title: Phenolic composition and antioxidant capacity of pomaces from four grape varieties (Vitis vinifera L.).
abstract: BACKGROUND
  Phenolic compounds are widely distributed secondary metabolites in plants usually conferring them with unique taste, flavour and health-promoting properties. In fruits of Vitis vinifera L., phenolic composition is highly dependent on grape variety. Differential extraction of these compounds from grapes during winemaking is critically associated with wine quality. By-products of winemaking, such as grape pomace, can contain significant amounts of polyphenols. However, information concerning the varietal effect on wine grape pomace is scarce. In this study, pomaces from Sauvignon Blanc (SB), Chardonnay (CH), Cabernet Sauvignon (CS) and Carménère (CA) grape varieties were characterized spectroscopically and by HPLC-DAD analysis.
  
  
  RESULTS
  White grape pomaces (SB and CH) presented higher antioxidant capacities and higher contents of total phenols and total proanthocyanidins compared with red grape pomaces (CS and CA), whereas the latter showed much higher anthocyanin levels and colour intensities. Concentrations of monomeric proanthocyanidins and low-molecular-weight phenols in the four grape pomace varieties were significantly different.
  
  
  CONCLUSIONS
  Grape pomaces from four varieties showed high but diverse contents of polyphenols and antioxidant capacities. Thus grape pomaces represent an important potential source of polyphenols, which could be useful for nutritional and/or pharmacological purposes.
authors.affiliation: Department of Agro-Industry and Enology, Faculty of Agronomical Sciences, University of Chile, PO Box 1004, Santiago, Chile.
authors.forename: Aarón
authors.initials: A
authors.lastname: de la Cerda-Carrasco
authors.forename: Remigio
authors.initials: R
authors.lastname: López-Solís
authors.forename: Hugo
authors.initials: H
authors.lastname: Nuñez-Kalasic
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Peña-Neira
authors.forename: Elías
authors.initials: E
authors.lastname: Obreque-Slier
mesh_terms: D000872:Anthocyanins / Q000032:analysis / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003116:Color; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D044945:Proanthocyanidins / Q000032:analysis / Q000494:pharmacology*; D013045:Species Specificity; D027843:Vitis / Q000737:chemistry* / Q000145:classification; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D044945:Proanthocyanidins
keywords: by-products; polyphenols; pomace; proanthocyanidins; winemaking