Effects of roasting conditions on Korean rice wine (Makgeolli) with licorice (Glycyrrhiza uralensis Fischer)

Abstract

The present study investigated the effect of roasting process (temperature: 150, 180, and 210 degrees C; time: 10, 20, and 30 min) of licorice on the browning index (BI), total flavonoid content (TFC), and antioxidant activity for ingredient of Makgeolli. The antioxidant activity was measured by assaying DPPH radical scavenging activity (DPPH center dot IC50) and Trolox equivalent antioxidant capacity (TEAC). In addition, the quality characteristics of Makgeolli with different amount (0%, 6%, 12%, and 18%) of roasted licorice extract (RLE) were measured comparison to un-roasted licorice extract (ULE). When superimposing the contour plots of the responses in which the limits of each response were determined, the optimum conditions for roasting licorice were 178 degrees C for 24 min. Moreover, results revealed that Makgeolli with 12% RLE under optimum roasting condition was superior with respect to antioxidant activity and more acceptable based on sensory properties than ULE.