Phenolic characterization of aging wine lees: Correlation with antioxidant activities

Abstract

Aging wine lees are water-wastes produced during the wine aging inside wood barrels that can be considered as alternative sources of bioactive compounds. Phenolic characterization and antioxidant activity (AA) measurements of wines lees solid-liquid extracts have been undertaken on a dry extract (DE) basis. Solvents with different polarities (water, methanol, ethanol, two hydroalcoholic mixtures and acetone) were used. Total phenolic (TPC) and total flavonoid contents (TFC) were determined. The mixture of 75:25(v/v) EtOH:HO showed the highest values with 254 mg/g and 146 mg/g respectively. HORAC, HOSC and FRAP were used to determine the AA of the extracts being also highest for the mixture of 75:25(v/v) EtOH:HO (4690 µmol/g, 4527 µmol/g and 2197 µmol/g, respectively). For ORAC method, methanol extract showed the best value with 2771 µmol/g. Correlations between TPC, TFC, phenolic compounds and AA were determined. Most relevant compounds contributing to AA were identified using data from mass spectrometry, being mainly anthocyanins.

Phenolic compounds and bioactivity evaluation of aqueous and methanol extracts ofAllium mongolicumRegel

“…Results from each program were pooled, and statistical analysis was conducted using GraphPad Prism 6.0. Romero-Diez et al (2018) also reported that aqueous extract of sample plant showed better extracting power for phenolic compounds compared with methanol extract. (Table 1) differed significantly (p < 0.05).…”

“…The data obtained in our study showed that the total phenolic and flavonoid content in A. mongolicum extracted by pure water was higher than that of methanol extract. Romero-Diez et al (2018) also reported that aqueous extract of sample plant showed better extracting power for phenolic compounds compared with methanol extract.…”

Identification and Antioxidant Activity of Flavonoids Extracted from Xinjiang Jujube (Ziziphus jujube Mill.) Leaves with Ultra-High Pressure Extraction Technology

“…It has been strongly substantiated that flavonoids are powerful radical quenchers in various systems. This phenomenon is presumably attributed to the high scavenging power of flavonoids, making it capable of rapidly deactivating a wide variety of radicals via electron transfer [32,33].…”

“…However, for both DPPH, ABTS assay and TFC, low correlations were all observed for R, Qu and A ( r = 0.554–0.779, p < 0.05). These differences observed between assays are related to the varieties, contents, molecular structures, and physical properties of individual compounds [32,34].…”

“…Thus, stereoisomerism, functional group distribution and any other structural parameters such as the oxidation state of the C-ring and the hydroxylation and methylation patterns are also expected to affect the final value [32,33,34,35]. It could be speculated that individual flavonoids exert their antioxidant activity differently.…”