Analytical Method Development for Analysis of Soybean Oil in the Mixture with Virgin Coconut Oil Using Infrared Spectroscopy and Chemometrics

Fourier Transform Infrared (FTIR) spectroscopy combined with the chemometrics techniques of Discriminant Analysis (DA) as well as multivariate analysis of Partial Least Square (PLS) and Principal Component Regression (PCR) has been developed for analysis of soybean oil (SO) in virgin coconut oil (VCO). The spectral bands correlated with VCO, soybean oil (SO), and their blends were scanned, interpreted, and identified. The combined wavenumber regions of 1200 - 1000 and 3025 - 2995 cm(-1) were used during analysis either in classification using DA or in quantification using PLS and PCR. DA can be successfully used for the classification of VCO and that added with SO with the accuracy level of 100 %. Furthermore, PLS using FTIR normal spectra was preferred to be used for the quantification of SO in VCO over PCR and the spectral derivatives. The coefficient of determination (R-2) value obtained for the relationship between actual and FTIR predicted value of SO is higher than 0.99 with acceptable errors, either in calibration or in validation models.