| Research Abstract |
(1)Sensory Test
Based on perceptional change of fragrance of essential oils, a simple screening test for efficacy of aroma was developed in relation to type of work, that is, mental work, physical work and hearing environmental (natural) sounds. In evaluating change in perception of a given aroma, a sensory test was employed, in which perception of fragrance was assessed by 13 contrasting pairs of adjectives. Scores were recorded after inhaling a fragrance before and after each type of work, and the statistical significance of the change of score for 13 impression descriptors was examined by Student's t-test for each type of work.
Among 16 essential oils examined in this study including orange, geranium, cypress, bergamot, juniper and others, it was confirmed that inhalation of essential oil caused a different subjective perception of fragrance depending on type of work. For example, inhalation of cypress after physical work produced a much more favorable impression than that before work
… More
in contrast to the case for orange, which produced an unfavorable impression after physical work when compared to that before work. As for mental work, too, inhalation of juniper seemed to create a favorable impression after work, while the feature was completely opposite to that for geranium and orange, both producing an unfavorable impression. We thus concluded that the sensory test might serve not only as a screening test for efficacy of aroma but also as a categorized table for aroma samples which can act as reference to each other.
(2) Study of Physiological Effects
As for the physiological effects on humans of inhalation of essential oils, optically active linalools were examined in terms of sensory tests and portable forehead surface electroencephalographic (IBVA-EEG) measurements from the view of their relation between odor distinctiveness and reactions by chiral isomers. R-(―)- linalools with specific rotation of 〔α〕ィイD2DィエD2=-15.1° was isolated by repeated flash column chromatography from lavender oil, while (S)-(+)-linalools with 〔α〕ィイD2DィエD2=17.4 and (RS)-(±)-linalools with 〔α〕ィイD2DィエD2=0°and content of R-form 50.9% and (S)-form 49.1% were obtained from coriander oil and commercial linalool, respectively, by using the same method. With use of inhalator, each was administered to subjects both before and after 10 minutes of work. It was found that enantiometric stereospecificity of linalool evoked different odor perception and responses not only with chiral-dependence but also with task-dependence. Less
|
