Orthogonal test design for optimisation of extraction of trans-resveratrol from Pinot Noir-grape pomace

Abstract

Yield of trans-resveratrol from Pinot Noir-grape pomace obtained by microwave-assisted extraction (MAE) through an orthogonal experiment (16 (4⁴)) was investigated to get the best extraction conditions. In this method, the highest yield was obtained when the extraction solvent used ethanol; the ratio of raw material to solvent, the extraction time, the extraction temperature and microwave irradiation power were 1 : 20 (g mL⁻¹), 30 min, 55°C and 1.0 kW, respectively. The average yield of trans-resveratrol was 90.87%, and the recovery was in the range of 85.49–89.04% with relative standard deviation lower than 1.39%. Then, the extract of MAE was separated by NKA-9 macroporous resin and re-crystallisation. Finally, the purity of trans-resveratrol was 97.47%.

Keywords:

• trans-resveratrol
• grape pomace
• microwave-assisted extraction
• macroporous resin
• re-crystallisation