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Headspace concentrations of ethyl esters at different alcoholic strengths
Author(s) -
Conner John M,
Birkmyre Lorraine,
Paterson Alistair,
Piggott John R
Publication year - 1998
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199805)77:1<121::aid-jsfa14>3.0.co;2-v
Subject(s) - chemistry , ethanol , partition coefficient , aroma , aqueous solution , solubility , chromatography , alcohol , flavour , ethyl ester , molecule , surface tension , activity coefficient , organic chemistry , food science , thermodynamics , physics
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.