Browsing by Author "Domingues, Joana Lopes"
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- Cistus ladanifer (Cistaceae) : a natural resource in Mediterranean-type ecosystemsPublication . Frazão, David F.; Raimundo, Joana; Domingues, Joana Lopes; Quintela-Sabarís, Celestino; Gonçalves, José Carlos; Delgado, F.M.G.Cistus ladanifer has a well-defined taxonomic identity. 2,2,6-trimethylcyclohexanone may be an authenticity and taxonomic marker. Its traits and applications make it a possible economic resource fitted for Mediterranean areas. Cistus ladanifer is a dominant shrub species endemic to the western Mediterranean region. Due to its dominant nature and its potential ecological, aromatic or pharmacological applications, C. ladanifer has been the object of numerous studies. In this review current knowledge on different aspects of this species is summarized, from its taxonomy to its chemical characterisation or its competitive traits. There are no doubts about the taxonomic entity of C. ladanifer, although the recognition of infraspecific taxa deserves more attention. Given that the fragrant exudate of C. ladanifer holds a very specific composition, one species specific carotenoid, 2,2,6-trimethylcyclohexanone, derivative is proposed as an authenticity marker for uses of C. ladanifer in pharmacological or aromatic industries. Evidence is also gathered on the extreme adaptation of C. ladanifer to stressful conditions in the Mediterranean region, such as the ability to survive in low hydric and high solar exposition conditions, presistence in poor and contaminated soils, and growth inhibition of several other plants through the release of allelochemicals. Thus, the finding of potential applications for this plant may contribute to enhance the economic dimension of derelict lands, such as mine tailings or poor agricultural Mediterranean areas.
- Desenvolvimento de novos produtos e análise sensorial : aplicação num creme para barrarPublication . Domingues, Joana Lopes; Pintado, Cristina Miguel; Peres, Maria de FátimaDesenvolvimento de novos produtos e análise sensorial : aplicação num creme para barrar.
- Desenvolvimento de pastas de azeitona e tremoçoPublication . Domingues, Joana Lopes; Peres, Maria de Fátima Pratas; Pintado, Cristina MiguelEste trabalho teve como principal objetivo o desenvolvimento de pastas de azeitona e tremoço, criando um alimento inovador, com uma melhor composição nutricional relativamente às pastas comummente comercializadas, sem aumentar o custo do produto. O desenvolvimento baseou-se em estudos de preferência, utilizando painéis de consumidores e painéis semi-treinados. Aplicaram-se diversas metodologias de avaliação sensorial recorrendo a testes de ordenação e a testes descritivos. A formulação final selecionada foi submetida a caracterização sensorial (análise descritiva), físico-química (teor de sal, humidade, cinzas, gordura, proteína, fibra, aw) e microbiológica (contagem de bactérias láticas, microrganismos a 30 °C, leveduras e bolores, Enterobactérias e pesquisa de Salmonella spp. e Listeria monocytogenes). A azeitona em salmoura e o tremoço também foram caracterizados. Numa primeira etapa, um painel de 60 consumidores avaliou pastas de azeitona e tremoço e pastas só de tremoço, constatando-se uma preferência pela pasta com os dois ingredientes. Seguidamente, prepararam-se formulações com diferentes proporções de tremoço que foram objeto de geração de descritores por um painel de provadores semi-treinados; este painel também preferiu a formulação inicialmente selecionada pelos consumidores. Eleita a formulação base, adicionaram-se oito aromas (alho, caranguejo, cebola, limão, louro, orégão, pimento vermelho e tomilho) e foram realizadas duas sessões de análise descritiva utilizando a folha de perfil construída com os descritores selecionados anteriormente. A formulação final, a pasta de azeitona e tremoço com aroma a alho, foi a preferida por um painel de 104 consumidores. A caracterização físico-química desta pasta mostra um produto com boas características nutricionais relativamente aos teores de fibra, proteína e de sal, o que pode representar uma vantagem relativamente a outros existentes no mercado. As matérias-primas e as pastas revelaram qualidade microbiológica satisfatória, refletindo a qualidade da matéria-prima e as boas práticas de produção.
- Essential oils of Lavandula stoechas subsp. luisieri as antifungal agent against fungi from strawberry tree fruitPublication . Domingues, Joana Lopes; Delgado, F.M.G.; Gonçalves, José Carlos; Pintado, Cristina SantosEssential oils of Lavandula stoechas subsp. luisieri as antifungal agent against fungi from strawberry tree fruit
- Essential oils of Lavandula stoechas subsp. luisieri as antifungal agent against fungi from strawberry tree fruitPublication . Domingues, Joana Lopes; Delgado, F.M.G.; Gonçalves, José Carlos; Pintado, Cristina SantosL. stoechas subsp. luisieri is one of the five spontaneous species of the genus Lavandula that occurs spontaneously in Portugal. The chemical profile and antifungal activity of L. stoechas subsp. luisieri essential oils were investigated. The essential oil of two phenological stages was isolated by hydrodistillation and their chemical components analyzed by GC-FID/GC-MS. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of both essential oils were determinate to verify antifungal activity against different strains of fungi isolated from strawberry tree. The fungi tested were Aspergillus carbonarius, Rhizopus stolonifer, Penicillium brevicompactum, Aureobasidium pullulans and Saccothecium rubi. Essential oils were characterized by a high percentage of oxygenated monoterpenes (46-64%) such as trans-α-necrodyl acetate (12.58%), fenchone (5.97%), 1,8-cineole (4.84%) and 5-methylene-2,3,4,4-tetramethylcyclopenten-2-enone (10.97%) were the major compounds in essential oil from dormancy stage, while the main compounds in flowering stage were trans-α-necrodyl acetate (26.90%), trans-α-necrodol (13.02%), lavandulyl acetate (6.53%) and linalool (5.82%). A strong antifungal activity of the essential oils was found against all strains, with MIC and MFC values ranged from 0.07-0.29 µL/mL and 0.58-9.33 µL/mL, respectively.
- Essential oils of two portuguese endemic species of lavandula as a source of antifungal and antibacterial agentsPublication . Domingues, Joana Lopes; Goulão, Manuela; Delgado, F.M.G.; Gonçalves, José Carlos; Gonçalves, Joana; Pintado, Cristina SantosChemical investigations of L. stoechas subsp. luisieri and L. pedunculata essential oils were analyzed by GC-MS, and the antimicrobial activity was performed against bacteria and fungi isolated from food sources. The cytotoxicity of the essential oil was performed in NHDF cells using the MTT method. According to the results, the main compounds of L. stoechas subsp. luisieri essential oil were trans-α-necrodyl acetate (40.2%), lavandulyl acetate (11%), and trans-α-necrodol (10.4%), while fenchone (50.5%) and camphor (30.0%) in L. pedunculata essential oil. The antifungal activity of essential oils was confirmed with MIC values ranging from 1.2 to 18.7 µL/mL; for bacteria, it ranged from 4.7 to 149.3 µL/mL. Both the Lavandula species tested showed low or equal MIC and MBC/MFC values for L. stoechas subsp. luisieri essential oil, revealing greater efficacy in antimicrobial activity. The L. stoechas subsp. luisieri essential oil revealed cytotoxic effects (30 ± 2% of cell viability) in NHDF cells at all concentrations tested.
- Evaluation of bioactive coatings in post-harvest physical and mechanical properties of cherriesPublication . Domingues, Joana Lopes; Soares, Henrique; Delgado, F.M.G.In the Beira Interior region, cherry production is one of the most representative crops, revealing a high economic value for the region. The cherry, being a seasonal fruit, has great temporal demand, not only due to its nutritional properties but also highly appreciated for its flavor and texture. However, it is a very perishable fruit, and immediately after harvesting, it must be kept at low temperatures and high relative humidity. In an attempt to avoid this degradation, in recent years, there has been the development of edible coatings/films with bioactive properties to extend the shelf life of foods, namely perishable fruits.
- In vitro propagation and conservation of Lavandula stoechas subsp. luisieri and Pterospartum tridentatum: two important medicinal and aromatic species from PortugalPublication . Domingues, Joana Lopes; Eira, Anabela; Ramalho, Isa; Barrocas, Inês; Gonçalves, José CarlosLavandula stoechas subsp. luisieri and Pterospartum tridentatum are two valuable aromatic and medicinal plants. Their biometric and morphological parameters, such as the number of new shoots, length of the longest shoot, multiplication rate, and fresh weight, were evaluated using the multiplication MS medium protocol. The rooting protocols involved immersing the explants in IBA (1 g L−1) and a commercial IBA (3.3 g L−1) preparation (Clonex®). Slow-growth conservation assays were carried out using two different sucrose concentrations (15 g L−1 and 30 g L−1), and a control, with the cultures kept at 4 °C for 12 months. The multiplication rate for L. stoechas subsp. luisieri was 6.8, and that of P. tridentatum was 13.3, achieved using the MS medium supplemented with 0.2 mg L−1 BAP, 1 mg L−1 BAP, and 0.5 mg L−1 IBA. The application of Clonex® showed the best ex vitro rooting results in L. stoechas subsp. luisieri (77%) and P. tridentatum (90%). In the slow-growth conservation assays, at 4 °C, in darkness for 12 months, an excellent survival rate was achieved in L. stoechas subsp. luisieri (>80%) and P. tridentatum (>90%), even at the reduced sucrose concentration. This study demonstrates the effectiveness of in vitro multiplication and ex vitro rooting protocols for two valuable aromatic and medicinal plants. These findings are significant for the ex situ conservation of these species, as they provide effective long-term preservation and utilization strategies.
- Lavandula spp. secção Stoechas : contribuição para a sua identificação na região da Beira BaixaPublication . Domingues, Joana Lopes; Barroca, Celina; Coelho, Maria Teresa; Lourenço, Catarina; Gonçalves, José Carlos; Delgado, F.M.G.; APH - Associação Portuguesa de HorticulturaEm Portugal, crescem espontaneamente espécies de Lavandula da secção Stoechas Ging. Estas espécies são consideradas Plantas Aromáticas e Medicinais (PAM) devido à produção de metabolitos secundários com propriedades terapêuticas e aromáticas. Devido ao seu elevado polimorfismo e capacidade de hibridação na natureza, torna-se importante o conhecimento e distinção entre as espécies e subespécies. Apesar de alguns dos constituintes químicos serem compartilhados entre estas espécies, a presença de outros e respetivas concentrações são exclusivas de cada uma e, por conseguinte, a sua aplicação e uso também deve ser diferenciado. De forma a contribuir para a diferenciação entre espécies e subespécies de Lavandula que crescem na região da Beira Baixa (BB) recorreu-se aos referenciais morfológicos de Portugal e Península Ibérica. Através da análise destes referenciais, pode-se concluir que existem alguns parâmetros morfológicos destacados e/ou diferenciadores entre espécies e subespécies, salientando-se o tamanho do pedúnculo e espiga e respetiva relação, o tamanho das brácteas inférteis e a forma das brácteas férteis. Neste trabalho, são apresentados os resultados da observação da maioria dos parâmetros diferenciadores, em 80 plantas recolhidas na região da BB. De acordo com os resultados, entre as subespécies, a maioria dos parâmetros são redundantes e comuns, pelo que a análise morfológica externa da planta não demonstrou ser suficiente para distinguir as subespécies. Considerando a evolução natural das espécies e polimorfismo, a integração de outros tipos de análises, como a análise dos constituintes químicos e/ou estudos genéticos, tornam-se importantes para a diferenciação das subespécies.
- Mediterranean lavenders from section stoechas : an undervalued source of secondary metabolites with pharmacological potentialPublication . Domingues, Joana Lopes; Delgado, F.M.G.; Gonçalves, José Carlos; Zuzarte, Mónica; Duarte, Ana PaulaGlobally, climate change and wildfires are disrupting natural ecosystems, thus setting several endemic species at risk. The genus Lavandula is widely present in the Mediterranean region and its species, namely, those included in the section Stoechas, are valuable resources of active compounds with several biological assets. Since ancient times lavenders have been used in traditional medicine and for domestic purposes. These species are melliferous, decorative, and essential oilproducing plants with a high economic interest in the pharmaceutical, flavor, fragrance, and food industries. The essential oils of Lavandula section Stoechas are characterized by high amounts of 1,8-cineole, camphor, fenchone, and specifically for L. stoechas subsp. luisieri one of the major compounds is trans-α-necrodyl acetate. On the other hand, the diversity of non-volatile components like phenolic compounds, such as phenolic acids and flavonoids, make these species an important source of phytochemicals with pharmacological interest. Rosmarinic, caffeic, and salvianolic B acids are the major phenolic acids, and luteolin and eriodictyol-O-glucuronide are the main reported flavonoids. However, the concentration of these secondary metabolites is strongly affected by the plant’s phenological phase and varies in Lavandula sp. from different areas of origin. Indeed, lavender extracts have shown promising antioxidant, antimicrobial, anti-inflammatory, and anticancer properties as well as several other beneficial actions with potential for commercial applications. Despite several studies on the bioactive potential of lavenders from the section Stoechas, a systematized and updated review of their chemical profile is lacking. Therefore, we carried out the present review that gathers relevant information on the different types of secondary metabolites found in these species as well as their bioactive potential.