Grape aroma composition

Methods for the study of grape flavour have often been employed in flavour analysis of other fruits and beverages. Techniques such as solvent extraction (Cacho et al. 1992) or headspace methods (Kallio 1991) may be used to isolate volatiles, and analysis usually involves gas-liquid chromatography (Cronin 1982), coupled with mass spectrometry (Merritt and Robertson 1982). Such methods have provided qualitative and some quantitative assessment of grape aroma composition, usually as part of research on wine flavour (Strauss et al. 1986 Rapp 1988 Eti vant 1991). 

The winemaker is always facing problems due to the weakness of grapes which composition is variable and different for each vintage. He tries to prevent oxidation and to work with soft conditions to preserve grapes components important for the wine s equilibrium. The sanitary state of the harvest is of first importance Grapes composition depends on the variety, terroir, viticulture and climatic conditions. The main objective for the winemaker is to keep and valorize grape components like aromas which will determine the quality of the wine... 

It is used in a large number of blossom fragrances. However, its use in perfumes for soap and cosmetics is limited because it causes discoloration. It is used in aroma compositions (e.g., in grape and citrus flavors). 

Most of the studies on Botrytis-specific aroma compounds have investigated the aroma composition of wines (Table 6.7). Only a few have focused on what occurs in the grape. On synthetic media, the main odorous compounds produced by B. cinerea are aromatic aldehydes (benzaldehyde, phenylacetaldehyde), and furfural (Kikuchi et al., 1983). Sarrazin et al. (2007a) confirmed the higher concentration of phenylacetaldehyde in noble-rotted grapes. 

Houtman, A. C., Morais, J., Du Plessis, C. S. (1980) Factors affecting the reproducibflity of fermentation of grape juice and of the aroma composition of wines. I Grape maturity, sugar, inoculation concentration, aeration, juice turbidity and ergosterol. Vitis, 19, 37-54. 

The next step of the biotechnical sequence, yeast fermentation, is of the utmost importance to the chemistry of winemaking as well as to the formation of flavor substances. We have investigated this previously using 14C-tagged compounds (16). Amino acids, for example, enter the yeast fermentation with a quasi biochemical valence with regard to the formation of metabolic side products like alcohols and esters. In that respect, the composition of the fermentation substrate, the grape must, is highly important to the formation of aroma substances by yeasts. 

Monoterpenoids have been described as being responsible for the varietal aroma of some wines. The characteristic composition of this chemical class in several grape varieties is claimed to be only marginally influenced by the growing area while other find effect of light exposure. These compounds are responsible for the aroma profile of the Muscat... 

Aroma components of citrus fruit juice128-132 are different from that of essential oils (see Section 4.15.4.5 for composition of the latter).133-135 Other familiar fruits like apples,136 grapes,137 strawberries,129 138 bananas,139 and pineapples140 were analyzed as well. Place of origin (e.g., grapes) and ripeness of the obtained fruit (e.g., pineapples), in many cases, bring substantial difference in its composition and enantiomeric properties (Table 14).141... 

Control of bacteria development is essential for the production of wines with consistent compositional and sensory characteristics. Although malolactic fermentation (MLF) is frequently carried out in the winery due to its beneficial effects on wine aroma and palate, for certain grape varieties and wine styles MLF is considered detrimental. Moreover, even in the cases where MLF is desirable, the wine might... 

EgUnton, J. M., McWilUam, S. J., Eogarty, M. W., Erands, 1. L., Kwiatkowski, M. J., H0j, P. B., Henschke, P. A. (2000) The effect of Saccharomyces bayanus-mediaHtd fermentation on the chemical composition and aroma profile of Chardonnay wine. Australian Journal of Grape and Wine Research, 6, 190-196. 

Francis, 1. L., Newton, J. L. (2005) Determining wine aroma from compositional data. Australian Journal of Grape and Wine Research, 11, 14-126. 

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