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- Bioactive extracts from brewer's spent grainPublication . Bonifácio-Lopes, Teresa; Boas, Ana Vilas; Coscueta, Ezequiel R.; Costa, Eduardo M.; Silva, Sara; Campos, Débora; Teixeira, José A.; Pintado, ManuelaIn this study antioxidant-rich extracts from brewer’s spent grain (BSG) extracted with solid-to-liquid extraction using different solvents water and ethanol and their mixtures at two ratios (80% ethanol:water (v/v) and 60% ethanol:water (v/v)) were characterized. Nutritional composition was evaluated for the extracts and for the solid residues obtained after extraction. Additionally, the extracts were analyzed for the total phenolic content and individual phenolic compounds and related biological properties including antioxidant capacity (ABTS; ORAC and DNA protection), antihypertensive capacity, antibacterial activity and antibiofilm capacity. Safety was also demonstrated through genotoxicity and cytotoxicity tests. The results obtained showed that while all the extracts exhibited high antioxidant capacity (except ethanolic extract), the highest values were obtained for the 60% ethanol:water extract. The identification of phenolic compounds using HPLC showed that catechin and vanillin were the main compounds identified with the highest concentration being obtained for 60% ethanol:water extraction. In the biological activity assays water and hydroethanolic extracts showed to be multifunctional (antioxidant and antihypertensive capacity, antibacterial and antibiofilm activity), the 80% ethanol:water presented better results in some assays. All were non-genotoxic, but the cytotoxicity was dependent on the extract concentration, with complete safe application for all up to 1 mg/mL. Therefore, this study shows the potential of a viable green solvent based and a low cost extraction recovery method of bioactive compounds from brewer’s spent grain.
- Impact of functional flours from pineapple by-products on human intestinal microbiotaPublication . Campos, Débora; Coscueta, Ezequiel R.; Vilas-Boas, Ana A.; Silva, Sara; Teixeira, José A.; Pastrana, Lorenzo M.; Pintado, Maria ManuelaSolid fractions from pineapple stems and peels are constituted by structural carbohydrates coupled with dietary fibre, simple sugars, but also vitamins and polyphenols, which together can have potential effects on human health. The present studies report for the first time the bioavailability and bioaccessibility of pineapple byproducts fractions throughout simulated gastrointestinal tract, evaluates prebiotic potential and in vitro human microbiota fermentation. The pineapple flours promoted the human faeces fermentation through growth of beneficial strains, being corroborated by the decrease of simple sugars and the production of healthy organic acids (acetic, propionic and butyric acids) - well known short chain fatty acids. On the other hand, a high phenolic compounds content was release through flours digestion, developing an antioxidant environment within human gut. Thus, was possible to conclude that pineapple flour promoted a positive modulation in the overall system, proving a synergetic interaction of dietary fibre and polyphenols upon human microbiota.
- The Health-Promoting Potential of Salix spp. Bark Polar Extracts: Key Insights on Phenolic Composition and In Vitro Bioactivity and BiocompatibilityPublication . Ramos, Patrícia A. B.; Moreirinha, Catarina; Silva, Sara; Costa, Eduardo M.; Veiga, Mariana; Coscueta, Ezequiel R.; Santos, Sónia A. O.; Almeida, Adelaide; Pintado, M. Manuela; Freire, Carmen S. R.; Silva, Artur M. S.; Silvestre, Armano J. D.Salix spp. have been exploited for energy generation, along with folk medicine use of bark extracts for antipyretic and analgesic benefits. Bark phenolic components, rather than salicin, have demonstrated interesting bioactivities, which may ensure the sustainable bioprospection of Salix bark. Therefore, this study highlights the detailed phenolic characterization, as well as the in vitro antioxidant, anti-hypertensive, Staphylococcus aureus growth inhibitory effects, and biocompatibility of Salix atrocinerea Brot., Salix fragilis L., and Salix viminalis L. bark polar extracts. Fifteen phenolic compounds were characterized by ultra-high-performance liquid chromatography-ultraviolet detection-mass spectrometry analysis, from which two flavan-3-ols, an acetophenone, five flavanones, and a flavonol were detected, for the first time, as their bark components. Salix bark extracts demonstrated strong free radical scavenging activity (5.58–23.62 µg mL−1 IC50 range), effective inhibition on angiotensin-I converting enzyme (58–84%), and S. aureus bactericidal action at 1250–2500 µg mL−1 (6–8 log CFU mL−1 reduction range). All tested Salix bark extracts did not show cytotoxic potential against Caco-2 cells, as well as S. atrocinerea Brot. and S. fragilis L. extracts at 625 and 1250 µg mL−1 against HaCaT and L929 cells. These valuable findings can pave innovative and safer food, nutraceutical, and/or cosmetic applications of Salix bark phenolic-containing fractions.