Robert W. Trenkle

The chemistry of flowers, fruits and spices: live vs. dead - a new dimension in fragrance research

The aromas of fruits, flowers, herbs, and spices perceptably change following picking of the plant part because the plant part is then, in effect, biologically dead. By collection and analysis of the headspace volatiles over various living and picked flowers, fruits, herbs, and spices the differences in the aroma profiles are traceable to quantitative differences in key volatile components. In addition, the same analytical technique permits the comparison of day vs. night volatile profiles for selected flowers and of various flower colors among the same family. The commercial application of this noble technology is also discussed.

Live vs. Dead. Part II. A Comparative Analysis of the Headspace Volatiles of Some Important Fragrance and Flavor Raw Materials

ABSTRACT The headspace volatiles of living and picked tea rose, narcissus, osmanthus, and spearmint were examined comparatively using Tenax as the trapping adsorbent and GC/MS as the method of analysis. It was found that the living rose possessed cis-3-hexenyl acetate (20.67%) as the major volatile component, whereas the major volatile component of the picked rose was 3,5-dimethoxy toluene. Living narcissus flowers were found to contain benzyl acetate (44.0%), 3,4- and 3,5-dimethoxy toluene (35.0%), and indole (5.0%), whereas picked flowers contained benzyl acetate (30–43%), 3,4- and 3,5-dimethoxy toluene (18–39.5%), and indole (0.3–1.0%). Osmanthus flowers (living) were found to possess β-damascenone, dihydro-β-ionol, and 4-keto-β-ionone, whereas these compounds were not detected in either air or nitrogen-purged picked flowers. Finally, harvested spearmint possessed carvone (70.0%) and limonene (2.0%) in its headspace, while the headspace of living spearmint was found to contain carvone (24.0%) and limon...