Percorrer por autor "Pais, Adriana C. S."
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- Chemical and bioactivity profiling of the invasive macroalga rugulopteryx okamurae collected in southern Portugal supporting biotechnological valorisation approachesPublication . D’Unienville, Amandine; Lasnel, Lucas; Macquigneau, Wadi; Trentin, Riccardo; Pais, Adriana C. S.; Rodrigues, Maria João; Santos, Sónia A. O.; Custódio, LuísaThe invasive brown macroalga Rugulopteryx okamurae has rapidly expanded across the Mediterranean–Atlantic region, generating severe ecological impacts. Nevertheless, the considerable amount of biomass available creates opportunities for valorisation within circular bioeconomy frameworks. This study provides an integrated characterization of the chemical profile and bioactivities of freshly collected floating biomass of R. okamurae from southern Portugal. Proximate composition was determined, and lipophilic (hexane) and hydrophilic (water) extracts were analyzed by GC–MS and spectrophotometric methods. Antioxidant activity was assessed using complementary radical-scavenging, reducing power, and metal-chelation assays, and enzyme inhibition was evaluated against targets associated with neurodegenerative, metabolic, and dermatological disorders. The lipophilic fraction was dominated by long-chain alkanes (≈101 mg/g extract) and sterols, particularly fucosterol (≈43 mg/g extract), but exhibited low radical-scavenging capacity (no EC50 reached in DPPH or ABTS assays), and no relevant enzyme inhibition. In contrast, the water extract contained measurable phlorotannins (6.61 mg PGE/g extract) and showed moderate antioxidant (ABTS: EC50 = 5.17 mg/mL; FRAP: EC50 = 0.78 mg/mL) and enzyme inhibition activities (BChE: IC50 = 5.17 mg/mL; tyrosinase: IC50 = 0.78 mg/mL). Compared with previous studies on R. okamurae, this work applies a systematic fractionation of biomass from southern Portugal into polar and non-polar fractions and, for the first time, correlates the resulting detailed chemical profiles with multiple bioactivities. This approach revealed a clear functional differentiation between fractions, with bioactivity being mainly associated with polar metabolites. Overall, these findings highlight the value of structured extraction strategies for biomass valorisation and support the sustainable management of R. okamurae.
- Polar lipids of commercial Ulva spp. of different origins: profiling and relevance for seaweed valorizationPublication . Moreira, Ana S. P.; da Costa, Elisabete; Melo, Tânia; Lopes, Diana; Pais, Adriana C. S.; Santos, Sónia A. O.; Pitarma, Bárbara; Mendes, Madalena; Abreu, Maria H.; Collén, Pi Nyvall; Domingues, Pedro; Domingues, M. RosárioMacroalgae of the genus Ulva have long been used as human food. Local environmental conditions, among other factors, can have an impact on their nutrient and phytochemical composition, as well as on the value of the seaweed for food and non-food applications. This study is the first to initiate a comparison between commercial Ulva spp. from different European origins, France (FR, wild-harvested Ulva spp.), and Portugal (PT, farm-raised Ulva rigida), in terms of proximate composition, esterified fatty acids (FA), and polar lipids. The ash content was higher in PT samples, while FR samples had higher levels of proteins, lipids, and carbohydrates and other compounds. The profile of esterified FA, as well as FA-containing polar lipids at the class and species levels were also significantly different. The FR samples showed about three-fold higher amount of n-3 polyunsaturated FA, while PT samples showed two-fold higher content of monounsaturated FA. Quantification of glycolipids and phospholipids revealed, respectively, two-fold and three-fold higher levels in PT samples. Despite the differences found, the polar lipids identified in both batches included some lipid species with recognized bioactivity, valuing Ulva biomass with functional properties, increasing their added value, and promoting new applications, namely in nutraceutical and food markets.