title: Discrimination of American ginseng and Asian ginseng using electronic nose and gas chromatography-mass spectrometry coupled with chemometrics.
abstract: BACKGROUND
  American ginseng (Panax quinquefoliusL.) and Asian ginseng (Panax ginsengMeyer) products, such as slices, have a similar appearance, but they have significantly different prices, leading to widespread adulteration in the commercial market. Their aroma characteristics are attracting increasing attention and are supposed to be effective and nondestructive markers to determine adulteration.
  
  
  METHODS
  The aroma characteristics of American and Asian ginseng were investigated using gas chromatography-mass spectrometry(GC-MS) and an electronic nose (E-nose). Their volatile organic compounds were separated, classified, compared, and analyzed with different pattern recognition.
  
  
  RESULTS
  The E-nose showed a good performance in grouping with a principle component analysis explaining 94.45% of variance. A total of 69 aroma components were identified by GC-MS, with 35.6% common components and 64.6% special ingredients between the two ginsengs. It was observed that the components and the number of terpenes and alcohols were markedly different, indicating possible reasons for their difference. The results of pattern recognition confirmed that the E-nose processing result is similar to that of GC-MS. The interrelation between aroma constituents and sensors indicated that special sensors were highly related to some terpenes and alcohols. Accordingly, the contents of selected constituents were accurately predicted by corresponding sensors with mostR2reaching 90%.
  
  
  CONCLUSIONS
  Combined with advanced chemometrics, the E-nose is capable of discriminating between American and Asian ginseng in both qualitative and quantitative angles, presenting an accurate, rapid, and nondestructive reference approach.
authors.affiliation: Department of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China; Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Cui
authors.affiliation: Department of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors.forename: Xinlei
authors.initials: X
authors.lastname: Wang
keywords: GC-MS; Panax ginseng; Panax quinquefolius; aroma characteristics; electronic nose