0000000000329541
AUTHOR
Marco Covarrubias-cervantes
Temperature effect on solubility of aroma compounds in various aqueous solutions
International audience; Solubility of nine aroma compounds (methyl ketones, ethyl esters, aldehyde and alcohol) in various aqueous solutions was measured by the mutual solubility method from -10 to +10degreesC. Influence of both, the nature (carbohydrates and polyols) and the substrate concentration (from 0 to 57.5g/100g) on aroma solubility in aqueous solutions was studied. Aroma solubility in water decreased when aroma hydrophobicity increased. Aroma solubility in various aqueous solutions decreased when substrate concentration increased; their solubility was higher in polyols solutions than in polysaccharides ones. Temperature effect on aroma solubility showed a noncontinuous evolution f…
Saturated vapour pressure of aroma compounds at various temperatures
Abstract The aim of this study was to determine experimentally the vapour pressures of aroma compounds at various temperatures, especially at negative ones. The aroma compounds were: acetone, 2-butanone, 2-hexanone, 2-octanone, ethyl acetate, ethyl butanoate, ethyl hexanoate, n-hexanal, n-hexanol and γ-hexalactone. The technique used was a static device where vapour pressure was measured at equilibrium. The temperatures of analysis varied from −40 to 25 °C. Volatility of a pure compound depends on characteristics such as length of the aliphatic chain, the functional group and temperature. Among an homologous series, volatility increases when the aliphatic chain decreases and when temperatur…
Translational diffusion coefficients of volatile compounds in various aqueous solutions at low and subzero temperatures.
International audience; Translational diffusion coefficients (D(12)) of volatile compounds were measured in model media with the profile concentration method. The influence of sample temperature (from 25 to -10 degrees C) was studied on translational diffusion in sucrose or maltodextrin solutions at various concentrations. Results show that diffusivity of volatile compounds in sucrose solutions is controlled by temperature, molecule size, and the viscosity of the liquid phase as expected with the Stokes-Einstein equation; moreover, physicochemical interactions between volatile compounds and the medium are determinant for diffusion estimation. At negative temperature, the winding path induce…
Aroma Volatility from Aqueous Sucrose Solutions at Low and Subzero Temperatures
International audience; The gas-liquid partition coefficients of ethyl acetate and ethyl hexanoate have been measured in water and aqueous sucrose solutions from 25 to -10 degrees C by dynamic headspace. Experiments were carried out on sucrose solutions at temperatures where no ice formation was possible. Results showed that when sucrose concentration increased, aroma volatility increased except for ethyl hexanoate and in the highest sucrose concentration solution (57.5%). A quasi-linear temperature decrease on aroma volatility was observed in sucrose solutions from 25 to around 4 and 0 degrees C. Then, from 0 to -10 degrees C, aroma volatility did not decrease: ethyl acetate volatility rem…
Effects of the nature and concentration of substrates in aqueous solutions on the solubility of aroma compounds
The solubility of nine aroma compounds (acetone, 2-butanone, 2-hexanone, 2-octanone, ethyl acetate, ethyl butanoate, ethyl hexanoate, n-hexanal, and n-hexanol) in both water and various aqueous solutions was measured at 25 °C using the mutual solubility method. The aqueous solutions consisted of sucrose, glucose, sorbitol, glycerol, polyethylene glycol 200, or maltodextrins at different concentrations. Aroma solubility in water decreased with increased hydrophobicity. For aroma molecules which have the same number of carbon atoms in their structure, aqueous solubility decreased as follows: aldehyde > methyl ketone > alcohol > ethyl ester. When using a group contribution method, the estimate…