Grape production

Caffeic acid is generally the most abundant hydroxycinnamic acid in fruit and vegetables. The richest sources are coffee (drink), lettuce, carrots, blueberries, blackberries, cranberries, sweet potatoes (whole, cooked, and raw) and potatoes (Table 2.2). Prunes, peaches, orange juice, apples, tomatoes, grapes, and grape products (Bet6s-Saura and others 1996) also contain small quantities of caffeic acid. 

Martin-Carron N, Goni I, Larrauri JA, Garcia-Alonso A and Saura-Calixto F. 1999. Reduction in serum total and LDL cholesterol concentrations by a dietary fiber and polyphenol-rich grape products in hypercholesterolemic rats. Nutr Res 19 1371-1381. 

Martin-Carron N, Saura-Calixto F and Goni I. 2000. Effects of dietary fibre and polyphenol-rich grape products on lipidaemia and nutritional parameters in rats. J Sci Food Agric 80 1183-1188. 

Makris DP, Kallithtaka S and Kefalas P. 2006. Flavonols in grapes, grape products and wine burden, profile and influential parameters. J Food Compos Anal 19 396-404. 

Mazza, G., Anthocyanins in grapes and grape products, Crit. Rev. Food Sci. Nutr., 35, 341, 1995. 

The anthocyanin pigments of native and hybrid varieties have been studied extensively. Much of the impetus for this work came from efforts to detect the addition of hybrid wine to vinifera wine in Europe and, conversely, the addition of vinifera grape concentrate to Concord concentrate, juice, and other grape products (48,49) in the United States. 

It was postulated that the inhibition of LDL oxidation by red wine may help to explain the French paradox. Since Frankel and co-workers [73] showed that red wine inhibit the oxidation of LDL, several in vitro studies have confirmed this finding [26,74,75]. There is controversy over whether or not the consumption of red wine by humans reduces the oxidation of LDL ex vivo. While several studies found resistance of LDL oxidation after 2 weeks of red wine consumption in healthy subjects [75,76], others found no effect on the oxidation of LDL ex vivo [26,77]. Recently, Stein and coworkers [78] showed that short-term ingestion of purple grape juice (7.7 1.2 mL/Kg/day for 14 days) reduced the susceptibility to oxidation in coronary artery disease patients and that this is a potential mechanism by which flavonoids in purple grape products may prevent cardiovascular events, independent of alcohol content. 

Phenolic compounds are of interest due to their potential contribution to the taste (astrin-gency, bitterness, and sourness) and formation of off-flavor in foods, including tea, coffee, and various fruit juices, during storage. Their influence on the appearance of food products, such as haze formation and discoloration associated with browning in apple and grape products, is also significant. Furthermore, analysis of these phenolic compounds can permit taxonomic classification of the source of foods. The importance of each phenolic compound and its association with the quality of various foods is described further in Sec. IV, on food applications. 

The anti-carcinogenic effects of resveratrol were also tested in vivo, by examination of mammary glands of mice treated with DMBA and TPA. A dose-dependent reduction in the formation of tumors was observed when the mice were treated with resveratrol. Resveratrol is present in high concentrations in the skins of grapes (50-100 pg/g) and, consequently, in red wine (1.5-3 mg/1). Based on these experiments, the consumption of grapes and grape products appears to have beneficial effects. 

Resveratrol and piceid are mainly present in grape and grape products, and its composition is affected by grape variety, maturity degree at harvest, fungal... 

Figure 5. Distribution of (W) wine production, (B) winery bottling, and (P) grape products production outside of California (23)...

Versini, G., Rapp, A., Marais, J., Mattivi, R, Spraul, M. (1996). A new 1,1,6-trimethyl-1, 2-dihydronaphtalene (XDN) precursor isolated from Riesling grape products Partial structure elucidation and possible reaction mechanism. Vitis, 35, 15-21. 

Wu, Q., Wang, M. and Simon, J.E. (2005) Determination of proanthocyanidins in fresh grapes and grape products using liquid chromatography with mass spectrometric detection, Rapid Commun. Mass Sp., 19(14), 2062-2068. 

Profiling and content of such compounds in grape products depends on the grape variety and how it interacts with berry ripeness and climatic and agronomic factors (Marais et al., 1992). 

Versini, G., Rapp, A., Reniero, F. and Mandery, H. (1991) Structural identification and presence of some p-menth-l-endiols in grape products, Vitis, 30, 143-149. 

Alcohol is an important food ingredient that is often used as a carrier for various flavourings and for the production of vinegar. In general grape products and related products must be produced completely by Jews in order to be acceptable as kosher. Once these are heated (e.g. pasteurised), however, or alcohol coming from other sources (i.e. potatoes) may be handled or manufactured by non-Jews. 

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