β-Cyclodextrin-assisted extraction of polyphenols from vine shoot cultivars

This work optimized the β-cyclodextrin (β-CD)-assisted extraction process of polyphenols from vine shoots. The efficiency of β-CD was compared to that of ethanol in terms of the quantity and antioxidant capacity (AC) of the extracted polyphenols. Response surface methodology permitted the optimization of the β-CD concentration, time, and temperature. The optimal polyphenol content (PC) [5.8 mg of gallic acid equivalent (GAE)/g of dry matter (DM)] and AC [3146 micromolar trolox equivalent per milliliter (μMTE)] were initially obtained with Syrah cultivar after an extraction of 48 h at 66.6 °C with a 37.7 mg/mL aqueous β-CD solvent. The same PC (5.8 mg of GAE/g of DM) was reached with 50% ethanol/water solvent after 1.65 h. However, a lower AC was found with ethanol (2000 μMTE) compared to β-CD. A comparison of the PC and AC of four different vine shoot cultivars was realized. Our results clearly show the capacity of β-CD to amplify polyphenol extraction from vine shoots.