Microwave-assisted hydrodistillation and integrated GC-MS/FID and HPLC-PDA/MS profiling of Rosa damascena Mill. petals: a novel insight into volatile and polyphenolic composition of Italian cultivars

The present study aimed to evaluate the chemical analysis and antimicrobial effects of the Thamnobryum alopecurum (Hedw.) Gangulee essential oils were obtained by different distillation methods (Clevenger apparatus hydrodistillation (HD) and microwave-assisted hydrodistillation (MD)). In this study obtained volatile oils were analyzed by gas chromatography-mass spectrometry which revealed the presence of forty-five compounds present in the essential oil obtained by HD method representing 99.48 % of the total identified compounds and thirty-four compounds were identified in the essential oil extracted by MD method representing 95.39 % of the total identified compounds. 3-octanone was the major constituent of the essential oils extracted by both HD (14.28 %) and MD (20.07 %). Terpenes were the major constituents in the essential oil extra-cted by both methods (54.41 % in HD and 52.21 % in MD) followed by oxygenated terpenoids (17.16 % in HD and 14.94 % in MD). The other major compounds of the essential oil in HD was limonene (9.65 %) followed by β-pinene (9.13 %), cuparene (6.04 %), gymnomitrone (5.72 %) and 4-epi-abietal (5.59 %). While in MD essential oil the other major compounds were β-pinene (12.20 %) followed by limonene (8.56 %), α-pinene (9.01 %), cupa-rene (6.44 %), abietadiene (5.97 %). The antimicrobial effects of the essential oils were determined tested quantitatively in respective broth media by using double microdilution and the minimal inhibition concentration (MIC) values (μg/mL). The isolated essential oils of T. alopecurum showed effective antimicrobial activities against Escherichia coli, Yersinia pseudotuberculosis, Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Mycobacterium smegmatis and Candida albicans. However, no activity was not observed against Pseudomonas aeruginosa. The hydrodistillation method was found to be more effective than the microwave method in iden-tifying the chemical composition of the structure of T. alopecurum essential oil. While for antimicrobial study MD method was found to be more effective in terms of antimicrobial effect. The T. alopecurum thus is a potential source of an antimicrobial agent with a wide range of chemical compounds that could be responsible for their activity.

Extraction of essential oils of Ferulago angulata with microwave-assisted hydrodistillation

Traditional methods of essential oil (EO) extraction are often associated with low yields, high energy consumption, and extended processing times, demanding the need for greener and more efficient alternatives. Thus, the present study optimized microwave assisted hydrodistillation (MAHD) for the extraction of Curcuma amada rhizome essential oil (CAREO) by evaluating the effects of microwave power, liquid-to-plant material ratio, and extraction time using central composite design of response surface methodology. The developed quadratic model (p < 0.0001, R² = 0.9966) was statistically significant, demonstrating a strong correlation between experimental and predicted responses. The optimized conditions (microwave power: 800 W, liquid to plant ratio: 2.5 mL/g, extraction time: 50 min) produced slightly higher essential oil yield (0.7 % (v/w)) than conventional hydrodistillation (HD, 0.6 % (v/w)). Both methods produced essential oils with comparable physical properties, but MAHD offered faster extraction, lower energy use, and reduced CO₂ emissions. Furthermore, GC-MS analysis revealed that the EOs obtained via MAHD and HD represented 98.62 and 97.47 % of CAREO composition, respectively. Moreover, both methods produced EO rich in monoterpene hydrocarbons with myrcene as the major constituent. FTIR spectral analysis showed no significant differences in functional groups indicating that both preserve the chemical integrity of EO components. However, SEM analysis revealed significant shrinkage of parenchymatous cells with greater loss of starch granules, thus, facilitating more release of oil in MAHD. Furthermore, MAHD was found to be more sustainable when assessed using AGREEprep and BAGI pictograms. Lastly, MAHD demonstrated higher DPPH and ABTS radical scavenging effects than HD. Overall, MAHD offers a viable eco-friendly option for CAREO extraction due to better extraction efficiency, higher yield and stronger antioxidant activity.

The region of Kozani, in northern Greece, is known for the cultivation of two unique aromatic plants that yield valuable natural products: Rosa damascena (Rosaceae) is commercialized for its rose oil and rose water while Crocus sativus (Iridaceae) is renowned for its red stigmas, an exclusive aliment (saffron). Several pharmacological properties, including antibacterial, antioxidant, antitussive and anti-diabetic have been attributed to rose petals. Crocus petals have displayed antioxidant and antibacterial activity and were found to reduce blood pressure and be effective in the treatment of mild to moderate depression. The aim of this work was to investigate the phytochemical profile of extracts deriving from the petals of these two plants, obtained by microwave-assisted-hydrodistillation (MAHD) and -extraction (MAE) techniques. Fresh rose petals were distilled with MAHD using various extractions times for the recovery of the rose oil which was analyzed with GC-MS. Citronellol and geraniol were found to be the main components. The aqueous residue that remained inside the clevenger apparatus was fed continuously to macroporous resins (XAD-4) in order to study the remaining phenolic compounds. Dried crocus petals were extracted by applying various extraction times in MAE with ethanol or aqueous ethanol. The optimal extract, in terms of yield, was fed continuously to macroporous resins (XAD-4) for the recovery of the phenolic compounds. The extracts were analyzed, concerning their phenolic constituents with HPLC-DAD and UHPLC-UV. A Folin-Ciocalteau assay was used for the determination of their total phenolic content and their antioxidant potential was evaluated in a DPPH assay. Further chromatographic separation for the purification of the principal bioactive compounds indicated that the rose extract was rich in glycosides of quercetin and kaempferol while the crocus extract contained mostly kaempferol 7-O-glucopyanosyl-3-O-sophoroside and kaempferol 3-O-sophoroside.

This article presents a comprehensive review of methods of extraction, properties, compositions and industrial application of lemongrass essential oil. Lemongrass (Cymbopogon citratus) essential oil has been used traditionally since ancient days in medicine as remedy to improve blood circulation, treat fever and malaria, promote digestion and as well used to increase immune system of the human body. Essential Oils of lemongrass are used in various industries. Some of the industries in which they are used extensively include Aromatherapy, Food and drink industry, Pharmaceuticals industry, Fragrance and Flavour industry, Agriculture and Livestock industry, Cosmetic and Soaps industry, House hold and Domestic. The quality of the essential oil from lemongrass strongly depends on the extraction method and operating conditions. Basically lemongrass essential oil can be obtained by various extraction methods, such as steam distillation, conventional solvent extraction, Soxhlet extraction, ultrasound-assisted extraction (UAE), hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), Simultaneous-distillation-extraction technique (SDE), Solvent-Free-Microwave-Extraction Technique (SFME) and supercritical fluid extraction (SFE) with CO2. The composition of essential oil of Cympobogon citratus contains α-pinene, β-pinene, delta-3-catrene, myrcene dipentene, β-phellandrene, β-cymene , methyl heptanene, citronellal, β-elemene, β-caryophyllene, citronellyl acetate, geranyl acetate , citral A , citral B, geraniol, elemol , and β-caryophyllene oxide, etc. In addition, lemongrass oil also contains essential minerals such as Fe, Zn, Mg, Na, K, Ca, Mn, P etc. The most important physicochemical properties of lemongrass oil includes specific gravity, Optical rotation, refractive index, percentage of citral, freezing point, moisture content, acid value, ester value, carbonyl value and phenol content . Nevertheless, the chemical composition of the essential oil of Lemongrass also varies with the geographical origin, cultivation practices, plant age, photoperiod, harvest period, cultivars, and extraction methods. However, for extraction of lemongrass oil, green technology such SFE, SDE, SFME and MAHD that are consumer and environmental friendly in industrial-scale essential oil production should be considered as a method to overcome the limitations of traditional distillation methods. KEYWORDS: Essential Oil, Lemongrass, Microwave-Assisted-Hydrodistillation. Solvent Extraction, Steam Distillation, Supercritical Fluid Extraction

Microwave assisted hydrodistillation (MAHD) and conventional hydrodistillation techniques were compared in the extraction of essential oils from Amomum subulatum seeds. The time required for MAHD method (70 min) is lesser than that for HD method (4 hr). There is a slight increase in the yield of extracted oil in MAHD method (3.35%) compared to HD (3%). GC-MS results show that MAHD extracted essential oil was wealthier in oxygenated compounds. 1, 8-Cineole was found to be a major compound in case of both the essential oil, followed by α-pinene. In MAHD the percentage of the major oxygenated monoterpene (1, 8- cineol) slightly increases from 88% to 89% as compared to hydrodistillation. Contrarily to this, the percentage of monoterpene hydrocarbon were decreased in MAHD than HD extracted oil. MAHD and HD extracted oils show good antibacterial activities against gram-negative and gram-positive bacteria. MAHD extracted oil shows better antibacterial activity than HD extracted against both gram positive and gram-negative bacteria. 2, 2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging antioxidant activities show that MAHD extract has better inhibition percentage than HD extract, and the IC50 value of MAHD was less than HD extracted oil.

Since ancient times, the three Salvia L. species: Salvia aegyptiaca L., Salvia lanigera Poir., and Salvia multicaulis Vahl, have been utilised in traditional medicine all across the world. These species are now subjected to in-depth chemical and pharmacological investigations in order to find physiologically active chemicals. In the present study, the essential oil composition and biological activity of these Salvia L. species were studied. Using various extraction methods: hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) to compare extraction efficiency, volatile metabolites were analysed and characterised by Gas chromatography/mass spectroscopy (GC/MS), while the antimicrobial efficiency for both the HD and MAHD essential oils was examined against four pathogens: Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida albicans using microdilution assay. S. aegyptiaca, 12 and 14 compounds, were characterised by HD and MAHD extraction, respectively. Sesquiterpene hydrocarbons (85.87% HD & 72.74% MAHD) repidentified by HD and MAHD extraction, respectively. Monoterpenes (36.58% HD and 49.63% MAHD) and their oxygenated derivatives (31.4% HD and 28.63% MAHD) were the predominant compound classes. From S. lanigera, 12 and 8 compounds were identified by HD and MAHD extraction, respectively. Sesquiterpene hydrocarbons were present in S. lanigera essential oils with 8.3% HD and 2.4% MAHD. Moreover, the most potent antimicrobial activity was observed with the S. multicaulis essential oil collection employing either HD or MAHD extraction, while S. lanigera essential oils extracted by MAHD exhibited almost as high antimicrobial activity. The approach of MAHD saves time with all the improvements in product yield. Essential oils extracted using MAHD might be used to treat bacterial infections instead of standard antibacterial medications.

A microwave-assisted hydrodistillation (MAHD) method was investigated for extraction of essential oils from lavender. The essential oil extracts at optimized MAHD conditions was compared with hydrodistillation (HD). Response surface methodology coupled with Box-Behnken design was applied to optimize the parameters for MAHD. The optimized MAHD conditions were 500 W microwave power, 17 mL/g liquid-to-solid ratio and 40 min microwave time. The ANOVA results revealed that microwave time had the greatest impact on the essential oil yield followed by liquid-to-solid ratio and microwave power. Under the MAHD optimized conditions, the essential oil yield was 3.19%, approximating the predicted yield (3.20%). MAHD was superior in terms of saving energy and extraction time (40 min, compared to 120 min in HD). The essential oil analyzed by GC-MS, presented 39 compounds constituting 98.37% and 97.51% of the essential oils obtained through MAHD and HD, respectively. No obvious differences were found in composition between MAHD oil and HD oil. Antimicrobial study showed that the lavender essential oil exhibited broad-spectrum antibacterial activity and the MAHD oil showed a higher antimicrobial activity than the HD oil. This study revealed that MAHD could be a good method for extracting essential oil in lavender and other aromatic plants.

Comparative study of chemical composition, antibacterial and antioxidant activity of essential oils isolated from the seeds of Amomum subulatum by using microwave extraction and hydro-distillation methods

The essential oils from Marchantia paleacea obtained by microwave-assisted hydro-distillation (MAHD) and conventional hydrodistillation (HD) methods were compared. For MAHD method, the effects of different parameters, such as extraction time, the moisture of the matrix and the irradiation power, on the yield of essential oils were investigated. Maximum global yields were obtained using the following conditions: extraction time, 40 min; the irradiation power, 450 V and the moisture of the matrix, 80 %. MAHD was superior in terms of saving energy and extraction time (40 min, compared with 3 h for HD). The yield of essential oils by MAHD method was ten-fold higher than that of HD method. The extracts of essential oils were analyzed by GC-MS. The obtained results were compared with references. The result also indicated that the using microwave irradiation did not change the composition of essential oils.

The demand of essential oil in current industry has increased due to its bioactive compound that shows various therapeutic effects. Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique, in which a microwave oven is used as the heating source. MAHD extraction of essential oil from Lemongrass (Cymbopogon Citratus) was studied. The effect of different parameters, such as water to plant material ratio (6:1, 8:1,10:1), microwave power (200 W,250W) and extraction time (30min,60min, 90min,120min) on the extraction yield and its major constituents were investigated and the results were compared with those of conventional HD. These essential oils were further analyzed by gas chromatography/mass spectrometric (GC-MS) to evaluate the effect of extraction method on the content of its main constituents which were neral, geranial and myrcene and some minor compounds such as linalool, geranic acid and citronellol. The optimum parameters were found at water to plant material ratio of 8:1, microwave power of 250W and 90 minutes of extraction and the yield obtained under this condition was 1.46%. GC-MS analysis has proved that the use of microwave irradiation did not adversely influence the composition of essential oils as the main constituents found through both methods were almost similar in term of quality and quantity. The results obtained indicate that MAHD method provided a good alternative for the extraction of essential oil from Lemongrass (Cymbopogon Citratus). I. INTRODUCTION Essential oils are botanical extracts of various plant materials, and do not only originate from flowers, but from herbs, trees and various other plant material. It is estimated that the global number of plants is of the order of 300,000 and about 10% of these contains essential oils and could be used as a source for their production (1).Their extracts are formed by combination of diverse and complex volatile mixtures of chemical compounds, with predominance of terpene associated to aldehydes, alcohols, and ketones which were accumulated in various structure of the plant (2). In industry, the essential oils are typically extracted from fresh or partially dried leaves using various method of extraction and the most common will be hydrodistillation. The use of medicinal plants extracts is part of a competitive market, which includes pharmaceuticals, food, cosmetics, and perfumery markets, mainly to use their active substance. The Asian continent with its diversity of climates appears to be the most vital producer of essential oils. China and India play a major role followed by Indonesia, Sri Lanka, and Vietnam

Kinetics of mace (Myristicae arillus) essential oil extraction using microwave assisted hydrodistillation: Effect of microwave power

This study investigated the potential use of microwave energy as an effective technique for the extraction of essential oil (EO) from some plant species belonging to Lamiaceae family growing in Egypt, involving Origanum majorana L., Mentha pipereta L., Mentha longifolia L., Origanum syriacum L., Lavandula angustifolia L., Rosmarinus officinalis L., and Thymus vulgaris L., in comparison with conventional extraction using hydrodistillation (HD) approach, in terms of extraction time, oil yields, and chemical composition. The results showed that the use of microwave in a relevant technique, namely microwave‐assisted hydrodistillation (MAHD) required an extraction of 60 minutes, while HD required 180 minutes. In general, EO yield being extracted by MAHD was higher than those extracted by HD. Gas chromatography in combination with mass spectrometry (GC/MS) analysis indicated noticeable quantitative changes in EOs composition extracted by MAHD and HD extraction methods. Except for O majorana L., GC/MS analysis of extracted oils using MAHD showed higher amounts of oxygenated constituents compared to HD extraction. The results of this study introduced MAHD as rapid, economical and environmental friendly extraction method. A comparative analysis was stated here between the EOs of all plant species under study on chemometric tools such as principal components analysis (PCA) and agglomerative hierarchical clustering (AHC). In general, the PCA results showed that there is significant variation between species in the quality and quantity of EO composition. However, no significant difference is observed based on the extraction method used (HD and MAHD).

Damask rose cultivated for essential oil production mainly used in perfume industry. Due to the highly perishable flowers, post-harvest handling of the flowers prior to oil extraction would be considered as a key point in rose essential oil production. Besides its major application in aroma and cosmetic industries, rose essential oil has been reported with valuable pharmacological properties such as antibacterial, antioxidant, and cytotoxic activities. Plant breeders are being encouraged to develop new damask rose cultivars with improved oil content and higher flower yield qualities due to rising market demand. The aforementioned qualities can be improved using traditional breeding methods such as clonal selection and intra-specific hybridization. But, through the convention breeding method creation of genetic variation is time taking, and the preservation of the authentic scent and quality of the rose oil is very difficult. Recent breakthroughs in molecular-markers techniques, genomics, and transcriptomics, have resulted in large volumes of data being generated in damask rose. Several attempts have been undertaken to accelerate the breeding of R.damascena using molecular technologies. However, due to the species' high heterozygosity and polyploidy nature, translating the findings of such studies to practical breeding remains a significant challenge. This review paper outlines recent advances in conventional and modern molecular breeding procedures, as well as their potential uses and limitations in improving the oil-bearing rose.

Evaluating the Effects of Microwave-Assisted Hydrodistillation on Antifungal and Radical Scavenging Activities of Oliveria decumbens and Chaerophyllum macropodum Essential Oils