Browsing by Author "Pereira, Leonel"
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- Antioxidant and antimicrobial properties of selected red seaweeds from Central PortugalPublication . Freitas, Marta V.; Inácio, Leonardo G.; Ruas, Ana; Silva, Isabela A.; Mouga, Teresa; Pereira, Leonel; Afonso, CléliaThroughout the ages, macroalgae have provided humankind with elements beneficial to human health, and often with bioactive abilities. Yet, while today we fully acknowledge such potential, especially that of the most widely known species, an even greater number of species remain unaknowledged. This holds particularly true for the highly diverse phylum Rhodophyta (red seaweeds) and, therefore, the present study aims to unveil the antioxidant and the antimicrobial potential of twelve red seaweed species collected in central Portugal. Results obtained from the antioxidant assays ABTS and TPC highlighted the high scavenging capacity of the coralline algae Corallina officinalis, Ellisolandia elongata and Amphiroa rigida, and the high phenolic content of Porphyra umbilicalis, whereas the antimicrobial analyses through MIC determination emphasized the activities of Sphaerococcus coronopifolius and Mesophyllum lichenoides against, respectively, Bacillus subtilis and Saccharomyces cerevisiae. This study raised awareness of the bioactive potential waiting to be discovered regarding less known Rhodophyta species, such as Amphiroa rigida and Mesophyllum lichenoides. Therefore, we believe this study provides extra steps in pinpointing Rhodophyta species with bioactive potential, encouraging further studies tailored toward a biotechnological perspective, and, ultimately, influencing current perspectives regarding the exploration of seaweeds.
- Antioxidant and antitumor potential of wild and IMTA-cultivated Osmundea pinnatifidaPublication . Silva, J. Paulo; Alves, Celso; Pinteus, Susete; Silva, Joana; Valado, Ana; Pedrosa, Rui; Pereira, LeonelOsmundea pinnatifida is a red edible seaweed known as pepper dulse. O. pinnatifida was cultivated in the farm of ALGAplus (Ílhavo, Portugal). This farm is integrated with a seabream and seabass commercial aquaculture and uses the nutrient-enriched water resultant from the fish production as its cultivation medium in the integrated multi-trophic aquaculture (IMTA) manner. Wild and IMTA-cultivated samples of O. pinnatifida were screened for antioxidant and antitumor activities. The antioxidant capacity of solvent extracts from wild and IMTA cultivated samples was assessed in two methods (2,2-diphenyl- 1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC)), and their total phenolic contents (TPC) were estimated. Antitumor activity was evaluated in three different tumor cell lines (HepG- 2, MCF-7, and SH-SY5Y) through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among the solvents used for extraction, dichloromethane was the most effective to extract phenolic compounds and presented higher ORAC. A significant correlation was found between TPC and ORAC, which was also sustained by the principal components analysis (PCA). Dichloromethane extracts induced a cytostatic effect on MCF-7 cells and showed weak cytotoxicity to SH-SY5Y cells and weak impact on cell proliferation. Overall, there were no statistically signifi cant diff erences in the biological activities shown by the wild and IMTA-cultivated samples. Hence, O. pinnatifida can be obtained in an economical and environmentally sustainable way through IMTA, maintaining bioactive properties in a high potential for further nutraceutical purposes.
- Different Chondrus crispus aquaculture methods and carrageenan extractionPublication . Tanoeiro, João Rui; Fortunato, Duarte; Cotas, João; Morais, Tiago; Afonso, Clélia; Pereira, LeonelWith the notable scarcity of Chondrus crispus on the Portuguese coast, and interest in exploiting compounds such as carrageenan, this study focuses on investigating different aquaculture methods and recording the yield of carrageenan from specimens grown by different methods. We compare the growth of Chondrus crispus in aquaculture using Free Floating, Cages, Attempted Fixation on Rock, and Fixed Line similar to Long Line. The best method was Free Floating where Nursery 0 had a 24-day Specific Growth Rate (SGR) of 2.08 ± 0.47%/day. The worst method in terms of growth was Nursery 2 (Attempted Fixation on Rock) where the SGR at 28 days was 0.33 ± 0.69%/day, and no fixation was observed. In terms of carrageenan extraction, all culture methods gave rise to biomass that had a lower extraction yield than wild specimens, at 50.95 ± 4.10%. However, the Free-Floating method from Nursery 1 showed an acceptable carrageenan content (31.43 ± 7.00%). Therefore, we demonstrate that the concept of C. crispus cultivation may be key to promoting the sustainability and stability of this species.
- Mapping invasive macroalgae in the Western Iberian Peninsula: a methodological guidePublication . Blanco, A.; Lemos, Marco F.L.; Pereira, Leonel; Gaspar, Rui; Mouga, Teresa; Neto, João M.; Troncoso, J. S.; Olabarria, Celia
- Primary composition and pigments of 11 red seaweed species from the Center of PortugalPublication . Freitas, Marta; Inácio, Leonardo G.; Martins, Mendelson; Afonso, Clélia; Pereira, Leonel; Mouga, TeresaMacroalgae have been regarded as a natural food source since ancient times, their nutritional value being not only proven by recent studies, but also triggering further in-depth research efforts on the matter. The present study aims to provide an insight into the nutritional potential of selected red seaweed species collected in central Portugal by specifically comparing the moist yield and ash content, crude protein, total lipids, carbohydrates and pigment content between species and, ultimately, finding out if there are differences between taxa. The results obtained highlighted the most nutritionally appealing species, namely, Plocamium cartilagineum with respect to protein content (23.18% dw) and Sphaerocococcus coronopifolius with respect to carbohydrate content (40.23% dw), while none of the species studied showed a lipid content higher than 1.80% dw. Regarding pigment content, the highest concentrations of phycoerythrin, carotenoid and chlorophyll a were obtained, respectively, from P. cartilagineum (0.09 mg.mL−1), Porphyra umbilicalis (1.88 µg.g−1 fw) and Jania rubens (38.41 µg.mL−1). We concluded that there are significant differences between the species studied regarding their nutritional profile, with a marked difference between Corallinales and all other species not belonging to this order; regarding pigment content, this variation between orders was not observed. Nevertheless, all the studied species may act as promising complements in a human healthy diet.
- Red seaweed pigments from a biotechnological perspectivePublication . Freitas, Marta V.; Pacheco, Diana; Cotas, João; Mouga, Teresa; Afonso, Clélia; Pereira, LeonelAlgae taxa are notably diverse regarding pigment diversity and composition, red seaweeds (Rhodophyta) being a valuable source of phycobiliproteins (phycoerythrins, phycocyanin, and allophycocyanin), carotenes (carotenoids and xanthophylls), and chlorophyll a. These pigments have a considerable biotechnological potential, which has been translated into several registered patents and commercial applications. However, challenges remain regarding the optimization and subsequent scale-up of extraction and purification methodologies, especially when considering the quality and quantity needs, from an industrial and commercial point of view. This review aims to provide the state-of-the-art information on each of the aforementioned groups of pigments that can be found within Rhodophyta. An outline of the chemical biodiversity within pigment groups, current extraction and purification methodologies and challenges, and an overview of commercially available products and registered patents, will be provided. Thus, the current biotechnological applications of red seaweeds pigments will be highlighted, from a sustainable and economical perspective, as well as their integration in the Blue Economy.
- Sabores do mar: algas edíveis do centro de PortugalPublication . Freitas, Marta v.; Pereira, Leonel; Afonso, Clélia; Mouga, TeresaDescrição das espécies alimentares da zona centro de Portugal
- Sabores do mar: algas edíveis do centro de PortugalPublication . Freitas, Marta; Pereira, Leonel; Afonso, Clélia; Mouga, Teresa
- Seasonal nutritional profile of Gelidium corneum (Rhodophyta, Gelidiaceae) from the center of PortugalPublication . Cavaco, Mário; Duarte, Adriana; Freitas, Marta; Afonso, Clélia; Bernardino, Susana M.; Pereira, Leonel; Martins, Mendelson; Mouga, TeresaGelidium corneum is a well-known agarophyte, harvested worldwide for its high agar quality. However, the species also exhibits an interesting nutritional profile, but with seasonal variations. Therefore, to evaluate the nutritional value of G. corneum, ash, crude protein, total lipids, and carbohydrates were analyzed at different times of the year. The heavy metals mercury, arsenic, lead, cadmium, and tin, as well as iodine were also measured. Finally, the seasonal antioxidant capacity of G. corneum extracts was evaluated. Our results indicate that the biomass is rich in protein (up to 16.25 ± 0.33%) and carbohydrates (up to 39.5 ± 3.29%), and low in lipids (up to 2.75 ± 0.28%), and especially in the summer, the AI, TI indexes, n-6/n-3 and h/H ratios (0.93, 0.6, 0.88 and 1.08, respectively) are very interesting. None of the contaminants exceeded the legally established limits, and the iodine values were adequate for a healthy diet. Finally, the antioxidant capacity is fair, with the DPPH ≤ 10.89 ± 1.46%, and ABTS ≤ 13.90 ± 1.54% inhibition, FRAP ≤ 0.91 ± 0.22 AAE.g−1, and TPC ≤ 6.82 ± 0.26 GAE.g−1. The results show that G. corneum is an attractive resource, with potential use as food or as a food supplement.
- The Vibrant Spectra of the Oceans: Unravelling the Diversity, Functions, and Applications of Seaweed PigmentsPublication . Freitas, Marta V.; Afonso, Clélia; Pereira, Leonel; Mouga, Teresa; Trivedi, , Nitin; Reddy,, C. R. K.; Critchley,, Alan T.Seaweeds are photosynthetic organisms that harvest sunlight and convert it into essential energy through a highly effective biochemical process powered by light, which in turn is captured and directed to the reactive centers by pigments. Seaweed pigments are fundamental to the seaweed photosynthetic process and are also responsible for their current taxonomic classification into three distinct divisions. The Chlorophyta comprises the green seaweeds, which hold high levels of both chlorophyll a and b, along with lesser amounts of β-carotene and xanthophylls. The Ochrophyta integrates the brown seaweeds (class Phaeophyceae), which are particularly rich in the xanthophyll fucoxanthin, while also showing lower levels of other xanthophylls, chlorophyll a and c, and β-carotene. The Rhodophyta houses the red seaweeds, which are characterized by holding high levels of phycoerythrin, as well as lower quantities of phycocyanin, chlorophyll a, β-carotene, and xanthophylls. However, regardless of their designation, seaweed species exhibit a significant range of colors and hues that go beyond “green,” “brown,” and “red,” rendering them visually unique, due to the relative composition and abundance of each pigment within their living cells. Nowadays, science has unveiled not only the diversity of these pigments, but also their biological function. Targeted extraction methods and potential end-use applications for these pigments have been researched and developed, with the resulting product often designed to protect and promote human health. Today, humankind acknowledges the benefits of natural products obtained from the oceans, including those obtained from seaweed pigments. This chapter aims to supply insight on the diversity, functions, and applications of the pigments found in all the three divisions, thus contributing to a greater understanding of the benefits these functional molecules can provide to humanity.