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

Abstract 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.

[1]  Elizabeth A. Baldwin,et al.  Electronic Noses and Tongues: Applications for the Food and Pharmaceutical Industries , 2011, Sensors.

[2]  R. Peakall,et al.  The production of a key floral volatile is dependent on UV light in a sexually deceptive orchid. , 2013, Annals of botany.

[3]  T. Ashman,et al.  Sources of floral scent variation , 2009, Plant signaling & behavior.

[4]  Alphus D. Wilson,et al.  Diverse Applications of Electronic-Nose Technologies in Agriculture and Forestry , 2013, Sensors.

[5]  Kun-song Chen,et al.  Scent profiling of Cymbidium ensifolium by electronic nose , 2011 .

[6]  M. Martí,et al.  Application of a headspace mass spectrometry system to the differentiation and classification of wines according to their origin, variety and ageing. , 2004, Journal of chromatography. A.

[7]  Kun-song Chen,et al.  Changes in aroma-related volatiles and gene expression during low temperature storage and subsequent shelf-life of peach fruit , 2011 .

[8]  R. A. Flath,et al.  Volatile components of the orchid Dendrobium superbum Rchb. f , 1982 .

[9]  Seiichi Fukai,et al.  DISCRIMINATION OF LILY FRAGRANCE BY USE OF AN ELECTRONIC NOSE , 2002 .

[10]  N. Bârsan,et al.  Electronic nose: current status and future trends. , 2008, Chemical reviews.

[11]  Yong Zhao,et al.  Electronic Nose Integrated with Chemometrics for Rapid Identification of Foodborne Pathogen , 2012 .

[12]  R. Infante,et al.  Monitoring the sensorial quality and aroma through an electronic nose in peaches during cold storage , 2008 .

[13]  Kenji Yamamoto,et al.  Objective Display and Discrimination of Floral Odors from Amorphophallus titanum, Bloomed on Different Dates and at Different Locations, Using an Electronic Nose , 2012, Sensors.

[14]  C. Hew.  Ancient Chinese orchid cultivation: A fresh look at an age-old practice , 2001 .

[15]  E. Pichersky,et al.  Floral fragrance. New inroads into an old commodity. , 2001, Plant physiology.