ACTIVITY-COEFFICIENTS OF AROMA COMPOUNDS IN MODEL SOLUTIONS SIMULATING APPLE JUICE

Infinite dilution activity coefficients (gamma-infinity) of several alcohols, aldehydes, and esters, considered to be the major components of apple aroma, were measured in model food solutions containing glucose, fructose, sucrose, and malic acid. Measurements were made by following the dilution exponential method, at temperatures ranging from 25 to 68-degrees-C. Experimental data were correlated with the one-parameter Wilson model. The results reveal that gamma-infinity values for a homologous series increase with the length of the carbon chain. Gamma-infinity values of lower alcohols and esters increase with temperature, while gamma-infinity values for heavier aromas either decrease or remain practically constant with temperature. Apple juice solutes increase the activity coefficients of most of the aroma compounds studied.