Comparison and analysis of tomato flavor compounds using different extraction methods

Aroma is an essential sensory characteristic of tomato fruit and it plays an important role in the classification and consumer acceptability of tomato products. In this study, five methods including stir bar sorptive extraction, purge and trap (P&T), solvent-assisted flavor evaporation (SAFE), solid-phase micro-extraction (SPME), dynamic headspace sampling (DHS) were used to extract the flavor compounds from tomato fruits. The performances of each method by gas chromatography-olfactometry-mass spectrometry were also compared. The results showed that DHS method was not suited for the flavor compounds extraction from tomato samples. A total of 85 flavor compounds were identified by the rest of four extraction methods, including aldehydes (24), alcohols (18), ketones (10), esters (8), phenols (11), olefins (4) and other compounds (10). Among the four extraction methods, SAFE and SPME methods had better extraction efficacy and 73 compounds which accounted for 87% of all flavor compounds were extracted by this two methods. Aroma extract dilution analysis and calculation of odor activity values indicated that hexanal, 3-hexenal, (E)-2-hexenal, 1-penten-3-one and guaiacol were active aroma compounds in tomato fruit.