Physiochemical, Clarification, and Antioxidant Properties of Aqueous Extract of Xiao-Chai-Hu-Tang as Affected by Membrane Process
ZER-RAN YU1, MEI-SU LIN2, YIH-MING WENG2 AND BE-JEN WANG2*
1. Graduate Institute of Natural Healing Sciences, Nanhua University, Chiayi, Taiwan, R.O.C.
2. Department of Food Science, National Chiayi University, Chiayi, Taiwan, R.O.C.
(Received: February 24, 2012; Accepted: August 31, 2012)
ABSTRACT
Xiao-chai-hu-tang (XCHT) is a traditional Chinese herbal medicine which has been demonstrated to exhibit antioxidant and hepatoprotective functions. To reduce the unpleasant dark brown color and precipitates during storage, the performances of membrane process on the clarification and antioxidant capability of XCHT was evaluated. A membrane system equipped with either a microfiltration membrane (0.45 μm) or one of four ultrafiltration membranes (UK 200, UK 50, UP 20 and UK 10) was used. Our results indicated that less total solid was filtered through the membranes and thus a higher degree of clarification degree was achieved in permeates. Higher concentrations of active compounds, such as total phenolic compounds, saikosaponins, glycyrrhizin and baicalin, were detected in permeate using membranes of smaller pore-size of membranes. Antioxidant capabilities, including scavenging of free radicals, reducing power and total antioxidant activity of permeates, increased as compared to those of feed, particularly of permeates obtained with a UK 10 ultrafiltration membrane. Taken together, membrane process clarified aqueous herbal extract and selectively partitioned bioactive components in permeates, thus enhancing the feasibility of XCHT to be a commercial health drink product.
Key words: membrane process, clarification, antioxidant, Xiao-chai-hu-tang, health herbal drinks