Characterization of Phenolic Compounds in Wine Lees

Abstract

The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant (p < 0.05) impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50–62%) and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity) assay was strongly correlated with the DPPH (α,α-diphenyl-β-picrylhydrazyl) assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications.

Olive Mill and Winery Wastes as Viable Sources of Bioactive Compounds: A Study on Polyphenols Recovery

“…This agrees with the results found here, i.e., samples from northern Spanish areas (O3, O4) and/or those produced with arbequina olives contain lower phenolic concentrations. Regarding winery residues, the yield for sample W3 (lees filters, white wine, chardonnay, sauvignon blanc, and xarel•lo varieties) was clearly lower than those of the rest of the winery samples, which is related to the lower phenolic contents of lees from white wines compared to lees of reed wines [49]. Conversely, the phenolic yield of sample W4 (lees filters, red wine, garnacha, tempranillo, cabernet sauvignon, and cariñena) was the highest, in the range of winery residue samples, and thus the filters of lees of red wine production appeared to be a good source for the recovery of polyphenols.…”

How to express the antioxidant properties of substances properly?

“…The antioxidant activity of the examined sample is expressed, similar to Trolox, as the gallic acid equivalent (GAE) in the units, for example mol/g sample (Sirivibulkovit et al 2018) or mg gallic acid equivalents (GAE)/100 g sample (dry weight) (Wang et al 2019). In all cases, the results were calculated according to the standard curve of gallic acid (Boutennoun et al 2017;Zhijing et al 2018). Similarly to the TEAC value, determining the GAE value is related to the lack of standardization of its determination and the unification of units.…”

Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees

“…Higher consumption of phenolic antioxidants (accomplished through moderate consumption of wine, especially red wine) correlates to a decreased incidence of certain coronary heart diseases [18][19][20][21][22][23]. The most relevant phenolic and polyphenolic compounds in red grapes are tannins, anthocyanins, flavanols, flavonols, and stilbenes of which most notable are the resveratrols, phenolic acids and their derivatives [24][25][26][27][28][29][30].An important compound in red wine containing particular antioxidant properties is resveratrol (3,5,4'-trihydroxy-stilbene) [31][32][33]. A very important class of polyphenolic compounds in wines are the flavonoids, which constitute >85% of the total phenol content in red wines.…”