Gas chromatographic investigation of rose concrete, absolute and solid residue

Abstract

The chemical composition and physical properties of the rose absolute produced from rose concretes and the extract, supplied by three different companies, were determined by GC and GC-MS. It was found that rose absolute consists mainly of β β β β β-phenylethyl alcohol, citronellol, geraniol, nerol, eugenol, methyl eugenol, geranyl acetate, benzyl alcohol, nonadecane, nonadecene and farnesol. The solid residue, which is the by-product of absolute production, was further divided on a silica gel column into three fractions by solvents having different polarities (n-hexane, 5% diethyl ether in n-hexane, and diethyl ether alone). A fraction eluated with n-hexane was analysed directly by GC and GC-MS. Two other fractions, after saponification, were converted to their methyl ester derivatives and then analysed by GC and GC-MS. It was observed that the solid residue contains mainly straight-chain saturated hydrocarbons with high molecular weight (C 15 -C 31 ) and the esters of carboxylic acids and a homologous series between them exists. It was also concluded that the extract obtained by solvent extraction from the residue of rose flower (Rosa damascena Mill.) which was subjected to steam distillation is also a valuable raw material.

Perceptual convergence of multi-component mixtures in olfaction implies an olfactory white

“…S4 for this and additional examples). Moreover, one of the components of rose alone, phenylethyl alcohol, contributes ∼70% of rose headspace (10), and indeed this component alone generates a poor-quality but unmistakable smell of rose. In other words, a natural olfactory object such as rose contains components that are clustered in olfactory space and are of unequal intensity and therefore does not smell white.…”

“…Each target mixture (1,4,10,15,20,30,40, or 43 components) was compared with all other mixtures (1,4,10,15,20,30,40, or 43 components) and, as a control, with itself. Other than comparisons of a mixture with itself, all comparisons were nonoverlapping; in other words, each pair of mixtures being compared had no components in common.…”

“…On one hand, humans are very poor at identifying the components of a mixture, even when they are able to identify the components alone (5-7). However, humans remain exquisitely capable of discriminating one mixture from another, and mixtures containing hundreds of different volatile molecules are associated with unique olfactory percepts such as wine (8), roasted coffee (9), or rose (10). At first, that such large odorant mixtures diverge in perception is apparently at odds with two standout phenomena of mixture perception in vision and audition.…”

Traditional Rosa damascena flower harvesting practices evaluated through GC/MS metabolite profiling of flower volatiles

“…Comparative GC and GCÀMS analyses of rose oil composition have also been used for characterisation of rose oils distilled from flowers of R. damascena cultivated in different geographic regions and/or representing different genotypes (Anac, 1984;Baser, 1992;Bayrak & Akgul, 1994;Dobreva & Kovacheva, 2010;Loghmani-Khouzani, Fini, & Safari, 2007;Naqvi & Mandal, 1997;Nikolov et al, 1977;Rezaei, Jaimand, Tabaei-Aghdaei, Barazandeh, & Meshkinzadeh, 2003;Sood, Singh, & Singh, 1992), as well as for assessment of the effect of stage of flower development , date and time of harvest (Baydar & Baydar, 2005;Dobreva & Kovacheva, 2010), flower storage and processing (Baydar & Baydar, 2005;Kazaz, Erbas, & Baydar, 2009;Kazaz, Erbas, Baydar, Dilmacunal, & Koyuncu, 2010;Staikov, Balinova-Tsvetkova, Decheva, & Kalaidjiev, 1975), and distillation procedure (Baydar & Baydar, 2005). In addition GC-MS analysis was applied for characterisation of the other rose flower products, including rose concrete, rose absolute, rose water (Ayci, Aydinli, Bozdemir, & Tutas, 2005;Kurkcuoglu & Baser, 2003) and volatile emissions of the flower headspace (Picone, Clery, Watanabe, MacTavish, & Turnbull, 2004). However, the studies above have focused on the characterisation of the end products from rose flower processing and oil distillation, which makes difficult the more precise study of the changes of levels of volatiles accumulation in rose flowers, in relation to other factors, like rose genotype, flower development, diurnal rhythm, etc.…”

Determination of volatile compounds of the first rose oil and the first rose water by HS-SPME/GC/MS techniques

“…Important industrial products such as oil, water, concrete and absolute are obtained from oil-bearing rose (Kurkcuoglu and Baser, 2003;Aycı et al, 2005). These are distillation and extraction products of freshly harvested rose flowers.…”