Monoterpenes cultivars

Volatiles of three cultivars of mango (Jaffna, Willard, and Parrot) from Sri Lanka were analysed, and among the 76 components identified, monoterpenes and sesquiterpenes hydrocarbons were described as the major contributors [42]. Variations in the amounts of esters, ketones, and alcohols were also related. 

The desired citrus flavor is the result of volatile compounds in specific proportions. Citrus oils have unique composition profiles depending on the cultivar, the processing conditions, and the storage conditions. There have been more than 200 different compounds identified in citrus oils. However, the degree of unsaturation in monoterpenes leads to rapid oxidation and unstable compounds. The reactivity and volatility of citrus oils require strict quality control protocols. 

GC-MS analysis to study the content and composition of extracts of celery revealed the presence of terpenoids, sesquiterpenoids and phthalides in the essential oils and extracts obtained with organic solvents from two celery cultivars (Wolski et al., 2004). The composition of the essential oil obtained from the fruits of three A. graveolens var. dulce cultivars, i.e. Helios, Orient and Zefir, showed that the main components of the essential oil were isoprenoids, including monoterpenes and sesquiterpenes. Essential oil content ranged from 2.5 to 3.0%. The percentage... 

Versini, G., Rapp, A., Dalla Serra A. and Nicolini, G. (1997) Use of bound forms profile to improve the variety discrimination capability of monoterpenes in wines from some floral and non-floral groups of cultivars the case of Rhine Riesling crosses, in H.P. Kruise and M. Rothe (Eds) Proceed. 5th Wartburg Aroma Symposium, Eisenach, Germany, Eigenverlag Univ., Postdam. 

Comparison of cultivars. The analysis of the monoterpene fraction of the aroma isolated from the three cultivars is given in table I. The analysis was carried out using both 0V-101 and Carbowax 20M... 

Table I. Monoterpenes found, in 3 blackcurrant cultivars (levels in...

Formation and metabolism of monoterpenes by yeasts. Although certain species of yeasts are capable of producing monoterpenes (80,81), the wine yeast species Saccharomyces cerevlslae appears not to share this capacity (82). Accordingly, it has been concluded that terpene composition in various grape cultivars and varietal wines is not Influenced by fermentation (6,82). Although apparently unable to biosynthesize monoterpenes, wine yeasts may carry out certain transformations of these compounds (e.g. double bond reduction) (83). 

In general, examinations of intraspecific floral scent indicate considerable variability in scent composition. Most information about qualitative variation within species comes from studies of domestically cultivated flowering plants. For a given species, it is possible that all plants produce flowers that have the same number and type of compounds. This was shown to be the case for the scents of 4 snapdragon cultivars, in which 8 volatile compounds occurred in all cultivars. A study by Kim et al. (2000) reported 41 compounds in the scent of roses including 8 different classes of compounds (alcohols, aldehydes, alkanes, monoterpenes, sesquiterpenes, ethers, esters, and ketones). They examined 3 cultivars and found that each had approximately 30 compounds, but only 19 of those (63%) were found in all 3 cultivars. Another study of 4 cultivars of lavender by Kim and Lee (2002) reported that each produced approximately 28 compounds, with only 14 in common (50%) (Fig. 8.2 and 8.3). ... 

Australian Journal of Grape and Wine Research 11,114-126 Genisheva, Z. Oliveira, J.M. (2009). Monoterpenic characterization of white cultivars from Vinhos Verdes appellation of origin. (North Portugal) Journal of the Institute of Brewing 115(4), 308-317... 

Figure 1.14. Monoterpenes present in some cultivars of Vitis vinifera.

Figure 1.15. Monoterpene glycosides present in some cultivars of Vitis vinifera. The R-groups represent geraniol, nerol, linalool, citronellol, or a-terpineol.

The monoterpene pattern can be used to differentiate cultivars. For example, a clear distinction can be made between wines from the grape cultivar White Riesling and wines from other grape cultivars which are also sold as Riesling . As shown in Fig. 20.7, the monoter-pene concentrations (especially of linalool, hotrienol, a-terpineol, and 3,7-dimethylocta-l,5-fraws-dien-3,7-diol) in White Riesling are considerably higher than in the other Riesling wines. 

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