Multi-element analysis and differentiation of Chilean wines using mineral composition and multivariate statistics

Abstract

Multi-element analysis and differentiation of Chilean wines using mineral composition and multivariate statistics. 2018. Cien. Inv. Agr. 45(2): 181-191. The concentration of seventeen metal elements was analyzed in 130 commercial samples of Chilean wines, using flame atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). The elements analyzed were within the usual concentration ranges previously reported in other wine regions (for example: Fe, 2.08 ± 0.99 mgL-1 ; Zn, 0.71 ± 0.44 mg L-1 ; K, 788± 219 mg L-1 ; and Na, 14.62 ± 8.6 mg L-1). When the metal content of the samples was compared among geographic areas, significant differences in the concentration of K, Na, Mn, Mg, Zn, and Cr were observed (p ≤ 0.05). Moreover, principal component and linear discriminant analyses, used to discriminate wines according to geographic area, obtained adjustments above 90% for white wines and over 70% for red wines.

The Use of Macro, Micro, and Trace Elemental Profiles to Differentiate Commercial Single Vineyard Pinot noir Wines at a Sub-Regional Level

“…The analyzed wine samples were collected from commercial wineries, and although winemaking procedures were similar, they were not identical and, thus, encompassed a larger heterogeneity in the elemental composition of wines than previously explored in wine authenticity studies [31]. At the same time, the collection of wine samples onsite, directly from fermentation vessels, provided much more experimental control and authenticity than studies that analyzed commercially produced wines purchased in supermarkets, where traceability was less certain [13,17,18,21,32].…”

“…Research efforts have shifted towards the applications of elements and elemental fingerprints, as well as isotope ratios, in determining wine authenticity, in part due to their chemical stability and independence of oxidation and aging reactions. Isotopic analyses such as D/H, 13 C/ 12 C, and 18 O/ 16 O but, also, 206 Pb/ 207 Pb, 208 Pb/ 206 Pb, and 87 Sr/ 86 Sr have shown great promise in authenticity studies; however, the limited precision of the standard quadrupole-mass spectrometer necessitates more expensive high-resolution mass spectrometry for such analyses [8,9]. Besides the need for isotopic databases, such as the EU Wine Isotopic databank, that measurements can be compared to, it is unclear how potential isotopic fingerprints will change due to the changing climate [10,11].…”

“…Studies using only inductively coupled plasma-optical emission spectroscopy (ICP-OES) [13], or other spectroscopy techniques, have been limited to major, and some micro-level, elements. By combining spectroscopic instruments, such as ICP-OES, with the low-detection limits of ICP-mass spectrometry (ICP-MS), a more complete set of elements can be utilized in wine discrimination [14][15][16][17][18][19][20]. Investigations relying specifically on ICP-MS either utilized different sample dilutions in order to analyze a more complete element profile [21,22] or limited the studies to trace any minor level elements [23][24][25].…”

“…Element profiles found in wine are believed to be related to the soil and environmental conditions where the grapes are grown; however, numerous studies have demonstrated that certain factors can alter the elemental content of a wine, such as processing [26][27][28], grape cultivar [22], wine style [15,18], vintage [15,29], and contamination [30]. Nevertheless, multiple studies have successfully distinguished the geographic origin of wine, such as elemental differences in wines made from of grapes grown in different countries [13,21,24,31] or the distinctions in wines originating from different regions within countries such as Canada [27,32], Slovenia [19], Italy [20,33], Spain [24], Germany [14,34], Portugal [17,35], New Zealand [36], Australia [15], the Czech Republic [16,30], South Africa [23,37,38], Chile [18,39], Romania [25,29], China [40], Brazil [41], and the United States [42]. The success of the authentication based on elemental fingerprints in these studies varied, possibly due to the analysis of different element profiles, wine styles, and winemaking practices and, possibly, the cultivars studied.…”

Mineral composition of organic and conventional white wines from Italy

“…The metal content of red wines is very different from that of white wines (Cabrita et al., 2018; Mirabal-Gallardo et al., 2018; Minganti and Drava, unpublished data); for this reason the present study was limited to white wines only.…”