Biotechnology and Bioprocess Engineering 2019; 24(6): 997-1006  
Preparation of Chlorophyll-free Young Barley Leaf Extract Powders Using Supercritical Carbon Dioxide Modified with Cosolvent
Jin-Hee Hong1, Seungjoo Haam1, Heaung-Shig Oh2, Giobin Lim2,*, and Jong-Hoon Ryu2,*
1Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Korea
2Department of Chemical Engineering, The University of Suwon 18323, Korea
Correspondence to: Giobin Lim*, Jong-Hoon Ryu*
Department of Chemical Engineering, The University of Suwon 18323, Korea
Tel: +82-31-220-2528
Received: June 18, 2019; Revised: August 29, 2019; Accepted: September 2, 2019; Published online: December 31, 2019.
© The Korean Society for Biotechnology and Bioengineering. All rights reserved.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
In this study, we attempted to prepare chlorophyll-free young barley leaf extract powders using three different supercritical carbon dioxide (SCCO2) drying processes. The pure SCCO2 drying process for a methanolic extract solution resulted in a ~30% increase in the antioxidant (saponarin and isovitexin) content and a ~75% decrease in the chlorophyll content compared to a solvent evaporation method. The drying process with ethanol-modified SCCO2 increased the antioxidant content considerably and completely removed the chlorophylls. However, this process could not dry an aqueous ethanolic extract solution with a more than 30% water content. The ethanol-modified SCCO2 drying process that employed a periodic flush with pure SCCO2 was found to effectively dry an aqueous ethanolic extract solution with more than 30% water content.
Keywords: supercritical carbon dioxide, young barley leaves, antioxidant, extract powders

This Article