Browsing by Author "Martins, Isabel M."
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- Advancements in conventional and supercritical CO2 extraction of Moringa oleifera bioactives for cosmetic applications: A reviewPublication . Kessler, Júlia C.; Martins, Isabel M.; Manrique, Yaidelin A.; Rodrigues, Alírio; Barreiro, M.F.; Dias, Madalena M.Moringa oleifera L. extracts (Mo) have attracted attention as a sustainable and effective alternative to synthetic ingredients for cosmetic formulations. The unique and diverse phytochemical profile of the Mo tree enhances the quality and appeal of commercial products, as evidenced by numerous studies and patents. Supercritical carbon dioxide extraction (SFE-CO2) is particularly advantageous for this purpose, offering enhanced thermostability and selectivity of extracted compounds compared to conventional methods. This review examines the safety and efficacy of Mo seed, leaf, and root extracts as cosmetic ingredients, focusing on their bioavailability and performance by considering the thermodynamics and operational benefits of SFE-CO2. The collected data highlights the method’s efficiency in terms of the total extraction yield and the recovery of target compounds from Mo, providing insights from optimisation studies and linking the solvation power of supercritical CO2 with the significant non-polar and low-polar compounds present in Mo extracts.
- Characterization and evaluation of commercial fragrance microcapsules for textile applicationPublication . Rodrigues, Carla Sofia; Martins, Isabel M.; Mata, Vera G.; Barreiro, M.F.; Rodrigues, AlírioIn this paper, some commercial microcapsule samples, containing different fragrances used for textile application purposes, were characterized and evaluated. Microcapsule samples were evaluated in terms of particle size, morphology, shell material composition, and fragrance intensity. The effectiveness of the textile impregnation and its durability were assessed. The selection of samples used in each study was made in order to the specific goals of characterization and evaluation of microcapsules. Lemon_Bayer, Lemon_Focor, Lemon_Horquim, Strawberry_Horquim, and Jasmine_Focor samples were used to study the morphology and particle size distribution, and it was observed that microcapsules have a spherical shape with size between 2 and 6 lm. The chemical composition of Lavender_Horquim, Mints_Horquim, Eucaliptus_Focor, and Apple_Focor samples was checked/ confirmed and was based on melamine copolymers including melamine-formaldehyde ones. Lemon_Horquim microcapsules were impregnated on textile substrates, and it was observed that a loss of 46% of limonene occurred after one domestic wash and a loss of 97% occurred after 20 domestic washes.
- Chemical and organoleptic properties of bread enriched with Rosmarinus officinalis L.: the potential of natural extracts obtained through green extraction methodologies as food ingredientsPublication . Kessler, Júlia C.; Vieira, Vanessa; Martins, Isabel M.; Manrique, Yaidelin A.; Ferreira, Patrícia; Calhelha, Ricardo C.; Afonso, Andreia; Barros, Lillian; Rodrigues, Alírio; Dias, Madalena M.The potential of R. officinalis L. (RO) extracts as a source of aromas was accessed by hydrodistillation (HD) and supercritical fluid extraction using carbon dioxide (SFE-CO2), followed by a series of analysis: quantification by GC-MS, sensory perception and description, and cytotoxicity against Vero cells. The extracts shown abundancy of α-pinene, eucalyptol, S-verbenone and camphor, contributing for the green, fresh, citric, and woody as main sensory notes. The odour threshold (ODT) value (less than 3.0 × 10- 3 μg⋅mL- 1) and the cytotoxic potential (ca. 220 μg∙mL- 1) defined the concentration range for food application. The most promising extract was added to bread doughs and the final volatile profile was characterised by GC-MS through HS-SPME over time. Among the 34 compounds found, furfural showed an evident contribution in the bread crust aroma, which persisted over four hours of storage, contributing to a pleasant bread fragrance according to the evaluators. This study aims to represent a stepping stone for the use of natural aromas as ingredients for the development of innovative food products.
- Continuous production of melamine-formaldehyde microcapsules using a mesostructured reactorPublication . Dias, Madalena M.; Moreira, Ana C.G.; Manrique, Yaidelin A.; Martins, Isabel M.; Fernandes, Isabel P.; Rodrigues, Alírio; Lopes, José Carlos B.A mesostructured NETmix reactor was adapted to develop a continuous process to produce microcapsules, focusing on the steps commonly used in batch formulation: the emulsion and cure. Microcapsules were formed through a polycondensation process by coating Miglyol, a skin-hydrating emollient, with melamine-formaldehyde, which is a resistant shell material with surface smoothness. Different recirculation times were tested for the cure step. Microcapsules show a spherical shape and smooth membrane. Efficiencies of encapsulation of 75%, core contents of 70%, and diameters around 20 μm, ideal range for textile impregnation, were obtained. Scanning electron microscopy shows the integrity of microcapsules on textiles after impregnation and their flexible behavior. The thermogravimetric analysis confirmed the thermal stability of microcapsules up to 210 °C. With the NETmix reactor, it is possible to reduce the cure time of traditional batch formulation in 80%, producing microcapsules with similar characteristics in a continuous process.
- Corrigendum to “chemical and organoleptic properties of bread enriched with Rosmarinus officinalis L.: the potential of natural extracts obtained through green extraction methodologies as food ingredients”Publication . Kessler, Júlia C.; Vieira, Vanessa; Martins, Isabel M.; Manrique, Yaidelin A.; Ferreira, Patrícia; Calhelha, Ricardo C.; Afonso, Andreia; Barros, Lillian; Rodrigues, Alírio; Dias, Madalena M.The authors regret the inconvenience caused but found an error in the text of section 2.5.3 - “Sensory evaluation of the aroma of bread” of the article. It should read “Four concentrations of R. officinalis extract were used: 0.0, 0.5, 1.0 and 2.0 μL/100 g of bread.” instead of “Four concentrations of R. officinalis extract were used: 0.0, 0.5, 1.0 and 2.0 g/100 g of bread.” The authors would like to apologise for any inconvenience caused.
- Evaluation of surfactants of thyme oil microcapsules by coacervationPublication . Martins, Isabel M.; Rodrigues, Sofia Nogueira; Barreiro, M.F.; Rodrigues, AlírioThe formation of microcapsules (size, shape and stability) is greatly affected by the conditions used in the o/w emulsion preparation, being particularly relevant the used surfactant. The objective of this work is to study the effect of using different surfactants with hydrophilic-lipophilic balance (HLB) values from 11 to 16.5 in the encapsulation process of thyme oil by coacervation using polylactide (PLA) with polymer wall. Different emulsions of thyme oil were prepared and the surfactants investigated were Tween® 20, Tween® 80, Tergitol™ 15-S-9 and a combination of Tergitol™ 15-S-9 with Span® 85. Microcapsules size, morphology and encapsulation efficiency were studied as a function of the used surfactant.
- Functionalized textiles with PUU/limonene microcapsules: effect of finishing methods on fragrance releasePublication . Silva, Mónica; Martins, Isabel M.; Barreiro, M.F.; Dias, Madalena M.; Rodrigues, AlírioThe majority of the commercially available microencapsulated fragrance systems with interest for textile applications are based on phenol–formaldehyde/melamine–formaldehyde resins. Recognized human health problems concerning formaldehyde emissions led to the use of poly(urethane–urea) (PUU) systems. In this work, fabrics were impregnated with PUU microcapsules containing limonene produced by interfacial polymerization. To aid the microcapsule impregnation, a specific binder was used followed by a drying and thermofixation process. The textiles were then subjected to abrasion and dry cleaning tests. Fragrance release was analysed for different binder to microcapsule ratios. SEM images of the impregnated samples indicate good adhesion of the microcapsules to the fabric fibres, but some capsule breakage was observed. Fragrance release tests were followed by GC–FID–HS and showed good resistance to abrasion tests with 30% of the initial limonene detected after 9000 abrasion cycles. A lower resistance was observed for the dry cleaning tests, although 20% of the limonene was still present after five dry cleaning cycles.
- Influence of environmental factors on α-tocopherol levels in Moringa oleifera extractsPublication . Kessler, Júlia C.; Manrique, Yaidelin A.; Martins, Isabel M.; Ribeiro, António E.; Rodrigues, Alírio; Barreiro, Filomena; Dias, Madalena M.Moringa oleifera L. extracts (Mo) have attracted attention as a sustainable and effective alternative to synthetic ingredients for cosmetic formulations. The unique and diverse phytochemical profile of the Mo tree enhances the quality and appeal of commercial products, as evidenced by numerous studies and patents. Supercritical carbon dioxide extraction (SFE-CO2) is particularly advantageous for this purpose, offering enhanced thermostability and selectivity of extracted compounds compared to conventional methods. This review examines the safety and efficacy of Mo seed, leaf, and root extracts as cosmetic ingredients, focusing on their bioavailability and performance by considering the thermodynamics and operational benefits of SFE-CO2. The collected data highlights the method’s efficiency in terms of the total extraction yield and the recovery of target compounds from Mo, providing insights from optimisation studies and linking the solvation power of supercritical CO2 with the significant non-polar and low-polar compounds present in Mo extracts.
- Microencapsulatin of thyme oil by coacervationPublication . Martins, Isabel M.; Rodrigues, Sofia Nogueira; Barreiro, M.F.; Rodrigues, AlírioThe objective of this work is to develop a novel coacervation process to produce microcapsules of polylactide (PLA) to encapsulate thyme oil that will be used in cosmetics. The novelty of this approach consists of dissolving PLA in dimethylformamide (DMF) which is a good solvent for PLA but in addition has high solubility in water. Upon contact with water, the homogeneous solution of PLA in DMF promotes the precipitation of PLA around the thyme oil core. The produced microcapsules have bimodal particle size distributions in volume with a mean particle size of 40 mm. Microcapsules analysis by microscopy have confirmed the spherical shape, the rough surface and allowed the estimation of the wall thickness around 5 mm. Quantification of the encapsulated thyme oil was performed by gas chromatography and allowed to evaluate the quality of the encapsulated oil and pointed out for a preferential encapsulation of thyme oil apolar compounds.
- Microencapsulation by coacervation of biodegradable polymer with thyme oilPublication . Martins, Isabel M.; Rodrigues, Sofia Nogueira; Barreiro, M.F.; Rodrigues, AlírioThe objective of this work is to develop a novel coacervation process to produce microcapsules of PLA to encapsulate thyme oil that will be used in cosmetics. PLA is soluble in organic solvents but insoluble in water. Generally, PLA is used to encapsulate water soluble active principles such as drugs, pesticides and dye-stuffs by coacervation, mainly by means of microspheres production or by using double emulsion techniques (o/w/o). However, the objective of this work is to encapsulate thyme oil, a water insoluble active principle that needs, in a first step, the preparation of an oil-in-water emulsion. The novelty of our process consists on dissolving PLA in dimethylformamide (DMF) which is a good solvent for PLA but in addition has high solubility in water. Upon contact with water, the homogeneous solution of PLA in DMF, promotes the precipitation of PLA around the thyme oil core. With this work we demonstrate a new, easy and executable method of coacervation by introducing modifications on microencapsulation process that allow the encapsulation of an oily active principle by simply preparing an o/w emulsion. Control of size and wall thickness of microcapsules, encapsulation efficiency, the influence of surfactants and release of thyme oil were studied. The produced microcapsules have bimodal particle size distributions in volume with a mean particle size of 40 μm. Microcapsules analysis by microscopy have confirmed the spherical shape, the rough surface, and allowed the estimation of the wall thickness around 5 μm. Quantification of the encapsulated thyme oil was performed by gas chromatography and allowed to evaluate the quality of the encapsulated oil and pointed out for a preferential encapsulation of thyme oil apolar compounds.
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