DETERMINATION OF PARTITION-COEFFICIENTS AND QUANTITATION OF HEADSPACE VOLATILE COMPOUNDS

A survey of partition coefficient values reported in the literature showed numerous discrepancies. These could be attributed to technical problems encountered during headspace measurements. Consequently, a novel method based on a combination of static headspace sampling and dynamic headspace traps was developed. The new method also includes determination of partition coefficients independently of the concentration of the reference. Once the partition coefficient is known, a simple calibration of the gas phase constituents can be performed. This headspace quantification method does not require addition of a standard. Estimation of variance showed the method to be accurate (0.5-15%, depending on component and matrix). A model mixture of flavors was investigated by the new method. Varying the concentration of one compound had no effect on the rest of the aroma profile. Small differences in the aroma profile due to changes in the matrix were investigated as exemplified by alterations in flavor retention observed when water, lipids, or emulsions were used as the solvent.