Identification and Authentication of Vegetable Oils by Digital Colorimetry and IR Spectrometry

Abstract

Potential of a simple and an available method for identifying and authenticating edible vegetable oils using digital colorimetry, Fourier-transform spectrometry in the near and middle IR spectral regions, and chemometric processing of the analysis results is shown. Identification by the type of oil (mustard, linseed, corn, olive, and sunflower) and authentication (authenticity and falsification) are carried out by the intrinsic color of vegetable oils and fluorescence upon irradiating samples with monochromatic light in the UV, visible, and IR regions (365, 390, 470, 565, 700, 850, 880, 940 nm, and 400−10 000 cm⁻¹). A device and a method for measuring colorimetric parameters using a smartphone and data processing using the RGBer, PhotoMetrix PRO^®, XLSTAT and The Unscrambler X specialized software are proposed. The use of chemometric analysis made it possible to establish the authenticity of vegetable oils and identify facts of falsification by diluting expensive oils with cheaper ones.