High Resolution Gas Chromatography-Selective Odorant Measurement by Multisensor Array: A Useful Technique to Develop Tailor-Made Chemosensor Arrays for Food Flavor Analysis

A technique combining a chemosensor array with high resolution gas chromatography (HRGC/SOMMSA) was used to systematically study the responses of several experimental and commercial chemosensors (metal oxides, surface acoustic wave devices, phthalocyanine sensors) to a number of selected food volatiles or aroma compounds. It was shown that the temperatures and the dopants used significantly influence the sensitivity and/or selectivity of the chemosensors. For example, a ZnO/Pt sensor, when operated at 300°C, was able to selectively detect the key bread crust odorant 2-acetyl-1-pyrroline. A copper phthalocyanine sensor selectively detected (E)-2-nonenal and (E,E)-2,4-decadienal in mixtures with several pyrazines. Based on such model studies, a portable sensor array was constructed which was able to detect degree of roasting, e.g., of toasted bread slices. A combination of Headspace-HRGC with the SOMMSA technique is proposed as useful approach to develop chemosensor arrays adapted to special targets in flavor control, based on quantitative correlations of key odorants with indicator volatiles.