Temperature dependence of acoustic parameters in pure and blended edible oils: Implications for characterization and authentication.

This research investigates the temperature-dependent variation of diverse acoustic parameters in samples of edible oils. It further supplements previous studies on the effectiveness of non-destructive ultrasonic inspection in the authentication of edible oils. The oils under examination consist of pure samples of olive, sunflower, and corn oils, as well as variable mixtures ranging from 20 % to 80 % of the more expensive one (olive oil) with the other two, simulating a hypothetical adulteration scenario. The studied acoustic parameters are related to the velocity, attenuation, and frequency components present in 2.25 MHz ultrasonic waves propagating through the oil samples within a temperature range of 24 °C to 34 °C. The results confirm the suitability of non-destructive ultrasonic inspection in evaluating and detecting the adulteration of olive oil with economically inferior oils such as sunflower and corn. Additionally, this study provides added value by laying the groundwork for a non-destructive and innovative determination of the fatty acid profile of an edible oil based on the evolution of the aforementioned ultrasonic parameters with temperature. The findings hold potential for enhancing the authenticity assessment and quality control of edible oils in the food industry.

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

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.

New findings of edible oil characterization by ultrasonic parameters.

The basic objective of the study was to confirm the usefulness of non-destructive ultrasonic testing in evaluating different edible oil samples. The experimental study was carried out for three types of edible oils (olive, sunflower, and corn) in which a 1.0 MHz ultrasound transducer was immersed. Density and viscosity values of the samples were determined simultaneously with the ultrasound tests. By themselves, ultrasound inspection, density, and viscosity, were able to characterize and distinguish each type from the others, but only the ultrasound inspection has a non-destructive nature. Moreover, significant correlations among density and viscosity with the acoustic parameters were found. The results postulate that ultrasound inspection is a fast and non-destructive tool to characterize and discriminate different types of edible oils.