Abstract
In the previous paper, it was reported that significant variation in patterns of carbon dioxide and ethylene production exists among melon cultivars in the course of fruit ripening. The present study describes changes in the production of low-boiling point volatiles in four cultivars of Raifu, Prince, Elizabeth, and Honey King melons harvested at different stages and stored at 20°C. For determination of volatiles, fru ts were confined individually for 4-6 hours and head space gas was with-drawn and analyzed by gas chromatography.
While the kinds of volatiles detected in the course of ripening were the same among the cultivars examined, the amounts and the patterns of volatiles production were different, and the difference was especially conspicuous between Raifu, which showed a typical respiratory climacteric, and the other three cultivars which were considered to be non-climacteric.
Volatiles production in Raifu fruits increased rapidly during the climacteric period, reaching a maximum 1-3 days after the peaks of ethylene and carbon dioxide production, and then declined as the senescence of the fruits progressed.
In Prince and Elizabeth fruits, volatiles production exhibited a similar trend and increased gradually with progressive ripening after the peak of ethylene production.
In Honey King fruits, volatiles production was at very low level and was detected only when the fruit became over-ripe about 17-19 days after harvest. In abnormally softened fruit (called fermented fruit), volatiles were detected early with a rise of respiration.
More volatiles production during ripening was found in fruits harvested at advanced maturity than for those harvested earlier, while the kinds of dominant substances differed among cultivars.
