This work investigates the production of fatty acid ethyl esters from soybean oil in sub-and supercritical ethanol. The experiments were performed in a tubular reactor in the temperature range of 473-648 K, from 7 to 20 MPa, adopting the oil-to-ethanol molar ratio interval from 1:10 to 1:100. Results showed that temperature and pressure below the solvent critical point led to very low reaction conversions while appreciable yields were verified around 623 K and 20 MPa using an oil-to-solvent molar ratio of 1:40 and with a reaction time of approximately 15 min. A pseudo-first-order kinetic modeling was employed in representing the experimental alcoholysis data with a satisfactory agreement between experimental and calculated conversion values.

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a b s t r a c tPervaporation experiments with PDMS membrane have been performed in a plate and frame module to investigate its ability to concentrate volatile compounds identified in an industrial soluble coffee solution. Eight compounds were chosen to depict key aroma of soluble coffee. The effect of feed flow rate, temperature and permeate pressure on the pervaporation performance has been analyzed. Concentration polarization phenomena was not identified in the feed flow rate studied. The temperature effect showed a good agreement with the nonlinear Arrhenius equation. The permeate pressure followed the solution-diffusion model behavior. Results showed that pervaporation is a promising alternative to concentrate aroma compounds from soluble coffee.

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Natural fruity aroma was produced during submerged fermentation by Pichia fermentans using sugarcane molasses as a cultivation broth. The aroma compounds were recovered from the fermentation by a pervaporation process using a polydimethylsiloxane membrane (Pervap 4060-Sulzer). Isoamyl acetate, a characteristic compound associated with fruity aromas, was the major compound produced. The pervaporation module was fed at three different temperatures to test the best conditions to recover the natural fruity aroma. The total flux (J ), partial fluxes of each component (J), and enrichment factors (β) were determined within the tested ranges. The process was performed at 45 °C, a feed flow of 1.5 mL/min and 0.1 kPa, for a duration of 13 h to concentrate the natural flavor. The pervaporation process can concentrate the isoamyl acetate from fermented broth from 9 to 61.8 mg/L in the first hour of pervaporation. As a single step of downstream operation, pervaporation was efficient for recovering and concentrating the natural fruity aroma. The obtained product was colorless and had a characteristic banana flavor.