Phytochemical Profiling of Limau Kuit (Citrus jambhiri Lush.) using FTIR Spectroscopy and Multivariate Analysis

Citrus jambhiri Lush., locally known as Limau Kuit, is an indigenous citrus species from South Kalimantan, Indonesia, traditionally used by the Banjar community for food and medicinal purposes. This study aimed to characterize the phytochemical composition of various parts (leaves, fruit peel, fruit pulp, and fruit juice) of C. jambhiri using Fourier Transform Infrared (FTIR) spectroscopy combined with principal component analysis (PCA). Extractions were performed using three solvents of varying polarity: n-hexane, ethyl acetate, and ethanol. The phytochemical profile of the extracts was characterized by Fourier Transform Infrared (FTIR) spectroscopy followed by multivariate data analysis with chemometric techniques. FTIR spectra revealed the presence of key functional groups such as O–H, C–H, C=O, and C=C, suggesting the existence of secondary metabolites, including flavonoids, terpenoids, and saponins. Chemometric analysis using principal component analysis (PCA) and cluster analysis showed that solvent polarity had a greater impact on chemical composition than plant part, with clear clustering observed among extracts prepared using the same solvent. Juice extracts formed a distinct cluster, indicating the presence of unique compounds compared to other parts. These findings underscore the importance of solvent selection in targeting specific bioactive constituents from C. jambhiri. The study provides a scientific basis for the potential development of C. jambhiri-based functional food ingredients and herbal formulations and highlights the value of FTIR–PCA as a rapid, non-destructive method for phytochemical profiling.