Variations in the Contents of Gingerols and Chromatographic Fingerprints of Ginger Root Extracts Prepared by Different Preparation Methods

Abstract

Abstract In the present study, an HPLC-DAD method was optimized for the quantitative determination of 6-gingerol, 6-shogaol, 8-gingerol, and 10-gingerol in gingerextracts. A chromatographic fingerprinting method was also established to differentiate and evaluate theginger extracts for bioactivity. Twenty-one extractswere prepared by methods differing in ginger type (fresh versus dried), solvent, and extraction methods.The ANOVA analysis showed the methods' influence on the mean extraction yields of gingerols increased inthe order of: high pressure-high temperature (HP)>blender (BD)>low pressure (LP). The optimal solvent to extract gingerols was found to be 95% ethanol. The type of ginger used had significant effects onthe content of gingerols, but its overall influence depended on the solvent used. In order to maximize the extraction efficiency of gingerols, a combinationof dry ginger, 95% ethanol, and the HPextraction method should be employed. The chromatographic fingerprints were obtained to differentiate the unknown components from all ginger extracts. The similarity of the chromatographic fingerprints was used to evaluatethe differences among all extracts. It can be concluded that the chromatographic fingerprints are able to ensure the stability of each extract and have somecorrelation with the observed bioactivity.