Application of Vis/NIR and FTIR spectroscopy combined with chemometrics for the authentication of red fruit oil from coconut oil

Red fruit is widely grown on the island of Papua and has multiple benefits. This research uses Visible Near-Infrared (Vis/NIR) spectroscopy and Fourier Transform Infrared (FTIR) combined with chemometrics, which has been developed for the analysis of red fruit oil (RFO) in a mixture of coconut oil (CO) as an adulterant in authentication studies. Scanning the binary mixture of CO and RFO using infrared spectroscopy in several frequency regions, both the near-infrared (680 - 2600nm) and the mid-infrared (4000 - 600cm-1) whose variations were observed to identify frequency regions that provide a multivariate calibration model based on partial least squares (PLS) is the most accurate. In addition, the Vis/NIR and FTIR spectra were derivatized (first and second derivative) to see which type of spectrum gave the best spectral performance in the calibration model. The results of this research show that the second derivatization Vis/NIR spectrum in the 680 - 2600 nm frequency region and the normal FTIR spectrum in the 4000 - 600cm-1 frequency region can determine CO in RFO more accurately with each RMSEC of 0.0238714 and 3.07, RMSEP of 0.0281795 and 0.0503, and R² value of 0.984 and 0.9903. The combination of Vis/NIR and FTIR spectra with PLS are a reliable method to verify the authenticity of RFO by quantitatively analyzing CO as an adulterant in RFO.