Recovery of flavonoids from grape skins by enzyme-assisted extraction

Abstract

Grape skin contains large amounts of different flavonoids so it can be used for their recovery. Optimization of enzyme-assisted extraction of flavonoids was conducted using oenological enzyme preparations with respect to enzyme dosage, temperature, extraction time, pH, and enzyme preparation. Optimal conditions were obtained using enzyme preparation Lallzyme EX-V, at the temperature of 45°C, time of 3 h, pH 2.0, and enzyme dosage of 10.52 mg/g. The new optimized extraction method is less expensive, simple, accurate, and selective for the recovery of simple flavonoids. It is based on an environmentally-friendly extraction solvent which may provide a valuable alternative to conventional methods.

Keywords:

• Enzyme-assisted extraction
• grape skins
• flavonoids
• pectinases

Acknowledgements

The authors are grateful to Vedran Plichta from the Ireks Aroma d.o.o. (Zagreb, Croatia) for providing enzyme preparations Endozym Contact Pelliculaire and Endozym Rouge. The authors wish to thank the student Matija Lesković for his great assistance in experimental section.