Grapes aromatic

The variability of grape aromatic content is even greater. Some varieties possess characteristic aromas. At present, not all of the molecules responsible for these aromas have been identified. In certain varieties, such as the Concord, descendant of... 

The addition of exogenous glycosidases enhance greatly aromas in wines in relation with the aromatic potential of grape varieties. Tastings confirm that the improvement is obvious for red and for white wines. Wines are always judged more fruity and more intense. 

Fig. 4.7.3 H NMR spectra of (a) apple juice and (b) grape juice samples. Vertical expansions are shown for aliphatic and aromatic regions and some assignments are indicated. (Permission granted to reprint this figure from Ref. [12].)...

Grapes release numerous hydrocarbons in the adjacent gas volume. We have found alkanes, alkenes, and aromatic hydrocarbons (II). Accordingly, we extracted the skin waxes of the grapes with n-pentane and investigated the extracts by using a combination GLC-mass spectrometer. The total amounts of the wax extracts contained about 0.5% paraffins, 89% of which were saturated hydrocarbons ranging from Ci3 to C3i. 

Amine and Aminophenol Derivatives. Amines and aminophenols (Table VIII) react with the F-C reagent about as predicted considering the aromatic amino groups equivalent to phenolic hydroxyls. This would be an important interference with total phenol assay in samples with appreciable aromatic amine content. Fortunately, for this and other reasons as well, the major wine grapes and most other fruit and vegetable products are free of significant concentrations of aromatic amines which would interfere. Correction might be made for methyl anthranilate... 

Both structures nicely illustrate the different characteristic oxygenation patterns in aromatic rings derived from the acetate or shikimate pathways. With the stilbenes, it is noted that the terminal ester function is no longer present, and therefore hydrolysis and decarboxylation have also taken place during this transformation. No intermediates, e.g. carboxylated stilbenes, have been detected, and the transformation from cinnamoyl-CoA/malonyl-CoA to stilbene is catalysed by the single enzyme. Resveratrol has assumed greater relevance in recent years as a constituent of grapes and wine, as well as other food products, with antioxidant, anti-inflammatory, anti-platelet, and cancer preventative properties. Coupled with... 

As outlined above, Vin Santo wines are essentially a group within the larger collection of dessert wines that are made mainly from non-aromatic grapes, and which in Italy are called "vino passito" or passito. This term "passito" generally means "wine made from dried grapes" (Italian vino da uve passite) (Table 3.2). 

TABLE 3.3 The non-aromatic passito wines (other than Vin Santo) produced in Italy from non-aromatic and semi-aromatic grape varieties... 

Vin Santo is made by starting with the choice of the best grapes (scelti) of the white varieties that are grown in each zone. As a "sweet wine that is little characterized by terpene aromas, the making of Vin Santo can use non-aromatic or semi-aromatic grape varieties. Not all of the "non-varietal" grapes, however, are suitable for producing Vin Santo,... 

Similarly, as for the production of other passito wines from partially dried grapes, such as Recioto, Albana passito, and Picolit (which we refer to as "non-aromatic passito wines"), generally the grape varieties and clones used should be those with a thicker skin and more open clustered small berries, as these are best for drying under mild conditions, with less... 

While most of the studies carried out to date have focused on the evolution of the primary compounds, such as the sugar and acid components, little data exist for the other quality characteristics, and in particular, for aroma. However, most of these studies have been conducted on the aromatic varieties. For instance, some experimental studies conducted on different aromatic cultivars under different conditions mainly reported the evolution of terpene compounds during the dehydration process. Accordingly, it has been showed that after the grape harvest, activation or inhibition of the metabolism involved in the biosynthesis of the aroma compounds is strictly dependent on the grape dehydration technique. 

Recently, a new style of port wine has been created, the Rose. This is a pink-colored wine, obtained by light maceration of red grapes. These are highly aromatic, with notes of cherry, raspberry, and strawberry, as well as appearing soft and pleasant on the palate. 

Oliveira, C., Silva Ferreira, A. C., Barbosa, A., Guerra, J., and Guedes de Pinho, P. (2006). Carotenoid profile in grapes related to aromatic compounds in wines from Douro region.. Agric. Food Chem. 71, S001-S007. 

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. 

Thibon, C., Shinkaruk, S., Jourdesa, M., Bennetau, B., Dubourdieu, D., and Tominaga, T. (2010). Aromatic potential of botrytized white wine grapes Identification and quantification of new cysteine-S-conjugate flavor precursors. Anal. Chim. Acta 660,190-196. 

Tominaga, T., Blanchard, L., Darriet, P., and Dubourdieu, D. (2000). A powerful aromatic volatile thiol, 2-furanmethanethiol, exhibiting roast coffee aroma in wines made from several Vitis vinifera grape varieties. ]. Agric. Food Chem. 48,1799-1802. 

The most important and frequent winds in winter are the Bora, which blows from the northeast, and the south wind, which blows from the southeast. In summer, beneficial and characteristic breezes blow from south to north. These breezes are important in facilitating the accumulation of aromatic compounds in grapes during ripening by generating desirable temperature fluctuations. 

Plants. In apples, grapes, rice, and sugar beet, the major component is unchanged tebufenozide. Small amounts of metabolites result from oxidation of the alkyl substituents of the aromatic ring, primarily at the benzylic positions Soil. Metabolic DTJ0 in soil 7-66 days DT50 for field dissipation 4—53 days. No mobility below 30 cm... 

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