The Effects of Different Plant Extracts on Wine Phenolic Contents and Antioxidant Activities Used as an Alternatives of Sulphur Dioxide During Wine Production

Sulphur dioxide (SO2) is commonly used as an antioxidant and antimicrobial additive during wine production. Nowadays, consumers preferred foods treated with natural preservatives. The aims this study was to determine the effects of different natural plant extracts as an alternative of sulphur dioxide used in wines. Wine production was done according to the accepted conventional method of red wines (Cabernet sauvignon). The experimental design was achieved by using different plant extracts (grape pomace, rosemary and blueberry) at different concentrations. As control groups were used wine samples produced without addition of SO2. At the end of production basic oenological analyses (total acidity, volatile acidity, pH, dry matter, ash, free and total SO2) and specific wine analyses (total phenols, total flavanols, tartaric ester content and antioxidant activity) were performed. Results demonstrated that each used plant exact have different effects on wine quality parameters. The lowest concentrations of grape pomace extract caused reduction of SO2 and keeping the required wine properties. The highest value of antioxidant activities and total phenols were determined in the wine treated with 25 mg/L SO2 and 1 ml/L rosemary extract (in the 1st mount of storage) and 25 mg/L SO2 and 1 ml/L grape pomace extract (in the 2nd and 3rd mount of storage) as 89.92%, 5550.48 mg/l GAE; 88.51%, 5028.65 mg/l GAE; 88.42%, 4974.25 mg/l GAE, respectively. Results emphasized the importance of used plant extracts and their concentrations. The study demonstrated the possibilities of optimization of SO2 and wines phenols on the base of used natural plant extracts.