Changes in ginsenoside compositions and antioxidant activities of hydroponic-cultured ginseng roots and leaves with heating temperature.
BACKGROUND
This study evaluated changes in ginsenoside compositions and antioxidant activities in hydroponic-cultured ginseng roots (HGR) and leaves (HGL) with heating temperature.


METHODS
Heat treatment was performed at temperatures of 90°C, 110°C, 130°C, and 150°C for 2 hours.


RESULTS
The ginsenoside content varied significantly with heating temperature. The levels of ginsenosides Rg1 and Re in HGR decreased with increasing heating temperature. Ginsenosides F2, F4, Rk3, Rh4, Rg3 (S form), Rg3 (R form), Rk1, and Rg5, which were absent in the raw ginseng, were formed after heat treatment. The levels of ginsenosides Rg1, Re, Rf, and Rb1 in HGL decreased with increasing heating temperature. Conversely, ginsenosides Rk3, Rh4, Rg3 (R form), Rk1, and Rg5 increased with increasing heating temperature. In addition, ginsenoside contents of heated HGL were slightly higher than those of HGR. The highest extraction yield was 14.39% at 130°C, whereas the lowest value was 10.30% at 150°C. After heating, polyphenol contents of HGR and HGL increased from 0.43 mg gallic acid equivalent/g (mg GAE eq/g) and 0.74 mg GAE eq/g to 6.16 mg GAE eq/g and 2.86 mg GAE eq/g, respectively.


CONCLUSIONS
Antioxidant activities of HGR and HGL, measured by 1,1-diphenyl-2-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging ability, increased with increasing heating temperature. These results may aid in improving the biological activity and quality of ginseng subjected to heat treatments.
Department of Food Science and Technology, Chungbuk National University, Cheongju, Korea.
Cho Rong
CR
Hwang
Department of Food Science and Technology, Chungbuk National University, Cheongju, Korea.
Sang Hoon
SH
Lee
Department of Food Science and Technology, Chungbuk National University, Cheongju, Korea.
Gwi Yeong
GY
Jang
Department of Agrofood Resources, National Academy of Agricultural Science, Suwon, Korea.
In Guk
IG
Hwang
Department of Functional Crop, National Institute of Crop Science, Miryang, Korea.
Hyun Young
HY
Kim
Department of Functional Crop, National Institute of Crop Science, Miryang, Korea.
Koan Sik
KS
Woo
Department of Food Science and Technology, Chungbuk National University, Cheongju, Korea.
Junsoo
J
Lee
Department of Food Science and Technology, Chungbuk National University, Cheongju, Korea.
Heon Sang
HS
Jeong
antioxidant activity; ginsenoside; heating temperature; hydroponic-cultured ginseng; polyphenol