Sulfide-bound copper removal from red and white wine using membrane and depth filters: Impacts of oxygen, H2S-to-Cu ratios, diatomaceous earth and wine volume

Xinyi Zhang; Paul Bowyer; Geoffrey R Scollary; Andrew C Clark; Nikolaos Kontoudakis

doi:10.1016/j.foodchem.2021.131758

Sulfide-bound copper removal from red and white wine using membrane and depth filters: Impacts of oxygen, H₂S-to-Cu ratios, diatomaceous earth and wine volume

Food Chem. 2022 May 30:377:131758. doi: 10.1016/j.foodchem.2021.131758. Epub 2021 Dec 2.

Authors

Xinyi Zhang¹, Paul Bowyer², Geoffrey R Scollary³, Andrew C Clark⁴, Nikolaos Kontoudakis⁵

Affiliations

¹ National Wine and Grape Industry Centre, Mambarra Drive, Wagga Wagga, NSW 2678, Australia; School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. Electronic address: xizhang@csu.edu.au.
² Blue H(2)O Filtration, Oakleigh, VIC 3166, Australia. Electronic address: paul@blueh2o.com.au.
³ National Wine and Grape Industry Centre, Mambarra Drive, Wagga Wagga, NSW 2678, Australia; School of Chemistry, The University of Melbourne, Vic. 3010, Australia. Electronic address: scollary@unimelb.edu.au.
⁴ National Wine and Grape Industry Centre, Mambarra Drive, Wagga Wagga, NSW 2678, Australia; School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. Electronic address: aclark@csu.edu.au.
⁵ National Wine and Grape Industry Centre, Mambarra Drive, Wagga Wagga, NSW 2678, Australia; School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia; Laboratory of Enology and Alcoholic Drinks, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens 11855, Greece. Electronic address: nkontoudakis@aua.gr.

PMID: 35032852
DOI: 10.1016/j.foodchem.2021.131758

Abstract

Sulfide-bound Cu in wine is a potential contributor to the reductive development of wine. This study examines the effectiveness of filtration for the adsorptive removal of this Cu fraction. The copper concentration in wine before and after filtration was determined by atomic spectroscopy (total) and by stripping potentiometry and/or adsorptive methodologies (Cu fractions). Membrane filters (4.7 cm²) removed significant amounts of sulfide-bound Cu from 10 mL of wine, including 60-80 % removal using nylon membranes, but they could not efficiently remove Cu from larger volumes. Dissolved oxygen concentration in the wine immediately prior to membrane filtration did not impact Cu removal, while a high sulfide-to-Cu(II) ratio did enhance removal. Depth filters incorporating diatomaceous earth with cellulose (45 mm-diameter, 3.5 mm-thickness) showed the most efficient removal of sulfide-bound Cu from wines even after treatment of 3.0 L. The relevance of these laboratory scale filtrations to winery scale filtration is discussed.

Keywords: Adsorptive filtration; Copper sulfide; Cu forms; Diatomaceous earth; Sulfide-bound Cu.

MeSH terms

Copper / analysis
Diatomaceous Earth
Oxygen
Sulfides
Wine* / analysis

Substances

Sulfides
Diatomaceous Earth
Copper
Oxygen