P-Damascenone

Of all these, probably P-phenethyl alcohol (2) comes closest to the odor of fresh rose petals however, mixing all these components does not reproduce the total fine character of the natural oil. It has been determined that a number of trace constituents representing less than 1% of the volatiles are critical to the development of the complete rose fragrance (10). These include cis- and trans-i.ose oxide (1), nerol oxide (12), rose furan (13), /)i7n7-menth-l-en-9-al (14), P-ionone (15), P-damascone (16), and P-damascenone (3). 

Rose. Rose is one of the most important florals ia perfumery, the most valuable derivatives of which are produced from Rosa damascena, which is grown principally ia Bulgaria, but also ia Russia, Turkey, Syria, India, and Morocco. The concrete, absolute, and steam-distilled essential oil (rose otto) are particularly valuable perfume iagredients. Careful handling and processiag of freshly picked flowers are required to produce these materials of warm, deeply floral, and rich odor quaUty. They are complex mixtures of which citroneUol (9), geraniol (8), phenethyl alcohol [60-12-8] (21), and P-damascenone [23726-93 ] (22) (trace component) are important odor constituents. 

In contrast to the rather simple cases of wintergreen and grape aromas, that for roses is complex. Rose oil contains at least 275 chemical constituents, of which citronellol is the major one. However, two of the minor constituents make the major contribution to rose aroma—p-damascenone and P-ionone ... 

Of the 400 volatiles detected in the tomato, only 17 have a positive impact on the flavor profile. Two of the most important ones are also key players in the aroma of roses p-ionone and p-damascenone. Another player is methyl salicylate, a compound we previously encountered in oil of wintergreen. Some of the most important flavor elements are present in very small concentrations but can be perceived by us at these extremely small concentrations. 

Figure G1.1.3 FID gas chromatogram of a direct injection of the headspace above concentrated extract of Concord grape essence using OV101 substrate. Note the size of the methyl anthranilate peak and the absence of a convincing peak for p-damascenone.

Figure G1.1.3 shows a chromatogram of the headspace of Concord grape essence prepared by direct injection. At retention index 1320 is the peak caused by methyl anthranilate, one of the strongest odorants characterizing Concord grapes however, (i-damascenone, the second most potent odorant in Concord grapes, elutes at 1360 but is not visible. This is because P-damascenone is lOOOx more potent (i.e., its odor threshold is lOOOx lower than methyl anthranilate). This is typical result for the direct injection of headspace from natural products. Figure Gl.1.4, on the other hand, shows the injection of an extract of Concord grape essence concentrated 500-fold with the fi-damascenone peak large enough for quantitation.

Figured.1.4 An FID chromatogram of concentrated extract of the same Concord grape essence shown Figure G1.1.3, drawn to display the data on a linear retention index scale. By simply comparing the index of a peak with the data listed in the flavornet, the odorants that have similar retention indices can be determined. Notice how large the methyl anthranilate peak is, but still no convincing peak for p-damascenone, even though both compounds have the same odor activity (intensity).

TCH increased (Fig. 5.12A), whereas the levels of p-ionone (Fig. 5.12B) and p-damascenone decreased. Over 40-year-old ports had, respectively, 15, 5, and 3 times higher levels of TDN, vitispirane, and TCH than young ports. 

In addition to GC-MS, recent studies have focused on the identification and quantitative analysis of impact odorants in botrytized wines using gas chromatography-olfactometry (GC-O) analysis. Sarrazin et al. (2007a) investigated numerous botrytized and nonbotry-tized Sautemes wines. They could identify several key odorants that were responsible for the sensory differences between the wines, notably 3-mercaptohexan-l-ol, various furanons, ethyl-hexanoate, methional, phenylethanol, phenylacetaldehyde, sotolon, p-damascenone, and 2-methyl-3-furanthiol. 

In a more recent study, Bailly et al. (2009) investigated the stability of key odorants during bottle aging in Sautemes wines. Except for 3SH, polyfunctional thiols were found unstable. However, most other key odorants (e.g., sotolon, phenylethanol, esters, y-lactones, p-damascenone, etc.) were still detected within 5-6 years. 

P-Damascenone Fruity, quince, canned apple Sauternes Sweet Fiano Bailly et al. (2009), Genovese et al. (2007), Sarrazin et al. (2007a)... 

Theaspirane p-Damascenone p-lonone aTDN 1,1,6-trimethyl-1,2-dihydronaphtalene... 

The significance of a minor component having an important contribution to the odour qualities is illustrated by P-damascenone. Although only present at about 0.14%, it gives 70% of the total odour. 

P-Damascenone Sambucus canadensis, S. nigra (Caprifoliaceae), OD-R (elderberry, fruity,... 

Fig. 4.6 Mechanisms of formation of a terpenes from geraniol and geranyl glucoside b p-damascenone from megastigm-5en-7yne-3,9-diol and its glucoside...

Kotseiidis, Y, Baumes, R., Skouroumounis, G. K. (1999a). Quantitative determination of free and hydrolytically liberated P-damascenone in red grapes and wines using a stable isotope dilution assay. J. Chromatogr. A, 849, 245-254. 

In contrast, odour intensity of other components related to off flavours ( herbal , sawdust , greasy , and cucumber ) can be seen to decrease with toasting. The same happened with the intensity of fruity and floral aromas of linalool oxide, p-damascenone, or 2-phenylethanol, and the oak lactones odour descriptors. 

Several Ci 3-norisoprenoids, including p-damascenone, p-ionone, and 1,1,6-trimethyl-1,2-dihydronaphtalene (TON), are powerful odorant in wine. P-Damascenone, which can be present in young wine at up to 180 times its odour threshold of 0.05 (Jig/L, has a stewed apple, rose, honey aroma (Francis and Newton 2005). P-Ionone, which has violet, flower, and raspberry aroma, is typically present at higher concentration in red wines. TDN develops a kerosene-like odour in aged whites, particularly Riesling (Francis and Newton 2005). 

Odor descriptions of dilute water solutions of P-damascenone and 1-nitro-2-phenylethane were also obtained using a panel of 18-20 judges. p-Damascenone as a 10 ppb solution in water was described as having an odor most similar to (1) prunes (2) apple (3) sweet character and (4) tomato in that order (i.e. being most like prunes). The odor of 1 ppm solutions of 1-nitro-2-phenylethane were described as (1) green (2) geranium (3) tomato and (4) oily in that order. 

The key odorants of fresh tomatoes and tomato paste are compared in Table 6.46. (Z)-3-hexenal (no. 1), p-damascenone (no. 2), epoxy-decenal isomers nos. 3 and 5, p-... 

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