E-Eye, Flash GC E-Nose, and HS-GC-MS Combined With Chemometrics to Identify the Different Processed Products of Cyperus rotundus.

Abstract

Introduction: Cyperus rotundus (CR) has been widely explored for the treatment and prevention of diseases. In traditional Chinese medicine (TCM), it is commonly used to treat liver diseases, abdominal pain, irregular menstruation, and dysmenorrhea. It has various processed products in clinical prescription; however, the quality distinctions among different processed products of CR remain unexplored.

Objectives: To explore the quality distinctions in color, flavor, and volatile compounds among four processed products of CR.

Methods: Eleven batches for each of the four processed products of CR were prepared. The color of the powders was determined utilizing the electronic eye (E-eye). The flavor information of each sample was analyzed with flash gas chromatography electronic nose (Flash GC e-nose). The volatile components were characterized using headspace gas chromatography-mass spectrometry (HS-GC-MS), and the data were analyzed employing chemometric methods.

Results: The color parameters L*, a*, and b* were consistently obtained by E-eye, and four discriminant functions were established to distinguish different CR products rapidly. Using the Flash GC e-nose, 20 odor compounds were identified, among which 2-methylpropanal, 2-methylbutanal, methyl 2-methylbutyrate, and ethyl 2-methylcrotonate were generated after vinegar-processing, wine-processing, and stir-frying. A total of 36 volatile compounds were identified by HS-GC-MS with acetic acid and furfural being newly generated. Four potential differential chemical markers were selected.

Conclusion: Overall, this study provides novel ideas and methods for the identification and quality evaluation of four processed products of CR. Furthermore, it also provides a reference for standardizing the processing technology of TCM.