The effects of copper fining on the wine content in sulfur off-odors and on their evolution during accelerated anoxic storage. (15th September 2017)

• Record Type: Journal Article
• Authors: Vela, Eduardo; Hernández-Orte, Purificación; Franco-Luesma, Ernesto; Ferreira, Vicente
• Is Part Of: Food chemistry. Volume 231(2017)
• Page Start: 212
• Page End: 221
• Publication Date: 2017-09-15
• Subjects: Reductive off-odors -- Sulfide -- Copper fining -- Reduction -- Sulfide-metal complexes -- Sulfide precursors; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2017.03.125
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: In some wines brine dilution (BR) method cannot detect some H2 S precursors. Copper treatments (CT) remove immediately free forms of H2 S and MeSH from wine. CT delay but do not impede the accumulation of H2 S and MeSH during anoxic storage. CT do not remove BR-forms and seem to induce a larger formation of BR-forms. Copper content does not change with CT, implying no CuS is separated. Abstract: Three different red wines with reductive character have been treated with two different doses of copper sulfate (0.06 and 0.5 mg/L) and with a commercial copper-containing product at the recommended dose (0.6 mg/L). Wines were in contact with copper one week, centrifuged and stored at 50 °C in strict anoxia for 2 weeks (up to 7 in one case). Brine-releasable (BR-) and free fractions of Volatile Sulfur Compounds were determined throughout the process. Relevant increases of BR-H2 S suggest that those wines contained other H2 S precursors non-detectable by the brine dilution method. Copper treatments had two major effects: 1) immediate decrease the levels of free H2 S and methanethiol (MeSH); 2) slow the rate at which free H2 S (not MeSH) increases during anoxic storage. After 7 weeks of anoxia levels of free H2 S and MeSH were high and similar regardless of the copper treatment. Higher copper doses could induce the accumulation of BR-H2 S.