Rapid detection of authenticity and adulteration of cold pressed black cumin seed oil: A comparative study of ATR-FTIR spectroscopy and synchronous fluorescence with multivariate data analysis

Here we report the comparison of ATR-FTIR and synchronous fluorescence (SyF) spectroscopy combined with multivariate data analysis to detect the authenticity of cold pressed black cumin seed oil (BCSO) and quantify adulterant levels of soybean oil (SBO). Forty pure oils, as well as ninety six oil blends, were analyzed using FTIR and SyF spectroscopy in combination with PCA, SIMCA and PLSR analysis. A SIMCA model of fluorescence data provided an excellent classification for pure BCSO and other vegetable oils, such as sunflower oils (SFOs), soybean oils (SBOs), hazelnut oils (HNOs), cotton seed oils (CSOs), grape seed oil (GSOs) and virgin olive oils (VOOs) from different brands and origins, with 99% significance level. The limit for detection of SBO adulteration in BCSO by fluorescence spectroscopy was also below 5%. In the optimum for both techniques, the plots of actual versus predicted values exhibited high linearity. R² and RMSEC of the PLSR calibration model for FTIR spectra were between 0.9250–0.9998 and 0.1685–4.4762, respectively. R² and RMSEC values of the PLSR calibration model for SyF spectra were between 0.9764–0.9975 and 0.8189–2.5122.