Classification of unifloral honeys with an MS-based electronic nose using different sampling modes: SHS, SPME and INDEX

An electronic nose based on mass spectrometry has been applied to the control of the authenticity of the botanical origin of honey. PCA and DFA models were built based on groups of samples identified as typical unifloral honey by a classical method, i.e. a combination of sensory, pollen and physicochemical analysis. Swiss unifloral honeys of the following types were analysed: acacia, chestnut, dandelion, lime, fir and rape. Three different sampling modes were tested: static headspace (SHS), solid-phase micro-extraction (SPME)and inside-needle dynamic extraction (INDEX). The last two showed interesting abilities to extract volatile components in a higher concentration and, most important, heavier compounds than SHS. The best classification, under the sampling conditions used, was provided by the SPME sampling mode. This method proved to be fast, reliable and powerful for this type of task. A good correlation was found between the present approach and the classical one for the determination of the botanical origin of honey.