Authentication of pure and adulterated edible oils using non-destructive ultrasound

•Pure edible olive, sunflower, and corn oils and blended batches were acoustically characterized by ultrasound.•Ultrasound measures distinguished and categorized three pure oil types via velocity, attenuation, and other frequency parameters.•Ultrasonic parameters allow the discrimination of different levels of olive oil adulteration.•Acoustic parameters were significantly correlated with viscosity and density.•Ultrasound is a feasible tool to classify pure and adulterated oil samples. At present, the quality of edible oil is evaluated using traditional analysis techniques that are generally destructive. Therefore, efforts are being made to find alternative methods with non-destructive techniques such as Ultrasound. This work aims to confirm the feasibility of non-destructive ultrasonic inspection to characterise and detect fraudulent practices in olive oil due to adulteration with two other edible vegetable oils (sunflower and corn). For this purpose, pulsed ultrasonic signals with a frequency of 2.25 MHz have been used. The samples of pure olive oil were adulterated with the other two in variable percentages between 20% and 80%. Moreover, the viscosity and density values were measured. Both these physicochemical and acoustic parameters were obtained at 24 °C and 30 °C and linearly correlated with each other. The results indicate the sensitivity of the method at all levels of adulteration studied. The responses obtained through the parameters related to the components of velocity, attenuation, and frequency of the ultrasonic waves are complementary to each other. This allows concluding that the classification of pure and adulterated oil samples is possible through non-destructive ultrasonic inspection.