Differentiating organically and conventionally grown oregano using ultraperformance liquid chromatography mass spectrometry (UPLC-MS), headspace gas chromatography with flame ionization detection (headspace-GC-FID), and flow injection mass spectrum (FIMS) fingerprints combined with multivariate data analysis

J Agric Food Chem. 2014 Aug 13;62(32):8075-84. doi: 10.1021/jf502419y. Epub 2014 Jul 31.

Abstract

Ultraperformance liquid chromatography mass spectrometry (UPLC-MS), flow injection mass spectrometry (FIMS), and headspace gas chromatography (headspace-GC) combined with multivariate data analysis techniques were examined and compared in differentiating organically grown oregano from that grown conventionally. It is the first time that headspace-GC fingerprinting technology is reported in differentiating organically and conventionally grown spice samples. The results also indicated that UPLC-MS, FIMS, and headspace-GC-FID fingerprints with OPLS-DA were able to effectively distinguish oreganos under different growing conditions, whereas with PCA, only FIMS fingerprint could differentiate the organically and conventionally grown oregano samples. UPLC fingerprinting provided detailed information about the chemical composition of oregano with a longer analysis time, whereas FIMS finished a sample analysis within 1 min. On the other hand, headspace GC-FID fingerprinting required no sample pretreatment, suggesting its potential as a high-throughput method in distinguishing organically and conventionally grown oregano samples. In addition, chemical components in oregano were identified by their molecular weight using QTOF-MS and headspace-GC-MS.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analytic Sample Preparation Methods
  • Chromatography, High Pressure Liquid
  • Discriminant Analysis
  • Flame Ionization
  • Food Inspection / methods*
  • Food, Organic / analysis*
  • Food, Organic / standards
  • Least-Squares Analysis
  • Molecular Weight
  • Multivariate Analysis
  • Origanum / chemistry*
  • Origanum / growth & development
  • Plant Leaves / chemistry*
  • Plant Leaves / growth & development
  • Principal Component Analysis
  • Spectrometry, Mass, Electrospray Ionization
  • Spices / analysis*
  • Spices / standards
  • Thymol / analysis
  • Thymol / chemistry
  • Time Factors
  • United States
  • Volatile Organic Compounds / analysis*
  • Volatile Organic Compounds / chemistry
  • Volatilization

Substances

  • Volatile Organic Compounds
  • Thymol