Influence of Geographical Origin on Essential Oil Contents in Curcuma aeruginosa Roxb. Rhizomes in Central Java, Indonesia

Curcuma aeruginosa Roxb. rhizome is a traditional herb used in several countries. Depending on where they are from, Curcuma aeruginosa Roxb. rhizomes can have different amounts of compounds. The purpose of this study was to evaluate the influence of geographical origin on the composition of essential oils extracted from the rhizomes of Curcuma aeruginosa Rox throughout the distribution area in Central Java, Indonesia using Gas Chromatography-Mass Spectrometry (GC-MS). The chemometrics of Principal Component Analysis (PCA) and Partial Least Squares Discriminative Analysis (PLS-DA) have been successfully employed for the classification of samples into different classes. The sand, clay, organic carbon, and yield were variables contributing significantly to PLS-DA modelling during the relationship among the sample locations, environmental factors, and micronutrient contents with the variable importance projection  (VIP) score of >1. Curzerenone is considered the most important variable contributing to PLS-DA modelling for the relationship between the chemical compounds of C. aeruginosa essential oils (CA-EOs) with the sample locations and soil micronutrients. This study showed that PCA and PLS-DA can offer a reliable platform for grouping and classifying samples, therefore, the determination of the variables contributing significantly toward the geographical origins of samples is essential since these variables affected the contents of CA-EOs. In addition, this research can help researchers and farmers choose the most suitable soil types to achieve the maximum yields of CA-EOs.