Browsing by Author "Machado, Manuela"
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- Application of encapsulated tomato by-product extract as a colorant in mascarponePublication . Molina, Adriana K.; Leichtweis, Maria Gabriela; Machado, Manuela; Silva, Sara; Pintado, Manuela; Barreira, João C.M.; Dias, Maria Inês; Prieto Lage, Miguel A.; Barros, Lillian; Pereira, CarlaAgricultural by-products, often underutilized, represent a significant opportunity to obtain sustainable value-added products to develop new functional foods. In this context, the (typically discarded) aerial parts of tomato plants (Solanum lycopersicum L. var. cerasiforme), were studied as new sources of natural bioactive compounds, focusing the extraction and encapsulation (using spray drying with maltodextrin as the encapsulant) of chlorophylls. The encapsulated natural colorant was subsequently incorporated into mascarpone cheese to assess its stability and effect on nutritional and antioxidant properties. The obtained extracts were mainly characterized by high concentrations of bioactive compounds, particularly quercetin-3-O-deoxyhexoside (14.4 ± 0.3 mg/g). The colorant imparted a greener hue to the mascarpone (a* –6.0 ± 0.05 vs. –1.7 ± 0.05 in control, p < 0.001) and maintained antioxidant activity (OxHLIA EC₅₀ = 1440 ± 72 to 1166 ± 66 μg/mL, p = 0.030) without altering the nutritional profile (p > 0.05). Moreover, no cytotoxicity was observed, and the fatty acid composition remained unchanged. Accordingly, the studied encapsulated colorant might be used as a functional ingredient in other dairy products, imparting an attractive color while preserving nutritional integrity. In conclusion, the incorporation of TAPC is an effective strategy to enrich dairy products with natural pigments and bioactive compounds without compromising quality. Future research is needed to explore its application in other food matrices and assess long-term storage effects.
- Extraction of bioactive compounds from plants as promising agentes against SARS-CoV-2Publication . Pedrosa, Mariana C.; Rodrigues, Cláudia; Heleno, Sandrina A.; Carocho, Márcio; Abreu, Rui M.V.; Ribeiro, Tânia; Machado, Manuela; Pinto, Manuel M.; Simas, João P.; Pintado, Manuela; Barros, LillianSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pathogenic virus with high transmissibility and infectivity, which began to spread across the globe in late 2019, which soon became the COVID-19 pandemic, causing social and economic impacts. In response to this situation, the scientific community started the development of effective substances against this virus. Bioactive molecules present in plants, mainly phenolic compounds, are promising altematives to combat pathological disorders. Therefore, the objective of this work was to use the aqueous extract of a mountain plant as an antiviral substance to neutralize COVID-19. MaterialslMethods: The mountain plant extract was obtained by dynamic maceration in water for I hour (twice). Afier obtaining the extracts, they were evaluated for their phenolic profile by high performance líquid chromatography coupIed to a diode array detector and a mass spectrometer detector (HPLC-DAD-MS). Cytotoxicíty was determined by the sulphorhodamine B assay in Vero cells, as well as the evaluation ofthe antivíral activity. Results: Regarding the phenolic profile, the main compounds found were trigalloyl-HHDPglucoside; pentagalloyl glucose, quercetin 3-0-glucuronide and quercetin O-hexoside. The GI50 (concentration able to inhibit 50% of cell proliferation) and the MNCC (maximum concentration without toxicity) were between 100 and 180.3 J.lg/rnL and between 85 and 120 J.lg/rnL, respectively. The MNCC value was obtained considering the concentration that allowed 90% of celI proliferation of Vero cells. In relation to the viral activity screening, the results achieved for the viral titre were between 5000 and 9000 PFU/rnL, while for the antiviral activity ranged between 0.5 and 3.0 Mv, being the percentage ofreduction in a range of85-95 %. • Conclusion: The mountain plant extracts showed in its composition bioactive compounds and consistent results of antiviral activity. Moreover, it presents itself as a potential substance for protection applications against the COVID-19 virus. However, further studies in specific products are required for validation and implementation.
- Fortification of yogurt with Solanum melongena phenolic extract: Physicochemical stability, bioaccessibility, bioavailability, and antioxidant effectsPublication . Añibarro-Ortega, Mikel; Gómez-García, Ricardo; Machado, Manuela; Pereira, Alexis; Costa, Eduardo M.; Pintado, Manuela; Barros, Lillian; Pinela, JoséThis study investigated the impact of fortifying yogurt with Solanum melongena phenolic extract by assessing its physicochemical, biochemical, and antioxidant stability, including its behavior during in vitro simulated digestion. Fortification influenced the yogurt's pH, titratable acidity, and color, and improved its cohesiveness during shelf life. The fortified yogurt exhibited higher glucose levels and reduced lactic acid production compared to the control. During simulated digestion, the extract modulated alterations in the protein and fatty acid profiles of the yogurt. Among phenolic compounds, 3-O-caffeoylquinic acids exhibited good stability during the oral and gastric phases but decreased in the intestinal digest. Some antioxidant effects were enhanced during digestion, particularly against lipid peroxidation, but declined during storage. Furthermore, phenolic acids were absorbed in an in vitro Caco-2 cell model, supporting their bioavailability. Overall, yogurt fortification with S. melongena extract improved nutritional and functional properties, highlighting its potential as a sustainable functional food. Future studies should address sensory acceptance, safety aspects, and in vivo health outcomes.
- Phenolic Profile and Antioxidant and Biological Activities of Plant Extracts Rich in Hydrolyzable TanninsPublication . Melo, Adma N.F.; Afonso, Tiago B.; Pedrosa, Mariana C.; Carvalho, Marta; Rodrigues, Cláudia; Dias, Maria Inês; Ribeiro, Tânia; Machado, Manuela; Tavaria, Freni K.; Carocho, Márcio; Simas, João P.; Teixeira, Paula; Barros, Lillian; Pintado, ManuelaIn this work, hydroethanolic plant extracts (acorn husk, laurel, eucalyptus, and rockrose leaves) were screened for their content in condensed tannins (HPLC-DAD/MS), polyphenol content, antioxidant, antimicrobial, and antiviral activities, and lack of toxicity. The results showed the highest values of condensed tannins found for laurel and eucalyptus extracts, while the total phenolic content ranged within 204.54 ± 2.0/326 ± 7.0 (mg GAE/g extract), with the acorn husk extract presenting the highest content (p < 0.05). The extracts showed good antioxidant activity, which varied with the type of assay. ABTS (1013 ± 5.0/1859 ± 6.0) with the rockrose Porto extract presented the highest content, DPPH (854 ± 6.0/1565 ± 4.0) with the acorn husk extract presented the highest content, and ORAC (2855 ± 10/3703 ± 87) with the laurel extract presented the highest content; all results were expressed in μmol Trolox/g extract. The most antimicrobial extracts were the rockrose and acorn husk. In terms of virus inhibition, all extracts showed an inhibition over 90%, although eucalyptus and the acorn husk reached an inhibition close to 99%. No mutagenicity by AMES assays and no cytotoxicity were detected for the extracts. This work highlights the potential of these plant extracts representing the source of bioactive components with antioxidant capacity to be applied in foods, food packaging, development of new natural cleaning agents, and/or other applications.