ABSTRACT
The analysis of volatile compounds, which are perceived by the human nose in the air above a food, has always been a goal in flavor research. Two different techniques, static and dynamic headspace sampling, have been proposed to solve this problem. Although dynamic headspace sampling usually provides sufficient amounts of odorants to obtain a signal, it has a strong dependence of the yield of the odorants on the velocity of carrier gas [1] and the selectivity of the adsorption and desorption processes [2, 3]. As it is very difficult to control these parameters accurately, reproducibility of measurements may be poor. On the other hand, as a result of its usually good reproducibility, cheap and rapid analysis, simplicity of the procedure, and availability of automated systems, static headspace sampling became very popular over the last few years. Here, generally two techniques, injection of gas samples by gastight syringes usually combined with cryofocusing or use of an adsorptive fiber such as solid-phase microextraction (SPME) [4-7] or headspace sorptive extraction (HSSE) [8] are used to analyze key odorants. Although both techniques can show good reproducibility, which allows comparison of samples relative to each other, they also suffer from analyte losses and gas phase distortion. Hence, care must be taken if elucidation of the true gas phase composition is the goal. A comparison of both techniques and their specific disadvantages is presented.
