Study of Unpicked Grapes Valorization: A Natural Source of Polyphenolic Compounds and Evaluation of Their Antioxidant Capacity
Author/s
Elejalde, Edurne; Villarán, María; Lopez-de-Armentia, Iratxe; Ramón, Daniel; Murillo, Raquel; [et al.]Date
2022-03-21Keywords
Unpicked grape
Polyphenols
Antioxidant capacity
Ultrasound-assisted extraction
Grape valorization
Abstract
Every year great amounts of high-quality wine grapes are left on the vine unpicked, and consequently lost, to control the overproduction in wine areas with limited appellation production yield. In the context of circular bioeconomy, the valorization of these grapes as a potential source of natural antioxidants is of great interest. The study carried out is focused on the polyphenolic profile characterization of different unpicked grape varieties using the ultrasound-assisted extraction technique to extract the polyphenolic fractions. Moreover, the evaluation of the antioxidant capacity by several assays was carried out: oxygen radical absorbance capacity (ORAC), stability of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant capacity (FRAP), cupric reducing antioxidant capacity (CUPRAC) and stability of 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) assays. The results showed a strong relationship between total phenolic content and hydroxy ...
Type
article