HS–SPME–GC–MS and Electronic Nose Reveal Differences in the Volatile Profiles of Hedychium Flowers

Abstract

Floral fragrance is one of the most important characteristics of ornamental plants and plays a pivotal role in plant lifespan such as pollinator attraction, pest repelling, and protection against abiotic and biotic stresses. However, the precise determination of floral fragrance is limited. In the present study, the floral volatile compounds of six Hedychium accessions exhibiting from faint to highly fragrant were comparatively analyzed via gas chromatography–mass spectrometry (GC–MS) and Electronic nose (E-nose). A total of 42 volatile compounds were identified through GC–MS analysis, including monoterpenoids (18 compounds), sesquiterpenoids (12), benzenoids/phenylpropanoids (8), fatty acid derivatives (2), and others (2). In Hedychium coronarium ‘ZS’, H. forrestii ‘Gaoling’, H. ‘Jin’, H. ‘Caixia’, and H. ‘Zhaoxia’, monoterpenoids were abundant, while sesquiterpenoids were found in large quantities in H. coccineum ‘KMH’. Hierarchical clustering analysis (HCA) divided the 42 volatile compounds into four different groups (I, II, III, IV), and Spearman correlation analysis showed these compounds to have different degrees of correlation. The E-nose was able to group the different accessions in the principal component analysis (PCA) corresponding to scent intensity. Furthermore, the pattern-recognition findings confirmed that the E-nose data validated the GC–MS results. The partial least squares (PLS) analysis between floral volatile compounds and sensors suggested that specific sensors were highly sensitive to terpenoids. In short, the E-nose is proficient in discriminating Hedychium accessions of different volatile profiles in both quantitative and qualitative aspects, offering an accurate and rapid reference technique for future applications.

Metabolite and Transcriptome Profiling Analysis Revealed That Melatonin Positively Regulates Floral Scent Production in Hedychium coronarium

“…Hedychium coronarium J. Koenig, commonly known as ginger lily, is an important ornamental/medicinal plant that is widely grown in tropical and semitropical regions of the world. Terpenoids (monoterpenes and sesquiterpenes) and benzenoids/phenylpropanoids are the main volatile components of H. coronarium flowers, and they are released in abundant amounts during the blooming period, which is consistent with previous reports (Yue et al, 2014(Yue et al, , 2021Ke et al, 2019;Zhou et al, 2021). However, the molecular regulatory mechanism of melatonin underlying floral aroma production remains unknown.…”

“…H. coronarium has long strap-like leaves and large spikes of fragrant white flowers that can grow up to 25 cm long. H. coronarium flowers release a huge number of volatile chemicals, including monoterpenes, sesquiterpenes and benzenoids (Fan et al, 2003;Ke et al, 2019;Abbas et al, 2021a,b;Zhou et al, 2021). Several structural genes encoding terpene synthases and benzoic/salicylic acid methyltransferase have previously been characterized in the H. coronarium volatile biosynthesis pathway.…”

“…The gas chromatography-mass spectrometry (GC-MS) technique has been widely used in metabolic profiling studies of plants. Recently, the GC-MS approach has been used to identify and quantify the volatile profiles of numerous flowering plants, including Lilium 'Siberia' (Abbas et al, 2019(Abbas et al, , 2020a(Abbas et al, ,b, 2021c, H. coronarium (Fan et al, 2007;Zhou et al, 2021), Silene latifolia (Dötterl et al, 2005), Rosa damascene (Rusanov et al, 2011), Osmanthus fragrans (Cai et al, 2014), Panax ginseng (Lee et al, 2017), Lantana canescens Kunth (Pino et al, 2011), and Luculia pinceana (Li et al, 2016). However, integrative transcriptome and metabolome analyses have been used as a unique tool for elucidating the mechanisms that regulate metabolic networks in plants (Fukushima et al, 2014).…”

Discrimination between raw and ginger juice processed Magnoliae officinalis cortex based on HPLC and Heracles NEO ultra‐fast gas phase electronic nose

“…Meanwhile, chemometric analysis, such as principal component analysis (PCA) and discriminant factor analysis (DFA), can be carried out to distinguish samples based on these data. Therefore, the Heracles NEO e‐nose not only has the qualitative analysis ability of GC/mass spectrometry (MS) but also has the discriminant ability of traditional sensor type e‐noses 26,27 . Moreover, compared with traditional chemical and chromatographic identification methods, the Heracles NEO e‐nose requires only a small amount of sample with easy pretreatment and consumes no organic reagents.…”

“…Therefore, the Heracles NEO e-nose not only has the qualitative analysis ability of GC/mass spectrometry (MS) but also has the discriminant ability of traditional sensor type e-noses. 26,27 Moreover, compared with traditional chemical and chromatographic identification methods, the Heracles NEO e-nose requires only a small amount of sample with easy pretreatment and consumes no organic reagents. As a quick and nondestructive instrument, it also provides a feasible method for identification and quality evaluation of precious TCMs.…”