title: Degradation of ginsenosides in American ginseng (Panax quinquefolium) extracts during microwave and conventional heating.
abstract: The degradation of ginsenosides in American ginseng (Panax quinquefolium) extracts during microwave and water (oil) bath heating (conventional heating) was investigated. Both the 50% ethanol-water extracts and the aqueous extracts were boiled in a modified laboratory microwave oven and in a water (or oil) bath, respectively. The neutral ginsenosides (Rb(1), Rc, Rd, and Re) and malonyl ginsenosides (m-Rb(1), m-Rc, and m-Rd) were determined by reverse-phase high-performance liquid chromatography. The results showed that the degradation of ginsenosides in 50% ethanol-water extracts was a first-order reaction. The malonyl ginsenosides were much less stable than the corresponding neutral ginsenosides, with the rate constant value of the malonyl ginsenosides being 3-60 times that of the neutral ginsenosides. At the same temperature, the effect of microwave heating on the degradation of ginsenosides was the same as that of conventional heating.
authors.affiliation: Department of Botany, The University of Hong Kong.
authors.forename: G
authors.initials: G
authors.lastname: Ren
authors.forename: F
authors.initials: F
authors.lastname: Chen
mesh_terms: D003296:Cooking; D036145:Ginsenosides; D006358:Hot Temperature; D008872:Microwaves; D005894:Panax / Q000528:radiation effects; D010936:Plant Extracts; D010946:Plants, Medicinal; D012503:Saponins / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D036145:Ginsenosides; D010936:Plant Extracts; D012503:Saponins