Patchouli oil (PO) is subject to various processing methods aimed at enhancing its quality, encompassing improvements in appearance, reduction of heavy metal content, decrease in acid numbers, and an increase in the concentration of Patchouli alcohol, a key active component. However, these treatments may inadvertently induce changes in the chemical composition of the oil, thereby altering its original character. This study sought to identify even the slightest shifts in the chemical composition resulting from the addition of zeolite adsorbent to PO. A classification model was developed employing FTIR spectra in conjunction with Chemometrics. The FTIR spectra ranging from 1800 to 650 cm-1 were subjected to Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA) for observation. The PO samples were collected from five locations in Gayo Lues Regency, Province of Aceh, Indonesia, with varying zeolite concentrations of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% (w/v). The classification model successfully distinguished between pure PO and PO samples with added zeolite at each concentration level. Prediction accuracy was validated using deviation and Inlier vs. Hotelling’s T2 tests, providing definitive insights, and the results were represented through a confusion matrix.

Keywords: Patchouli oil, zeolite, PCA, PLS-DA