Utilization of ATR-FTIR Spectroscopy-Multivariate Chemometric Analysis in the Examine of Food Quality Edible Sesame Oils

Abstract

Attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) and multivariate chemometric analysis was established to distinguish and classify edible sesame oils of various branded (refined) and unbranded (cold pressed) oils and principal components. For this determination, available branded and unbranded traditional cold pressed sesame oils from southern districts of Tamilnadu, India were qualitative and quantitatively analyzed and authenticated. The FTIR spectra were generated in absorption ranges from 599- 4000 cm-1 observed through ATR mode. The generated spectral data combined with multivariate chemometric analyses such as Principal components analysis (PCA), Principal coordinate analysis (PCoA), Agglomerative hierarchical clustering analysis (AHC), Discriminant analysis (DA) were analyzed. Further, observed qualitative analyses through colour, UV-light absorption, absolute viscosity, saponification and iodine values were well differentiated between branded and unbranded sesame oil samples. Based on the multivariate chemometric analysis, unbranded 2 and branded 1 sesame oil samples have shown essential phytocomponents like sesamin, sesaminol, and sesamolin. However, other oil samples did not show those essential phytocomponents and may be missing/eliminated during the refining/filtration processes. In addition, branded and unbranded sesame oil samples have been classified through discriminant analysis (DA) based on the major absorption frequencies. As per the experimental and statistical outcomes, it might be established that ATR-FTIR method has potential to detect and identify essential components of similar food products for classification and authentication, further; it is nondestructive, effective and simple alternative method.