Detection of adulteration in olive oil using rheological and ultrasonic parameters

Commercially available extra virgin oil is added with coconut oil and sunflower oil at different proportion. The variation of rheological and ultrasonic parameters in the binary mixtures of the oils are studied and reported. The oil is subjected to frying temperature 210°C repeatedly so that compositional changes take place in the fatty acids. A general decrease in the viscosity of oils is observed with increase in temperature and the difference in the variation in terms of percentage of adulteration is also studied. An empirical correlation between viscosity and temperature is also determined so as to predict viscosity and adulteration in oil at intermediate temperatures. The changes in the quality of olive oil is premeditated from the changes in the parameters such as viscosity, density, ultrasonic velocity, acoustic impedance, adiabatic compressibility and intermolecular free length, from which the adulteration in the oil can be easily perceived compared to analytical techniques.