Grapes monoterpenes important

By contrast, biosynthetic studies on whole fruits have been limited and, probably because of the low levels of monoterpenes In grapes, the pathways In Vltls species remain unexplored. Since monoterpenes important to the flavor of grapes are mainly acyclic, Interconversions of neryl, geranyl and llnalyl derivatives may be of special significance. The oxidative steps leading to polyol production represent a shunt of flavor-active compounds to flavorless forms and require investigation. 

Monoterpenes, norisoprenoids - some C13 megastigmane compounds -some benzenoid compounds called shikimates because of their origin from shikimic acid, and some polyfunctional sulphured compounds, are the most important grape-derived aroma compounds. In the winemaking process, these molecules are transferred to the wine both as free and bound forms. 

Monoterpenes1, mostly present as alcohols, ethers and hydrocarbons, represent the most important category associated with basic floral aroma, beginning from linalool recognized in Muscat grapes about 50 years ago (Cordonnier, 1956). Free and bound monoterpenes are... 

The Importance of Monoterpenes to the Flavor of Vitls vlnifera Grapes and Wines... 

An important aspect in understanding the metabolic processes is a knowledge of the control mechanisms involved. When the regulatory mechanisms inducing fruit to produce monoterpene flavorants become known It may be possible to alter varietal character of grapes by application of appropriate regulatory substances. It would then follow that vines could be adjusted to produce grapes tailor-made to the winemakers flavor specifications. 

Monoterpenes, Ci3-norisoprenoids, and some benzenoid compounds are the most important grape aroma substances present in the pulp and skin of berries in both free and glycoside forms. Profiles of these compounds in the grape are mainly dependent on the variety, even if environmental variables and agricultural practices influence their contents (Marais et al., 1992). These compounds are transferred to the wine in winemaking and depend on the process used. 

Monoterpenes in wines (principal structures are reported in Fig. 4.1) are mostly mono- and dihydroxylated alcohols and ethers (Strauss et al., 1986 Rapp et al., 1986 Versini et al., 1991 Winterhalter et al., 1998 Bitteur et al., 1990 Guth, 1995 Farina et al., 2005). These compounds, associated with the floral aroma of aromatic grapes, such as Muscat and Malvasie, Gewiirztraminer, and Riesling, are important variety markers (Rapp et al., 1978). 

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