Pulse echo method for characterizing the ultrasonic properties of argan oil compared to vegetable oils with similar fatty acid profiles

Abstract This study investigates the use of a non-destructive ultrasonic pulse-echo method to characterize argan oil and other vegetable oils with similar fatty acid profiles. Ultrasonic parameters such as velocity, acoustic attenuation and reflection coefficient were measured across different temperatures. These parameters were used to create predictive models of ultrasonic velocity using partial least squares regression. Results demonstrated significant correlations between ultrasonic properties, oil temperature and fatty acid content. Specifically, ultrasonic velocity was found to be directly proportional to the content of saturated fatty acids and inversely proportional to the content of monounsaturated and polyunsaturated fatty acids. The reflection coefficient was also found to correlate with the fatty acid composition and temperature of the oils. Additionally, both ultrasonic velocity and acoustic attenuation decreased as the temperature increased from 25 °C to 50 °C. At 25 °C, the acoustic attenuation for argan oil was 22.37 Np/m, decreasing to 11.37 Np/m at 50 °C. These correlations allowed for the differentiation between food-grade argan oil, argan oil from seeds regurgitated by goats, sesame oil and peanut oil. The developed predictive models exhibited high coefficients of determination, with a value of 97.03 for argan oil, indicating strong agreement between measured and predicted ultrasonic velocities. This research highlights the potential of ultrasonic techniques for oil characterization and quality control.