Changes in the texture of kiwifruit are an important index for
determining the degree of ripening. A significant decrease in firmness
was observed in treated kiwifruit as compared to the controls
after 2 d (Fig. 1A). The firmness values in treated kiwifruit declined
from 4.03 N to 1.49 N and were atthe eating ripe stage at day 4 while
firmness of the control fruit reached a similar value (1.43 N) at day
7. The results indicated that ripening of kiwifruit can be stimulated
strongly by external application of ethephon at 25 ◦C.
Changes in SSC and TAin control and ethephon-treated kiwifruit
are summarized in Fig. 1. In treated fruit, SSC increased sharply
to around 10% after only 3 d, while the control maintained low
SSC for about 7 d but reached values similar to those of treated
fruit (Fig. 1B). The TA decreased significantly after 5 d for treated
kiwifruit while the control showed no significant differences over
the experiment(Fig. 1C). We found thatthe SSC increase was correlated
with the decreases in TA and firmness. These physicochemical
changes of kiwifruit during ripening are similar to those reported
previously (Park et al., 2006a,b).