Equilibrium data for the system rice bran oil plus fatty acids plus ethanol plus water at 298.2 K

This work presents experimental data for the model system refined rice bran oil + commercial oleic acid + ethanol + water at 298.2 K. These data were correlated by the NRTL and UNIQUAC models, with a global deviation of approximately 0.7% for both models. The equilibrium of crude rice bran oil + aqueous ethanol was predicted with success using the adjusted interaction parameters, with deviation between calculated and experimental results not higher than 0.54%. The results showed that the addition of water to the solvent increases the solvent selectivity, reducing the losses of neutral oil and nutraceutical compounds, and expands the region of phase splitting, allowing the refining of highly acidic crude rice bran oils by solvent extraction.48236737

Phase equilibrium for the system rice bran oil plus fatty acids plus ethanol plus water plus gamma-oryzanol plus tocols

This work reports experimental equilibrium data for fatty systems containing rice bran oil, free fatty acids, ethanol, water, gamma-oryzanol and tocols, at 298.2 K. Model fatty systems composed by refined rice bran oil, commercial oleic acid, gamma-oryzanol, ethanol and water were used for adjusting NRTL and UNIQUAC interaction parameters between gamma-oryzanol and the other pseudocompounds. UNIQUAC interaction parameters between tocols and the other pseudocomponents were determined assuming that the tocols are present at infinite dilution in the liquid-liquid equilibrium system. Despite the complexity of the systems studied, the interaction parameters obtained were capable of correctly predicting the equilibrium for systems containing Brazilian and Thai crude rice bran oils and aqueous ethanol. (C) 2003 Elsevier B.V. All rights reserved.216227128

Optimization of the rice bran oil deacidification process by liquid-liquid extraction

The present paper reports the process variable influence on the losses/transfer of fatty compounds during the deacidification process of rice bran oil by liquid-liquid extraction. The influence of process variables such as free fatty acid concentration in the oil, water content in the ethanolic solvent and oil:solvent mass ratio, were analyzed using the response surface methodology, having the aim to maximize the transfer of free fatty acids and minimize the losses of neutral oil plus minor compounds. In addition, the UNIQUAC equation was used to predict the transfer/losses of fatty and nutraceutical compounds to the alcohol phase. Both methodologies, the mathematical model from non-linear multiple regression and the UNIQUAC model, presented good agreement with the experimental data. (c) 2005 Elsevier Ltd. All rights reserved.73437037

Deacidification of Brazil nut and macadamia nut oils by solvent extraction: Liquid-liquid equilibrium data at 298.2 K

The present paper reports phase equilibrium experimental data for two systems composed by Brazil nut oil or macadamia nut oil + commercial oleic acid + ethanol + water, at 298.2 K and different water contents in the solvent. The addition of water to the solvent reduces the loss of neutral oil in the alcoholic phase and improves the solvent selectivity. The experimental data were subsequently correlated by the NRTL and UNIQUAC models. Global deviations between calculated and experimental results not higher than 1.5% were obtained for all systems, indicating that both models were able to reproduce correctly the experimental data, although the NRTL model presented a better performance.50251752

Comparison of near-infrared emission spectroscopy and the Rancimat method for the determination of oxidative stability

This work presents a comparison between a new method for the determination of the oxidative stability of edible oils at frying temperatures, based on near-infrared emission spectroscopy (NIRES), and the Rancimat method at 110 degrees C. In the NIRES-based method, the induction time (IT) is determined by means of the variation of the emission band at 2900 nm during heating at 160 degrees C. The comparison between the IT values obtained with the two methods for 12 samples of edible oils shows some correlation for samples of the same type once there is an agreement on the sequence of highest to lowest IT values between the methods, but a poor correlation considering all samples (correlation coefficient of 0.78). This lack of correlation demonstrates that the results obtained with the Rancimat method cannot be used as an indication of the oxidative stability, or the resistance to degradation, of edible oils at frying temperatures. The difference in the heating temperatures used in the two methods leads to 20-36 times higher IT values for the Rancimat method in relation to the NIRES-based method, but with similar repeatabilities (2.0 and 2.8%, respectively).1091616

Storage of refrigerated raw goat milk affecting the quality of whole milk powder

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aim of this study was to evaluate the influence of the growth of lipolytic bacteria in raw goat milk stored under refrigeration for different periods on quality parameters of goat milk powder during its shelf life. Fresh goat milk (100 L) was collected after milking, divided into 3 identical fractions, and stored at 4 degrees C for 1, 3, and 5 d. On d 1, 3, and 5, one sample (1 L) was collected and used for microbiological and chemical analysis, and the remaining fraction (almost 30 L) was spray dried and stored at 25 degrees C. Milk powder was submitted to microbiological, chemical, and sensory analysis immediately after production, and on d 60, 120, and 180. Lipolytic psychrotrophic counts and total free fatty acid content did not increase in raw milk during storage. However, peroxide value, caprylic and capric acid concentrations, and total free fatty acid content of milk powder increased during 180 d of storage, with higher levels found in milk powder manufactured with raw milk stored for 5 d. Capric odor and rancid flavors increased in milk powder during storage, regardless the of storage of raw milk for 1, 3, or 5 d. Heat treatments used during powder processing destroyed lipolytic psychrotrophic bacteria, but did not prevent lipolysis in milk powder. Results of this trial indicate that the storage of raw goat milk at 4 degrees C should not exceed 3 d to preserve the quality of goat milk powder during its shelf life of 180 d.96747164724Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2006/61095-5