Effect of variety, time of eating, and fruit-to-fruit variation on volatile release during eating of tomato fruits (Lycopersicon esculentum)

Tomato fruits were eaten by one individual while expired air from the nose was sampled into an atmospheric pressure ionization-MS fitted with an air-sampling interface. The release of seven volatile compounds from four different types of tomato was followed, and the concentration of volatiles on the breath with time was determined. Different tomato types contained significantly different concentrations of each compound, resulting in a type-specific volatile "fingerprint". However, the temporal aspects of the release profile of each compound were consistent across all types and were specific for that compound, except for enzymically released compounds from Delice tomatoes. Three classes of compound were identified in terms of their release characteristics. Some compounds (e.g., isobutylthiazole) are formed during ripening and show rapid release, other compounds are formed by the lipid oxidation pathway when tissue is macerated and are released rapidly (hexenal) or more slowly (hexenol) depending on the enzyme reactions that form them.