Possible influence of breathing on detection frequency and intensity rating in gas chromatography-olfactometry

Gas chromatography-olfactometry (GCO) is a useful method to screen potent odorants in food aromas. In this technique, the human olfactory sense is used to detect the odor-active compounds eluted from a gas chromatograph. A particularity of GCO, compared to other sensory analyses, is to combine two discontinuous phenomena:the aperiodic and unpredictable elution of odorous compounds from the chromatographic column and the breathing process. We wanted to see whether absence of detection could be attributed to expirations and whether odor intensity rating was influenced by the relative temporal positions of compound elutions and inspiration periods. A tendency for higher odor detection frequency by fast-breathing subjects was observed in the three experiments. It appeared that a subject who was asked to breath faster rated odors more intensively, suggesting a possible individual influence of breathing.