Contributions of Distillate Components to Disperse Phase Structures in Model Spirit Solutions

Abstract

The dispersed phase of a Scotch distillate behaved differently from that of a model solution containing solely the esters that are normally present in such whiskeys. The presence of surface active distillate components, such as long-chain alcohols, aldehydes, and esters, had the major stabilizing influence on dispersed phase agglomerates. Increasing the hydrophilicity of the end group and the length of the aliphatic chain of individual congeners made positive contributions to surface activity. Possible surface active components in the test distillate were the long-chain aliphatic alcohols tetradecanol and hexadecanol and possibly ethyl esters of 18-carbon acids. The optimum ethanol concentrations for agglomerate stability were 1% in the presence of surface active agents and 3% in the absence of such components. Excess ethanol appeared to reduce the stabilizing effect of surface active compounds. Gas chromatography of new distillate headspaces over 4 h following dilution showed no significant changes in concentration of volatiles above the liquid phase. This suggests that changes in agglomerate diameter would have no effect on the assessment of spirit for the duration of a normal sensory panel. The formation of stable agglomerates may alter the release of aroma compounds in the mouth, influencing concentrations of compounds reaching the retronasal cavity and so influencing perceptions of flavor. Keywords: Ethyl esters; whiskey; photon correlation spectroscopy; interfacial tension