Commercial Linoleic Acid Research Articles

Deacidification and ethyl biodiesel production from acid soybean oil using a strong anion exchange resin

The objective of this work was to investigate simultaneously the deacidification and the ethyl biodiesel production from soybean oil using the Amberlyst A26 OH anion exchange resin. The behavior of the process was investigated as a function of resin loading, ethanol concentration and initial free fatty acids (FFAs) content. To obtain the acidified oil, degummed soybean oil and commercial linoleic acid were mixed. The Langmuir model was able to better describe the FFAs adsorption isotherms in comparison to the Freundlich equation. A high removal of FFAs with high deacidification rate could be obtained using lower initial ratios of FFAs per mass of dry resin, being this the more favorable condition for oil deacidification. Ester formation showed to be affected by the resin loading, initial FFA content and ethanol concentration in the medium. The adsorption of FFAs seemed to deactivate the catalytic activity of the resin sites. For this reason, a high resin loading was required, although it was still possible to obtain a satisfactory biodiesel production. The present work makes possible deeper understanding of oil processing by anion exchange resins in the presence of an alcoholic solvent.

Synthesis of Linoleic Acid Hydroperoxides as Flavor Precursors, Using Selected Substrate Sources

AbstractThe objective of the research was the synthesis of linoleic acid hydroperoxides (HPOD) and their recovery, using selected sources of linoleic acid (LA) as substrate. This is part of on‐going work aimed at the development of an economically viable biotechnological process for the production of natural flavors. The investigated sources included pure (100 %) LA and commercial (67 %) LA as well as safflower oil (SO) and its hydrolyzed product. A model describing commercial LA oxidation by lipoxygenase, based on Michaelis–Menten kinetics, was developed. The conversion of pure LA and commercial LA resulted in insignificant differences in HPOD yield of 69.7 and 68.9 %, respectively. However, there was a significant difference in the HPOD yield, obtained from the SO (2.0 %) and that from the hydrolyzed SO (58.0 %) in comparison to that from pure LA (69.7 %). The ratios of the different 9‐ and 13‐HPOD isomers were insignificantly different for the sources containing free LA, with 13‐(9Z,11E)‐HPOD was the highest relative percentage. Using optimized conditions, HPOD yields were 85.9 and 74.0 % for the commercial LA and the hydrolyzed SO, respectively. Based on experimental findings, commercial (67 %) LA was selected as the most appropriate alternative to pure LA for the production of HPOD. An efficient extraction procedure for the recovery of HPOD was also developed.

Experimental data for liquid–liquid equilibrium of fatty systems with emphasis on the distribution of tocopherols and tocotrienols

The present paper reports liquid–liquid equilibrium data for systems composed of degummed soybean oil+commercial linoleic acid+anhydrous ethanol, degummed soybean oil+commercial linoleic acid+ethanol+water, refined rice bran oil+commercial oleic acid+anhydrous ethanol and refined rice bran oil+commercial oleic acid+ethanol+water at 298.15K, 313.15K and 323.15K. α, β, γ and δ tocopherol and tocotrienol contents in both phases were analyzed. The parameters of the NRTL model were adjusted to the experimental data. For higher temperatures and the free fatty acid contents, higher are distribution coefficients of tocopherols and tocotrienols, due to the increase in solubility among the systems components. In contrast, the distribution coefficients of tocopherols and tocotrienols decrease when water is added to ethanol, which represents the increase in retention of tocopherols and tocotrienols in the oil phase. The NRTL model represented well the experimental data, and the global deviations between calculated and experimental data were 1.02% and 0.95% for systems composed of degummed soybean oil and refined rice bran oil, respectively.

Densities, Viscosities, Interfacial Tensions, and Liquid−Liquid Equilibrium Data for Systems Composed of Soybean Oil + Commercial Linoleic Acid + Ethanol + Water at 298.2 K

This work presents densities, viscosities, interfacial tensions, and liquid−liquid equilibrium data for systems of interest in vegetable oil refining and biodiesel production, composed of soybean oil + commercial cis,cis-octadeca-9,12-dienoic acid (linoleic acid) + ethanol + water at 298.2 K with water mass fractions in the alcohol solvent (ethanol + water) of 0.05, 0.08, 0.11, and 0.14. Experimental phase compositions at equilibrium were correlated using the nonrandom two-liquid (NRTL) model. For all systems, the global deviations between calculated and experimental phase compositions were no greater than 0.0005. All physical properties were evaluated by empirical correlations as functions of phase compositions. The absolute relative deviations between calculated and experimental data were no greater than 6.36 %. Water content in the solvent presented a considerable effect on the physical properties of the systems and phase compositions at equilibrium, even more so on its interfacial tensions.

Liquid–liquid equilibria for systems composed of refined soybean oil, free fatty acids, ethanol, and water at different temperatures

Soybean oil can be deacidified by liquid–liquid extraction with ethanol. In the present paper, the liquid–liquid equilibria of systems composed of refined soybean oil, commercial linoleic acid, ethanol and water were investigated at 298.2 K. The experimental data set obtained from the present study (at 298.2 K) and the results of Mohsen-Nia et al. [1] (at 303.2 K) and Rodrigues et al. [2] (at 323.2 K) were correlated by applying the non-random two liquid (NRTL) model. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. Among variables, the water content of the solvent had the strongest effect on the solubility of the components. The maximum deviation and average variance between the experimental and calculated compositions were 1.60% and 0.89%, indicating that the model could accurately predict the behavior of the compounds at different temperatures and degrees of hydration.

Vegetable Oils Deacidification by Solvent Extraction: Liquid−Liquid Equilibrium Data for Systems Containing Sunflower Seed Oil at 298.2 K

Liquid−liquid equilibrium experimental data for refined sunflower seed oil, artificially acidified with commercial oleic acid or commercial linoleic acid and a solvent (ethanol + water), were determined at 298.2 K. This set of experimental data and the experimental data from Cuevas et al.,(1) which were obtained from (283.2 to 333.2) K, for degummed sunflower seed oil-containing systems were correlated using NRTL and UNIQUAC models with temperature-dependent binary parameters. The deviation between experimental and calculated compositions presented average values of (1.13 and 1.41) % for NRTL and UNIQUAC equations, respectively, indicating that the models were able to correctly describe the behavior of compounds under different temperature and solvent hydration.

Liquid–Liquid Equilibrium Data for Reactional Systems of Ethanolysis at 298.3 K

The objective of this work was to determine liquid–liquid equilibrium data at (298.3 ± 0.2) K for systems of interest in biodiesel production, such systems being composed of vegetable oils + anhydrous ethanol + hexane. The measurements were performed using near-infrared spectroscopy (NIR) for quantification of the phases in equilibrium. The following vegetables oils were investigated: pretreated cottonseed oil, corn oil, canola oil, refined soybean oil, and degummed soybean oil. Initially, with the purpose of validating the NIR methodology, equilibrium data for the system composed of pretreated cottonseed oil (neutral) + commercial linoleic acid + anhydrous ethanol were determined at (298.2 ± 0.1) K by a conventional method based on acid–base titration and solvent evaporation and by the NIR method. The relative errors between the phase compositions determined by both analytical methods were 2.1 % for the alcoholic phase and 2.0 % for the oil phase. The mass balance errors for all investigated systems vari...

Phase equilibrium for systems composed by refined soybean oil + commercial linoleic acid + ethanol + water, at 323.2 K

The present paper reports liquid–liquid equilibrium data for the system refined soybean oil + commercial linoleic acid + ethanol + water at 323.2 K. The deviation between experimental and calculated compositions, using NRTL equation, presented a maximum value of 1.21% and an average of 0.82%. The obtained parameter set enables the simulation of liquid–liquid extractors for edible oil deacidification.

Equilibrium data for systems composed by cottonseed oil + commercial linoleic acid + ethanol + water + tocopherols at 298.2 K

The present paper reports liquid–liquid equilibrium data for the system refined cottonseed oil + commercial linoleic acid + ethanol + water at 298.2 K. The experimental data were used for adjusting parameters of the NRTL and UNIQUAC models. The global deviations between calculated and experimental concentrations were 0.80% for the NRTL model and 1.44% for the UNIQUAC equation. The influence of the solvent on the distribution coefficient of tocopherols was also studied. UNIQUAC and NRTL interaction parameters between tocopherols and the other pseudocomponents were determined assuming that the nutraceutical compound is present at infinite dilution in the liquid–liquid equilibrium system. The obtained parameter set enables the simulation of liquid–liquid extractors.

Calcium-translocating and cardiotonic properties of oxidation products of linoleic acid.

Calcium-translocating activity of linoleic acid and its lipoxygenase (linoleate: oxygen oxidoreductase; EC 1.13.11.12) metabolites or autoxidation products was determined in vitro by estimation of 45Ca transport from a bulk aqueous to a bulk organic phase. Fresh commercial linoleic acid, tested immediately after removal from a sealed vial, stimulated calcium translocation only at concentrations greater than 1 mM. In contrast, 45Ca translocation by linoleic acid exposed to air was detectable at 10 microM. Oxidation products of linoleic acid obtained either by incubation with lipoxygenase or by autoxidation were much less potent than the calcium ionophore A23187. The products obtained by enzymic oxidation of linoleic acid enhanced contractility in the Langendorff-perfused guinea pig heart up to 45% over control (at 3 X 10(-8) M). The inotropic response was transient with rapid onset and not affected by the beta-adrenergic antagonist, propranolol. The autoxidation products of linoleic acid increased cardiac contractility up to 43% at 10(-6) M. In contrast, fresh linoleic acid caused only a negative inotropic effect at 10(-8) to 3 X 10(-7) M, progressing to contracture at 10(-6) M. These findings suggest that conflicting reports on the cardiostimulant effect of linoleic acid may be due to varying levels of the autoxidation products. Linoleic acid metabolites in vivo may have a physiological role in myocardial function related to their Ca2+-ionophoric activity.

収穫時期におけるリンゴ‘ジョナゴールド’果皮の脂質の変化

To determine the cause of a greasy phenomenon of the peel of apple cv. ‘Jonagold’, the main lipids of the peel were analyzed by gas chromatograph-mass spectrometer, particularly noting the unsaturated fatty acids which were fluid at normal temperature.As harvest was delayed, the number of components and the quantity of the lipids of the peel increased. The compositions of 17 aliphatic lipids were identified.In the stages before ripening, palmitic acid, stearic acid, oleic acid, linoleic acid and triacontane were scarcely detected, whereas in the stages after ripening, these lipids increased. Among them, lipids fluid at normal temperature were oleic acid and linoleic acid. Oleic acid was detected later than linoleic acid. The time of the increase in linoleic acid coincided with the appearance of greasiness of the peel.When commercial linoleic acid was painted on peel which had not shown the greasiness, the wax of the peel was melted and the greasy phenomenon similar to the natural appearance was produced.It was concluded that the natural greasiness of the ‘Jonagold’ peel was caused by linoleic acid and oleic acid.