3.5. Changes in concentration of total and individual organic
acids
The concentrations of total organic acids, citric acid, malic acid,
shikimic acid and fumaric acid in the pulp tissue declined with
the advancement of fruit ripening irrespective of the treatment
applied (Fig. 5A–C and some data not shown). The exogenous application
of ABA and NDGA only had an effect on the concentrations
of total organic acids and citric acid (Fig. 5A and B). The concentrations
of total organic acids and citric acid in the pulp declined at
a faster rate from days 2 to 4 of ripening in ABA-treated fruit than
in the control. In NDGA-treated fruit, the concentrations of total
organic acids and citric acid in the pulp declined at a slower rate
until day 4 of ripening than in the control. At the ripe stage (days
8 and 10 of ripening), the concentrations of total organic acids and
citric acid did not differ among treatments. The concentrations of
trace organic acids (tartaric acid, malic acid, and shikimic acid) did
not vary among treatments during the ripening period (data not
shown).