ESTM - Comunicações em conferências e congressos internacionais
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Browsing ESTM - Comunicações em conferências e congressos internacionais by Author "Afonso, Clélia"
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- Effect of different drying temperatures on the moisture, content of phytochemical constituents and technological properties of Peniche coast seaweedsPublication . Augusto, Ana; Nunes, Paulo M.; Mendes, Susana; Afonso, Clélia; Mouga, Teresa
- Effects of different drying conditions on the rehydration ratio and water holding capacity properties in three different species of algae Ulva lactuca, Codium vermilara and Codium tomentosumPublication . Rodrigues, Sidónio; Afonso, Clélia; Mouga, Teresa; Nunes, PauloOver the last years, algae have been increasingly used in Human food due their rich chemical and nutritional composition, particularly the high supply of essential nutrients to the human body such as protein and dietary fiber. Dietary fiber can be divided into two different types: soluble and insoluble. The characteristics of soluble dietary fiber are related to some physical and chemical properties such as rehydration ratio and water holding capacity and are important in assigning the functional and organoleptic properties and in preventing some human pathologies such as cardiovascular disease and obesity. The present study aimed to investigate the influence of different drying conditions on the rehydration ratio and water holding capacity of three green algae, Codium vermilara, Codium tomentosum and Ulva lactuca. The methods used for the determination of water retention capacity and rehydration ratio were similar to those used in previous studies (Susuki, T. et al., 1996). The algae were processed in a tray dryer and the drying conditions were: Temperature: 30ºC and 40ºC; Relative Humidity: 28%47% ; air velocity 1,9 m/s. In this work, it was concluded that higher drying temperature conditions originate lower rehydration ratio and consequent lower water holding capacity possibly due to a higher physical damage in the algae tissues. It was also observed that both Codium species have higher values for these two parameters than Ulva lactuca, under the same rehydration conditions.
- Environmental limits of low salinity to Gracilaria gracilis development. Where do we draw the line?Publication . França, Marcela; Afonso, Clélia; Baptista, Teresa; Pombo, Ana; Mouga, Teresa
- Essential oil of two plant species from Peniche coast Crithmum maritimum l. and Juniperus phoenicea subsp. turbinata (Guss. parl.): assessment of antimicrobial and antioxidant activitiesPublication . Santos, Gabriela; Ferreira, Carla; Cabral, Célia; Mouga, Teresa; Afonso, Clélia
- Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal): antimicrobial and antioxidant activityPublication . Pena, Carlos; Mouga, Teresa; Sampaio, Maria Manuel; Afonso, CléliaCoastal areas are highly complex and dynamic ecosystem of interface between land, sea and atmosphere, which also suffer biotic influences. These areas play several important ecological functions, and here we can find an enormous biodiversity. The coastline of Portugal features a high number of endemic flora and vegetation with the potential to provide functional compounds that may provide physiological benefits at nutritional and therapeutic levels, as sources of bioactive substances with antimicrobial, antioxidant, antifungal, antitumalr and antiinflammatory activity. Among these compounds, we find essential oils, also known as volatile oils, which are a result of secondary metabolism of aromatic plants, containing a large number of substances with varied chemical composition that can be obtained by different methods of extraction. The aim of this study was to extract essential oils of native plants and seaweeds from the coast of Peniche by hydrodistillation in Clevenger apparatus, with optimization of the purification process. Extracted essential oils were tested as to their ability as antibacterial and antifungal agents, and also as antioxidants. The plants studied for this purpose were Inula chritmoides L., Juniperus phoenicea subsp. turbinata (Guss.) Nyman, Daucus carota spp. halophilus and the seaweeds Fucus spiralis L., Codium tomentosum Stackhouse, Stypocaulon scoparium (Linnaeus) Kützing and Plocamium cartilagineum (Linnaeus) P.S.Dixon. The antimicrobial ability was tested in two bacteria species, Bacillus subtilis and Escherichia coli and in the yeast Saccharomyces cerevisiae, using standard procedures. The antioxidant potential was evaluated and from the results obtained, we can conclude that the essential oils extracted by the hydrodistillation method of plants and algae contain bioactive compounds present in its constitution with interesting bioactivity that can offer significant benefits and biotechnological relevance.
- Growth of Arthrospira platensis under laboratory and outdoor conditions: assessment of the effects of light and different nutrient mediaPublication . Carneiro, João; Gomes, Sílvia; Freitas, Marta; Afonso, Clélia; Mouga, Teresa
- In-vitro setting and multiplication of Pulicaria microcephala, an endemic species from Berlengas IslandPublication . Franco, Inês; Mouga, Teresa; Afonso, Clélia
- New applications for Gelidium corneum: Antimicrobial and antioxidant activity within a biorefinery conceptPublication . Mouga, Teresa; Cavaco, Mário; Duarte, Adriana; Correia, Ana Patrícia; Freitas, Marta V.; Bernardino, Susana; Afonso, CléliaThere are more than four hundred endogenous seaweeds that occur in Portugal, and red seaweeds (Rhodophyta) are the most abundant. Among these, Gelidium corneum, common in the Atlantic coast of Portugal, is currently being collected in the wild, in S. Martinho do Porto, exclusively for the extraction of agar. During the summer season this species is harvested from the bottom of the ocean, dried and sold, representing an important economic local activity. Yet, besides agar, this species is important for its bioactivities, namely for its antioxidant and antimicrobial capacities, thus most of the biomass is currently being disregarded as an important marine resource. Therefore, to further research the potential of G. corneum as a source of bioactive compounds, the biomass was seasonally harvested and characterized (protein, ash, moisture), and different extract were made (aqueous and ethanolic). These extracts were analyzed for the antioxidant potential (DDPH, ABTS, TPC and FRAP), and for antimicrobial capacity (against Escherichia coli, Bacillus subtilis, Candida albicans, Saccharomyces cerevisiae and Staphylococcus epidermidis). Preliminary results show that there are seasonal variations in the chemical composition of the biomass. Extracts tested also show interesting free radical scavenging capacity and antimicrobial activity against some of the strains tested. The attained results demonstrate that the biorefinery concept should be implemented to the agar industry, valuing the seaweeds’ biomass so to allow its use in other industries, such as textiles or cosmetics.
- Sustainable use of seaweeds from S. Martinho do Porto, Portugal - past, present and future perspectivePublication . Cavaco, Mário; Duarte, Adriana; Bernardino, Susana; Afonso, Clélia; Mouga, Teresa; J. R. da Costa Sanches GalvãoSeaweeds have long been used by populations on the coast of Portugal as fertilizers or food during periods of scarcity. Both uses have decreased dramatically since the introduction of chemical fertilizers and horticulture food. Even so, in the past decades, globalization has brought new interest to the consumption of these organisms, raising interest on algae as a healthy and tasty food. Much scientific research is underway on the properties of seaweeds, and it is proven that past uses are well-founded. S. Martinho do Porto, in the Centre of Portugal is the only location where the commercial harvesting of seaweeds still takes place. Gelidium corneum is harvested because this species produces high-quality agar, a much sought-after phycocolloid, which is used in the food industry as gelling or thickening agent. However, the species shows other properties that have been disregarded by the seaweeds’ industry. There are also some invasive species, namely Asparagopsis armata, which is causing considerable ecological problems to local ecosystems. Thus, the Mar2020 project Limo do Cais was approved to study the sustainable use the algal biomass from S. Martinho do Porto taking into account its industrial potential. In this way, the properties of G. corneum are being studied, to increase its commercial value. As to A. armata, it shows important antimicrobial properties that are being studied aiming the use of the algal biomass in the pharmaceutical industry. Thus, past uses of seaweeds will be discussed, as well as new potential uses that scientific research has uncovered.
- The vegetation of Berlengas’ island: an attempt to promote the recovery of Armeria berlenguensis (Plumbaginaceae)Publication . Mendes, Susana; Franco, Inês; Fagundes, Isabel; Oliveira, Nuno; Crisóstomo, Paulo; Morais, Lurdes; Afonso, Clélia; Mouga, Teresa