Identifikasi sifat fisikokimia minyak sumbawa dari NTB menggunakan FTIR fingerprint yang dikombinasikan dengan kemometrik

Abstract

Sumbawa oil is a traditional remedy unique to Sumbawa Island, West Nusa Tenggara. It is produced through the process of blending coconut oil with various herbal plants that grow in the mountainous areas of Sumbawa Besar Regency. This research aimed to identify the physicochemical properties of Sumbawa oil in comparison to virgin coconut oil (VCO) and olive oil using FTIR fingerprinting combined with chemometrics. The method used in this study involved analysis with an FTIR spectrophotometer (PerkinElmer One) over a wavenumber range of 4000–400 cm⁻¹ to obtain IR spectra. These spectra were then used to identify the functional groups of compounds present in the Sumbawa oil samples. Furthermore, absorbance at frequencies of 3459.26 cm⁻¹, 3005.55 cm⁻¹, 2924.01 cm⁻¹, 2853.33 cm⁻¹, 1744.25 cm⁻¹, 1645.68 cm⁻¹, 1464.98 cm⁻¹, 1378.20 cm⁻¹, 1161.20 cm⁻¹, and 721.84 cm⁻¹ was analyzed using Minitab version 7.0 with the Principal Component Analysis (PCA) statistical method. Based on the research findings, the physicochemical properties of Sumbawa oil were identified to be similar to those of VCO. The level of similarity was determined through dendrogram clustering, score plots, and loading plots. From the dendrogram clustering and score plot results, Sumbawa oil and VCO exhibited the highest degree of similarity compared to olive oil. The dendrogram clustering showed a similarity value of over 50%, with closely related score plot values. Meanwhile, the loading plot indicated that the wavenumber 3005.55 cm⁻¹, representing the C-H stretch sp² functional group (saturated bond), contributed significantly to PC1 and PC2.