Assessment of Bioactive Compounds in Red Wines Available for Purchase in Latvia

Moderate consumption of wine is associated with positive health effects. Red wine contains more polyphenolic compounds than white wine, so it is considered healthier. The aim of the study was to determine the concentration of bioactive compounds of red grape and berry wines available for purchase in Latvia. A selection of 15 red grape and berry wines purchased in Latvian supermarkets were analysed. The total phenol concentration was determined using the Folin-Ciocalteu spectrophotometric method with minor modifications. Total flavonoid concentration was determined using the colorimetric flavonoid determination method. Antiradical activity was determined using the DPPH (2,2-diphenyl-1-picrylhydraziyl) reagent and ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation determination method. The results show that the analysed red wine samples can be divided into five clusters according to the concentration of total phenols, flavonoids, and antiradical activity. Cluster 1 separately divided Latvian black chokeberry wine, with high total phenol concentration (TPC) and total flavonoid concentration (TFC), high antiradical activity via the DPPH method, and relatively low antiradical activity via ABTS method. Cluster 4 combined red wines with medium TPC, high TFC and high antiradical activity via both DPPH and ABTS methods, and included grape wines from different countries of origin. Cluster 5 combined red wines with high TPC, medium TFC, and medium antiradical activity via both DPPH and ABTS methods.