“XX SAVETOVANJE O BIOTEHNOLOGIJI” Zbornik radova, Vol. 20.(22), 2015. 347 POLYPHENOLS AND ANTIOXIDANT ACTIVITY OF DIFFERENT VINEGRAPE LEAVES Blaga Radovanović 1 , Marko Andjelković 1 , Vladimir Radovanović 1 , Ana Milenković-Andjelković 1 , Snežana Đekić 2 Abstract: The volume of the grape waste produced directly relates to the volume of grapes pressed and in turn depends on the specific climatic conditions of the relevant vintage. The aim of this work is to evaluate vinegrape leaves as a potential source of natural antioxidants – polyphenols for their possible use as dietary supplement or food antioxidants. To this purpose antioxidant activity and contents of phenolic compounds of the leaves extracts of five grape varieties of Vitis vinifera L (Vranac, Prokupac, Merlot, Gamay and Italian Rizling), grown in southern Serbia were investigated. The analysis show high content of polyphenols reflecting their high antioxidant activity (R 2 = 0.9819, p<0.01). According to the obtained results, the leaves extracts, can be considered rich natural source of phenolic compounds with good antioxidant properties. Key words: vinegrape leaves, polyphenols, antioxidant activity, tradicional medicine Introduction Grapes are the world`s largest fruit crop with more than 60 million metric tons (67.5 x 106 tons during 2009) produced annually (International Organization of Vine and Wine - OIV, 2010, www.oiv.int ).. Approximately 71% of world grape production is used for wine, 27% as fresh fruit, and 2% as dried fruit. However wine making leads to the generation of large quantities of grape waste (around 5-9 million tons per year, worldwide), which considerably increase the chemical oxygen demand (COD) and the biochemical oxygen demand (BOD) due to a high pollution load (high content of organic substance such as sugars, tannins, polyphenols, polyalcohols, pectins and lipids) with detrimental effects on the flora and fauna of dischanged zones (Baydar et al., 2004; Oreopoulou and Tzia, 2007). Serbia constitutes one of the middle grape and wine producers, with a grape production was 330 000 tonnes of which remains about 7 000 tons of grape by-products (skins, seeds, leaves and stems) which is only used for the production of alcohol, and most of ending up in landfills as organic waste (Statistical Serbian Office – RZS, 2012, www.stat.gov.rs ). 1 University of Niš, Faculty of Science and Mathemathics, Višegradska 33, 18000 Niš, Serbia (blaga_radovanovic@yahoo.co.uk ) 2 University of Niš, Faculty of Economics, Trg kralja Aleksandra 11, 18000 Niš, Serbia brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by CaSA NaRA