Efecto de la microoxigenación después de la fermentación maloláctica en el aroma y composición fenólica de un vino cencibel

Se microoxigenó un vino Cencibel, variedad autóctona en la región de Castilla-La Mancha, de contenido polifenólico medio (IPTde50), durante dos meses después de la fermentación maloláctica, con una dosis de oxígeno total de 7mL/L, y se comparó con un vino control de elaboración tradicional. Se evaluaron los parámetros de compuestos volátiles (GC/MS) y compuestos responsables del color de los vinos (HPLC/MS y espectrofotometría), así como la evaluación sensorial realizada por catadores expertos. Se apreciaron diferencias organolépticas entre los vinos control y microoxigenados, no encontrándose apenas variaciones en los compuestos responsables del aroma y del color.Ministerio de Educación y Ciencia (España): proyecto AGL 2004-0720

Monitoring selected monomeric polyphenol composition in pre- and post-fermentation products of Vitis vinifera L. cv. Airén and cv. Grenache noir

A mass balance approach was used quantify select polyphenols in pre- and post-fermentation products resulting from the fermentation of Vitis vinifera cv. Grenache noir and Airén. For Grenache noir, the overall mass recovery was 102.7%. The main products were wine (78.3%), pomace (8.5%), lees (4.2%), and rachises (3.4%). Pomace was a rich source of all identified polyphenols. Lees sorbed significant amounts of gallic acid, catechin, epicatechin, malvidin-3-O-glucoside, malvidin-3-acetylglucoside, quercetin-3-O-glucoside, and quercetin. An approximately 200% increase in the total amount of gallic acid occurred during fermentation. For the Airén grapes, the overall mass recovery was >90%. The pomace, rachises, juice solids after settling, and lees constituted ∼50% of the total mass of products obtained; pomace alone accounted for 40% of the total product mass. Over 90% of the total amount of gallic acid, catechin and epicatechin and ∼50% of the quercetin-3-O-glucoside were found in the pomace

Analysis of volatile compounds of eucalyptus honey by solid phase extraction followed by gas chromatography coupled to mass spectrometry

Solid-phase extraction (SPE) followed by gas chromatography coupled to mass spectrometry has been used for the analysis of volatile compounds of eucalyptus honey. Different amounts of honey and dichloromethane were employed to optimize solid-phase extraction conditions. The best result was obtained with 20 g of honey eluted with 60 mL of dichloromethane. This method presented a good precision for volatile compounds usually found in honeys and allowed the quantification of 35 volatile compounds (terpenes and derivatives, furan and pyran compounds, ketones, benzene compounds, acids, and norisoprenoids) of eucalyptus honey.The authors are grateful to the Spanish Ministry of Agriculture, Fisheries and Food (INIA) for financial support under project API 99-004.Peer reviewe