Browsing by Author "El Kharraf, Sara"
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- Encapsulation of Rosmarinus officinalis essential oil in β‐cyclodextrinsPublication . El Kharraf, Sara; Farah, Abdellah; El Hadrami, El Mestafa; El‐Guendouz, Soukaïna; Lourenço, João P.; Rosa Da Costa, Ana; Miguel, MariaThe aim of this study was to investigate the encapsulation process of R. officinalis (rosemary) essential oil (REO) in beta cyclodextrin (beta-CD), by co-precipitation, using response surface methodology (RSM), specifically the face-centered central composite design (FCCCD). Solid-to-solid (beta-CD/REO) and liquid-to-liquid (ethanol/water) ratios were selected as independent variables and their influence on the dependent variables was assessed. The recovered powder was characterized by different techniques, such as scanning electron microscope (SEM), Fourier Transform-Infrared Spectroscopy (FTIR) and X-Ray Diffractometry (XRD). Moreover, the release of REO from the beta-CD complexes was investigated at different temperatures and pH values. The responses were affected by the concentration of ethanol in the reaction mixture and the amount of REO used. The optimal responses set by the RSM model (p-value < 0.05) were obtained for the optimal parameters ranging from 1.25:1 to 1.7:1 and 16.25:83.75 to 17.5:82.5 for ethanol/water and beta-CD/REO ratios, respectively. The size of the inclusion complexes from the experimental condition 1:1 ethanol/water and 10:90 beta-CD/REO ratios was the highest, with a value of 2.735 +/- 0.192 mu m. Furthermore, the FTIR spectra of inclusion complexes revealed a band downshift relative to the spectrum of beta-CD, attributable to hydrogen bonding between REO components and beta-CD, as well as a new band at 1,747 cm(-1), revealing the presence of oil components, while the XRD patterns of beta-CD recorded before and after the inclusion process indicate a change from a cage-type packing to a channel-type packing of cyclodextrin, which, in turn, indicates a successful inclusion process. Practical applications The encapsulation of EOs into cyclodextrins can enhance their biological properties, which include antioxidant, antimicrobial, anticarcinogenic, anti-inflammatory, and antidepressant activities. Nevertheless, a careful evaluation of the encapsulation conditions should be carried out in order to ensure the highest encapsulation yield without quality loss. In this way, pH and temperature, among other conditions, must be considered for evaluation since food or other matrices may present diverse pH values and be subjected to different temperatures. The present work may contribute to the use of rosemary EOs, with antioxidant and antimicrobial properties, in food and cosmetic industries, avoiding the sometimes-unpleasant flavor and aroma characteristics.
- Simultaneous Hydrodistillation-Steam Distillation of Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium from Morocco, Major Terpenes: Impact on Biological ActivitiesPublication . El Kharraf, Sara; Faleiro, Maria Leonor; Abdellah, Farah; EL-GUENDOUZ, Soukaina; El Hadrami, El Mestafa; Miguel, MariaInterest in the use of essential oils (EOs) in the biomedical and food industries have seen growing over the last decades due to their richness in bioactive compounds. The challenges in developing an EO extraction process that assure an efficient levels of monoterpenes with impact on biological activities have driven the present study, in which the EO extraction process of rosemary, lavender and citrus was performed by simultaneous hydrodistillation–steam distillation, and the influence of EO composition on biological activities, namely antioxidant, anti-inflammatory, antidiabetic, anti-acetylcholinesterase, anti-tyrosinase, antibacterial, and antibiofilm activity, were evaluated. The EO yields of combinations were generally higher than the individual plants (R. officinalis (Ro), L. angustifolia (La), and C. aurantium (Ca)) extracted by the conventional hydrodistillation. The EOs obtained by this process generally had a better capacity for scavenging the free radicals, inhibiting αglucosidase, and acetylcholinesterase activities than the individual EOs. The combination of EOs did not improve the ability for scavenging peroxide hydrogen or the capacity for inhibiting lipoxygenase activity. The antioxidant activity or the enzyme inhibition activity could not only be attributed to their major compounds because they presented lower activities than the EOs. The chemical composition of the combination Ro:La:Ca, at the ratio 1/6:1/6:2/3, was enriched in 1,8-cineole, linalool, and linalyl acetate and resulted in lower MIC values for all tested strains in comparison with the ratio 1/6:2/3:1/6 that was deprived on those components. The biofilm formation of Gram positive and Gram negative bacteria was impaired by the combination Ro:La:Ca at a sub-inhibitory concentration.
- Two extraction methods of essential oils: conventional and non-conventional hydrodistillationPublication . El Kharraf, Sara; Farah, Abdellah; G, Miguel; EL-GUENDOUZ, Soukaina; El Hadrami, El MestafaThe traditional extraction of essential oils exposes plant material to high temperatures for hours, which may lead to the production of artifacts, even originating unpleasant odors and loss of quality. In addition, this procedure is energy-consuming, which makes it an expensive method. The present work has been focused on a method that combines hydrodistillation and subsequent extraction with water vapor and volatiles of essential oil in the same apparatus, that we called non-conventional hydrodistillation (NCH). Three aromatic plants were used: Rosmarinus officinalis leaves (X-1), Lavandula angustifolia flowers (X-2), and Citrus aurantium leaves (X-3). In the processes, the operating parameters as vegetal mass moisture, total sum vegetal mass used, and water flux rate have been fixed at 17 %, 100 g, and 0.97 L/h, respectively. The extraction process was made using mixture experimental design, taking into account the plants used (one plant, binary and ternary combinations); the position of the plants in the apparatus to study essential oils' yields. The results showed that NCH of binary and ternary mixtures allows obtaining higher yields than expected with values superior to 2 % for the following combinations: X-1:X-2 (50:50), X-1:X-3 (50:50); X-1:X-2:X-3 (33:33:33) and X-1:X-2:X-3 (0.67: 0.16:0.16). The new NCH had a high kinetic coefficient k (2.98) and lower extraction time (70 min) than conventional hydrodistillation (CH), which means less energy consumption.
- β-Cyclodextrin inclusion complexes of combined Moroccan Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium volatile oil: production optimization and release kinetics in food modelsPublication . El Kharraf, Sara; Farah, Abdellah; EL-GUENDOUZ, Soukaina; Lourenço, João P.; Rosa Da Costa, Ana; El Hadrami, El Mestafa; Machado, Alexandra M.; Tavares, Cláudia S.; Figueiredo, A. Cristina; Miguel, MGA combined volatile oil (VO) was extracted from Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium by simultaneous hydro- and steam-distillation, and encapsulated in beta-cyclodextrin by co-precipitation. Response surface methodology (RSM) was used to optimize microencapsulation conditions. The variable recovered powder, VO retention degree, and inclusion efficiency were investigated based on two factors: solid-to-liquid and liquid-to-liquid (ethanol/water) ratios. The responses were influenced by the concentration of ethanol in the reaction mixture and the amount of VO used. VO release from the inclusion complexes was investigated in 10% ethanol and in 3% acetic acid. The obtained data were fitted to the first-order Korsmeyer-Peppas, Higuchi, and Peppas-Sahlin models. The Higuchi model gave the fittest approach for the VO release profile in both cases, showing that the release mechanism was controlled by Fickian diffusion.