Experimental investigation of electro-rheological properties of modeled vegetable oils.

Vegetable oil becomes polarized on oxidation and polymerization resulting in the formation of peroxide, triglycerides, etc. The quality and reusable state were investigated for sunflower, sesame, rice bran oil and model oil with the addition of oleic acid (2, 4 and 6 %) and antioxidants (citric and tert-Butyl hydroquinone-TBHQ). Excessive reclaims of cooking oil produce toxic by-products due to chemical breakdown that induce the production of polar compounds in oil. To determine the consumable fitness, variations of dielectric constant are observed at different temperatures (29 to 70 °C) and frequencies (1 to 10(7)Hz) for the cooking oil. Physical parameters, such as viscosity and density associated with the saturated and unsaturated fatty acid, are also measured at different temperatures to determine the quality of oil. Dielectric constant and viscosity are correlated and analyzed using a newly developed equation with high correlation constant (R (2)  = 0.998) for oil added with citric acid. Oil added with 2-4 % of oleic acid is observed to have high determination coefficient (R (2)  > 0.92). A lowest correlation (R (2)  = 0.6-0.7) was observed for the oil added with TBHQ. The present study also states that addition of TBHQ to oil does not impede oxidation reaction. Besides, even the shelf life of the oil could not be enhanced and may produce adverse effects in human health.