LAUSR

The sensomics approach was applied to both green and red Toona sinensis (TS) varieties dried with different methods (freeze-drying, solar-drying, and oven-drying) to elucidate their influences on the key odorants in TS. Odorant screening via comparative aroma dilution analysis revealed eugenol with the highest flavor dilution factor in all six samples. Quantitation of 44 odorants via stable isotope dilution assays and semiquantitation of six compounds via internal standard method showed (E,E)-, (E,Z)-, and (Z,Z)-di-1-propenyl disulfide, dimethyl sulfide, β-ionone, eugenol, cis- and trans-2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, 2- and 3-methylbutanal, and 2-isopropyl-3-methoxypyrazine with high odor activity values (OAVs) in all samples. Differences were found for (E,Z)-2,6-nonadienal, (E,E)-, (E,Z)-, and (Z,Z)-di-1-propenyl trisulfide, 3-methylnonane-2,4-dione, and (E)-2-hexenal with clearly higher OAVs in freeze-dried (FDTS) and solar-dried TS (SDTS) compared to oven-dried TS (ODTS). Linalool, 2-methoxyphenol, and 4-ethylphenol (the latter two only for red TS) were obtained with high OAVs only in FDTS. In general, ODTS showed lowest OAVs, whereas FDTS as the gentlest drying process revealed the highest OAVs for most odorants, and consequently, the highest aroma quality. However, the overall aroma of SDTS did not differ too much from FDTS, and thus, solar-drying as much easier and cheaper technique might be the best choice.