Thermodynamic and structure-property study of liquid-vapor equilibrium for aroma compounds.
Thermodynamic parameters (T, DeltaH degrees , DeltaS degrees , K) were collected from the literature and/or calculated for five esters, four ketones, two aldehydes, and three alcohols, pure compounds and compounds in aqueous solution. Examination of correlations between these parameters and the range values of DeltaH degrees and DeltaS degrees puts forward the key roles of enthalpy for vaporization of pure compounds and of entropy in liquid-vapor equilibrium of compounds in aqueous solution. A structure-property relationship (SPR) study was performed using molecular descriptors on aroma compounds to better understand their vaporization behavior. In addition to the role of polarity for vapor-liquid equilibrium of compounds in aqueous solution, the structure-property study points out the role of chain length and branching, illustrated by the correlation between the connectivity index CHI-V-1 and the difference between T and log K for vaporization of pure compounds and compounds in aqueous solution. Moreover, examination of the esters' enthalpy values allowed a probable conformation adopted by ethyl octanoate in aqueous solution to be proposed.
Tromelin
Anne
A
Centre des Sciences du Gout et de l'Alimentation, UMR1324 INRA, UMR6265 CNRS Universite de Bourgogne, Agrosup Dijon, Dijon. Tromelin@dijon.inra.fr
Andriot
Isabelle
I
Kopjar
Mirela
M
Guichard
Elisabeth
E
D015394:Molecular Structure; D009930:Organic Chemicals / Q000737:chemistry*; D012995:Solubility; D013816:Thermodynamics; D014835:Volatilization
D009930:Organic Chemicals