Fragrance discrimination of Chinese Cymbidium species and cultivars using an electronic nose

The sensory quality of orchid flowers has a major impact on consumer preference. It has been noticed that orchid blossoms with different genetic backgrounds exhibit differences in fragrance; however, most of these observations are based on subjective evaluation. An objective approach to study the sensory quality of orchids is greatly needed. In the present study, four species of Chinese orchid (Cymbidium spp.) consisting of 2-6 cultivars each, including Cymbidium goeringii, Cymbidium faberi, Cymbidium ensifolium, Cymbidium kanran, were selected for sensory quality determination using an electronic nose (e-nose) equipped with 18 metallic oxide sensors. e-Nose sensors were mainly grouped into two types according to the intensity produced by each sensor element when exposed to volatiles emitted by orchid flowers. Principal component analysis (PCA) and discriminant factor analysis (DFA) were used to dissect out difference between orchid samples, in which DFA exhibited more effective discriminating results either within a species or between species. Odor distance was further calculated to produce statistical values showing the level of difference between orchid samples, in which closely related e-nose fragrance signatures were observed between C ensifolium and C. kanran. In addition, under the controlled experimental conditions, changes in sensory quality of blossoms were found to be mainly influenced by blooming time. (C) 2014 Elsevier B.V. All rights reserved.