Abstract

Chilean wine exports increased from 52 to 835 millions US-dollars between 1990 and 2004. They mainly consist of the red varieties Cabernet Sauvignon, Merlot and Carmenère. For sustainable long term growth, it is essential to develop a reliable system to verify product authenticity. For varietal authenticity in red wine, various authors proposed the use of the ratio between acetylated and coumaroylated anthocyanins (Rac/cum). In the present paper, the anthocyanin, flavonol, and shikimic acid profiles were determined in wines produced in Chile during the vintages 2001-2004, in order to differentiate between wine varieties. The results of principal component analysis of anthocyanins show that it is possible to differentiate between the three grape varieties using only their anthocyanin profiles. This is confirmed by linear discriminant analysis of these compounds, which classified well a total of 95.8% of the investigated wines. Only by the Rac/cum ratio, it is not possible to differentiate between Merlot and Carmenère, however, this ratio tends to discriminate between Cabernet Sauvignon and the other two varieties. The concentration of shikimic acid improves the differentiation between Cabernet Sauvignon and Merlot or Carmenère, but not between the latter two varieties. With respect to flavonols, our results show that the ratio of total quercetin/ total myricetin (TQ/TM) in combination with peonidin-3-glucoside in a simple ratio or with all anthocyanins determined in a model improves the differentiation between Carmenère and Merlot. The high error of classification in Merlot is in part attributed to the fact that in Chilean vineyards this variety was previously confused with Carmenère.