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Partition equilibria of three aroma compounds in three different biphasic systems were studied by a liquid/liquid partition technique to investigate interactions that occur between volatiles and lipids in biphasic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl acetate, 2,5-dimethylpyrazine, and oct-1-en-3-ol. The results showed that the intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or aroma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This method confirmed the presence of hydrogen bonds between linoleic acid and 2,5-dimethylpyrazine or oct-1-en-3-ol and also between molecules of oct-1-en-3-ol when the latter are present at high concentrations in lipids. The observations provided sufficient information to explain the behavior of oct-1-en-3-ol in biphasic solutions, but further work is needed to fully elucidate the nature of interactions between ethyl acetate or 2,5-dimethylpyrazine and lipids and also to explain the behavior of these compounds in biphasic solutions.

Partition equilibria of three aroma compounds in three different biphasic systems were studied by a liquid/liquid partition technique to investigate interactions that occur between volatiles and lipids in biphasic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl acetate, 2,5-dimethylpyrazine, and oct-1-en-3-ol. The results showed that the intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or aroma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This method confirmed the presence of hydrogen bonds between linoleic acid and 2,5-dimethylpyrazine or oct-1-en-3-ol and also between molecules of oct-1-en-3-ol when the latter are present at high concentrations in lipids. The observations provided sufficient information to explain the behavior of oct-1-en-3-ol in biphasic solutions, but further work is needed to fully elucidate the nature of interactions between ethyl acetate or 2,5-dimethylpyrazine and lipids and also to explain the behavior of these compounds in biphasic solutions.

Taking into account interactions between aroma compounds and food components is necessary to better manage the flavoring of food products. These interactions occur at a molecular level and reflect changes, at a macroscopic level, in thermodynamic equilibria, such as solubility or volatility. The rate of transfer of an aroma compound from the liquid to the vapor phase can be affected as well. The behavior of aroma compounds in water and lipid solutions was studied in two complementary ways, a thermodynamic and a kinetic approach (head-space analysis). The transfer rate of volatiles at the liquid-water interface does not only depend on the hydrophobicity of the aroma compounds. Vapor-liquid partition and activity coefficients show the presence of solute-solvent interactions. The Gibbs free energy values indicate their physicochemical nature.

Taking into account interactions between aroma compounds and food components is necessary to better manage the flavoring of food products. These interactions occur at a molecular level and reflect changes, at a macroscopic level, in thermodynamic equilibria, such as solubility or volatility. The rate of transfer of an aroma compound from the liquid to the vapor phase can be affected as well. The behavior of aroma compounds in water and lipid solutions was studied in two complementary ways, a thermodynamic and a kinetic approach (head-space analysis). The transfer rate of volatiles at the liquid-water interface does not only depend on the hydrophobicity of the aroma compounds. Vapor-liquid partition and activity coefficients show the presence of solute-solvent interactions. The Gibbs free energy values indicate their physicochemical nature.

The author provides insights on planning and implementing diverse programs for adult students in U.S. colleges and universities. Student programming boards are advised to obtain campus population data from the institutional research office. The importance of searching for co-sponsorships, being open-minded and considering family-oriented events is emphasized. He adds that programming boards should bear in mind other demographics during the planning phases.