The Effect of Different Fining Treatments on Phenolic and Aroma Composition of Grape Musts and Wines

Abstract

The study evaluated the effect of different fining treatments such as oenological additives and the influence of oxygen and hyperoxygenation on the phenolic and aroma composition of grape musts and wines. The oxidative method, hyperoxygenation and fining agents polyvinyl polypyrrolidone (PVPP), pea protein and chitosan were used for the removal of phenolic compounds compared to the control experiment. The content of phenolic substances was determined by high performance liquid chromatography. A total of 24 volatiles—higher alcohols, ethyl esters and acetate esters were determined using gas chromatography-mass spectrometry. A lower concentration of caftaric acid was observed in hyperoxygenated (0.21 mg·L−1), oxidated (0.37 mg·L−1), PVPP-treated (35.50 mg·L−1), pea protein-treated (42.56 mg·L−1) and chitosan-treated variants (44.40 mg·L−1), in contrast to the control must (caftaric acid 50.38 mg·L−1). In the final wine, the results were similar with a lower concentration of caftaric acid in hyperoxygenated (7.10 mg·L−1), oxidated (14.88 mg·L−1), PVPP-treated (23.49 mg·L−1), pea protein-treated (29.49 mg·L−1) and chitosan-treated variant (30.02 mg·L−1), in contrast to the control wine (caftaric acid 32.19 mg·L−1).

Keywords

• fining
• polyphenolic compounds
• volatile compounds
• white wine