Experiments to extract the essential oil from rosemary (Rosmarinus officinalis L.) were carried out using a new process: 'Détente Instantanée Contrôlée (DIC) or controlled instantaneous decompression. This process involves subjecting the rosemary leaves for a short period of time to a steam pressure varying from 0.5 to 3 bar, followed by an instant...
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... variations of process parameters are summarized in Table 2. Another experiment (run No. 4) was carried out at 3 bar and with the initial water content at 35%, but for 8 minutes instead of 10 and with two decompressions at 4 minute intervals. Table 3 shows that the higher pressure increased the extraction eciency of the extraction using the DIC process: the quantity of residual oil was 9% at 1 bar and less than 3% at 3 bar (run No. 3). This result shows that compared with other`¯ashother`¯ash' extraction processes, 16 extraction by DIC treatment is more ecient and thus, at the industrial level, the steam distillation step is not necessary. ...
Urinary tract infections (UTIs), caused by Escherichia coli 80% to 85% of the time, are one of the most important causes of morbidity and health care spending affecting persons of all ages. These infections lead to many difficult problems, especially increasing resistance to antibiotic drugs. Bacterial biofilms play an important role in UTIs, respo...
Freshwater resources are threatened by harmful algal blooms (HABs) internationally. The HABs are sometimes direct result of eutrification status caused by pollution entering water bodies, such as partially treated nutrient-rich effluents discharged in the rivers, in addition to fertilizers and animal wastes. The anti-cyanobacterial activity of Rosm...
Methicillin-resistant Staphylococcus aureus is a major human pathogen that poses a high 13 risk to patients due to the development of biofilm. Biofilms, are complex biological systems difficult 14 to treat by conventional antibiotic therapy, contribute to >80% of humans infections. In this report, 15 we examined the antibacterial activity of Origan...
Essential oils extraction from Bunium Persicum (Boiss) was performed using instant controlled pressure drop (in French: Détente Instantanée Contrôlée or DIC) thechnology and optimum extraction conditions were obtained. Response surface methodology (RSM) was used to determine the optimal conditions and the results were 20s heating time, 3.5bar pressure, 0.44mm particle diameter and 9 cycles. Essential oils extraction was also compared with Hydrodistillation (HD), ultrasound-assisted extraction (UAE) and Soxhlet (SOX) extraction. Results show higher efficiency of the DIC than other methods and more oxygenated components were observed. Impact of DIC, HD, UAE and SOX on the morphological structure of the plant was studied by SEM. Antioxidant activity and total phenolic content (TPC) of the extract were determined and comapred by HD. Results show that DIC facilitates achieving to higher TPC and more antioxidant activity.
In this research work, instant controlled pressure drop process (ICPD) was used as a texturing pretreatment to enhance extraction efficiency of phenolic compounds from pomegranate peel. Response surface methodology (RSM) was used to optimize ICPD. Experiments were carried out at steam pressures from 1 to 3 bar, steam exposure time from 10 to 60 s and number of pressure drop cycles from 1 to 5. The textured samples were extracted by 60% (v/v) methanol solution and the best operating conditions for ICPD were determined to be at 3 bar, 60 s and 1 cycle. In comparison with un-textured samples, total phenolic content (TPC) and antioxidant activity as inhibition percent were increased from 38.77 to 46.02 mg GA/g dry basis, and from 62.10 to 74.12%, respectively. Scanning electron microscopy (SEM) of the treated peel illustrated remarkable modification in the texture. Results showed a linear relationship between TPC and antioxidant activity of the textured pomegranate peel. Industrial relevance Increasing valuable compounds extraction efficiencies and achieving higher qualities are some of most important goals in food industry. Extraction of total phenols and antioxidants from natural resources and using them in different food products formulations is an interesting research area. This paper shows an efficient way for texturing pomegranate peel to enhance extraction yield of total phenols and antioxidants.
Background: Rosemary (Rosmarinus officinalis L.) is a widely consumed aromatic plant that belongs to the Lamiaceae family. Fresh and dried leaves are frequently used in traditional Mediterranean cuisine and in folk medicine. Scope and approach: For this study, an extensive bibliographic review on rosemary was carried out, including its main uses, components (both nutrients and bioactive), biological activities, interactions with drugs and potential applications. Key findings and conclusions: The nutrient composition of rosemary reveals a great amount of vitamins and minerals. The most well studied bioactive compounds are carnosic acid, carnosol, caffeic acid and its derivative, rosmarinic acid. The levels on bioactive compounds depend on many factors, such as the variety, plant part, edafoclimatic conditions, drying conditions (if applied) and extraction and analysis methods. Numerous biological activities of rosemary are recognized including antioxidant, antibacterial and antifungal, anti-cancer, anti-inflammatory, among others. Therefore it has a vast range of industrial applications such as food and food packaging, pharmaceutical, perfumery and cosmetics industries.
The aim of this study was to describe the chemical composition of Tunisian Mentha pulegium L. essential oils from Monastir and to test their antibacterial activity. The essential oils, obtained from fresh and dried aerial parts by hydrodistillation, were analysed by gas chromatography and mass spectrometry. The leaf extracts were used to test the antimicrobial activity against nine hospital bacteria and five reference strains. The minimum inhibitory concentrations and the minimum bactericidal concentrations were determinated by sub-culture at TSA agar plates which were incubated at 37°C during 18-24 h. Thirty four compounds were identified. All the oils were found to be rich in oxygen monoterpen hydrocarbons. The oils tested displayed antimicrobial activities. Aeromonas hydrophila, Vibrio cholerae non-O1 and Enterococcus faecalis were the most sensitive strains. Gram-positive strains are more susceptible to the essential oils from the fresh leaves collected at the vegetative state than from the dried ones.
The first aim of this study was to describe in detail the chemical composition of Tunisian Rosmarinus officinalis L. essential oil (EO) from Kasrine. The second aim was to test its antibacterial and antimutagenic activities. EOs were extracted from rosemary leaves by hydrodistillation using a Clevenger-type apparatus. The chemical analysis was carried out by using gas chromatography and mass spectrometry (GC-MS). Forty chemical compounds were identified in EOs. The quantitative composition of EOs differs between geographical sources. The antimicrobial activity was evaluated against five pathogenic bacterial strains: Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus, Staphylococcus epidermidis and Micrococcus luteus. All EOs were dissolved in Tween-80. The minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) were determined by sub-culture at TSA agar plates which were incubated at 37°C during 18-24 h. The antimutagenic effect was tested by Ames test on Salmonella typhimurium TA97. Rosemary EOs had a good antimicrobial activity against all bacteria tested, E. coli being the most sensitive. EOs can be suggested as an antimutagenic agent. The antibacterial and antimutagenic activities are not related only to major compounds but also to the minor components of rosemary EOs. Rosemary oil can be used as an antimicrobial agent in hospitals by pulverisation or in soaps and in foods such as fish, meat, milk and its derivatives. Regular use of honey based on rosemary might help to treat chronic bacterial infections or cancer.
We carried out experiments concerning the treatment by Instantaneous Controlled Pressure-drop (DIC) in the case of juniper berries (Juniperus Excelsa). We study how DIC is able to extract essential oil by applying an abrupt pressure drop toward vacuum whose rate is ΔP/Δt >5bar s−1, which implies an autovaporization of water and some volatile molecules, leads a cooling effect and modifies the structure. We analyze the effect of both steam pressure (from 1 up to 6 bar) and treatment time (from 10 seconds up to 3 minutes) in term of extraction yield. We proved that the higher the pressure, the higher the extraction yields. A double DIC treatment at 6 bars during 150 seconds, allowed us to extract 95 % of essential oils extracted normally in 12 hours by steam distillation.
The study investigated the intensification and improvement of oil extraction from orange peel through a thermomechanical process: the Instantaneous Controlled Pressure Drop (briefly D.I.C process). This process involves subjecting orange peel for a short time to steam pressure, followed by an instantaneous decompression to vacuum at 50 mbar. Central composite design was used to study the combined effects of processing steam pressure (1–7 bar; which corresponds to a temperature ranging between 100°C and 162 °C respectively), processing time (0.3 – 3.7 min.) and initial moisture content of orange peel before thermomechanical oil extraction (9.8 – 60.2 % on dry material basis). The quantitative analysis, have been undertaken on oil present in orange peels, after processing. Correlation analysis of the mathematical regression model indicated that quadratic polynomial model could be employed to optimize the extraction of oil from orange peel. From response surface plots, the three variables exhibited a linear effect with the strongest effect for the processing pressure. The optimum reaction conditions selected with response surface analysis were as follows: steam processing pressure: 6.6 bar, processing time: 3.68 min, initial moisture content: 53.6 % d.m basis. Under these conditions, experimental yield of orange peel oil was close to predicted value (99 %) calculated from the polynomial response surface model equation. A kinetic study indicated that extraction performed by D.I.C process is clearly quicker than conventional steam distillation method.
Rosemary oil may be isolated by three different processes, including steam distillation, water distillation and controlled instantaneous decompression. The concrete resulting from extraction by volatile organic solvents was also made using hexane, dichloromethane and ethanol. The oils and extracts obtained were analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectroscopy (GC/MS) in order to determine their chemical composition. A scanning electron microscope was used to observe the impact of different processes on the structure of leaves and essential oil bearing trichomes.
The essential oils extracted by Clavenger apparatus from leaves of Rosmarinus officinalis cultivated in different areas in Djerba (Island in the southern of Tunisia) were evaluated for their chemical composition (GC and GC-MS methods), antioxidant (DPPH method) and antibacterial activities (agar-well diffusion method). GC-MS analysis revealed the presence of three chemotypes of oils: 1,8-cineole, 1,8-cineole/camphor/α-pinene/camphene and 1,8-cineole/camphor/α-pinene/ verbenone/borneol which was not previously detected in Tunisian Rosmarinus officinalis. The three chemtypes exhibited moderate antioxidant activity with an IC 50 ranged from 4.186 mg/ml for chemotype I to 7.298 for chemotype II and showed strong to moderate antibacterial activity against the six bacterial strains tested with a MIC ranged from 0.156 to 1.25 mg/mL (Chemotype I and chemotype II) and from 1.25 to 5 mg/mL (chemotype III). This study showed that the essential oil extracted from Rosmarinus officinalis cultivated in Djerba has similar chemical composition and biological activities as essential oil isolated from wild growing Rosmarinus officinalis.
The isolation of cananga oil by a new process, Instantaneous Controlled Pressure Drop (DIC), was investigated. This process consists in heating the dry cananga (Cananga odorata Hook. fil. et Thomson, forma macrophylla) flowers for a short time period by steam, followed by an abrupt pressure drop into a vacuum (about 5 kPa). This pressure drop provokes auto-vaporization of the volatile compounds, puffing of flowers, breaking of cell walls and cooling. The effect of the process parameters, namely number of DIC cycles (1–9), saturated steam pressure (0.2–0.6 MPa), and heating time (0.5–20 min) on the oil yield and oil composition was examined. The results indicated a significant increase of oil yield with increasing processing pressure and number of DIC cycles, however the total heating time was not a significant parameter. The DIC oil was compared with the oil obtained using steam distillation (SD). DIC exhibited better results than SD concerning rapidity (4 min versus 24 h), oil yield (2.74% versus 2.60%) and also oil quality.