Biological potential (phenolic complex and antioxidant activity) of white grapes and wines from varieties with different genetic origin, grown in the region of Central Northern Bulgaria

Introduction.The aim of the present study is to define the biological potential (based on phenolic complex and antioxidant activity) of white grapes (and their corresponding wines) grown under the influence of the terroir of Central Northern Bulgaria. Materials and methods.The objects of the research were grapes and wine from the white varieties Chardonnay, Dimyat and Druzhba, harvest 2021, grown in the experimental plantations of the Institute of Viticulture and Enology (IVE), Pleven.Chemical analysis, analysis of phenolic compounds and antioxidant activities of grape musts and wines were made.Results and discussion.The highest amount of total phenolic compounds (TPC) was found in the grape must of the local variety Dimyat.The study of the presence of flavonoid phenolic compounds (FPC) in the grape musts showed that Chardonnay has the highest potential for FPC accumulation.The highest amount of non-flavonoid phenolic compounds (NPC) was found in the grape must of the control introduced variety Chardonnay.At titratable acid (TE) 600.00 mg/dm 3 , the highest antioxidant activity was found in the grape must of the Druzhba hybrid.Dominance in the content of TPC was found in the wine form the local variety Dimyat (0.93±0.000 g/dm 3 ), while the Chardonnay showed the lowest amount of TPC (0.45±0.000 g/dm 3 ).In terms of FPC content, Chardonnay wine dominated (696.46±0.37 mg/dm 3 ), and Dimyat had the lowest content (439.38±3.35mg/dm 3 ).The highest concentration of NPC was found in the wine of the Druzhba hybrid (130.47±0.59mg/dm 3 ).The lowest result according to this indicator was found in the wine of the control variety Chardonnay (84.13±0.43mg/dm 3 ).The Chardonnay wine showed significantly higher antioxidant activity compared to the other two studied varieties -1.5 times higher radicaleliminating activity compared to Dimyat and compared to Druzhba -2 times higher.Conclusions.The research proved that the white varieties and wines grown in the region of Central Northern Bulgaria showed a balanced biological activity and potential, comparable to wines and grapes from other regions of the world.