Pilot Study on Adulteration in Extra Virgin Olive Oil: A Multiblock Approach to Relate Gas Chromatography, Digital Imaging, and Spectroscopy

Analysis of olive oil coloration using ultraviolet-visible (UV-Vis) spectroscopy is an efficient technique for detecting adulterations, offering advantages over traditional methods like gas chromatography (CG) and high-performance liquid chromatography (HPLC) in terms of cost, time, and expertise. The development of a method that integrates fatty acid composition and spectral properties into a portable analytical technique, such as smartphone-based digital image analysis, can enhance cost-effectiveness and environmental friendliness in food quality control. This study aimed to establish this relationship using common dimension analysis (ComDim) on authentic and adulterated extra virgin olive oil (EVOO) samples. Commercially available EVOOs were mixed with refined soybean oil, showing a correlation of 79.18% between techniques for detecting adulterations exceeding 20%. Refined soybean oil was associated with fatty acids stearic, α-linolenic, γ-linolenic, behenic, and the B (blue) color channel, while authentic EVOO samples were correlated with fatty acids palmitic, palmitoleic, 7-hexadecenoic, vaccenic, oleic, arachidic, and with absorbance at 456 nm.