Effects of blanching on antioxidant activity and total phenolic content according to type of medicinal plants

The present study was conducted in order to evaluate the effects of blanching on the total and individual phenolic and antioxidant activities of 4 young sprouts of medicinal plants: dureup (Aralia elata), caster aralia (Kalopanax pictus), tree-of-heaven (Cedrela sinensis), and ogapi (Acanthopanax sessiloflorus). Caster aralia and dureup displayed significant reduction of Fe2+ chelation following blanching, but no alteration of DPPH or ABTS radical scavenging activity. Blanched ogapi displayed lower Fe2+ chelation as well as decreased DPPH and ABTS radical scavenging activities compared to raw sample. In contrast, tree-of-heaven displayed significantly increased antioxidant activity after blanching. Major phenolic compounds in mountain vegetables were chlorogenic acid and vanillic acid. In particular, chlorogenic acid contents increased by 11.2-68.1% in all vegetables except for ogapi after blanching. The results of this study show that blanching might be a useful tool for improving the beneficial properties of tree-of-heaven.