Karin Wendin1,2, Kelly R Atkinson3, Andrea Manu3, and Sara R Jaeger2,3
1) SIK – The Swedish Institute for Food and Biotechnology, Sweden
2) University of Copenhagen, Dept of Food Science, Denmark
3) The New Zealand Institute for Plant & Food Research Limited, New Zealand
Fundamentals of human perception are studied by sensory analyses and other methods, eg observational studies have shown relations between facial reactions and pleasantness. It has further been shown that taste stimuli perceived equally pleasant, differed in facial expressions, meaning that facial reactions can be stimuli specific. Facial reactions have not been reported to be odor specific. The aim of this project was to study relationships between perception of two odors and facial reactions.
The odors were cis-3-hexen-1-ol and β-ionone (aqueous solutions). The concentrations represented perceptions just above threshold, high above and very high above. Cis-3-hexen-1-ol was analysed by 10 sensitive panelists and β-ionone by 10 sensitive and 10 non-sensitive. Odor intensity and pleasantness were rated on scales and the panellists described their experiences verbally. The test sessions were recorded and then coded according to a selection of FACS units.
Results showed that perceived odor intensity differed significantly between concentrations of stimuli. However, perceived intensity was significantly higher for sensitive panelists. Pleasantness was lower for high concentrations, no significant difference between sensitive panelists and non-sensitive was obtained. As in earlier studies cis-3-hexen-1-ol was described as “fresh green”, “herbal” and “crushed weeds”. Sensitive panelists described β-ionone as other publications; “floral”, “perfumey” and “fragrant”. Non-sensitives described β-ionone as “musty”, “earthy” and “chemical”. Sensitive panelists’ facial reactions became more intense with higher concentrations, while non-sensitives did not. No significant differences between the two odor compounds according to facial reactions in sensitive panelists were obtained. It can be concluded that facial reactions induced by the two stimuli mirrored sensitivity and pleasantness, but were not stimuli specific. This might be explained by fact that the two odors are both perceived as pleasant and commonly found in the same products, eg white wine. Future studies on more distant odors are recommended.
