| Abstract
| - Melon varieties (Cucumis melo L.) differ in a range of physical and chemical attributes. Sweetnessand aroma are two of the most important factors in fruit quality and consumer preference. Volatileacetates are major components of the headspace of ripening cv. Arava fruits, a commerciallyimportant climacteric melon. In contrast, volatile aldehydes and alcohols are most abundant in cv.Rochet fruits, a nonclimacteric melon. The formation of volatile acetates is catalyzed by alcoholacetyltransferases (AAT), which utilize acetyl-CoA to acetylate several alcohols. Cell-free extractderived from Arava ripe melons exhibited substantial levels of AAT activity with a variety of alcoholsubstrates, whereas similar extracts derived from Rochet ripe melons had negligible activity. Thelevels of AAT activity in unripe Arava melons were also low but steadily increased during ripening.In contrast, similar extracts from Rochet fruits displayed low AAT activity during all stages ofmaturation. In addition, the benzyl- and 2-phenylethyl-dependent AAT activity levels seem wellcorrelated with the total soluble solid content in Arava fruits. Keywords: Aroma; volatile acetates; biosynthesis; alcohol acetyltransferase; melons (Cucumismelo. L)
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