A clustering of red wines based on physicochemical and optical properties

Abstract

Sixty-nine samples of red wines, produced in different regions of Bulgaria, Chile and South Africa from the Merlot (42 samples) and Cabernet Sauvignon (27 samples) grape varieties are characterized by 13 physicochemical and optical properties. The physicochemical characteristics (antioxidant activity and anthocyanin content) have been obtained spectrophotometrically, while the antioxidant activity (AOA) has been measured by using both DPPH and ABTS methods. Based on a hierarchical cluster analysis with an average linkage algorithm, the studied wines from grape variety Merlot as well as the ones from grape variety Cabernet Sauvignon, according to their antioxidant activities (AOA ABTS and AOA DPPH) and anthocyanins content are grouped into three generalized groups. When integral fluorescence intensities at an excitation wavelength of 265 nm are added as a factor, for the wines from the grape variety Cabernet Sauvignon there is not any difference in their grouping, and for the ones from grape variety Merlot, the only difference is that one sample of wine passes to the first cluster. The results, obtained from the clustering procedure are presented graphically by dendrograms.