Variation in the mineral composition of wine produced using different winemaking techniques

Abstract

It has been reported that the concentrations of minerals in wines can be used to discriminate their geographical origin. However, some winemaking techniques may also affect the mineral concentration of the final product. In this study, we examined the effects of various winemaking techniques, including (i) fining, (ii) aging with oak tips, (iii) maceration with grape skins, (iv) chaptalization and acidification, and (v) yeast nutrient addition for alcohol fermentation, on the concentration of 18 minerals (Li, B, Na, Mg, Si, P, S, K, Ca, Mn, Co, Ni, Ga, Rb, Sr, Mo, Ba and Pb) in a total of 154 wine samples using grapes from different production areas. Among the various winemaking techniques, maceration with grape skin had the largest effect on mineral content, significantly changing the concentrations of 17 or 18 elements (B, Na, Mg, Si, P, S, K, Ca, Mn, Co, Ni, Ga, Rb, Sr, Mo, Ba and Pb). Fining treatment using bentonites had the second largest effect, altering the concentrations of 14 elements (Li, B, Na, Si, P, S, Ca, Co, Ga, Rb, Sr, Mo, Ba and Pb). However, in principal component analysis using all data (n = 154), the wine samples were clearly clustered according to grapes used in the experiments rather than the winemaking technique. In conclusion, some winemaking techniques significantly altered the concentration of some minerals in wine; however, the principal factor influencing wine mineral composition seems to be its geographical origin.

Keywords: Elemental composition; Geographical origin; Inductively coupled-plasma atomic emission spectrometry; Inductively coupled-plasma mass spectrometry; Metrology; Multi-element analysis; Oenology; Wine.