THE RELEVANCE OF POLYAMINE LEVELS IN CHERIMOYA (ANNONA-CHERIMOLA MILL) FRUIT RIPENING

Free polyamine levels were determined in cherimoya (Annona cherimola Mill. cv. <Fino de Jete>) fruit during ripening at 20 degrees C. Several parameters including respiration rate, ethylene production and total titratable acidity were analyzed. The polyamine prevailing after harvest was spermidine, although a sharp increase was observed in putrescine content during ripening. The possible relationship between this rise in putrescine level and the ripening process was studied on the basis of the pattern of diamine content in fruit stored over a range of low temperatures (10, 8 and 6 degrees C). Retardation of the ripening process by cold storage was concurrent with a slower rate of increase in the free putrescine level. Moreover, where ripening was inhibited by storage at the chilling temperature (6 degrees C), no increase in free putrescine was observed. While no variation was observed in spermidine and spermine content in fruit ripening at 20 degrees C, levels did undergo change during low temperature storage. The possibility that significant accumulation of the free putrescine titer may be associated with high acidity levels in ripening cherimoya tissues is discussed.