This study investigated the physicochemical properties of roasted red ginseng (RRG) and their drips according to the roasting and particle sizes by grinding. A red ginseng sample was ground to 3.0±0.3 mm and roasted at 130°C, 150°C, and 170°C for 20 and 30 min. The RRGs were separated using standard sieves into the following particle sizes: very fine (less than 200 μm), fine (200∼279 μm), medium (279∼381 μm), coarse (381∼535 μm), and very coarse (over 535 μm). The physicochemical properties of the RRGs were analyzed in terms of the ginsenosides, benzopyrene, colors, and volatile flavors. For each particle size and drip of the various RRGs, the ginsenosides, colors, and antioxidant activities were analyzed. The ginsenoside-Rb1, -Re, and -Rg1 content decreased and the ginsenoside-Rg3, -Rg5, and -Rg6 content increased with increasing roasting temperature and time. The total ginsenoside content in RRG roasted at 150°C for 30 min (RRG 150-30) was 20.50 mg/g, which was high. Benzopyrene was detected in the RRG 170-20 and RRG 170-30 at 0.03±0.01 ppb and 0.11±0.01 ppb, respectively. As the roasting temperature and time were increased, and as the particle size decreased, the L-value decreased, and the a- and b-values increased. A total of 32 volatile compounds trapped by solid-phase microextraction fiber (polydimethylsiloxane 65 μm) in the RRG were detected, which were increased by roasting; the highest value was obtained from RRG 150-30. Their main compounds were α-neoclovene, β-panasinsene, α-gurjunene, trans-β-farnesene, β-gurjunene, β-elemene, γ-gurjunene, and α-humulene. The ginsenoside content eluted by dripping RRG 150-30 with a very fine size was the highest at 23.2±0.17 mg/200 mL (1.2 g/bag). The antioxidant activity of the RRG 150-30 drips was similar to brown rice-green tea sold at the market.

Keywords: red ginseng, roasting, drip, physicochemical characteristics, ginsenoside