Gas chromatography/olfactory

Ong PKC and Acree TE. 1998. Gas chromatography/olfactory analysis of lychee (Litchi chinensis Sonn.). J Agric Food Chem 46(6) 2282-2286. 

Chromatography, see also Gas chromatography Gas chromatography/olfactory High-performance liquid chromatography Thinlayer chromatography of cholesterol, 453-458, 460 (table),... 

Behavioral bioassays are inextricably linked with chemical studies to decipher the information content of olfactory signals (Albone 1984). As a complement to the experimental approach described above, several research groups have applied chemical approaches, particularly gas chromatography and mass spectrometry (GC-MS),... 

Within Severn Trent a modified version of this procedure is utilised for the analysis of malodorous emissions. The most significant difference in this approach compared to those already discussed is the use of high resolution gas chromatography in combination with olfactory detection. This method also combines physico-chemical and olfactometric or sensory techniques but in an alternative manner. Utilisation of gas chromatography combined with odour detection is not a new concept and has been employed fairly commonly for the analysis of food aromas, essential oils and other fragrances. The technique is equally applicable to environmental problems and is used frequently in this laboratory for the analysis of atmospheric emissions and taste and odours in water. Three important benefits accrue from this approach in the context of odour emission analysis. 

Of secondary importance as judged by gas chromatography with olfactory detection are -... 

A variety of compounds have been identified as key contributes to certain malodorous emissions originating from water reclamation works. The most important are considered to be polymeric sulphides, volatile fatty acids, indole and cresol. The utilisation of high resolution gas chromatography in conjuction with olfactory detection is identified as a valuable aid to the analytical procedure. 

Struble, D. L. and Arn, H. (1984). Combined gas chromatography and electroantennogram recording of insect olfactory responses. In Techniques in Pheromone Research, eds. 

Toasted wood extracts and standard media heated in the laboratory were analyzed by gas chromatography and olfactory detection. Several toasty aromatic... 

For identifying the biologically relevant plant odorants used by insects, the most precise method is gas chromatography linked to eleetrophysiological recordings from single olfactory receptor neurons (GC-SCR). " This allows naturally produced plant odorants to be separated in the column of the gas chromatograph and tested directly on each neuron. By the use of two columns with different properties... 

GC-EAD is gas chromatography method in which a unique biological detector, based on living insect antenna, is used as one of two detection systems. GC-EAD is an analytical method which offers very fast and reliable identification of compoimds in complex natural mixtures that stimulate the olfactory sensilla of insect antennae (Struble Am, 1984). In other words, the GC-EAD helps to discover what specific chemicals in tested mixture an insect can smell, respective, which compound elicits the electric antennal response. 

Various unknown compounds were isolated by preparative capiQary gas chromatography in microgram-quantities in order to elucidate tiieir structures by IR and NMR spectroscopy, and to check their olfactory properties. The spectroscopic data and sensory impressions are given. Many of the analyzed flavor compounds were synthesized. In particular, a series of new thiophenes is presented. Their formation led to the explanation of one of the main hitherto unknown degradation pathways of thermally treated thiamin. 

Flowever, human olfactory sensitivity, and especially aroma perception, can be affected by a large number of factors, such as age, gender, smoking habits, disease, or injury [5-8]. Such modulation of olfactory capacity can have dramatic impact on the results of sensory evaluation studies based on olfactory tasks. This is especially important in studies using only a few panelists [gas chromatography olfactometry (GCO), quantitative flavor profiling, etc.]. It thus seems that food flavor studies eould benefit from their panelists being assessed for olfactory and other sensory performance. 

Gas chromatography olfactometry (GCO) is a valuable technique [1-4]. Combining the human perception of odor and chromatographic separation of compounds offers great possibilities. Applications include correlating sensory responses with volatile ehemieals, resolving off-flavor problems, and assessing olfactory acuity of individuals. 

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