Subcritical Extraction of Rosa alba L. in Static and Dynamic Modes
by
, ,
Ana Dobreva
1
,
Daniela Nedeltcheva-Antonova
2,3,*,
Kamelia Gechovska
2,
Nenko Nenov
4 and
Liudmil Antonov
3,*
1
Institute for Roses and Aromatic Plants, Agricultural Academy, 6100 Kazanlak, Bulgaria
2
Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
3
Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria
4
InnoSolv Ltd., 4000 Plovdiv, Bulgaria
*
Authors to whom correspondence should be addressed.
Chemistry 2025, 7(5), 149; https://doi.org/10.3390/chemistry7050149
Submission received: 30 July 2025
/
Revised: 30 August 2025
/
Accepted: 11 September 2025
/
Published: 15 September 2025
(This article belongs to the Section Biological and Natural Products)
Abstract
The chemical composition of Rosa alba L. aromatic products extracted with liquified 1,1,1,2-tetrafluoroethane (freon R134a) has been evaluated in static and dynamic modes of extraction. The yield varies in the range 0.039–0.048% for the different variants. In order to reveal the chemical composition and aroma profile of the extracts, they were analyzed by means of gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). As a result of the analysis, more than 80 compounds with concentrations higher than 0.01% were identified and quantified in the extracts, representing 92.7, 88.4, and 88.0% of the total content. The study indicated that 2-phenyl ethanol (12.57–14.97%), geraniol (12.09–14.82%), nerol (5.90–6.39%), benzyl alcohol (3.63–5.34%), and citronellol (3.21–4.04%) were the main components of the aroma-bearing fraction. The solid phase consists mainly of nonadecane+nonadecene (15.21–16.85%), heneicosane (11.81–13.78%), and tricosane (2.46–2.96%). In addition, olfactory evaluation of the extracts was performed. The comprehensive assessment of the quantitative and qualitative characteristics of the extracts indicates that the static, one-stage mode is the most appropriate for the subcritical extraction of R. alba blossoms with freon R134a.
1. Introduction
Rosa alba L. is industrially cultivated only in Bulgaria, where it is considered an essential oil production alternative to Rosa damascena [1,2]. In terms of tolerance to adverse climatic conditions and disease resistance, R. alba is superior to the damask rose but with substantially lower rose oil yield [3]. The composition of the oil is very close to that of R. damascena and shows many beneficial properties for perfumery, cosmetics, and medical applications, due to the very low toxic potential [4,5,6]. This fact is attributed to the very low content of undesirable components, such as allergenic and potentially carcinogenic methyl eugenol [7]. It is interesting to note that the R. alba hydrosol does not show any cytotoxic effect in the plant test system in vivo [8], and even the waste waters demonstrate beneficial potential with some antineoplastic activity [9].
The “classical” rose oil production is based on double distillation from fresh rose flowers, but the very low yield makes the product very expensive [2,10]. At the same time, the high-temperature production process could lead to degradation and/or transformation of many natural compounds [11]. As an alternative, the rose aromatic products could be obtained by solvent extraction, where different mechanisms and conditions produce macerates, concretes, absolutes, or, more generally, extracts [12,13,14,15,16]. As a rule, the extraction yields are higher than those from the distillation, but in recent decades public awareness regarding sustainable development and environmental protection has placed high demands on these productions, and this becomes a serious challenge for technology [10,17]. The solvents should be safe and without any residues in the final product, not generating toxic wastes and with noxious carbon emissions. The use of liquefied gases removes most of the limitations associated with conventional extraction methods. The main advantages of the extraction with liquefied gases are low temperature, which reduces thermal degradation of the substances, and flexibility for the mode with high product quality and reduced energy costs [18]. Supercritical carbon dioxide and subcritical 1,1,1,2-tetrafluoroethane (freon R134a) are green alternatives for the oil-bearing rose extraction, allowing quercetin extraction (supercritical CO2 at pressure 10–30 MPa/35–55 °C [19]), rose concrete fractionation (supercritical CO2 at 80 bar [20]), supercritical CO2 extraction of rose concrete to obtain volatile oil [21], and supercritical CO2 extraction procedure to recover volatile compounds and polyphenols [22], which were made with dried flowers. The great prospects for industrial application were initiated by supercritical fluid extraction of R. damascena with a mixture of solvents, preserving this way the thermally unstable compounds [23]. Our previous investigations revealed freon 134a as a suitable solvent for valuable rose aromatic products [1,24]. Baser et al. [25] extracted fresh flowers of R. damascena with CO2 and tetrafluorethane with co-solvent at different conditions to obtain the final extract with the major component phenylethyl alcohol. Overall, the increase in pressure, temperature, and time of contact decreases the extract quality [20,22,25]. Obtainment of absolute from rose concrete with freon R134a resulted in a relatively low yield product, where fourteen compounds were identified, such as phenylethyl alcohol, citronellol, geraniol, nonadecane, and heneicosane [26].
Bearing in mind that the average yields of the Rosa genus are usually low and the fact that R. alba has twice lower essential oil content compared to R. damascena, only a few percent increase in extraction efficiency can be very valuable in terms of economic benefits. Currently, there is no published data in the literature regarding optimization of the operating conditions of the R. alba subcritical treatment. Based on the previous experience of the authors and generally accepted practice for the extraction of roses, we have investigated the influence of different extraction regimes with 1,1,1,2-tetrafluoroethane on white oil-bearing roses. The yield and the quality of the obtained product were used as criteria for the efficacy of the process. An odor assessment of the obtained extracts has been made in addition in order to value the quality and scent intensity of the extracts.
2. Materials and Methods
2.1. Materials
Fresh rose blossoms of Rosa alba L. were picked up early in the morning from the experimental field at the Institute for Roses and Aromatic Plants, Kazanlak, Bulgaria. Because the rose flowers are very delicate and ephemeral, and the extraction plant was remote, the raw material was stored by freezing until processing. According to Seify et al. [27], this is the most appropriate storage method for preserving the plant material quality. The moisture content of the material was 80–82%, measured by drying to constant weight.
A food-grade 1,1,1,2-tetrafluoroethane (CAS number 811-97-2), purchased from Frigo Chem Ltd. (Plovdiv, Bulgaria), was used as an extractant. It is a non-polar, pressurized gas solvent featuring colorless and practically odorless liquid with the following parameters: dipole moment of 2.058 Debay [28]; dielectric constant of 3.54 [29]; boiling temperature of −26 °C at 0.101 MPa; saturation pressure at 20 °C of 0.57 MPa dynamic viscosity at 20 °C of 0.2 MPa; and surface tension at the same temperature of 8.5 mN/m [30].
2.2. Methods
Extraction of the raw material by using 1,1,1,2-tetrafluoroethane was performed on installation as previously described [24]. The extractions were carried out using 300 g of plant material for a single charge.
The static mode was conducted as the raw material was poured with solvent, and after the contact time, the supernatant was drained into a separator. There the solvent was evaporated at a lower pressure, and in the last few minutes, low heat was used to completely eliminate the vapor.
The dynamic mode was demonstrated as continuous circulation of the solvent through the material and collecting the supernatant in the separator. The flow rate was 4–5 mL/min.
2.3. Analysis
2.4. Olfactory Evaluation
The olfactory evaluation of the samples was performed in a perfumery laboratory at the Institute for Roses and Aromatic Plants, Bulgaria. The professional perfumers and chemists (four females, one male, experts with experience) estimated the samples independently. The psychophysiological state of the testers during the assessment was normal. They used a test strip dipped in the rose product for around a 1 cm2 area. The procedure was performed in triplicate on different days, after which the experts gave their estimation in the form of rating analysis.
2.5. Statistics
Each technological variant was performed in triplicate. The extract yields were measured as % (v/w). Results are expressed as mean value ± standard deviation (SD).
3. Results and Discussion
3.1. Effect of the Extraction Mode on the Yield
The extraction yields of R. alba subcritical treatment with freon R134a are presented in Figure 1.
The maximum level of exhaustion was achieved with circulation mode V2—0.048%. The one-stage static extraction gave the lowest result—0.039%. Although for Damask rose two-stage batch extraction (V3) was the optimal option [1], this model was not confirmed for the white rose. Variant 3 also has the largest error in replicates, probably due to the two-step process.
Compared to the hydrodistillation, where the average yield is 0.015–0.030%, subcritical extraction with freon R134a was found to be more prospective with twice the extracted substances. A comparison to the conventional extraction with hexane (0.21%) and ethanol (0.125%) to obtain rose absolute [34] showed lower yield. Considering that in both cases the process takes place at a low temperature and pressure, these results could be explained by the specificity of the solvent. The same dependence was found for R.damascena products [1].
It would be interesting to draw a parallel with supercritical CO2 extraction conditions, but so far there is no data on such a treatment.
The other flower feedstock, e.g., jasmine, showed equal yields from both methods [35]. According to Atanasova et al. [36] and Merdjanov et al. [37], the yields of hyacinth flowers and white lilies were 0.19% and 0.38%, respectively. These values were obtained using a static process mode with the same solvent and applying the same pressure and can be referred to for the specifics of the particular raw material.
3.2. Effect of the Extraction Mode on the Chemical Composition
The extracts were analyzed by GC-MS and GC-FID in order to reveal the chemical composition and aroma profile. Representative GC-MS and GC-FID chromatograms of R. alba blossom extract with freon R134a are presented in the Supplementary Material (Figure S1). The main identified components, together with the data about their scent description, are collected in Table 2.
As a result of the analysis, more than 120 compounds with concentrations higher than 0.01% were detected in rose subcritical extracts, and 83 of them, containing C7–C30 carbon atoms, were identified by GC-MS and simultaneously quantified by GC-FID. The analysis data in Table 2 displayed 83 identified components that represent, respectively, 92.70%, 88.37%, and 88.00% of the total number of the identified components for V1, V2, and V3 extracts, respectively. The static extraction modes show almost equal numbers of detected constituents—64 and 68—while in the dynamic mode they were significantly less—49. Besides being few in number, most of the identified constituents for Variant 2 are odorless (lines 42–83 in Table 2).
As seen from Table 2, the main constituents of rose extracts are representatives of the following chemical classes: monoterpenes and their derivatives, sesquiterpenes, benzenoids, and aliphatic hydrocarbons (paraffins) [11,14,22]. It has been shown that different rose genotypes have the same qualitative composition, and their differences are manifested in the quantities of individual ingredients [38]. In this case, extracts from R. alba have the typical composition of the species [3,5,7,24].
To facilitate the interpretation of the results, the components are grouped and discussed in classes:
Monoterpenes:
Monoterpene hydrocarbons are detected at almost trace levels in all extracts, and their total amount decreased from 0.26% to 0% in V1 to V3, respectively. Despite being found in low concentrations, these components influence the odor and antibacterial properties of the extracts. Their loss directly affects the quality of the aroma product.
Oxygenated monoterpenes. The total content of oxygenated monoterpenes also decreased from V1 to V2 to V3, respectively, with 26.29%, 24.57, and 22.81%. The monoterpene alcohols geraniol, nerol, and citronellol are the main compounds responsible for the fragrance and biological activity of the rose aroma products. Citronellol and nerol give the characteristic rosaceous essence. Geraniol is also basic for the scent and exerts the major pharmacological effects of the rose oil, such as antitumor, antibacterial, antifungal, antioxidant, and anti-inflammatory effects [39]. Geraniol was found to be the major compound for R. alba essential oil and extracts [24,34]. In this study, its content varies from 12.09 (V2) to 14.82 (V1). It was found that in the V2 (dynamic mode), there is the greatest loss of these important terpene alcohols. At the same time, the rule of static extraction for delicate flower raw materials was confirmed.
Sesquiterpenes. The group of sesquiterpenes ranged from 0.25% to 1.80%. Although they represent a relatively small segment in the overall content, the sesquiterpenes contribute with their olfactory potential. Data showed the trend of losses in V2 and V3.
Phenylpropanoids are responsible for the natural rose scent in the rose flower to a particularly large extent—phenylethyl alcohol [25,38]. It is the main compound in the rose water and extractive products [14,15,16,26]. Benzyl alcohol has a sweet, floral aroma. This phenyl derivative component is present in relatively high levels in white rose extracts and emerges as their specific constituent [24]. They both have a calming, pain-relaxing, and euphoric mental impact, highly valued effects of the rose. V1 extraction mode stored the maximal amount of these substances—21.31%, while in V3 their content is significantly lower—16.90%. The rate of decrease is 26%.
The four listed groups form the so-called eleoptene—the liquid phase that contains the odor components.
Paraffins. Aliphatic hydrocarbons (saturated and unsaturated) are practically odorless substances, but they have an important role in the stability of aroma, making up the solid part of rose oil—stearoptene. The optimal ratio between the liquid and solid phases is in favor of the eleopten, especially for extractives [13,14,26,34]. This means that the large amount of hydrocarbons is considered undesirable. In our study, their total content progressively increases from V1 to V3 with values from 41.46% to 46.97%. The stearopten content is dominated by nonadecane+nonadecene in the ranges 15.21–16.85%, followed by heneicosane in the limits 11.81–13.78%. V2 extraction mode shows the maximum for both total amount and individual content.
3.3. Effect of the Extraction Mode on the Aroma Profile
The aromatic products are characterized by their chemical composition and scent. In addition to the comprehensive chemical profile analysis, the samples were subjected to the olfactory evaluation in order to reveal their complete aroma profile. A stages scale was used to conduct sensory assessment on ten indicators. The volatile fingerprints are presented in Figure 2, Figure 3 and Figure 4 to make the results clearer.
It is easy to see that V1 achieves high marks in most indicators, and the area of its figure is the largest. The floral note is well related to the highest content of monoterpene derivatives—geraniol, nerol, and citronellol. These three alcohols are typical for the rose oil, but in different descending order—citronellol, geraniol, and nerol. They all form the characteristic rose odor, each contributing with its own distinct pleasant note. In part, this is also due to phenyl derivatives—phenylethyl alcohol and benzyl alcohol. The first one gives a typical rose warm note. The second one complements the quality of the scent. Their highest content was preserved in V1.
The dynamic mode (V2) has the lowest scores, and its profile is limited around the center of the plot. The chemical composition is directly related to this result, because almost all the aroma-bearing compounds (till line 40 in Table 2) were not detected in the V2 extract. The main terpene alcohols (geraniol, nerol, and citronellol) were found in the lowest levels. It is worth mentioning, that this is the only sample with a herbaceous note more than 0.
The static extraction in two stages (V3) has some evaluation peaks, but overall its values were low. Only the “fresh” note achieved the highest value, 5. This could be due to the presentation of nerol, anethol, geranic acid, and some ingredients with lemon- and citrus-like aromas; however, without reaching maximum intensity on their own scale (the indicator “citrus” has lower value).
4. Conclusions
The chemical composition of Rosa alba L. aromatic products extracted with liquified 1,1,1,2-tetrafluoroethane (freon R134a) in static and in dynamic modes was evaluated in order to reveal the effect on the yield, chemical composition, and aroma profile.
The dynamic conditions of subcritical extraction with freon R134a in R. alba bring maximum extraction yield, while the static conditions give 19% (in the case of single extraction) and 13% (in the case of double extraction) less extract. At the same time, the solvent dynamics lead to losses of components in the eleoptene within 12% (V2) and 20% (V3) compared to static V1.
The aroma profiles are directly related to the extraction conditions. The final olfactory analysis showed the advantage of the static mode variant. After a complex assessment of the quantitative and qualitative properties of the extracts, the static, one-stage mode (V1) seems to be the most appropriate for this kind of treatment of white rose blossoms.
The chemical profile of the subcritical R. alba extracts brings them closer to the rose absolute and could be successfully used as its green alternative in cosmetics, foods, and aromatherapy.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/chemistry7050149/s1, Figure S1. Representative GC-MS (TIC) (a) and GC-FID (b) chromatograms of R. alba blossom extract with freon R134a.
Author Contributions
Conceptualization, D.N.-A.; methodology, D.N.-A. and A.D.; formal analysis, K.G.; investigations, D.N.-A. and N.N; resources, A.D. and N.N.; writing—original draft preparation, D.N.-A. and L.A.; writing—review and editing, D.N.-A., L.A. and A.D.; funding acquisition, L.A.; project administration, D.N.-A. and L.A. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by Project KP-06-OPR-01/5, National Science Fund (Ministry of Education and Science).
Data Availability Statement
Dataset available on request from the authors.
Conflicts of Interest
Author Nenko Nenov was employed by the company InnoSolv Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
- Dobreva, A.; Dincheva, I.; Nenov, N. On the Subcritical Extraction of Rosa Damascena Mill. Bulg. J. Agric. Sci. 2021, 27, 785–791. [Google Scholar]
- Kovacheva, N.; Rusanov, K.; Atanassov, I. Industrial Cultivation of Oil Bearing Rose and Rose Oil Production in Bulgaria During 21st Century, Directions and Challenges. Biotechnol. Biotechnol. Equip. 2010, 24, 1793–1798. [Google Scholar] [CrossRef]
- Rusanov, K.; Kovacheva, N.; Rusanova, M.; Atanassov, I. Flower Phenotype Variation, Essential Oil Variation and Genetic Diversity among Rosa alba L. Accessions Used for Rose Oil Production in Bulgaria. Sci. Hortic. 2013, 161, 76–80. [Google Scholar] [CrossRef]
- Jovtchev, G.; Stankov, A.; Georgieva, A.; Dobreva, A.; Bakalova, R.; Aoki, I.; Mileva, M. Cytotoxic and Genotoxic Potential of Bulgarian Rosa alba L. Essential Oil—In Vitro Model Study. Biotechnol. Biotechnol. Equip. 2018, 32, 513–519. [Google Scholar] [CrossRef]
- Verma, A.; Srivastava, R.; Sonar, P.K.; Yadav, R. Traditional, Phytochemical, and Biological Aspects of Rosa alba L.: A Systematic Review. Futur. J. Pharm. Sci. 2020, 6, 114. [Google Scholar] [CrossRef]
- Vilhelmova-Ilieva, N.; Dobreva, A.; Doynovska, R.; Krastev, D.; Mileva, M. Antiviral Activity of Rosa Damascena Mill. and Rosa alba L. Essential Oils against the Multiplication of Herpes Simplex Virus Type 1 Strains Sensitive and Resistant to Acyclovir. Biology 2021, 10, 746. [Google Scholar] [CrossRef]
- Nedkov, N.; Dobreva, A.; Kovacheva, N.; Bardarov, V.; Velcheva, A. Bulgarian Rose Oil of White Oil-Bearing Rose. Bulg. J. Agric. Sci. 2009, 15, 318–322. [Google Scholar]
- Gerasimova, T.; Jovtchev, G.; Gateva, S.; Topashka-Ancheva, M.; Stankov, A.; Angelova, T.; Dobreva, A.; Mileva, M. Study on Cytotoxic and Genotoxic Potential of Bulgarian Rosa Damascena Mill. and Rosa alba L. Hydrosols—In Vivo and In Vitro. Life 2022, 12, 1452. [Google Scholar] [CrossRef]
- Georgieva, A.; Ilieva, Y.; Kokanova-Nedialkova, Z.; Zaharieva, M.M.; Nedialkov, P.; Dobreva, A.; Kroumov, A.; Najdenski, H.; Mileva, M. Redox-Modulating Capacity and Antineoplastic Activity of Wastewater Obtained from the Distillation of the Essential Oils of Four Bulgarian Oil-Bearing Roses. Antioxidants 2021, 10, 1615. [Google Scholar] [CrossRef]
- Shishkova, M.; Ivanova, B.; Beluhova-Uzunova, R.; Harizanova, A. Opportunities and Challenges for Sustainable Production and Processing of Rosa Damascena in Bulgaria. Ind. Crops Prod. 2022, 186, 115184. [Google Scholar] [CrossRef]
- Babu, K.G.D.; Singh, B.; Joshi, V.P.; Singh, V. Essential Oil Composition of Damask Rose (Rosa Damascena Mill.) Distilled under Different Pressures and Temperatures. Flavour Fragr. J. 2002, 17, 136–140. [Google Scholar] [CrossRef]
- Alborzi, S.S.; Roosta, A. The Effect of Different Solvents on the Production of Rose Concrete and Rose Absolute, Experimental Study and Thermodynamic Aspects Using the UNIFAC Model. Chem. Eng. Res. Des. 2022, 184, 326–337. [Google Scholar] [CrossRef]
- Antonova, D.V.; Medarska, Y.N.; Stoyanova, A.S.; Nenov, N.S.; Slavov, A.M.; Antonov, L.M. Chemical Profile and Sensory Evaluation of Bulgarian Rose (Rosa Damascena Mill.) Aroma Products, Isolated by Different Techniques. J. Essent. Oil Res. 2021, 33, 171–181. [Google Scholar] [CrossRef]
- Aycı, F.; Aydınlı, M.; Bozdemir, Ö.A.; Tutaş, M. Gas Chromatographic Investigation of Rose Concrete, Absolute and Solid Residue. Flavour Fragr. J. 2005, 20, 481–486. [Google Scholar] [CrossRef]
- Moates, G.K.; Reynolds, J. Comparison of Rose Extracts Produced by Different Extraction Techniques. J. Essent. Oil Res. 1991, 3, 289–294. [Google Scholar] [CrossRef]
- Sofiya, K.; Kumar, G.B. Study on the Effect of Dual Solvent Proportions on Composition ofRosa x Damascena Concrete Oil Obtained Using Soxhlet Extraction Method. Asian J. Chem. 2021, 34, 78–84. [Google Scholar] [CrossRef]
- Chemat, F.; Abert Vian, M.; Fabiano-Tixier, A.-S.; Nutrizio, M.; Režek Jambrak, A.; Munekata, P.E.S.; Lorenzo, J.M.; Barba, F.J.; Binello, A.; Cravotto, G. A Review of Sustainable and Intensified Techniques for Extraction of Food and Natural Products. Green Chem. 2020, 22, 2325–2353. [Google Scholar] [CrossRef]
- Reverchon, E.; De Marco, I. Supercritical Fluid Extraction and Fractionation of Natural Matter. J. Supercrit. Fluids 2006, 38, 146–166. [Google Scholar] [CrossRef]
- Ghoreishi, S.M.; Hedayati, A.; Mousavi, S.O. Quercetin Extraction from Rosa Damascena Mill via Supercritical CO2: Neural Network and Adaptive Neuro Fuzzy Interface System Modeling and Response Surface Optimization. J. Supercrit. Fluids 2016, 112, 57–66. [Google Scholar] [CrossRef]
- Reverchon, E.; Delta Porta, G. Rose Concrete Fractionation by Supercritical CO2. J. Supercrit. Fluids 1996, 9, 199–204. [Google Scholar] [CrossRef]
- Reverchon, E.; Della Porta, G.; Gorgoglione, D. Supercritical CO2 Extraction of Volatile Oil from Rose Concrete. Flavour Fragr. J. 1997, 12, 37–41. [Google Scholar] [CrossRef]
- Da Porto, C.; Decorti, D.; Natolino, A. Application of a Supercritical CO2 Extraction Procedure to Recover Volatile Compounds and Polyphenols from Rosa Damascena. Sep. Sci. Technol. 2015, 50, 1175–1180. [Google Scholar] [CrossRef]
- Li, S.; Guo, L.; Liu, C.; Zhang, Y. Application of Supercritical Fluid Extraction Coupled with Counter–Current Chromatography for Extraction and Online Isolation of Unstable Chemical Components from Rosa Damascena. J. Sep. Sci. 2013, 36, 2104–2113. [Google Scholar] [CrossRef]
- Dobreva, A.; Nedeltcheva-Antonova, D.; Nenov, N.; Getchovska, K.; Antonov, L. Subcritical Extracts from Major Species of Oil-Bearing Roses—A Comparative Chemical Profiling. Molecules 2021, 26, 4991. [Google Scholar] [CrossRef]
- Baser, K.H.C.; Kurkcuoglu, M.; Özek, T. Turkish Rose Oil Research: Recent Results. Perfum. Flavorist 2003, 28, 34–42. [Google Scholar]
- Kurkcuoglu, M.; Baser, K.H.C. Studies on Turkish Rose Concrete, Absolute, and Hydrosol. Chem. Nat. Compd. 2003, 39, 457–464. [Google Scholar] [CrossRef]
- Seify, Z.; Yadegari, M.; Pirbalouti, A. Essential Oil Composition of Rosa Damascena Mill. Produced With Different Storage Temperatures and Durations. Korean J. Hortic. Sci. Technol. 2018, 36, 552–559. [Google Scholar] [CrossRef]
- Solkane®134a Pharma; SOLVAY FLUOR: Bad Wimpfen, Germany. Available online: https://www.solvay.com/sites/g/files/srpend221/files/2021-01/PSS-Tetrafluoroethane.pdf (accessed on 15 July 2025).
- Barao, T.; de Castro, C.A.N.; Mardolcar, U.V.; Okambawa, R.; St-Arnaud, J.M. Dielectric Constant, Dielectric Virial Coefficients, and Dipole Moments of 1,1,1,2-Tetrafluoroethane. J. Chem. Eng. Data 1995, 40, 1242–1248. [Google Scholar] [CrossRef]
- Solkane®134a Thermodynamics; SOLVAY FLUOR GMBH: Bad Wimpfen, Germany. Available online: http://chlazeni.kovosluzbaots.com/chlazeni/pdf402/chladiva/r134a.pdf (accessed on 15 July 2025).
- Antonova-Nedeltcheva, D.; Dobreva, A.; Gechovska, K.; Antonov, L. Volatile Compounds Profiling of Fresh R. Alba L. Blossom by Headspace—Solid Phase Microextraction and Gas Chromatography. Molecules 2025, 30, 3102. [Google Scholar] [CrossRef]
- Acree, T.; Arn, H. Flavornet and Human Odor Space. Available online: http://www.flavornet.org/flavornet.html (accessed on 15 July 2025).
- Surburg, H.; Panten, J. Common Fragrance and Flavor Materials: Preparation, Properties and Uses, 1st ed.; Wiley: Hoboken, NJ, USA, 2016; ISBN 978-3-527-33160-4. [Google Scholar]
- Dobreva, A. Aromatic Products of the White Oil-Bearing Rose (Rosa alba L.). Sci. Work. Univ. Food Technol. 2010, LVII, 354–358. [Google Scholar]
- Supanivatin, P.; Siriwattanayotin, S.; Thipayarat, A.; Ekkaphan, P.; Wongwiwat, J. Effect of Overfilled Solvent and Storage Time of Subcritical Extraction of Jasminum Sambac on Yield, Antioxidant Activity, Antimicrobial Activity and Tentative Volatile Compounds. Plants 2023, 12, 585. [Google Scholar] [CrossRef] [PubMed]
- Atanasova, T.; Nenov, N.; Lazarov, A.; Takov, T.; Stoyanova, A. Low Temperature Extraction with Liquefied Gases of Essential Oil Raw Materials. 3. Hyacinth Flowers (Hyacinthus orientalis L.). Sci. Work. Russe Univ. Bulg. 2009, 48, 131–135. [Google Scholar]
- Merdjanov, P.; Denkova, V.; Janakieva, V.; Nenov, N.; Atanasova, T.; Stoyanova, A. Low Temperature Extraction with Liquefied Gases of Essential Oil Raw Materials. 13. White Lilium (Lilium candidum L.). J. Voronezh State Agrar. Univ. 2013, 3, 116–120. [Google Scholar]
- Feng, D.; Jian, H.; Zhang, H.; Qiu, X.; Wang, Z.; Du, W.; Xie, L.; Wang, Q.; Zhou, N.; Wang, H.; et al. Comparison of Volatile Compounds between Wild and Cultivated Roses. HortScience 2022, 57, 657–663. [Google Scholar] [CrossRef]
- Hadian, Z.; Maleki, M.; Feizollahi, E.; Alibeyk, S.; Saryazdi, M. Health Aspects of Geraniol as a Main Bioactive Compound of Rosa Damascena Mill: A Systematic Review. Electron. Physician 2020, 12, 7724–7735. [Google Scholar] [CrossRef] [PubMed]
Figure 1.
Comparative yield analysis of R. alba subcritical extraction in different modes (mean value ± SD).
Figure 1.
Comparative yield analysis of R. alba subcritical extraction in different modes (mean value ± SD).
Figure 2.
Olfactory evaluation of the Variant 1 (static mode) subcritical extract.
Figure 3.
Olfactory evaluation of the Variant 2 (dynamic mode) subcritical extract.
Figure 4.
Olfactory evaluation of the Variant 3 (static double-staged) subcritical extract.
Table 1.
Experimental conditions and parameters of freon R134a extraction in static and dynamic mode.
Table 1.
Experimental conditions and parameters of freon R134a extraction in static and dynamic mode.
| Variation | Mode | Extraction Time, min |
|---|---|---|
| Variant 1 (V1) | Static | 60 |
| Variant 2 (V2) | Dynamic | 60 |
| Variant 3 (V3) | Static double-staged | 5–30 |
Table 2.
Chemical composition of R. alba subcritical extracts and scent analysis of the components, determined by GC-FID.
Table 2.
Chemical composition of R. alba subcritical extracts and scent analysis of the components, determined by GC-FID.
| No | Compound | LRIexp DB-17HT | Rel. %, as Determined by GC-FID | Scent Description | ||
|---|---|---|---|---|---|---|
| Variant 1 | Variant 2 | Variant 3 | ||||
| 1. | α-Pinene | 845 | 0.13 | n.d. | 0.05 | Herbal type |
| 2. | β-Pinene | 944 | 0.01 | n.d. | n.d. | Woody-green, pine-like |
| 3. | β-Myrcene | 968 | 0.04 | n.d. | 0.02 | Sweet-balsamic-resinous |
| 4. | Limonene | 1003 | 0.08 | n.d. | 0.03 | lemon-like |
| 5. | Cymene | 1026 | 0.01 | n.d. | n.d. | Harsh chemical, woody and terpy-like |
| 6. | Benzaldehyde | 1051 | n.d. | n.d. | 0.07 | Sharp, sweet, bitter almond cherry |
| 7. | Linalool | 1201 | 0.01 | n.d. | 0.05 | Floral, spicy wood, |
| 8. | Benzyl alcohol | 1223 | 5.34 | 3.63 | 4.05 | Slightly sweet, floral |
| 9. | Octanoic acid | 1298 | 0.02 | n.d. | n.d. | Pungent |
| 10. | Phenyl ethyl Alcohol | 1317 | 14.97 | 12.57 | 13.11 | Rose note, very lasting/mild and warm rose honey |
| 11. | Citronellol | 1366 | 4.04 | 3.21 | 3.16 | Sweet, rose-like |
| 12. | Nerol | 1374 | 6.10 | 5.90 | 6.39 | Rose-like, fresh green note |
| 13. | Phenyl ethyl formate | 1381 | 0.09 | n.d. | n.d. | Green floral rose-like |
| 14. | Neral | 1392 | 0.08 | n.d. | n.d. | Citrus, milder, and sweeter |
| 15. | Geraniol | 1414 | 14.82 | 12.09 | 13.62 | Sweet, floral, rose-like |
| 16. | Geranial | 1440 | 0.92 | 1.12 | 0.84 | Strong, lemon-like |
| 17. | Phenyl ethyl acetate | 1469 | 0.06 | n.d. | n.d. | Sweet, rosy-fruity, honey-like |
| 18. | β-Elemene | 1472 | 0.01 | n.d. | n.d. | Herbal type |
| 19. | Cytronellyl acetate | 1475 | 0.10 | n.d. | n.d. | Fresh, rosy, fruity |
| 20. | Anethole | 1482 | 0.25 | n.d. | 0.14 | Fresh, green, spicy |
| 21. | Pentadecane (C15) | 1500 | 0.09 | n.d. | n.d. | - |
| 22. | β-Caryophyllene | 1506 | 0.98 | 0.25 | 0.53 | Softly spicy, woody |
| 23. | Geranic acid | 1522 | 0.26 | n.d. | 0.19 | Soft, fresh, green-floral |
| 24. | Geranyl acetate | 1540 | 0.03 | n.d. | 0.09 | Floral, fruity, rose-like |
| 25. | α-Caryophyllene | 1552 | n.d. | n.d. | 0.03 | Sweet, woody spice |
| 26. | Hydroxy linalool | 1568 | 0.03 | n.d. | n.d. | - |
| 27. | Eugenol | 1574 | 0.08 | n.d. | 0.03 | Spicy, clove-like |
| 28. | β-Cubebene | 1598 | 0.25 | n.d. | n.d. | Herbal type |
| 29. | α-Muurolene | 1607 | 0.04 | n.d. | 0.07 | - |
| 30. | δ-Guaiene | 1611 | 0.21 | n.d. | n.d. | Spicy, powdery, balsamic |
| 31. | β-Copaene | 1616 | 0.04 | n.d. | n.d. | - |
| 32. | β-Cadinene | 1646 | n.d. | n.d. | 0.06 | Woody |
| 33. | Heptadecane (C17) | 1700 | 1.65 | 0.48 | 0.68 | - |
| 34. | Hedycaryol | 1703 | 0.25 | n.d. | 0.28 | - |
| 35. | Heptadecene (C17:1) | 1710 | 0.01 | n.d. | n.d. | - |
| 36. | Benzyl tiglate + Heptadecadiene (C17:2) | 1714 | 0.07 | n.d. | 0.07 | - |
| 37. | γ-Eudesmol | 1796 | 0.02 | n.d. | n.d. | Waxy, sweet |
| 38. | Octadecane (C18) | 1800 | n.d. | n.d. | 0.05 | - |
| 39. | τ-Cadinol | 1805 | 0.09 | n.d. | 0.07 | Balsamic |
| 40. | α-Eudesmol | 1819 | 0.02 | n.d. | 0.07 | - |
| 41. | β-Eudesmol | 1826 | 0.14 | n.d. | 0.14 | Woody green |
| 42. | Nonadecane+Nonadecene (C19+ C19:1) | 1900 | 15.66 | 16.85 | 15.21 | - |
| 43. | Hexadecanal | 1936 | 0.04 | n.d. | 0.03 | Cardboard-like |
| 44. | Eicosane (C20) | 2000 | 1.50 | 1.66 | 1.43 | - |
| 45. | Unknown | 2054 | 0.47 | 0.39 | 0.58 | |
| 46. | Unknown sesquiterpene derivative | 2079 | n.d. | 0.08 | 0.08 | - |
| 47. | Heneicosane(C21) | 2100 | 11.83 | 13.78 | 11.81 | - |
| 48. | Heneicosene (C21:1) | 2105 | 1.31 | 1.41 | 1.34 | - |
| 49. | Heneicosene (C21:1), isomer | 2121 | 0.25 | 0.28 | 0.27 | - |
| 50. | Docosane (C22) | 2200 | n.d. | 0.45 | 0.39 | - |
| 51. | Docosene (C22:1) | 2211 | n.d. | 0.12 | 0.11 | - |
| 52. | Tricosane (C23) | 2300 | 2.46 | 2.96 | 2.62 | - |
| 53. | Tricosene (C23:1) | 2318 | 1.86 | 2.13 | 1.91 | - |
| 54. | Tricosene (C23:1), isomer | 2334 | 0.33 | 0.28 | 0.34 | - |
| 55. | 1,1,9-Eicosadiene | 2348 | 0.12 | 0.06 | 0.11 | - |
| 56. | Tetracosane (C24) | 2400 | n.d. | 0.16 | 0.15 | - |
| 57. | Cyclotetracosane | 2408 | n.d. | 0.24 | 0.20 | - |
| 58. | Farnesol, isomer | 2423 | n.d. | 0.06 | 0.07 | Floral, green, milky, muguet, waxy, oily, dairy, fatty, soapy |
| 59. | Hexanoic acid, 2-ethyl, tetradecyl ester | n.d. | 0.10 | 0.09 | - | |
| 60. | Pentacosane (C25) | 2500 | 0.48 | 0.56 | 0.57 | - |
| 61. | Pentacosene (C25:1) | 2511 | 0.21 | 0.15 | 0.18 | - |
| 62. | Pentacosene (C25:1) | 2524 | 0.97 | 1.26 | 1.05 | - |
| 63. | Pentacosene (C25:1) | 2532 | 0.32 | 0.44 | 0.35 | - |
| 64. | Unknown | 2541 | 0.29 | 0.13 | 0.26 | - |
| 65. | Nonanoic acid, tetradecyl ester | 2548 | 0.04 | 0.06 | 0.05 | Waxy, fatty type |
| 66. | Hexacosane (C26) | 2600 | 0.05 | 0.07 | 0.06 | - |
| 67. | Hexacosene (C26:1) | 2612 | 0.20 | 0.27 | 0.23 | - |
| 68. | Hexadecyl octanoate | 2668 | n.d. | 0.17 | n.d. | - |
| 69. | Heptacosane +Heptacosene (C27 + C27:1) | 2700 | 0.21 | 0.30 | 0.25 | - |
| 70. | Heptacosene (C27:1), isomer | 2708 | 0.27 | 0.40 | 0.34 | - |
| 71. | Heptacosene (C27:1), isomer | 2721 | 1.19 | 1.75 | 1.45 | - |
| 72. | Stearic acid, citronellyl ester | 2843 | n.d. | 0.06 | 0.05 | - |
| 73. | Unknown geranyl ester | 2876 | n.d. | 0.08 | 0.09 | |
| 74. | Nonacosene (C29:1) | 2911 | 0.49 | 0.74 | 0.68 | - |
| 75. | Unknown phenyl ethyl ester | 0.52 | 0.54 | 0.66 | - | |
| 76. | Dodecanoic acid, phenyl methyl ester | 2939 | n.d. | 0.17 | 0.15 | - |
| 77. | Unknown citronellyl ester | 2942 | n.d. | 0.13 | 0.12 | - |
| 78. | Unknown phenyl ethyl ester | 2956 | n.d. | 0.08 | 0.07 | - |
| 79. | Unknown neryl ester | 2961 | 0.29 | 0.28 | 0.30 | - |
| 80. | Unknown phenyl ethyl ester | 2964 | n.d. | 0.08 | 0.09 | - |
| 81. | Olean-12-en-3-one | 3468 | n.d. | 0.15 | 0.15 | - |
| 82. | α-Amyrin + Unindentified triterpene | 3476 | n.d. | 0.10 | 0.07 | - |
| 83. | Lupeol | 3616 | n.d. | 0.14 | 0.15 | - |
| Number of detected compounds | 64 | 49 | 68 | |||
| Monoterpene hydrocarbons, % | 0.26 | 0.10 | 0 | |||
| Oxygenated monoterpenes, % | 26.29 | 24.57 | 22.81 | |||
| Sesqiterpene hydrocarbones, % | 1.80 | 1.00 | 0.25 | |||
| Phenylpropanoids, % | 21.31 | 18.22 | 16.90 | |||
| Paraffins, % | 41.46 | 41.78 | 46.97 | |||
| Others, % | 1.58 | 2.70 | 1.10 | |||
| Total identified, % | 92.70 | 88.37 | 88.00 | |||
Legend: n.d.—not detected.
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Dobreva, A.; Nedeltcheva-Antonova, D.; Gechovska, K.; Nenov, N.; Antonov, L. Subcritical Extraction of Rosa alba L. in Static and Dynamic Modes. Chemistry 2025, 7, 149. https://doi.org/10.3390/chemistry7050149
AMA Style
Dobreva A, Nedeltcheva-Antonova D, Gechovska K, Nenov N, Antonov L. Subcritical Extraction of Rosa alba L. in Static and Dynamic Modes. Chemistry. 2025; 7(5):149. https://doi.org/10.3390/chemistry7050149
Chicago/Turabian StyleDobreva, Ana, Daniela Nedeltcheva-Antonova, Kamelia Gechovska, Nenko Nenov, and Liudmil Antonov. 2025. "Subcritical Extraction of Rosa alba L. in Static and Dynamic Modes" Chemistry 7, no. 5: 149. https://doi.org/10.3390/chemistry7050149
APA StyleDobreva, A., Nedeltcheva-Antonova, D., Gechovska, K., Nenov, N., & Antonov, L. (2025). Subcritical Extraction of Rosa alba L. in Static and Dynamic Modes. Chemistry, 7(5), 149. https://doi.org/10.3390/chemistry7050149
