Effect of Strong Electrolytes on Edible Oils Part III: Viscosity of canola oil in 1,4- dioxane in the presence of HCl, NaOH and NaCl at different Temperatures

Effect of strong electrolytes on the viscosity of canola oil in 1,4 dioxane was undertaken. The viscosity of oil in 1,4 dioxane was found to increase with the concentration of oil and decrease with rise in temperature. Strong electrolytes reduce the rate of flow of oil in 1,4 dioxane. It was noted that amongst these electrolytes, NaOH is more efficient reducing electrolyte than HCl and NaCl. The study was also extended in terms of ion-ion and ion-solvent interactions. The values of Jones-Dole coefficients (A and B) were evaluated graphically. The increase in negative values of A-cefficient with temperature is due to agitation of the molecules at higher temperature, dissociation and partial association of electrolytes in 1,4 dioxane. The positive values of B-cefficient show that these electrolytes behave as structure breaker in 1,4 dioxane. Distortion of the solvent structure is not appreciable (small), which resulted in the positive values of B-coefficient. Fluidity parameters were also evaluated and the change in these values with temperature and concentration of oil shows that the electrolytes behave as structure breaker. The energy of activation, latent heat of vaporization and molar volume of oil were also evaluated and discussed. @JASEM Omega-3 and Omega-6 are important fats associated with a nutrient diet. The primary sources of Omega-6 are maize, soya, canola, safflower and sunflower oils. These oils are overbundent in the typical diet, which explains our excess Omega-6 levels. These oils also contain considerable quantity of Omega-3 but best sources of Omega-3 are fish, flaxseed and walnut oils. Omega-3 in fish is high in two fatty acids essential to human health DHALEPA. These two fatty acids are pivotal in preventing heart disease, cancer and many other diseases. For people who cannot contemplate eating fish, the Omega-3 must come from alpha-linolenic acid. This can be achieved by increasing intake of Omega-3 rich food such as flaxseed (linseed oil), rapeseed (canola) oil, China seed, Walnut oil and dark green leafy vegetables. The ideal ratio of Omega-3 and Omega-6 fats is 1:1. Usually majority of people do not maintain this ratio. Probably it is completely economical problem. Our earlier papers (Khan et al, 2005) report the effect of strong electrolytes (HCl, NaOH and NaCl) on the rates of flow of sunflower oil and maize oil using 1,4dioxane as solvent. Viscosities of these oils in 1,4dioxane get increased with increasing concentration of the oils and decreased with increase in temperatures. Unsaturated ingredients of these oils play an important role in this connection. Thermal effect activation radically, the acids which causes the polymerization result in increasing the viscosity. The saturated ingredients behave as chain transfer agent and terminate the growing polymer chain of these monoglycerides and diglycerides present in the oils. Beside, the shape of the molecules also influences the viscosity. Liquids with large irregular shaped molecules are generally known to be more viscous than those with small symmetrical molecules. This paper deals with the effect of strong electrolytes on viscosity of canola oil in 1,4-dioxane at different temperatures. EXPERIMENTAL Material: The electrolytes like (HCl, NaOH and NaCl), oxalic acid of E.merck and 1,4-dioxane (BDH) are used without further purification. Canola oil was extracted from dried, dehulled seeds. The density of oil was measured at different temperatures with a difference of 5 K. These are 0.978 (298 K), 0.975 (303 K), 0.972 (308 K), 0.967 (313 K), 0.962 (318 K) and 0.955 (323 K) g/cm. Procedure: Viscosities were measured according to the procedure given elsewhere (Khan et al, 2005). The viscosity of canola oil solutions in 1,4-dioxane was measured at different temperatures ranging 298323K with the Ostwald viscometer type Techniconominal constant 0.1(Cs/S) capillary ASTMD 445. Three observations were taken to ensure the reproducibility of the measurements. JASEM ISSN 1119-8362 All rights reserved J. Appl. Sci. Environ. Mgt. March 2006 Vol. 10 (1) 47. 54 Full-text Available Online at www.bioline.org.br/ja Effect of Strong Electrolytes on Edible Oils Part III... A. RASHEED KHAN; SHAMA, REHANA SAEED; FAHIMUDDIN 1 Table 1: Viscosities of Canola oil in 1,4 –dioxane at different temperatures (K). Viscosity (cp) at different temperature (K) Concentration of oil (%) 298 303 308 313 318 323 5 1.358 1.222 1.154 1.056 1.017 0.938 10 1.581 1.436 1.330 1.227 1.156 1.044 15 1.845 1.672 1.555 1.431 1.195 1.121 20 2.122 1.890 1.780 1.620 1.524 1.424 25 2.552 2.293 2.138 1.940 1.809 1.714 [HCl]10 (mol.dm) Viscosity of 5% Canola oil solution in presence of electrolyte. 1.0 1.378 1.246 1.137 1.004 0.928 0.900 2.0 1.414 1.279 1.155 1.020 0.957 0.928 3.0 1.432 1.296 1.171 1.034 0.972 0.943 4.0 1.451 1.313 1.188 1.050 0.987 0.958 5.0 1.487 1.331 1.205 1.066 0.958 0.973 [NaOH]10 (mol.dm) 1.0 1.381 1.261 1.249 1.048 1.016 0.937 2.0 1.416 1.278 1.235 1.079 1.032 0.952 3.0 1.451 1.295 1.205 1.094 1.063 0.981 4.0 1.469 1.312 1.222 1.110 1.079 0.997 5.0 1.488 1.329 1.239 1.126 1.094 1.012 [NaCl]10 (mol.dm) 1.0 1.361 1.243 1.137 1.002 0.913 0.858 2.0 1.396 1.261 1.154 1.018 1.928 0.873 3.0 1.415 1.278 1.170 1.033 1.943 0.887 4.0 1.433 1.295 1.187 1.049 1.958 0.903 5.0 1.451 1.312 1.204 1.065 1.973 0.918 RESULTS AND DISCUSSION Density of extracted oil was measured at different temperatures with a difference of 5 K. It decreases slightly with change in temperature. The densities of maize oil, soyabeen oil, sunflower oil at 298 K are respectively as 0.960, 0.986, and 0.978 gm/cm where as that of canola is 0.981 gm /cm. It shows that this oil is thick and spread slowly due to the bonding of ingredients present in the oil. Viscosity of canola oil and its solutions in 1,4-dioxane were measured at different temperatures ranging 298-323 K (Table 1). The viscosity of oil solutions gets increased with the increment of concentration of oil and decrease with the increase in temperature. The relative molecular mass of canola oil was also calculated graphically by plotting 1/Voln η / ηo versus Vo at different temperatures over the range of 298-323 K. The representative linear plot is shown in Fig 1 with the correlation coefficient of 0.09. Vc→o [1/Vo ln η / ηo] (1) 0 0.01 0.02 0.03 0.04