3. Results
Ripening stages were determined by the established methods
for each fruit: skin and pulp color comparison with the available
charts,
flesh
firmness, total soluble solids, or starch–iodine staining
(Supplementary Table S1 and Supplementary Figs. S1–4). The
results indicated that regardless of the treatment, fruit ripening
occurred as previously described; therefore, the ripening stages
were comparable. In addition, as expected, ethylene treatment
caused an earlier onset of the breaker (Br) stage and a significant
increase in speed in reaching ripe (R) stages when compared to all
non-treated fruit.
3.1. Ethylene treatment negatively affects folate content in papaya
fruit
Total folate content in the control papaya fruit increased almost
two-fold as it ripened, with THF and 5-CH3-THF being the
predominant folate species (Fig. 2). Ethylene treatment induced
the fruit to turn to the Br and R stages one and eight days earlier,
respectively, than the controls. Ethylene treatment did not cause