Headspace concentrations of ethyl esters at different alcoholic strengths
J.M. Conner, Lorraine Birkmyre, Alistair Paterson, John Piggott
Journal of the Science of Food and Agriculture
Abstract
Ester concentrations in the headspace influence the aroma character of alcoholic drinks. Activity coefficients for esters showed log-linear decreases as ethanol concentration was increased from 17% (v/v), with rates inversely related to ester acid chain length. At concentrations below 17% (v/v) the activity coefficient remained constant. This could be related to structural changes in ethanol/water mixtures. Below 17% (v/v), ethanol forms a monodispersed aqueous solution. Above 17% (v/v), ethanol molecules cluster to reduce hydrophobic hydration and esters partition into these ethanol-rich clusters, where the lower ester interfacial tension reduces the free energy of mixing and hence the activity coefficient. The increased solubility of the ester reduced the headspace concentration of the esters, and hence total ester content may not be a good indicator of their flavour impact. © 1998 SCI.
Extracted Claims
9 claims extracted from this paper into the knowledge graph
activity coefficient remain constant
“At concentrations below 17% (v/v) the activity coefficient remained constant.”
ethanol form monodispersed aqueous solution
“Below 17% (v/v), ethanol forms a monodispersed aqueous solution.”
activity coefficients for esters decrease log-linearly
“Activity coefficients for esters showed log-linear decreases as ethanol concentration was increased from 17% (v/v), with rates inversely related to ester acid chain length.”