Precursors of Aroma Compounds

Aroma compounds are formed during the oxidative degradation of carotenoids. Such compounds, their precursors and the foods in which they occur are listed in Table 3.59. The mentioned ionones and 3-damascenone 

Tomato, raspberry, blackberry, passion fruit, black tea 

Tomato, coffee, black tea, wine, beer, honey, apple 

The odor thresholds of the R- and S-form (about 1 pg/kg, water) differ rarely. 

Of all Ci3-norisoprenoids, P-damascenone and P-ionone, smelling like honey and violets respectively, have the lowest odor threshold values (Table 3.59). Precursor of P-damascenone is neoxanthine, out of which the Grasshopper ketone (I in Formula 3.142) is formed by oxi- 

---