Journal article

Production and Isomeric Distribution of Xanthylium Cation Pigments and Their Precursors in Wine-like Conditions: Impact of Cu(II), Fe(ll), Fe(III), Mn(II), Zn(II), and AI(III)

Anque Guo, Nikolaos Kontoudakis, Geoffrey R Scollary, Andrew C Clark

Journal of Agricultural and Food Chemistry | American Chemical Society | Published : 2017

Abstract

This study establishes the influence of Cu(II), Fe(II), Fe(III), Zn(II), Al(III), and Mn(II) on the oxidative production of xanthylium cations from (+)-catechin and either tartaric acid or glyoxylic acid in model wine systems. The reaction was studied at 25 °C using UHPLC and LC-HRMS for the analysis of phenolic products and their isomeric distribution. In addition to the expected products, a colorless product, tentatively assigned as a lactone, was detected for the first time. The results show the importance of Fe ions and a synergistic influence of Mn(II) in degrading tartaric acid to glyoxylic acid, whereas the other metal ions had minimal activity in this mechanistic step. Fe(II) and Fe(..

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University of Melbourne Researchers

Grants

Awarded by Wine Australia


Awarded by Key Agricultural Technology Program of Shaanxi Province, China


Funding Acknowledgements

This project (NWG1401) was funded by Wine Australia with funds from Australian grape growers and winemakers with matching funds from the Commonwealth of Australia. The National Wine and Grape Industry Centre (NWGIC) is a research center within Charles Sturt University in alliance with the Department of Primary Industries NSW and the NSW Wine Industry Association. The research visit to the NWGIC by Dr. Anque Guo was funded by the China Scholarship Council and compliments the research of the Key Agricultural Technology Program of Shaanxi Province, China (2015NY131).