Subcritical Water Extraction of Phenolic Compounds from Vineyard Pruning Residues: Evaluation of Chemical Composition and Bioactive Properties

Abstract

The objective of this work was to optimize subcritical water extraction (SWE) conditions of phenolic compounds and antioxidant activity from vineyard pruning residues. For that, a central composite design (CCD) was conducted to investigate the influence of temperature (123–307 °C) and time (14–56 min). The optimal extraction conditions were 33 min and 280 °C, revealing a high TPC (229 ± 23 mgGAE/g dw) and antioxidant activity by FRAP and ABTS assays (228 ± 20 and 236 ± 11 mgAAE/g dw). The phenolic composition revealed high amounts of catechin, gallic acid and quercetin. SWE demonstrated to be a powerful extraction technique for polyphenols recovery from vine-canes.

Keywords

• vineyard pruning residues
• safety
• polyphenols
• antioxidants
• valorization