Authentication of the geographical origin of patchouli oil using front‐face fluorescence spectroscopy and chemometric analysis

Increasing consumer awareness of the authenticity of products has led to a demand for rapid measurement methods to support the traceability of high‐value commodities. In this research, a front‐face method was used to obtain fluorescence excitation–emission matrix fingerprints of patchouli oil samples from different geographical origins in Indonesia. Principal component analysis ( PCA ) was then used to explore the excitation–emission matrix ( EEM ) data structure of the samples, and 3D eigenvector value thresholding was used to discriminate important variables. It was found that there were five important EEM regions representing the sample variation. A decision‐tree model with a subset of two important regions, i.e. regions 1 and 3, was then developed for the classification of patchouli oils from different Indonesian islands. These results show that front‐face fluorescence spectroscopy has the potential to be used as a supporting tool for the discrimination of the geographical origin of patchouli oils.