production seasons. The textural changes were most noticeable at the preclimacteric stage in ripening fruit. The water-soluble pectin (WSP) increased at a different rate than firmness decreased. No correlation between PG or PME activity and changes in firmness was observed in ripening fruits, though a low correlation was seen between β-GAL activity and softening in climacteric stage. Greatest loss of firmness occurred in climacteric stage. Fruit pulp softening was not dependent on a single enzyme activity.