ABSTRACT
Grape (Vitis vinifera) is one of the world’s largest fruit crops with a global production of around 55 million tones and 26 million tones of wine in 2008. Ÿis generates a large amount of pomace, including grape stems, skins, and seeds (OIV 2009). Recent investigations have stressed the importance of vini¤cation by-products as plant materials, particularly rich in a wide range of polyphenols. Phenolics are chemicals that have di•erent structures and biological activity and can be divided into two groups: non¨avonoids (hydroxybenzoic and hydroxycinnamic acids and stilbenes) and ¨avonoids (anthocyanins, ¨avonols, and ¨avanols) (Rodríguez Montealegre et al. 2006). Red grape seeds are excellent sources of monomeric phenolic compounds such as catechin, epicatechin, epicatechin gallate, and dimeric, trimeric, and tetrameric procyanidins as well as highly polymerized proanthocyanidins. Phenolic
34.1 Introduction 329 34.2 Phenolic Compounds in Red Grape Seeds 330 34.3 Color-Composition Relationships of Grape Seed Extracts 332 34.4 Conclusions 335 Acknowledgment 335 References 335
compounds of wine have also attracted much interest due to their antioxidant properties and their potentially bene¤cial e•ects for human health (Scalbert et al. 2005), and they are important determinants in sensory and nutritional quality of fruits and vegetables. Ÿe study of polyphenols and its relationship with the antioxidant power is very interesting for the wine sector (Borbalán et al. 2003) because by-products are cheap sources of natural antioxidants.
