Abstract: In order to explore the differences in volatile components and aroma profiles between the peel and flesh of tomato fruit, two inbred lines were used for this study, namely, CI1005 (red cherry tomato) with high concentrations of volatile components and TI4001 (green large-fruited tomato) with low concentrations of volatile components. Peel and flesh samples were taken at different maturation stages (mature green, turning, orange, and red stages) to analyze their volatile components as well as odor characteristics and intensity using headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry-olfactometry (GC-MS-O). The results showed that there was little difference in volatile components between the peel and flesh of the same inbred line during fruit ripening. The concentrations of volatile components were significantly higher in the peel than in the flesh of CI1005 at each ripening stage, especially aldehydes, alcohols, esters, acids, and ketones. On the contrary, the concentrations of volatile components were significantly higher in the flesh of TI4001, especially aldehydes, esters, and acids. The aroma intensity was significantly stronger in the peel of CI1005, especially in terms of fatty, malty and green aroma, while the flesh showed stronger sweet taste. The peel and flesh had the strongest grassy and fruity aroma, respectively. During fruit ripening, the aroma of the peel increased more than that of the flesh. The maximum difference occurred at the red mature stage. Aroma intensity was stronger in the flesh than in the peel of TI4001, especially in terms of fatty, mushroom-like and green aroma. The strongest fatty aroma was found in the flesh and the strongest floral aroma in the peel. At the turning stage, both the peel and flesh had the strongest aroma, and the maximum difference occurred at this stage. The concentrations of volatile components and the aroma intensity of CI1005 were significantly higher than those of TI4001. In conclusion, significant differences in volatile components and aroma existed between the peel and flesh of tomatoes.

Key words: Solanum lycopersicum; inbred line; fruit tissue; volatile organic compound; odor activity value; olfactory evaluation