Volatile compounds grapes

Feeding repellents for pest birds are the most important application of chemical stimuli to manipulate bird behavior. Methyl anthranilate (Fig. 13.1) and dimethyl anthranilate, esters of benzoic acid, are found in concord grapes and are used as artificial flavorings. Starlings, Sturnus vulgaris, have an aversion to methyl anthranilate, which irritates the trigeminal nerve, and they feed less on food flavored with a variety of anthranilates. They avoid the more volatile anthranilates most. The odor is partly responsible for the effect contact is not necessary. In one particular experiment, only volatile compounds were aversive (Mason and Clark, 1987). If only anthranilate-treated food is offered, the birds will accept more of the flavored food than they do if they offered a choice between... 

White musts and wines made without maceration contain very low amounts of flavonoids. However, when making white wine from white grapes, skin contact at low temperature is sometimes performed before pressing and fermentation to increase extraction of volatile compounds and aroma precursors. After 4h of skin contact, the concentration of flavanol monomers and dimers in must was increased threefold. Delays between harvest and pressing, especially if sulfur dioxide is added to prevent oxidation, as well as thorough pressing, similarly result in increased concentrations of flavonoids in white musts and wines. " " ... 

Bellincontro, A., De Santis, D., Botondi, R., Villa, I., and Mencarelli, F. (2004). Different postharvest dehydration rate affects quality characteristics and volatile compounds of Malvasia, Trebbiano, and Sangiovese grapes for wine production. ]. Sci. Food Agric. 84, 1791-1800. 

Fig. 4.4 Effect of alcoholic fermentation and yeast strain on the concentration of glycoside-derived volatile compounds and of different classes of glycosidic precursors during the fermentation of a model grape juice containing Muscat glycosides. The control refers to a non-fermented sample kept under the same conditions utilized for fermentation, which accounts for add catalysed hydrolysis of glycosides (adapted from Ugliano 2006)...

Ugliano, M., Bartowsky E.J., McCarthy, J., Moio, L. Henschke P.A. (2006). Hydrolysis and transformation of grape glycosidicaUy bound volatile compounds during fermentation with three Saccharomyces yeast strains. J. Agric. Food Chem., 54, 6322-6331. 

Wirth, J, Guo, W., Baumes, R. Gunata, Y. Z. (2002). Volatile compounds released by enzymatic hydrolysis of glycoconjugates of leaves and grape berries from Vitis vinifera Muscat of Alexandria and Shiraz cultivars. J. Agric. Food Chem., 49, 2917-2923. 

Spillman, P. 1., Sefton, M. A., Gawel, R. (2004a). The effect of oak wood source, location of seasoning and coopering on the composition of volatile compounds in oak-matured wines. Aust. J. Grape Wine Res., 10, 216-226. 

Hanseniaspora uvarum (anamorph Kloeckera apiculata) is commonly the major yeast present on the grape berry and in musts and juices, but due to low tolerance to ethanol, populations decline quickly in the presence of Saccharomyces cerevisiae. Strains are typically characterised by low fermentative ability and high production of acetic acid, ethyl acetate and acetaldehyde, which render such strains more suitable to vinegar production. Nevertheless, Ciani and Maccarelli (1998) surveyed 37 isolates and found considerable variability, with some strains producing concentrations of these compounds approaching concentrations present in wines made with Saccharomyces cerevisiae (Table 8D.6). Cofermentation fermentation with Saccharomyces cerevisiae can produce wines with an acceptable balance of volatile and non-volatile compounds and sensory scores (Ciani et al. 2006 Jemec and Raspor 2005 Jolly et al. 2003b Zohre and Erten 2002). 

Ugliano, M. Moio, L. (2008). Free and hydrolytically released volatile compounds of Vitis vinifera L. cv. Fiano grapes as odour-active constituents of Fiano wine. Analytica Chimica ACTA, 621, 79-85. 

Lopez, R., Ezpeleta, E., Sanchez, I., Cacho, J., and Ferreira, V. (2004). Analysis of the aroma intensities of volatile compounds released from nuld acid hydrolysates of odourless precursors extracted from TempranUlo and Grenache grapes using gas chromatography-olfactometry. Food Chem., 88, 95-103. 

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