Zhang Xinyi, Kontoudakis Nikolaos, Wilkes Eric, Scrimgeour Neil, Hirlam Kieran, Clark Andrew C
National Wine and Grape Industry Centre, Wagga Wagga, NSW 2678, Australia; School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
National Wine and Grape Industry Centre, 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.
Food Chem. 2021 Sep 30;357:129764. doi: 10.1016/j.foodchem.2021.129764. Epub 2021 Apr 9.
Specific forms of Cu in wine can influence wine flavour and development. The co-polymer polyvinylimidazole/polyvinylpyrrolidone (PVI/PVP) is known to remove Cu from wine, but its impact on different Cu forms is uncertain. In this study, three Cu fractions in white wine were determined by colorimetry and two Cu fractions in red wine were determined by diatomaceous earth depth filtration and atomic spectroscopy. PVI/PVP, with either silica or chitosan formulations, reduced all three fractions of Cu measured in white wines, and sulfide-bound Cu in red wines. The inefficient removal of organic acid-bound Cu in red wines was linked to the higher pH of red wines. After PVI/PVP treatment, wines showed lower concentrations of hydrogen sulfide, but minimal changes in weaker Cu binding agents. These results demonstrate that PVI/PVP efficiently removes the least desirable form of Cu present in wine, along with its detrimental binding agent (i.e., hydrogen sulfide).
葡萄酒中特定形态的铜会影响葡萄酒的风味和发展。已知共聚物聚乙烯基咪唑/聚乙烯基吡咯烷酮（PVI/PVP）能去除葡萄酒中的铜，但其对不同形态铜的影响尚不确定。在本研究中，采用比色法测定白葡萄酒中的三种铜组分，采用硅藻土深度过滤和原子光谱法测定红葡萄酒中的两种铜组分。含二氧化硅或壳聚糖配方的PVI/PVP降低了白葡萄酒中测得的所有三种铜组分以及红葡萄酒中硫化物结合态的铜。红葡萄酒中有机酸结合态铜去除效率低与红葡萄酒较高的pH值有关。经过PVI/PVP处理后，葡萄酒中硫化氢的浓度降低，但较弱的铜结合剂变化极小。这些结果表明，PVI/PVP能有效去除葡萄酒中最不理想的铜形态及其有害结合剂（即硫化氢）。
