Edible oil adulteration has been a considerable problem worldwide, and rapid detection methods should be established. In this study, a validation method for edible oil adulterated with used frying oil (UFO) was introduced through Fourier transform infrared (FTIR) spectroscopy. The spectral region of 6000-400 cm-1 was determined through FTIR by using a disposable polyethylene film, and absorption profiles at 1550-650 cm-1 region could be used for detection analysis. A qualitative analysis model was established through discriminant analysis, and edible oil adulteration with more than 1% content of UFO could be qualitatively analyzed. A quantitative analysis model was also created through partial least squares regression. When the actual value was more than 1.5%, the predicted and actual values showed good linear correlation. FTIR coupled with chemometric analysis is a useful tool to detect edible oil adulteration.
Keywords: FTIR; adulteration; edible oils; used frying oil.