Effects of Ripening Processes on Chemistry of Tomato Volatiles123

Abstract

Investigations were carried out to isolate, identify, and characterize major volatile components of tomato fruit. Simultaneously, the confirmation was extended to the reported tomato volatiles. The volatile extracts from field and artificially-ripe fruits were compared qualitatively as well as quantitatively. The changes occurring in the volatile components of the fruit at the onset of senescence also were delineated.A typical chromatogram from field ripe tomatoes contained 60 peaks. The functional group properties of individual peaks were derived by chemical analysis and approximate concentrations of individual groups were calculated. Among alcohols and carbonyls, 3-pen tanol, 1-nonanal, 1-decanal, and 1-dodecanal, and among esters, propyl acetate, geranyl acetate, and citronellyl butyrate were tentatively identified as volatile compounds of tomato fruit. Linalyl acetate, citronellyl butyrate, and geranyl butyrate were identified for the first time as the components of tomato volatiles. The concentrations of short-chain (C 4 -C 6 ) compounds were higher in the artificially ripe fruits while the long-chain (C 9 -C 12 ) carbonyls and the terpene esters were predominant in the field ripe fruits. These differences were discussed. It was indicated that major contributions of the long-chain carbonyls and the terpene esters are essential for ripe tomato aroma. An attempt has been made to theorize the mechanisms of the biogenesis of these compounds. During senescence the amounts of alcohols, aldehydes, ketones, acetates, and propionates generally decreased. However, the concentrations of diacetyl and butyric acid esters increased.