Microwave Heating Rapidly Alters Ginsenoside Composition of Fresh Ginseng ( Panax ginseng CA Meyer)

Abstract

Heating and drying is an important process to improve the preservation of herbs and its bioactive constituents. Ginseng is most popular medical herbs worldwide. Red ginseng is one of the products, which is prepared by heating and drying fresh ginseng. Red ginseng have ginsensides Rg3, Rg3, and Rk1 which is known for beneficial effect on inflammation, cancer, and obesity compared with other types of ginseng product. However, it is required to spend for long time to produce red ginseng with traditional preparation method. Thus, we aimed to develop a convenient ginseng process method that increases the unique form of bioactive ginsenoside in fresh ginseng. Microwave heating was used as a source of heating energy to dry and heating of fresh ginseng. Our result showed that fresh ginseng treated with microwave heating for 40 min efficiently increased the both of protopanaxadiol (PPD) and protopanaxatriol (PPT) in ginseng. In particular, red ginseng specific-detected ginsenosides Rg3, Rg5, and Rk1 were found in ginseng treated with microwave heating for 40 min compared with other periods of microwave heating condition. In addition, the appearance quality of ginseng after heating and drying affect the market value of ginseng. We observed that fresh ginseng treated with microwave heating for 40 min increased the composition of ginsenoside with proper color change of ginseng. Thus, microwave heating not only can alter the composition of ginsenosides in the short time, but also can improve the appearance of ginseng after heating and drying the processes. Moreover, our method might bring a benefit to produce high quantity of bioactive ginsenoside with a convenient process in ginseng-associated food industry.