Browsing by Author "Amorim, Manuela"
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- Angiotensin-converting enzyme-inhibitory activity of extracts of hydrolysed k-casein glycomacropeptide: stability under simulated gastrointestinal digestionPublication . Tavares, Tânia; Amorim, Manuela; Pintado, Manuela; Récio, Isidra; Malcata, F. XavierDietary proteins usually possess a wide range of nutritional, functional and biological properties; many of such biological properties have been attributed to physiologically active peptides, which are encrypted within the protein sequence. k‐Casein glycomacropeptide (CMP) – one of the main components of whey, is released in the first step of (enzymatic) cheese making – and has been claimed to act as mediator in important biological pathways. Peptides released from CMP via enzymatic or microbial activity have indeed been proven to posses inhibitory activity against the angiotensin‐converting enzyme (ACE). However, they will not act properly in the human body unless they can resist gastrointestinal digestion, as well as be absorbed and reach the cardiovascular system in active form. On the other hand, several studies have already demonstrated the important role of gastrointestinal digestion upon ACE‐inhibitory peptide formation. Therefore, the aim of this study was to evaluate the ACE‐inhibitory activity of peptide extracts obtained via hydrolysis of CMP, using an extract of Cynara cardunculus as enzymatic vector. Moreover, such peptides were subjected to simulated gastrointestinal digestion, in order to assess their stability and the evolution of their ACE‐inhibitory activity. A 40 g/L solution of CMP, hydrolysed with 8.5 %(w/w) commercial crude extract of C. cardunculus, exhibitedACE‐inhibitory activity corresponding to IC50 values of 296.0 mg/mL (total fraction), 63.0 mg/mL (3000 Da fraction). The identification of peptides proceeded by LC‐MS, and permitted identification of the following peptides: MAIPPKKNDQD (k‐CN f106‐115), as potentially responsible for antihypertensive activity; and TVQVTSTAV (k‐CN f161‐169) and MAIPPKKNDQD (k‐CN f106‐115), as potentially responsible for antithrombotic activity, because both encompass sequences analogous to the bioactive fragment f400‐411 of fibrinogen g‐chain. A new peptide, KTEIPIN (k‐CN f116‐123), was also identified to relatively high concentrations, with a promising antihypertensive activity. Studies concerning the in vitro simulation of gastrointestinal digestion were conducted; the gastrointestinal stability of the total extract and of the 3000 Da peptide fraction, as well as of the plain CMP (used as control), following incorporation in water and fruit juice, was tested in said gastrointestinal model, but none of said fractions was significantly affected.
- Antiulcerative and antitumoral properties of spent brewer's yeast peptide extracts for incorporation in foodsPublication . Amorim, Manuela; Pereira, Joana; Monteiro, Karin; Ruiz, Ana; Pinheiro, Hélder; Carvalho, João; Pintado, ManuelaToday, the inflammatory bowel diseases such as ulcerative colitis are increasing and have been associated to contemporary people. Additionally, the increasing of cancer in the world is also a current fact. These issues are attracting attention in the search of new ingredients used in the prevention and improvement of these diseases. Particularly, several compounds, when added to foods, are able to positively stimulate certain biological systems leading to health improvement. Thereby, extracts obtained from the combined autolysis and hydrolysis of yeast cells possess compounds such peptides and amino acids, which eventually may control the production of inflammatory cytokines, thus leading to an anti-inflammatory activity and antitumoral properties. Thus, the main objective of the present work is to study the antiulcerative and antitumoral potential of yeast peptide extract for further incorporation in functional foods to prevent or improve symptoms in these chronic diseases. Peptide concentrates obtained by hydrolysis of spent brewer yeast proteins with extracts of Cynara cardunculus were studied using animal models to prove possible protection of the stomach mucosa against ulcerative lesions caused by oral administration of absolute ethanol. The peptide fraction below 3 kDa (peptidic extract) from yeast proteins was able to reduce gastric injuries to significant levels (p < 0.05). Additionally, the anti-proliferative activity of these extracts in nine cell lines of different human tumor was tested. The results exhibited a promising antiproliferative activity against leukemia cells. These results suggest that this new peptide extract can be used to develop new functional foods, although further studies are required.
- Biopolymer from Annona muricata residues as a potential sustainable raw material for industrial applicationsPublication . Ramos, Igor F. S.; Dias, Samuel C.; Lopes, Talissa B. C.; Júnior, Francisco T. dos S. Silva; Araújo, Ricardo de; Gutierrez, Stanley J. C.; Pessoa, Claudia; Osajima, Josy A.; Rizzo, Marcia S.; Silva-Filho, Edson C.; Amorim, Manuela; Ramos, Óscar; Ribeiro, Alessandra B.; Costa, Marcilia P.Annona muricata is a fruit species belonging to the Annonaceae family, which is native to the warmer tropical areas of North and South America. A large amount of discarded residue from A. muricata is of interest for obtaining new industrial inputs. To propose the applications of the biopolymer from A. muricata residues (Biop_AmRs), this study aimed to characterize this input chemically and functionally, as well as to evaluate its potential for hemocompatibility and cytotoxicity activity in vitro. Biop_AmRs is an anionic heteropolysaccharide composed of glucose, arabinose, xylose, galactose, mannose, uronic acid, and proteins. This biopolymer exhibited a semicrystalline structure and good thermal stability. Biop_AmRs exhibited excellent water holding capacity, emulsifying properties, and mucoadhesiviness and demonstrated hemocompatibility and cytocompatibility on the L929 cell line. These results indicate possible applications for this biopolymer as a potential environmentally friendly raw material in the food, pharmaceutical, biomedical, and cosmetic industries.
- Breaking the virus: yeast glucans as an effective alternative to acyclovir in HSVI treatmentPublication . Tavares-Valente, Diana; Moreira, Helena; Sousa, Pedro; Amorim, Manuela; Conde, António; Pintado, Manuela; Fernandes, João; Azevedo-Silva, JoãoGlucans, structural polysaccharides in the yeast cell wall, are known for their biological and immunomodulatory capacities, helping in prevention and management of infections. Herpes simplex virus type 1 (HSVI) is a prevalent infection that causes great comorbidity and is challenging to treat due to the adverse effects of standard antiviral drugs like acyclovir. This study assessed the potential of yeast glucans extracted from two different origins − a steviol-glycoside producing strain and a wild-type strain- to circumvent HSVI infection, either in vitro and ex vivo. Treatment with glucans in keratinocytes and macrophages in vitro reduced cell infection similarly to acyclovir. However, unlike acyclovir, glucans demonstrated an immunostimulatory effect, increasing the production of IL-1β, TNF-α and IL-6. Additionally, both glucans were formulated with squalane for skin application. This formulation improved glucans penetration in the skin, restored skin structure and reduced the cytopathic effect of HSVI infection. In summary, this study highlights yeast glucans as a natural therapeutic alternative for HSVI treatment, offering an option with an excellent safety profile. Moreover, using glucans from industrial side-streams promotes a sustainable approach, contributing to the circular economy.
- Cannabidiol and cannabigerol exert antimicrobial activity without compromising skin microbiotaPublication . Luz-Veiga, Mariana; Amorim, Manuela; Pinto-Ribeiro, Inês; Oliveira, Ana L. S.; Silva, Sara; Pimentel, Lígia L.; Rodríguez-Alcalá, Luís M.; Madureira, Raquel; Pintado, Manuela; Azevedo-Silva, João; Fernandes, JoãoCannabidiol (CBD) and cannabigerol (CBG) are two pharmacologically active phytocannabinoids of Cannabis sativa L. Their antimicrobial activity needs further elucidation, particularly for CBG, as reports on this cannabinoid are scarce. We investigated CBD and CBG’s antimicrobial potential, including their ability to inhibit the formation and cause the removal of biofilms. Our results demonstrate that both molecules present activity against planktonic bacteria and biofilms, with both cannabinoids removing mature biofilms at concentrations below the determined minimum inhibitory concentrations. We report for the first time minimum inhibitory and lethal concentrations for Pseudomonas aeruginosa and Escherichia coli (ranging from 400 to 3180 µM), as well as the ability of cannabinoids to inhibit Staphylococci adhesion to keratinocytes, with CBG demonstrating higher activity than CBD. The value of these molecules as preservative ingredients for cosmetics was also assayed, with CBG meeting the USP 51 challenge test criteria for antimicrobial effectiveness. Further, the exact formulation showed no negative impact on skin microbiota. Our results suggest that phytocannabinoids can be promising topical antimicrobial agents when searching for novel therapeutic candidates for different skin conditions. Additional research is needed to clarify phytocannabinoids’ mechanisms of action, aiming to develop practical applications in dermatological use.
- Chemical and bioactive characterization of coriolus versicolor, hericium erinaceus and pleurotus ostreatus mushroom biomassPublication . Araújo-Rodrigues, Helena; Amorim, Manuela; Salsinha, Ana Sofia; Marçal, Sara; Tavaria, Freni K.; Relvas, João Bettencourt; Pintado, Manuela E.
- Chemical and structural characterization of Pholiota nameko extracts with biological propertiesPublication . Rodrigues, Dina; Freitas, Ana C.; Sousa, Sérgio; Amorim, Manuela; Vasconcelos, Marta W.; Costa, João P. da; Silva, Artur M. S.; Rocha-Santos, Teresa A. P.; Duarte, Armando C.; Gomes, Ana M. P.Edible mushrooms including Pholiota nameko are excellent sources of extractable bioactive compounds with much to explore. Enzymatic extractions with Cellulase and Viscozyme were responsible for highest extraction yields (67-77%). No strong antioxidant activity was observed although extracts were able to scavenge ABTS(+) and OH(+). Potential prebiotic activity was observed in all extracts, some increasing 1.4-2 Log cycles of Lactobacillus acidophilus La-5 and Bifidobacterium animalis BB12. 30-50% α-glucosidase inhibition was observed in ultrasound, Flavourzyme and Cellulase extracts. Flavourzyme and Cellulase extracts are richer in macro (Mg, K and P) and micro elements (Zn, Mn and Fe) in comparison to mushroom. Monosaccharides content and profile varied slightly among both extracts with predominance of glucose, galactose and mannose with no uronic acids detection; Flavourzyme extract reported higher free amino acids content. Presence of α and β-glycosidic structures such as glucans and glucan-protein complexes are among the polysaccharides found in both extracts.
- Circular economyeast: saccharomyces cerevisiae as a sustainable source of glucans and its safety for skincare applicationPublication . Sousa, Pedro; Tavares-Valente, Diana; Pereira, Carla F.; Pinto-Ribeiro, Inês; Azevedo-Silva, João; Madureira, Raquel; Ramos, Óscar L.; Pintado, Manuela; Fernandes, João; Amorim, ManuelaGlucans, a polysaccharide naturally present in the yeast cell wall that can be obtained from side streams generated during the fermentation process, have gained increasing attention for their potential as a skin ingredient. Therefore, this study focused on the extraction method to isolate and purify water-insoluble glucans from two different Saccharomyces cerevisiae strains: an engineered strain obtained from spent yeast in an industrial fermentation process and a wild strain produced through lab-scale fermentation. Two water-insoluble extracts with a high glucose content (> 90 %) were achieved and further subjected to a chemical modification using carboxymethylation to improve their water solubility. All the glucans' extracts, water-insoluble and carboxymethylated, were structurally and chemically characterized, showing almost no differences between both yeast-type strains. To ensure their safety for skin application, a broad safety assessment was undertaken, and no cytotoxic effect, immunomodulatory capacity (IL-6 and IL-8 regulation), genotoxicity, skin sensitization, and impact on the skin microbiota were observed. These findings highlight the potential of glucans derived from spent yeast as a sustainable and safe ingredient for cosmetic and skincare formulations, contributing to the sustainability and circular economy.
- Comparative analysis of polysaccharide and nutritional composition of biological and industrial-scale cultivated pleurotus ostreatus mushrooms for functional food and nutraceutical applicationsPublication . Araújo-Rodrigues, Helena; Amorim, Manuela; Freitas, Victor de; Relvas, João B.; Tavaria, Freni K.; Pintado, ManuelaThis study chemically characterized three Pleurotus ostreatus fruiting bodies cultivated in the Iberian Peninsula under different conditions (biological and industrial), with emphasis on polysaccharide analysis. Comprehensive comparative data on cultivation-dependent nutritional variations will potentially improve their nutritional and therapeutic applications. Industrial mushrooms (POC and POA) contained significantly higher carbohydrate content (74%), while the biologically cultivated mushroom (POL) exhibited more protein (22.6%), fat (4.2%), and ashes (8.0%). Monosaccharide analysis showed glucose dominance (28.7–45.5%), with mannose, galactose, xylose, and arabinose also present. Trehalose was the primary free sugar (4.8–14.9%). The (1→3)(1→6)-β-glucans varied significantly across samples (POL: 20.5%; POC: 29.3%; POA: 34.3%). Nuclear magnetic resonance analysis suggested complex polysaccharide arrangements. Water-soluble carbohydrates and proteins showed molecular weight distributions of 0.18–21 kDa and 0.20–75 kDa, respectively. All mushrooms were rich in essential amino acids, phosphorus (2.79–3.07%), potassium (0.56–0.68%), linoleic acid (0.82–1.14%), and oleic acid (0.22–0.31%). Fourier transform infrared confirmed a mushroom-specific biochemical profile. These findings corroborate the high nutritional value of POL, POC, and POA, with a significant contribution to the daily requirements of fiber, protein, and minerals (phosphorus, potassium, magnesium, iron, zinc, copper, and selenium), making them suitable for functional foods and nutraceuticals with cultivation-dependent nutritional profiles.
- Development of a cashew nut coated with bioactive whey peptide extract with antihipertensivePublication . Pereira, Joana Odila; Amorim, Manuela; Silva, L. B.; Ormenese, R.C.S.C.; Pacheco, M.T.B.; Pintado, ManuelaThere is a growing concern in the consumer’s habits seeking healthy foods, which has opened new markets for functional foods. This global demand led to the development of functional foods, searching new ingredients to incorporate into conventional foods. Whey proteins are studied not only from the nutritional and functional properties, but also as a source of peptides that may exert biological functions, particularly antihypertensive activity. These bioactive peptides are released by enzymatic hydrolysis and according the final composition they may exert biological activities. Cashew nut was used as matrix for incorporation functional ingredients due to its nutritional properties conveyed by the high content of folic acid and essential fatty acids. The aim of this study was to develop a cashew nut coated with peptide fraction obtained from whey and to evaluate the antihypertensive activity and consumer acceptance of the new functional cashew nuts. The fraction with MW < 3000 Da was obtained by hydrolysis of whey with Cynara cardunculus followed by nanofiltration to obtain low MW fraction, exhibited very high ACE-inhibitory activity, IC50 12.8 μg /mL protein. The incorporation of peptides (2 %) in cashew nut led to a reduction to values of ACEinhibitory activity, 532.2 μg/mL. However, this is close the values reported by other products in the market claiming antihypertensive activity. In the formulation there is space to increase concentration and biological activity. Nevertheless, it is important to highlight that the antihypertensive activity was not lost even when high temperatures during coating and processing of the product were used. The sensory analysis of the functional cashew nut showed high acceptability by the consumers. Our results suggest that the application of these bioactive peptide extracts with antihypertensive activity in the development of a new snacks with reduce salt content is promising in the improvement of new value-added food products.
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