Estudo dos compostos fenólicos, potencial antioxidante e perfil dos ácidos graxos presentes em bagaço de uva da variedade Cabernet Sauvignon

Abstract

The wine processing generates several wastes, the pomace is the most abundant of them. Studies indicate that these products of winemaking are rich in fatty acids and phenolic compounds, so the objective of this research was to study the phenolic compounds, antioxidant potential and profile of fatty acids present in grape pomace of Cabernet Sauvignon. Ethanol 40% (v/v) was used as solvent extractor of phenolic compounds, which were measured by the Folin-Ciocalteau reagent. Flavonoids were estimated using the colorimetric method with aluminum chloride and the pH differential was used to determine the monomeric anthocyanins. The antioxidant potential was assessed by the methods of Sequestration Radical DPPH and ABTS and Ferrous Ion Chelating activity. The lipid extract was obtained by cold solvent extraction and the methyl esters by acid catalysis. High Performance Liquid Chromatography and Gas Chromatography were used to identify and quantify the phenolic compounds and the profile of fatty acids, respectively. The pomace showed a concentration of 5101.82 ± 119.03 mg GAE.100 g-1 for phenolic compounds, 2983.91 ± 51.76 mg CE.100 g-1 for total flavonoids and 2092.93 ± 71.57 mg mal-3-glu.100 g-1 for monomeric anthocyanins. The sample showed EC50=5048.00 ± 0.04 μg.mL-1 in the DPPH• assay, EC50=764.00 ± 0,01 μg.mL-1 in the ABTS+• assay and EC50=72.98 ± 0.59 μg.mL-1 in the study of the chelating ability of ferrous ion. Using the HPLC, resveratrol, vanillic acid and gallic acid were identified. The gallic acid had the greater quantity. The GC analysis showed that the lipid extract is rich in linolenic acid, and, moreover, was observed the presence of nine fatty acids. The analyzed by-product was rich in bioactive compounds, so the feasibility of extracting should be studied, because would originate natural products, which please to consumers and also protects the environment.