By En-Qin Xia, Gui-Fang Deng, Ya-Jun Guo and Hua-Bin Li
Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China
International Journal of Molecular Sciences, 2010
Grapes have a long and abundant history. During the ancient Greek and Roman civilizations, grapes were revered for their use in wine making. Nowadays, there are three main species of grapes: European grapes (Vitis vinifera), North American grapes (Vitis labrusca and Vitis rotundifolia) and French hybrids. Grapes are classified as table grapes, wine grapes (used in viniculture), raisin grapes, and so on, with edible seeds or seedless. People often enjoy the various grape products, such as fruit, raisins, juice and wine. Grape fruit contains various nutrient elements, such as vitamins, minerals, carbohydrates, edible fibers and phytochemicals. Polyphenols are the most important phytochemicals in grape because they possess many biological activities and health-promoting benefits [1–3]. The phenolic compounds mainly include anthocyanins, flavanols, flavonols, stilbenes (resveratrol) and phenolic acids [4–6]. Anthocyanins are pigments, and mainly exist in grape skins. Flavonoids are widely distributed in grapes, especially in seeds and stems, and principally contain (+)-catechins, (−)-epicatechin and procyanidin polymers. Anthocyanins are the main polyphenolics in red grapes, while flavan-3-ols are more abundant in white varieties [7–9].
From the clue of "French paradox", polyphenolics from grapes and red wines attracted the attention of scientists to define their chemical composition and their properties for human health [10]. The reported evidences of beneficial health effects of phenolic compounds include inhibiting some degenerative diseases, such as cardiovascular diseases [11–14], and certain types of cancers [15–17], reducing plasma oxidation stress and slowing aging [18,19]. Phenolic compounds are also regarded as reservatives against microbes and oxidation for food [20,21]. What’s more, in vivo assays showed that phenolic compounds are bioavailable [10,22]. Therefore, besides wine and juice, grape diet supplements would be promising functional foods worthy of popularization. However, some reports have also shown that at higher concentrations the effect of phenolic compounds on health was negative and some structures in particular promoted the negative effects [23]. In addition, some high molecular weight phenolics could not be absorbed [24,25]. Apparently, research on direct ingestion of different doses and compositions of grape products are the urgent task in the field.
The dietary consumption of grape and its products is associated with a lower incidence of degenerative diseases such as cardiovascular disease and certain types of cancers. Most recent interest has focused on the bioactive phenolic compounds in grape. Anthocyanins, flavanols, flavonols and resveratrol are the most important grape polyphenols because they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, antiaging and antimicrobial properties. This review summarizes current knowledge on extraction, isolation and identification methods, bioactivities, bioavailability and potential toxicity of grape phenolics. Special attention is paid to the bioactivities, including antioxidant, cardioprotective, anticancer, anti-inflammation, antiaging and antimicrobial properties. Finally, this paper tries to show some directions for further research and applications of grapes.
Download Full PDF Article: Biological Activities of Polyphenols from Grapes
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.
This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
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This page created 26 Sep 2010 17:36
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