Poulli succeeded in the detection of sunflower oil in virgin olive oil at levels as low as 3.4% (w/v) in just two and a half minutes with synchronous fluorescence spectroscopy (Poulli, Mousdis, & Georgiou, 2006). The aim of this work was to detect the authenticity of walnut oil and the extent of adulteration of soybean oil in walnut oil using FTIR and fluorescence spectroscopy, and the determination limits and prediction deviation were compared.