Differentiation of Cordyceps sinensis by a PCR-single-stranded conformation polymorphism-based method and characterization of the fermented products in Taiwan

Cordyceps sinensis (Berk.) Sacc., which is a part of traditional Chinese medicine, has been used as a tonic food and herbal medicine in Asia for centuries. C. sinensis is sold as powders, and the quality is often questionable. To confirm the quality of C. sinensis , products were purchased from different supermarkets in Taiwan. Product samples were analyzed using PCR-single-stranded conformation polymorphism (PCR-SSCP) assay based on internal transcribed spacer 2 (ITS2). PCR-SSCP patterns distinguished ten samples into six groups, but no sample was grouped with representative C. sinensis (rCS). Only two of the ten C. sinensis functional ingredient samples (CSFFMS) tested CB and ST, were similar to the reference product of C. sinensis . This in consistent result could be caused by poor fermentation control process, contamination of original marketing samples or adultration. Therefore, the use of PCR-SSCP could be used for species differentiation or the detection of mutations based on ITS2 region in C. sinensis . The method represents a potential novel means for the differentiation of Cordyceps herbal medicines/functional ingredients and could be used as a quality control in the Cordyceps fermentation industry.