MARE - Comunicações em conferência com publicação em atas
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Browsing MARE - Comunicações em conferência com publicação em atas 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
- 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.
- Producing cyanobacteria to use as biostimulantsPublication . Mouga, Teresa; Simões, Fátima; Moreira, Vitória; Martins, Alice; Ferreira, Carolina; Ramos, Rute; Afonso, CléliaBy 2050, the world’s population will reach about 10 billion people, which will the need for food by about 60% more than is available today. To meet this need, new processes are emerging to allow more efficient and sustainable intensification of agriculture. In this context, the use of biostimulants has received increasing attention, due to their ability to improve plant quality and yield, stress tolerance, and/or improve the availability of nutrients in the soil. When it comes to Cyanobacteria, the preferred ones are N2-fixing species, which increase organic nitrogen in the soil, and produce hygroscopic exopolysaccharides, which alter the distribution of water by reducing soil hydrophobicity. Therefore, they decrease soil evaporation and retain moisture, improving soil stability. Wild strains of filamentous N2 fixing Nostoc 135, Nostoc 136, Nostoc 137, and Anabaena 4, provided by Alga2O Lda., were grown in the laboratory with the aim of selecting those that presented the necessary physiological characteristics to be efficiently grown in the laboratory. Therefore, the growth rate, productivity, and exopolysaccharides (EPS) contents were analysed. The EPS obtained from each strain culture (3% g/L) was applied to lettuce seeds (Lactuca sativa), to determine the germination rate, primary root length and number of primary leaves produced. As confirmed by other authors, Cyanobacteria are interesting biostimulants regarding germination rates. Other effects to be tested in the future are heat and drought tolerance, water, nutrients, essential oil, and pigment content, all of which are positive aspects that have been previously reported for other Nostoc and Anabaena species.
- 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.