Regional classification of New Zealand red wines using inductively-coupled plasma-mass spectrometry (ICP-MS)

Abstract

Red wines in a dataset of 120 single-region wines could be classified into seven of the major New Zealand winegrowing regions with an overall accuracy of 80.8% using leave-one-out linear discrimination with the elements Sr, Rb, Ni, Co, Pb, Mn, Cd, Ga and Cs. A higher classification accuracy of 94.4% was achieved when regions were combined into North Island, Nelson, and other South Island regions. The rare earth elements did not prove useful for regional classification, both because of their low and variable concentrations and because their concentrations can be increased upon bentonite fining. Wines originating in the Gimblett Gravels Winegrowing District could be discriminated from wines grown in the remainder of the Hawke's Bay region with a high degree of accuracy using Ba, Cs, Rb, and Pb. A small difference in elemental composition between Pinot Noir, Cabernet Sauvignon, and Merlot wines originating from the Hawke's Bay region was observed. However, despite this difference greater classification accuracy was obtained with a database containing all the red wines than a subset containing only Pinot Noir wines.