Identification and Authentication of Vegetable Oils by Digital Colorometry and IR Spectroscopy Methods

The possibility of a simple and accessible method of identification and authentication of edible vegetable oils using methods of digital colorometry, Fourier transform infrared spectroscopy in the near and middle spectral regions and chemometric processing of the analysis results is shown. Identification by species of oils (mustard, linseed, corn, olive and sunflower), authentication (authenticity and adulteration) was carried out by the intrinsic coloring of vegetable oils and fluorescence when the samples were irradiated with monochromatic light in the UV, visible and infrared regions. (365, 390, 470, 565, 700, 850, 880, 940 nm and 400–10 000 cm–1). A device and method for measuring colorometric parameters using a smartphone and data processing using RGBer, PhotoMetrix PRO®, XLSTAT, and The Unscrambler X specialized software are proposed. Application of chemometric analysis allowed to establish the authenticity of vegetable oils and to reveal the facts of adulteration by diluting expensive oils with cheaper ones.