Chemometric classification of red ginger (Zingiber officinale var. Rubrum) oleoresin from different regions using Fourier-transform infrared-ATR spectroscopy.

Red ginger contains valuable oleoresins, primarily gengerols, shogaol, and zingerone. However, its chemical profile can vary by geographic origin. This study aimed to classify the red ginger samples from different regions based on their chemical characteristics. Ethanol extracts of red ginger were prepared via maceration. Chemical profiles were obtained using Fourier-transform infrared (FTIR) spectroscopy, and the data were analyzed using principal component analysis-correspondence analysis (PCA-CA) chemometrics for classification. PCA-CA analysis revealed the highest similarity between samples from Pematang Simalungun and Sidomulyo Jalur 18 villages. When compared against a zingerone standard, only the sample from pagerharjo village showed a close chemical relationship. FTIR combined with PCA-CA chemometrics effectively distinguishes red ginger based on its chemical composition and geographic origin.