Discrimination of Two Cultivars of <i>Alpinia Officinarum</i> Hance Using an Electronic Nose and Gas Chromatography-Mass Spectrometry Coupled with Chemometrics

• Main Authors: Qin Long, Zhong Li, Bin Han, Hamid Gholam Hosseini, Huaying Zhou, Shumei Wang, Dehan Luo
• Format: Article
• Language: English
• Published: MDPI AG 2019-01-01
• Series: Sensors
• Subjects: <i>A. officinarum</i>; Zhutou galangal; Fengwo galangal; sensors; E-nose; GC-MS; PCA; PLS
• Online Access: https://www.mdpi.com/1424-8220/19/3/572

<i>Background</i>: <i>Alpinia officinarum</i> Hance is both an herbal medicine and a condiment, and generally has different cultivars such as Zhutou galangal and Fengwo galangal. The appearance of these <i>A. officinarum</i> cultivars is similar, but their chemical composition and quality are different. It is therefore important to discriminate between different <i>A. officinarum</i> plants to ensure the consistency of the efficacy of the medicine. Therefore, we used an electronic nose (E-nose) to explore the differences in odor information between the two cultivars for fast and robust discrimination. <i>Methods</i>: Odor and volatile components of all <i>A. officinarum</i> samples were detected by the E-nose and gas chromatography-mass spectrometry (GC-MS), respectively. The E-nose sensors and GC-MS data were analyzed respectively by principal component analysis (PCA), the correlation between E-nose sensors and GC-MS data were analyzed by partial least squares (PLS). <i>Results</i>: It was found that Zhutou galangal and Fengwo galangal can be discriminated by combining the E-nose with PCA, and the E-nose sensors S2, S6, S7, S9 were important sensors for distinguishing different cultivars of <i>A. officinarum</i>. A total of 56 volatile components of <i>A. officinarum</i> were identified by the GC-MS analysis, and the composition and content of the volatile components from the two different <i>A. officinarum</i> cultivars were different, in particular the relative contents of 1,8-cineole and &#945;-farnesene. The classification result by PCA analysis based on GC-MS data was consistent with the E-nose results. The PLS analysis demonstrated that the volatile terpene, alcohol and ester components primarily interacted with the sensors S2 and S7, indicating that particular E-nose sensors were highly correlated with some aroma constituents. <i>Conclusions</i>: Combined with advanced chemometrics, the E-nose detection technology can discriminate two cultivars of <i>A. officinarum</i>, with GC-MS providing support to determine the material basis of the E-nose sensors&#8217; response.