title: Influence of Grape Seeds and Stems on Wine Composition and Astringency.
abstract: The aim of this paper is to study the real influence of seeds and stems on wine composition, astringency, and bitterness. A decolored grape juice and a grape juice macerated for 4 days from the same Cabernet Sauvignon grapes were fermented with or without supplementation with 100% seeds, 300% seeds, or 100% stems. Once alcoholic fermentation had finished, the wines were analyzed and tasted. The presence of seeds and stems increased the concentration of flavan-3-ol monomers with respect to the controls. However, the seeds mainly released (+)-catechin and (-)-epicatechin, whereas the stems mainly released (+)-catechin and (+)-gallocatechin. The seeds and stems also released proanthocyanidins; those from seeds have a lower mDP and a high percentage of galloylation, whereas those from stems have a higher mDP and a relatively high percentage of prodelphinidins. The presence of seeds and stems brought about a slight but significant increase in pH and lowered titratable acidity and ethanol content. The presence of seeds boosted color intensity, whereas stems had the opposite effect. Finally, both seeds and stems increased wine astringency and bitterness.
authors: Departament de Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili , C/Marcel.li Domingo s/n, 43007 Tarragona, Spain.
authors: Olga
authors: O
authors: Pascual
authors: Departament de Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili , C/Marcel.li Domingo s/n, 43007 Tarragona, Spain.
authors: Elena
authors: E
authors: González-Royo
authors: Departament de Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili , C/Marcel.li Domingo s/n, 43007 Tarragona, Spain.
authors: Mariona
authors: M
authors: Gil
authors: Instituto Regional de Investigación Científica Aplicada, Universidad de Castilla-La Mancha , Campus Universitario s/n, 13071 Ciudad Real, Spain.|Fundación Parque Científico y Tecnológico de Albacete , Paseo de la Innovación 1, 02006 Albacete, Spain.
authors: Sergio
authors: S
authors: Gómez-Alonso
authors: Instituto de la Vid y el Vino de Castilla-La Mancha , Ctra. Toledo-Albacete s/n, 13700 Tomelloso, Ciudad Real, Spain.
authors: Esteban
authors: E
authors: García-Romero
authors: Departament de Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili , C/Marcel.li Domingo s/n, 43007 Tarragona, Spain.
authors: Joan Miquel
authors: JM
authors: Canals
authors: Instituto Regional de Investigación Científica Aplicada, Universidad de Castilla-La Mancha , Campus Universitario s/n, 13071 Ciudad Real, Spain.
authors: Isidro
authors: I
authors: Hermosín-Gutíerrez
authors: Departament de Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili , C/Marcel.li Domingo s/n, 43007 Tarragona, Spain.
authors: Fernando
authors: F
authors: Zamora
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D001252:Astringents / Q000032:analysis*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D010936:Plant Extracts / Q000032:analysis*; D018547:Plant Stems / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013649:Taste; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D001252:Astringents; D010936:Plant Extracts
keywords: astringency; bitterness; seeds; stems; wine composition