Polyphenolic composition of grape stems

Abstract

This study is focused on the study of polyphenolic compounds in grape stems as by-product of winemaking industry. Two white varieties of Grüner Veltliner and Sauvignon and two red varieties of Blauer Portugieser and Cabernet Moravia were selected for the study. Antioxidant activity, concentration of total polyphenols and concentration of individual phenolic compounds were determined. The results show a higher concentration of polyphenols and higher values of antioxidant activity in red varieties. The Blauer Portugieser variety contained the highest concentrations of syringic acid 1.346 mg.L-1, caffeic acid 20 mg.L-1, ferulic acid 1.192 mg.L-1, coumaric acid 3.231 mg.L-1, trans-resveratrol 14.195 mg.L-1, catechin 79.314 mg.L-1 and epicatechin 33.205 mg.L-1. Cabernet Moravia contained the highest concentration of protocatechuic acid 1.201 mg.L-1, the Sauvignon variety reached the highest concentration of gallic acid 4.015 mg.L-1 and hydroxybenzoic acid 0.076 mg.L-1. The highest values of alpha-amino acids were determined in the Blauer Portugieser variety 165.3 mg L-1 and the lowest in the Grüner Veltliner variety 33.3 mg L-1. The highest concentration of ammonia nitrogen was 214 mg L-1 for the Blauer Portugieser variety and the lowest concentration of ammonia nitrogen was measured in Cabernet Moravia 35.7 mg L-1.

Exploring the Antioxidant Potential of Phenolic Compounds from Winery By-Products by Hydroethanolic Extraction

“…Catechin was also found in the studies performed by Leal et al [ 12 ], Costa-Pérez et al [ 17 ], Esparza et al [ 56 ], and Prusova et al [ 57 ].…”

Grapevine Wastes: A Rich Source of Antioxidants and Other Biologically Active Compounds

“…Prusova et al [ 29 ] have conducted a comparative study between different grape stalks from white (Sauvignon blanc and Grüner Veltliner) and blue (Blauer Portugieser and Cabernet Moravia M-43) grape varieties. The waste material was first crushed and homogenized.…”

Content of selected polyphenolic substances in parts of grapevine

“…Water content in grape stems varies in the range of 55-80%, depending on the grape variety, and the dry matter contains 71% of alcohol-insoluble residues. No differences were reported between red and white varieties (González-Centeno et al, 2012;Prusova et al, 2020).…”

“…Ordinarily, the same results were measured in Mandilaria, Mavrotragano, Voidomatis, Asyrtiko, Athiri and Aidani in the range 70-469 µg/g dw. Quite higher results were discovered byRadovanović et al (2019) using extraction with MeOH/H 2 O/HCl (1,430-1,580 µg/g dw) andAnastasiadi et al (2012) (10.5-11.5 mg/g of residue).The lowest concentration of 0.822-4.005 µg/mL of extract was measured byPrusova et al (2020). The reason for different results could be the extraction method.…”