Empirical models to correlate the basic physical and chemical indices of modified rice bran and mustard oil

Abstract

Modified rice bran oil (RBO) and modified mustard oil (MO) were prepared by adding oleic acid and oxidized oil separately. The physical and chemical indices like dielectric constant, viscosity, peroxide value (PV), acid value (AV), free fatty acids (FFA), iodine value (IV), and saponification value (SV) of pure and modified RO and MO were determined and correlated. Dielectric constant and viscosity were found to decrease in a non-linear fashion with increase in temperature (30°C-75°C). The dependence of dielectric constant and viscosity with temperature was investigated using model empirical equations. The dielectric variation was studied using Akerlof and Oshry's model equations, which exhibited high dependency of R 2 ranges from 0.99 to 0.997. The behaviour of viscosity with temperature was studied with Wright's equation and the correlation coefficient (R 2 ) was found to be 0.998. Model equations were developed, which relates dielectric constant with IV, SV, and PV with the regression coefficients R 2 = 0.955, 0.936, and 0.994, respectively. The developed equations can be used in processing, pipelining, and to predict the parameters at a desired temperature. On comparing the correlations between the physical and chemical properties of the oil samples, RBO and its modified forms exhibited more oxidative stability than modified MO. ARTICLE HISTORY

Modelling, characterization and quality analysis of heated oil using electric moment and chemical properties

“…Peroxide value of oil samples was determined by the standard AOCS official method Cd 8-53 Method. The oil sample was dissolved in acetic acid and isooctane, added potassium iodide and titrated for free iodine to get the end point with 0.01 mol/L sodium thiosulfate (Crowe and White 2001;Phebee Angeline et al 2016).…”

“…It is a measure of polarised compound that moves towards the electrode with respect to the applied electric field at constant frequency. Increase in dielectric constant is due to increase in storage of electric charges produced on chemical breakdown (Shah and Tahir 2011;Phebee Angeline et al 2016). At low frequency, increase in DC (permittivity) is due to the space charge and atomic polarisation of polar compounds in sample.…”