Evaluation of some spectroscopic characteristics and chemical composition of wines from the Thracian lowland.

Moderate consumption of wine 1-2 glasses a day during meals contributes to the supply of various antioxidants and essential elements for the body. Wines from the region of the Thracian lowland of varieties Dimiat, Sauvignon Blanc, Cabernet Fran, Rubin, Syrah, Merlot, and Chardonnay have been studied. Fluorescence spectra at the wavelength for excitation light at 245, 265, 275, and 295 nm were studied. The fluorescence peak in the region 400-420 nm at excitation wavelengths 260-275 nm is associated with the presence of flavonoids and polyphenols. The color parameters in the CIELab colorimetric system and the transmission spectra of the samples in the visible spectrum were measured. From the data on the optical density at 420, 520, and 620 nm, parameters such as color intensity and hue were calculated, which are qualitative characteristics related to the age of the wine. According to the data, the white wine Sauvignon Blanc belongs to the group of aged wines. The presence of a predominant green component (a<0) in the Bulgarian white wines of the Chardonnay variety distinguishes them from other wine varieties. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine the concentration of toxic and essential elements that are important for the quality of wines. The presence of some elements such as Pb and Cd is of particular interest due to their toxicity in case of overuse. On the other hand, the presence of high concentrations of Fe, Zn, and Cu has a negative effect on the organoleptic properties of wine [ABSTRACT FROM AUTHOR]