Browsing by Author "Prieto, Miguel A."
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- Exploring the potential of invasive species Sargassum muticum: microwave-assisted extraction optimization and bioactivity profilingPublication . Silva, Aurora; Cassani, Lucia; Carpena, Maria; Lourenço-Lopes, Catarina; Grosso, Clara; Chamorro, Franklin; García-Pérez, Pascual; Carvalho, Ana; Domingues, Valentina F.; Barroso, M. Fátima; Simal-Gandara, Jesus; Prieto, Miguel A.Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and β-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger.
- Lemna minor: unlocking the value of this duckweed for the food and feed industryPublication . Sosa, Diana; Alves, Felipe M.; Prieto, Miguel A.; Pedrosa, Mariana C.; Heleno, Sandrina A.; Barros, Lillian; Feliciano, Manuel; Carocho, MárcioDuckweed (Lemna minor L.) is a small floating aquatic plant that has an important economic impact in several industrial areas. With its high biomass production, reasonable protein content, and resilience to several climates, it has been attracting increasing interest for potential use in animal and human food systems. Historically consumed in southwest Asia, this duckweed is now gaining attention as a potential novel food in Europe. This manuscript explores the contributions of duckweed to various food and feed industries, including aquaculture and livestock, while also pointing out the incipient research carried out for human consumption. Most importantly, it highlights the potential of Lemna minor as a vegetable for future human consumption whether eaten whole or through extraction of its nutrients.
- Screening of bioactive properties in brown algae from the Northwest Iberian PeninsulaPublication . Silva, Aurora; Rodrigues, Carla; Garcia-Oliveira, Paula; Lourenco-Lopes, Catarina; Silva, Sofia A.; Garcia-Perez, Pascual; Carvalho, Ana P.; Domingues, Valentina F.; Barroso, M. Fátima; Delerue-Matos, Cristina; Simal-Gandara, Jesus; Prieto, Miguel A.Algae are an underexploited source of natural bioactive compounds in Western countries, so an increasing interest in the valorization of these marine organisms has emerged in recent years. In this work, the effect of extracting solvent on the extraction yield, phenolic content, antioxidant capacity, and antimicrobial activity of nine brown macroalgae species (Ascophyllum nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissima, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum, and Fucus spiralis) was assessed. Total phenolic content (TPC) and the antioxidant properties of extracts by different assays: radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) were performed. The antimicrobial activity of extracts was studied against six different foodborne microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa. The highest extraction yield was achieved in ethanolic extracts. However, the highest TPC and FRAP values were obtained on the ethyl acetate extracts, especially from A. nodosum. Concerning algal species, the highest TPC and FRAP values were found in A. nodosum, while the highest DPPH-RSA values were achieved in the hexane extracts of B. bifurcata. The antimicrobial activity of algal extracts varied according to the solvent and alga selected, suggesting the species- and solvent-dependent behavior of this property, with B. bifurcata extracts showing the highest results for a wide range of bacteria. Our results provide insight on the characterization of widespread brown algae in the coasts of the North-Western region of the Iberian Peninsula, reflecting multiple health-enhancing properties which may lead to their exploitation in food, pharmacological, and cosmetic industries.
- Supercritical fluid extraction of polyphenols from almond oil industry by-products: evaluating bioaccessibility and bioavailability through in vitro digestionPublication . Spréa, Rafael Mascoloti; Rodrigues, Daniele B.; Brassesco, María E.; Pintado, Manuela; Santoyo, Susana; Arranz, Elena; Prieto, Miguel A.; Amaral, Joana S.; Barros, LillianSupercritical fluid extraction (SFE) has emerged as an advanced green technology for the recovery of bioactive compounds, offering enhanced extraction efficiency while eliminating the need for toxic organic solvents. In this context, industrial residues from almond oil production were subjected to CO? SFE by ISANATUR (Navarra, Spain), a company specializing in by- product valorization. Specifically, almond press cake (APBF+) from cold press extraction was submitted to SFE using 20 MPa and 24 MPa for further oil extraction, yielding two additional by- products (APBF20 and APBF24, respectively). Given the potential application of these by-products (APBF+, APBF20 and APBF24) in functional food formulations and nutraceuticals, this study aimed to assess and compare the bioaccessibility of polyphenols following in vitro gastrointestinal digestion. The samples were digested using the standardized INFOGEST 2.0 static protocol. Polyphenolic compounds and their bioaccessible fraction (post-dialysis) were characterized by HPLC-DAD-ESI-MS. Additionally, both non-digested and digested samples were evaluated for their antioxidant capacity using DPPH and TBARS assays. The prebiotic potential of the non-bioaccessible fraction was assessed in vitro using three Lactobacillus and one Bifidobacterium strains. Finally, the bioaccessible fraction was subjected to Caco-2 cell transport assays to evaluate intestinal permeability. A total of 22 polyphenols were identified in all almond by-products with the SFE-treated samples exhibiting only around 10% loss of polyphenols. After digestion, an average of 64% of total polyphenols in APBF+ remained bioaccessible. Notably, SFE-treated samples exhibited enhanced polyphenol bioaccessibility, reaching 73% and 72% for APBF20 and APBF24, respectively. Interestingly, the digested extracts exhibited a reduction in EC?? values in both antioxidant assays, indicating enhanced antioxidant capacity after in vitro digestion. Both non- digested and digested samples showed prebiotic activity, yielding higher optical density values compared to the positive control (fructooligosaccharides), which suggests that the digested almond by-products can promote gut health. This work shows that SFE by-products retain a high content of polyphenols, with high bioaccessibility and antioxidant activity after in vitro digestion, thus reinforcing the potential of almond by-products as sustainable sources of functional ingredients for the food and nutraceutical industries.