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- Optimization of heat and ultrasound-assisted extraction of Eucalyptus globulus leaves reveals strong antioxidant and antimicrobial propertiesPublication . Lima, LaĆres; Pereira, Ana I.; Vaz, Clara B.; Ferreira, Olga; Dias, Maria InĆŖs; Heleno, Sandrina A.; Calhelha, Ricardo C.; Barros, Lillian; Carocho, MĆ”rcioThe extraction of phenolic compounds from eucalyptus leaves was optimized using heat and ultrasound-assisted techniques, and the bioactive potential of the resulting extract was assessed. The independent variables, including time (t), solvent concentration (S), and temperature (T) or power (P), were incorporated into a fivelevel central composite design combined with Response Surface Methodology. Phenolic content was determined by HPLC-DAD-ESI/MS and used as response criteria. The developed models were successfully fitted to the experimental data to identify the optimal extraction conditions. Heat-assisted extraction proved to be the most efficient method for phenolic recovery, yielding 27 Ā± 2 mg/g extract under optimal conditions (120 min, 76.5 ā¦C, and 25 % ethanol, v/v). The extracts exhibited a high concentration of phenolic glycoside derivatives, including gallotannin, quercetin, and isorhamnetin. These findings suggest that the extracts hold promise as natural additives in food technology, owing to their moderate antimicrobial activity and strong antioxidant properties.
- Patente Nacional NĀŗ 117561 - ObtenĆ§Ć£o de bioativos de folhas de Eucalyptus globulus: aplicaƧƵes antioxidantes e antimicrobianasPublication . Barros, Lillian; Carocho, MĆ”rcio; Pereira, Ana I.; Ferreira, Olga; Vaz, Clara B.; Lima, LaĆresA presente invenĆ§Ć£o descreve o processo de obtenĆ§Ć£o de um extrato a partir das folhas de Eucalyptus globulus para utilizaĆ§Ć£o como uma alternativa promissora aos componentes antioxidantes e antimicrobianos jĆ” existentes. Este processo Ć© detentor de inĆŗmeras vantagens, tais como: o facto de ser um mĆ©todo de extraĆ§Ć£o simples com o uso moderado de solventes orgĆ¢nicos; a obtenĆ§Ć£o de extratos com Ć³timas capacidades bioativas tornando-os uma interessante alternativa Ć s formulaƧƵes jĆ” existentes no mercado; e a utilizaĆ§Ć£o de uma matriz que possui uma ampla gama de substĆ¢ncias com potencial bioativo, visto ser uma matriz rica em compostos fenĆ³licos, nomeadamente digaloil-glucĆ³sido (fig. 1a) e Ć”cido 5-o-cafeoilquĆnico (fig. 1b). Para alĆ©m destas caracterĆsticas, Ć© tambĆ©m uma planta de fĆ”cil aquisiĆ§Ć£o no mercado, e sem citotoxicidade na gama de concentraƧƵes estudadas. A obtenĆ§Ć£o de matrizes vegetais com alta capacidade bioativa estĆ” alinhada com as preocupaƧƵes e necessidades de vĆ”rios sectores industriais que necessitam de alternativas naturais isentas de toxicidade, viabilizando a incorporaĆ§Ć£o do extrato ou alteraĆ§Ć£o de formulaƧƵes existentes que apresentam complicaƧƵes associadas. Os extratos obtidos detĆŖm um enorme potencial de aplicaĆ§Ć£o em vĆ”rias vertentes do sector industrial, dentre elas alimentar, farmacĆŖutica e cosmĆ©tica.
- Extraction of bioactive compounds from the leaves of Eucalyptus globulus using green solventsPublication . Lima, LaĆres; Carocho, MĆ”rcio; Pereira, Ana I.; Vaz, Clara B.Eucalyptus globulus is a well-known source of phenolic compounds with many applications in the pharmaceutical, cosmetic, and food industries, being extensively found in Portuguese territory. Several studies have shown that the E. globulus extract contains important compounds for pharmacological and medicinal use with analgesic, antimicrobial, anti-inflammatory, antioxidant effects, among other applications. The use of its natural extracts has also been suggested as an alternative to synthetic drugs and additives, aiming to avoid possible undesirable side effects and prevent the development of resistance by microbiological organisms. The study of the matrix composition is essential to the development of new applications by obtaining bioactive compounds with high added value. In this work, the extraction of phenolic compounds from eucalyptus leaves was applied through heat-assisted and ultrasound-assisted techniques, using a green solvent (ethanol:water). Each extraction process was optimized using Response Surface Methodology (Traditional and Dynamic). The extraction time, solid/liquid ratio, the proportion of ethanol in the solvent, and temperature (or power, in the case of ultrasound-assisted extraction) were used as independent variables, and the extraction yield, phenolic acids, flavonoids, and total phenolic contents were the dependent variables. To support the development of new applications, bioactivity studies were carried out to evaluate the antioxidant, antimicrobial, anti-inflammatory and cytotoxicity activities of the extracts obtained under optimized conditions. Maximum antioxidant concentrations, between 5.95 to 6.85 Ī¼g/mL of dry extract, were determined by TBARS, expressed in terms of EC50. The antimicrobial activity was tested against several pathogens (Gram-positive and Gram-negative bacteria), demonstrating the ability to inhibit their growth. The highest antibacterial activity was obtained, with minimum inhibition concentration values of 0.6 mg/mL, for Yersinia enterocolitica and 0.3 mg/mL for Staphylococcus aureus. For the antifungal activity, Aspergillus fumigatus presented the highest sensibility. The anti-inflammatory activity was confirmed by inhibition of nitric oxide release in RAW 264.7 cells (murine macrophage). The extracts did not show cytotoxicity for the cell line tested (Vero cell line). The results obtained indicate that the extracts of E. globulus leaves have high bioactive capacity. Further studies should be conducted to verify the expected variability in the bioactive profile over time by collecting and analyzing periodically samples from the same region and under the same conditions.
- Ultrasound-assisted extraction of leaves of the olive tree (Olea europaea L.): response surface analysis optimization approachPublication . Pedrosa, Mariana C.; Lima, LaĆres; Heleno, Sandrina A.; Carocho, MĆ”rcio; Ferreira, Isabel C.F.R.; Barros, LillianThe olive tree (Olea europaea L.) is a plant with great relevance in Mediterranean countries, being responsible for production of olives and olive oils. The leaves are rich sources of bioactive compounds (e.g., phenolic compounds) with antioxidant, antimicrobial and anti-inflammatory activities. The negative perception that consumers have of artificial preservatives has been driving the industry to seek substitution with natural compounds, with plant derivatives being strong candidates, being the first step the extraction of these compounds. The efficient extraction will allow a better functionalization of these substances in the final product, by improving the yield in specific bioactive compounds. The main objective of this work was to optimize the extraction yields of olive leaves (Olea europaea L.), through ultrasound assisted extraction by applying the response Surface Methodology. The factors analyzed were time (F1), ranging from 10 to 60 min, ultrasonic power (F2), ranging from 50 to 500 W and solvent (F3), ranging from 0 to 100% ethanol, using the Box-Behnken design with 17 individual randomized runs. The response was the dry weight of the extraction, which varied between 7.9 to 64.4 mg. The RSM analysis rendered a reduced quadratic model with no transformation for UAE. The optimization studies have shown a tendency to increase yield with the increase of time and power. Thus, higher limits on time and power could imply even higher extraction yields. The optimal dry weight extraction point (Y1) was obtained at 29 min (F1), 488 W (F2) and 14 % (F3) of ethanol. Future studies are being carried out with other responses, namely specific yields of bioactive molecules, with the ultimate goal of studying the potential of incorporating olive extracts in foods as natural preservatives.
- History of secondary metabolites: from ancient myths to modern scientific validationPublication . Pedrosa, Mariana C.; Lima, LaĆres; Aloso-Esteban, JosĆ© Ignacio; Roriz, CustĆ³dio Lobo; Barros, Lillian; Ferreira, Isabel C.F.R.; Carocho, MĆ”rcioThe study of primary plant metabolism has been the main focus of scientists for several years, seconding research related to the secondary metabolism. Nowadays, with the better understanding of the processes and products involved in primary metabolism, the focus has switched to the expansion of knowledge involving secondary metabolism. Initially, plants were the focus of secondary metabolite studies due to their ease of acquisition and availability, reasons for being a term coined by plant physiologists. Only in the twentieth century has the secondary metabolites from microorganisms began to be recognized and investigated due to the value that these metabolites could bring to science. Not by chance, it was in the twentieth century that the era of antibiotics began. In this chapter, a voyage through the centuries is proposed, focused on secondary metabolism and metabolites, highlighting how they shifted from disregarded molecules to the powerhouses of bioactivity for modern science.
- Optimization through Response Surface Methodology of dynamic maceration of olive (Olea europaea L.) leavesPublication . Pedrosa, Mariana C.; Lima, LaĆres; Heleno, Sandrina A.; Carocho, MĆ”rcio; Ferreira, Isabel C.F.R.; Barros, LillianBioactive compounds derived from plants are secondary metabolites that can act through various bioactivities, namely as antioxidant, antimicrobial, anti-inflammatory, anti-hypertensive, and hypoglycemic agents. Combined with the pressure generated by consumers for more natural products with beneficial effects on health, these compounds may be suitable candidates to act as preservatives in food products. For this purpose, the extraction process becomes essential for the acquisition of a quality extract with efficiency and with the desired final properties. Therefore, the main objective of this work was to perform the optimization of the extraction yield of olive leaves (Olea europaea L.), by applying response surface methodology (RSM) and employing dynamic maceration as extraction technique. Three factors were analyzed: time (F1), temperature (F2), and solvent (F3), ranging from 5 to 120 min, 25 to 100 C, and from 0 to 100% ethanol, respectively. The study used the Box Behnken design, relying on 17 individual randomized runs. The response was the dry weight of the extract (Y1), which ranged from 21.1 to 90.5 mg. The optimization studies pointed to the increase of yield with the increase of time and temperature, but inversely by applying higher time and lower temperature values and higher temperature and lower time values. The highest yield of the dry extract was achieved at 120 min (F1), 25 C (F2), and 87% (F3) of ethanol:water. Future studies will be carried out to analyze the preservative effects of incorporating olive extract in foods, as well as analysis of other response for optimizing the best food preserving extract.
- Food metabolites as tools for authentication, processing, and nutritive value assessmentPublication . Pedrosa, Mariana C.; Lima, LaĆres; Heleno, Sandrina A.; Carocho, MĆ”rcio; Ferreira, Isabel C.F.R.; Barros, LillianSecondary metabolites are molecules with unlimited applications that have been gaining importance in various industries and studied from many angles. They are mainly used for their bioactive capabilities, but due to the improvement of sensibility in analytical chemistry, they are also used for authentication and as a quality control parameter for foods, further allowing to help avoid food adulteration and food fraud, as well as helping understand the nutritional value of foods. This manuscript covers the examples of secondary metabolites that have been used as qualitative and authentication molecules in foods, from production, through processing and along their shelf-life. Furthermore, perspectives of analytical chemistry and their contribution to metabolite detection and general perspectives of metabolomics are also discussed.
- Dynamic response surface method combined with genetic algorithm to optimize extraction process problemPublication . Lima, LaĆres; Pereira, Ana I.; Vaz, Clara B.; Ferreira, Olga; Carocho, MĆ”rcio; Barros, LillianThis study aims to find and develop an appropriate optimization approach to reduce the time and labor employed throughout a given chemical process and could be decisive for quality management. In this context, this work presents a comparative study of two optimization approaches using real experimental data from the chemical engineering area, reported in a previous study [4]. The first approach is based on the traditional response surface method and the second approach combines the response surface method with genetic algorithm and data mining. The main objective is to optimize the surface function based on three variables using hybrid genetic algorithms combined with cluster analysis to reduce the number of experiments and to find the closest value to the optimum within the established restrictions. The proposed strategy has proven to be promising since the optimal value was achieved without going through derivability unlike conventional methods, and fewer experiments were required to find the optimal solution in comparison to the previous work using the traditional response surface method.
- UtilizaĆ§Ć£o de aplicativos m-health na oncologia: uma revisĆ£o sistemĆ”ticaPublication . Martins, Danilo M.D.; Lima, LaĆres; Vaz, Clara B.; Pereira, Ana I.O presente trabalho consiste em uma revisĆ£o sistemĆ”tica de literatura acerca de estudos recentes sobre aplicativos mĆ³veis relacionados com saĆŗde (m-health) na prĆ”tica clĆnica de doenƧas oncolĆ³gicas para catalogaĆ§Ć£o das principais caracterĆsticas dos aplicativos desenvolvidos.
- Mixture design: development of a graphical user interface for determining mixture parametersPublication . Lima, LaĆres; Pereira, Ana I.; Vaz, Clara B.; Ferreira, OlgaPredicting the performance of a mixture is crucial to designing experiences in product development and formulation research. In this work, an application, MDesign, is proposed to construct models in a mixture design with a practical, educational, and intuitive approach. Developed in MATLAB software, the standalone application aims to contribute to the study of mixtures through the definition of multivariate models of different orders, enabling their statistical analysis to verify the robustness of each of those models. Compared to the obtained results from other applications using data experiments published in the literature, the proposed application presents accurate results and good execution. MDesign can be considered an automatic, robust, and valuable tool to support the mixture design in an industrial context.