The sugars and sugar phosphates generated during the catabolism of starch are metabolized
through the glycolysis and citric acid cycle (Fig. 3.4). Sugar phosphates can also
be channeled through the pentose phosphate pathway, which is a major metabolic cycle
that provides reducing power for biosynthetic reactions in the form of NADPH, as well as
supplying carbon skeletons for the biosynthesis of several secondary plant products. The
organic acids stored in the vacuole are metabolized through the functional reversal of respiratory
pathway, which is termed as gluconeogenesis. Altogether, sugar metabolism is a
key biochemical characteristic of the fruits.