“…Except for a set of 16 volatiles characterized as possessing higher concentrations than their odor thresholds (Buttery, 1993), some compounds might act as background notes to impact overall aroma quality in spite of their negative odor units (Klee & Giovannoni, 2011;Tandon, Jordan, Goodner, & Baldwin, 2001). These compounds are derived from a serial of healthpromoting compounds, and thus could act as the signals of tomato ripeness and nutritional quality (Goff & Klee, 2006;Ponce-Valadez et al, 2015). During fruit ripening or after treatments, change in the concentrations of some volatile compounds might result in the alternations of the log odor units, ratio of the volatile compounds as well as their interaction, resulting in the changes in tomato aroma (Klee & Giovannoni, 2011;Wang, Baldwin, Plotto, et al, 2015).…”