Sara Nunes da Costa e Silva

@ucp.pt

Centro de Biotecnologia e Quimica Fina
Universidade Católica Portuguesa

Sara Silva is, presently, a Researcher at Centro de Biotecnologia e Química Fina (CBQF), with analysis of her CV showing that her research efforts followed three main topics: i) Valorisation of agro-food byproducts in a circular economy context through the exploitation of the biological potential of their constituents; ii) characterization of extracted compounds¿ biological potential targeting desirable properties such cellular metabolism, immune and gut microbiota modulation; iii) designing of delivery and formulation solutions for the usage and delivery of bioactive compounds. Author of 65 international peer-reviewed papers (63% Q1; 35% Q2) and 7 book chapters. According to Scopus (May 2023) she has been cited 1844 times by 1599 papers which resulted in an h-index of 24. Her main publication areas are Agricultural and Biological Sciences followed by Biochemistry, Genetics and Molecular biology.

EDUCATION

I hold a B.Sc. in Biosciences (15 out of 20), a M.Sc. in Microbiology (18 out of 20) and a Ph.D. in Biotechnology (Summa Cum Laude) all from Escola Superior de Biotecnologia of Universidade Católica Portuguesa.

RESEARCH, TEACHING, or OTHER INTERESTS

Biotechnology, Immunology and Microbiology, Applied Microbiology and Biotechnology, Food Science

75

Scopus Publications

Scopus Publications

  • Iron-peptide complexes from spent yeast: Evaluation of iron absorption using a Caco-2 monolayer
    Ana Sofia Oliveira, Carlos M.H. Ferreira, Joana Odila Pereira, Sara Silva, Eduardo M. Costa, Ana Margarida Pereira, Margarida Faustino, Joana Durão, Manuela E. Pintado, and Ana P. Carvalho

    Elsevier BV

  • Evaluation of Antimicrobial and Antioxidant Activities of Alginate Edible Coatings Incorporated with Plant Extracts
    Ana I. Lopes, Adma Melo, Cristina Caleja, Eliana Pereira, Tiane C. Finimundy, Tiago B. Afonso, Sara Silva, Marija Ivanov, Marina Soković, Freni K. Tavaria,et al.

    MDPI AG
    Plant extracts (PEs) are natural substances that perform interesting bioactivities. However, they have some limitations. In this work, PEs from licorice, eucalyptus, sage, and thyme were produced and characterized. These extracts showed good bioactive properties. Alginate-based edible coatings and films incorporated with the extracts were produced and their antimicrobial and antioxidant properties were determined. The results showed that the coatings completely inhibited or reduced the growth of all bacteria (E. coli, P. aeruginosa, B. cereus, L. monocytogenes, and S. aureus), except the coating with sage extract. However, only the films incorporated with licorice and eucalyptus could inhibit the growth of Gram-positive bacteria and none of the films were able to inhibit Gram-negative bacteria. The film incorporated with sage extract was the one with the best antifungal property. All films possess a good antioxidant property (ABTS: 942.52–5654.62; DPPH: 1040.67–5162.93 Trolox equivalents (µM)/mg film). Based on the results, it is possible to conclude that alginate coatings and films with PEs present good bioactive properties and can potentially be used as new, biodegradable packages. However, further experiments need to be performed to assess their safety profile, and to prove that they can be a real alternative to traditional food packaging.

  • Are Antimicrobial Peptides a 21st-Century Solution for Atopic Dermatitis?
    M. Machado, Sara Silva and E. Costa


    Atopic dermatitis (AD) is a chronic inflammatory skin disorder that is the result of various environmental, bacterial and genetic stimuli, which culminate in the disruption of the skin’s barrier function. Characterized by highly pruritic skin lesions, xerosis and an array of comorbidities among which skin infections are the most common, this condition results in both a significant loss of quality of life and in the need for life-long treatments (e.g., corticosteroids, monoclonal antibodies and regular antibiotic intake), all of which may have harmful secondary effects. This, in conjunction with AD’s rising prevalence, made the development of alternative treatment strategies the focus of both the scientific community and the pharmaceutical industry. Given their potential to both manage the skin microbiome, fight infections and even modulate the local immune response, the use of antimicrobial peptides (AMPs) from more diverse origins has become one of the most promising alternative solutions for AD management, with some being already used with some success towards this end. However, their production and use also exhibit some limitations. The current work seeks to compile the available information and provide a better understanding of the state of the art in the understanding of AMPs’ true potential in addressing AD.

  • Understanding the Anti-Obesity Potential of an Avocado Oil-Rich Cheese through an In Vitro Co-Culture Intestine Cell Model
    Manuela Machado, Eduardo M. Costa, Sara Silva, Luís M. Rodriguez-Alcalá, Ana Maria Gomes, and Manuela Pintado

    MDPI AG
    Nowadays, with consumers’ requirements shifting towards more natural solutions and the advent of nutraceutical-based approaches, new alternatives for obesity management are being developed. This work aimed to show, for the first time, the potential of avocado oil-fortified cheese as a viable foodstuff for obesity management through complex in vitro cellular models. The results showed that oleic and palmitic acids’ permeability through the Caco-2/HT29-MTX membrane peaked at the 2h mark, with the highest apparent permeability being registered for oleic acid (0.14 cm/s). Additionally, the permeated compounds were capable of modulating the metabolism of adipocytes present in the basal compartment, significantly reducing adipokine (leptin) and cytokine (MPC-1, IL-10, and TNF-α) production. The permeates (containing 3.30 µg/mL of palmitic acid and 2.16 µg/mL of oleic acid) also presented an overall anti-inflammatory activity upon Raw 264.7 macrophages, reducing IL-6 and TNF-α secretion. Despite in vivo assays being required, the data showed the potential of a functional dairy product as a valid food matrix to aid in obesity management.

  • Effect of Mannan Oligosaccharides Extracts in Uropathogenic Escherichia coli Adhesion in Human Bladder Cells
    Margarida Faustino, Sara Silva, Eduardo M. Costa, Ana Margarida Pereira, Joana Odila Pereira, Ana Sofia Oliveira, Carlos M. H. Ferreira, Carla F. Pereira, Joana Durão, Manuela E. Pintado,et al.

    MDPI AG
    Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.

  • Insights into the Antimicrobial Potential of Acorn Extracts (Quercus ilex and Quercus suber)
    Sara Silva, Manuela Machado, Marta Coelho, Eduardo M. Costa, and Manuela Pintado

    MDPI AG
    Acorns, frequently left uncollected in the fields, have been a part of the traditional medicine of different cultures. Among the different properties associated with them, their antimicrobial potential is of particular importance. However, this characterization has long been superficial and has not ventured into other topics such as biofilm inhibition. Thus, the current work aimed to characterize the antimicrobial and antibiofilm potential of an array of phenolic rich extracts attained from acorns, two different acorn varieties Q. ilex and Q. suber, considering the fruit and shell separately, fresh and after heat-treating the acorns to aid in the shelling process. To accomplish this, the extracts’ capacity to inhibit an array of different microorganisms was evaluated, the minimum bactericidal concentration (MBC) was determined, time-death curves were drawn whenever an MBC was found and the antibiofilm potential of the most effective extracts was drawn. The overall results showed that Gram-positive microorganisms were the most susceptible out of all the microorganisms tested, with the shell extracts being the most effective overall, exhibiting bactericidal effect against S. aureus, B. cereus and L. monocytogenes as well as being capable of inhibiting biofilm formation via the two S. aureus strains. The attained results demonstrated that acorn extracts, particularly shell extracts, pose an interesting antimicrobial activity which could be exploited in an array of food, cosmetic and pharmaceutical applications.

  • Carboxymethyl Cellulose as a Food Emulsifier: Are Its Days Numbered?
    Eduardo M. Costa, Sara Silva, Carla F. Pereira, Alessandra B. Ribeiro, Francisca Casanova, Ricardo Freixo, Manuela Pintado, and Óscar L. Ramos

    MDPI AG
    Carboxymethyl cellulose use in industry is ubiquitous. Though it is recognized as safe by the EFSA and FDA, newer works have raised concerns related to its safety, as in vivo studies showed evidence of gut dysbiosis associated with CMC’s presence. Herein lies the question, is CMC a gut pro-inflammatory compound? As no work addressed this question, we sought to understand whether CMC was pro-inflammatory through the immunomodulation of GI tract epithelial cells. The results showed that while CMC was not cytotoxic up to 25 mg/mL towards Caco-2, HT29-MTX and Hep G2 cells, it had an overall pro-inflammatory behavior. In a Caco-2 monolayer, CMC by itself increased IL-6, IL-8 and TNF-α secretion, with the latter increasing by 1924%, and with these increases being 9.7 times superior to the one obtained for the IL-1β pro-inflammation control. In co-culture models, an increase in secretion in the apical side, particularly for IL-6 (692% increase), was observed, and when RAW 264.7 was added, data showed a more complex scenario as stimulation of pro-inflammatory (IL-6, MCP-1 and TNF-α) and anti-inflammatory (IL-10 and IFN-β) cytokines in the basal side was observed. Considering these results, CMC may exert a pro-inflammatory effect in the intestinal lumen, and despite more studies being required, the incorporation of CMC in foodstuffs must be carefully considered in the future to minimize potential GI tract dysbiosis.

  • Modulation of the Gut Microbiota by Tomato Flours Obtained after Conventional and Ohmic Heating Extraction and Its Prebiotic Properties †
    Marta C. Coelho, Célia Costa, Dalila Roupar, Sara Silva, A. Sebastião Rodrigues, José A. Teixeira, and Manuela E. Pintado

    MDPI AG
    Several studies have supported the positive functional health effects of both prebiotics and probiotics on gut microbiota. Among these, the selective growth of beneficial bacteria due to the use of prebiotics and bioactive compounds as an energy and carbon source is critical to promote the development of healthy microbiota within the human gut. The present work aimed to assess the fermentability of tomato flour obtained after ohmic (SFOH) and conventional (SFCONV) extraction of phenolic compounds and carotenoids as well as their potential impact upon specific microbiota groups. To accomplish this, the attained bagasse flour was submitted to an in vitro simulation of gastrointestinal digestion before its potential fermentability and impact upon gut microbiota (using an in vitro fecal fermentation model). Different impacts on the probiotic strains studied were observed for SFCONV promoting the B. animalis growth, while SFOH promoted the B. longum, probably based on the different carbohydrate profiles of the flours. Overall, the flours used were capable of functioning as a direct substrate to support potential prebiotic growth for Bifidus longum. The fecal fermentation model results showed the highest Bacteroidetes growth with SFOH and the highest values of Bacteroides with SFCONV. A correlation between microorganisms’ growth and short-chain fatty acids was also found. This by-product seems to promote beneficial effects on microbiota flora and could be a potential prebiotic ingredient, although more extensive in vivo trials would be necessary to confirm this.

  • Production of Sustainable Postbiotics from Sugarcane Straw for Potential Food Applications
    Ana L. S. Oliveira, Marta Seara, Maria João Carvalho, Nelson Mota de Carvalho, Eduardo M. Costa, Sara Silva, Marco Duarte, Manuela Pintado, Carla Oliveira, and Ana Raquel Madureira

    MDPI AG
    The production of postbiotics for food applications has been growing in recent years owing to their biological potential and superior technological performance over probiotics. Their production involves the use of synthetic culture media, and in this work, we propose using sugarcane straw as a source of sugar and biological components and a sustainable alternative. Thus, this by-product was used as a substrate to produce a postbiotic extract using Saccharomyces cerevisiae as a fermentative microorganism. Sugarcane straw underwent a precedent saccharification step to release the fermentable sugars. The final extracts were characterized for their total content of sugars, phenolic compounds, organic acids, and their respective chromatographic profiles. Seventeen different polyphenols were identified with the predominance of three classes, the hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids, where ferulic acid, 3,4-dihydroxybenzaldehyde, and 2,5-dihydroxybenzoic acid were most prevalent. The current work evaluated the potential use of this postbiotic extract for food applications, its antioxidant activity, gut microbiota modulatory effect, and intestinal anti-inflammatory potential. The resultant extracts showed considerable antioxidant activity and the ability to lower the pro-inflammatory mediators (i.e., interleukin 6, 8, and tumor necrosis factor-alpha) in Caco-2 cells. During the fecal fermentability assay, no modulatory effect was observed on the main beneficial bacteria, such as Lactobacillus and Bifidobacterium. Nevertheless, a significant increase in short-chain fatty acids, namely, acetate, propionate, butyrate, and valerate was observed. Moreover, the extract also demonstrated capacity to inhibit the proliferation of putrefactive bacteria such as Enterobacteriaceae. Finally, sustainable postbiotic extracts produced by S. cerevisiae fermentation using sugarcane straw as a substrate exhibited relevant biological properties with potential use as food and nutraceutical ingredients.

  • Selective Activity of an Anthocyanin-Rich, Purified Blueberry Extract upon Pathogenic and Probiotic Bacteria
    Sara Silva, Eduardo M. Costa, Manuela Machado, Rui M. Morais, Conceição Calhau, and Manuela Pintado

    MDPI AG
    Blueberry extracts have been widely recognized as possessing antimicrobial activity against several potential pathogens. However, the contextualization of the interaction of these extracts with beneficial bacteria (i.e., probiotics), particularly when considering the food applications of these products, may be of importance, not only because their presence is important in the regular gut microbiota, but also because they are important constituents of regular and functional foodstuffs. Therefore, the present work first sought to demonstrate the inhibitory effect of a blueberry extract upon four potential food pathogens and, after identifying the active concentrations, evaluated their impact upon the growth and metabolic activity (organic acid production and sugar consumption) of five potential probiotic microorganisms. Results showed that the extract, at a concentration that inhibited L. monocytogenes, B. cereus, E. coli and S. enteritidis (1000 μg mL−1), had no inhibitory effect on the growth of the potential probiotic stains used. However, the results demonstrated, for the first time, that the extract had a significant impact on the metabolic activity of all probiotic strains, resulting in higher amounts of organic acid production (acetic, citric and lactic acids) and an earlier production of propionic acid.

  • Chitosan Nanoparticles Production: Optimization of Physical Parameters, Biochemical Characterization, and Stability upon Storage
    Eduardo M. Costa, Sara Silva, and Manuela Pintado

    MDPI AG
    Ionic gelation is among the simplest processes for the development of chitosan nanoparticles reported so far in the literature. Its one-shot synthesis process in conjunction with the mild reaction conditions required are among the main causes for its success. In this work, we sought to optimize a set of physical parameters associated with the ionic gelation process at two different pH values. Following that, the NPs’ freeze-drying and long-term storage stability were assayed, and their biocompatibility with HaCat cells was evaluated. The results show that NPs were more homogenously produced at pH 5, and that at this pH value, it was possible to obtain a set of optimum production conditions. Furthermore, of the assayed parameters, TPP addition time and overall reaction time were the parameters which had a significant impact on the produced NPs. Nanoparticle freeze-drying led to particle aggregation, and, of the cryoprotectants, assayed mannitol at 10% (w/v) presented the best performance, as the NPs were stable to freeze-drying and maintained their size and charge in the long-term stability assay. Lastly, the chitosan NPs presented no toxicity towards the HaCat cell line.

  • Cannabidiol and Cannabigerol Exert Antimicrobial Activity without Compromising Skin Microbiota
    Mariana Luz-Veiga, Manuela Amorim, Inês Pinto-Ribeiro, Ana L. S. Oliveira, Sara Silva, Lígia L. Pimentel, Luís M. Rodríguez-Alcalá, Raquel Madureira, Manuela Pintado, João Azevedo-Silva,et al.

    MDPI AG
    Cannabidiol (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.

  • Spent Yeast Waste Streams as a Sustainable Source of Bioactive Peptides for Skin Applications
    Eduardo M. Costa, Ana Sofia Oliveira, Sara Silva, Alessandra B. Ribeiro, Carla F. Pereira, Carlos Ferreira, Francisca Casanova, Joana O. Pereira, Ricardo Freixo, Manuela E. Pintado,et al.

    MDPI AG
    Spent yeast waste streams are a byproduct obtained from fermentation process and have been shown to be a rich secondary source of bioactive compounds such as phenolic compounds and peptides. The latter are of particular interest for skin care and cosmetics as they have been shown to be safe and hypoallergenic while simultaneously being able to exert various effects upon the epidermis modulating immune response and targeting skin metabolites, such as collagen production. As the potential of spent yeast’s peptides has been mainly explored for food-related applications, this work sought to understand if peptide fractions previously extracted from fermentation engineered spent yeast (Saccharomyces cerevisiae) waste streams possess biological potential for skin-related applications. To that end, cytotoxic effects on HaCat and HDFa cells and whether they were capable of exerting a positive effect upon the production of skin metabolites relevant for skin health, such as collagen, hyaluronic acid, fibronectin and elastin, were evaluated. The results showed that the peptide fractions assayed were not cytotoxic up to the highest concentration tested (500 µg/mL) for both cell lines tested. Furthermore, all peptide fractions showed a capacity to modulate the various target metabolites production with an overall positive effect being observed for the four fractions over the six selected targets (pro-collagen IαI, hyaluronic acid, fibronectin, cytokeratin-14, elastin, and aquaporin-9). Concerning the evaluated fractions, the overall best performance (Gpep > 1 kDa) was of an average promotion of 41.25% over the six metabolites and two cell lines assessed at a concentration of 100 µg/mL. These results showed that the peptide fractions assayed in this work have potential for future applications in skin-related products at relatively low concentrations, thus providing an alternative solution for one of the fermentation industry’s waste streams and creating a novel and highly valuable bioactive ingredient with encompassing activity to be applied in future skin care formulations.

  • Structural diversity of marine anti-freezing proteins, properties and potential applications: a review
    Soudabeh Ghalamara, Sara Silva, Carla Brazinha, and Manuela Pintado

    Springer Science and Business Media LLC
    AbstractCold-adapted organisms, such as fishes, insects, plants and bacteria produce a group of proteins known as antifreeze proteins (AFPs). The specific functions of AFPs, including thermal hysteresis (TH), ice recrystallization inhibition (IRI), dynamic ice shaping (DIS) and interaction with membranes, attracted significant interest for their incorporation into commercial products. AFPs represent their effects by lowering the water freezing point as well as preventing the growth of ice crystals and recrystallization during frozen storage. The potential of AFPs to modify ice growth results in ice crystal stabilizing over a defined temperature range and inhibiting ice recrystallization, which could minimize drip loss during thawing, improve the quality and increase the shelf-life of frozen products. Most cryopreservation studies using marine-derived AFPs have shown that the addition of AFPs can increase post-thaw viability. Nevertheless, the reduced availability of bulk proteins and the need of biotechnological techniques for industrial production, limit the possible usage in foods. Despite all these drawbacks, relatively small concentrations are enough to show activity, which suggests AFPs as potential food additives in the future. The present work aims to review the results of numerous investigations on marine-derived AFPs and discuss their structure, function, physicochemical properties, purification and potential applications. Graphical Abstract

  • Insights into the Biocompatibility and Biological Potential of a Chitosan Nanoencapsulated Textile Dye
    Eduardo M. Costa, Sara Silva, Freni K. Tavaria, and Manuela Pintado

    MDPI AG
    Traditionally synthetic textile dyes are hazardous and toxic compounds devoid of any biological activity. As nanoencapsulation of yellow everzol textile dye with chitosan has been shown to produce biocompatible nanoparticles which were still capable of dyeing textiles, this work aims to further characterize the biocompatibility of yellow everzol nanoparticles (NPs) and to ascertain if the produced nanoencapsulated dyes possess any biological activity against various skin pathogens in vitro assays and in a cell infection model. The results showed that the NPs had no deleterious effects on the HaCat cells’ metabolism and cell wall, contrary to the high toxicity of the dye. The biological activity evaluation showed that NPs had a significant antimicrobial activity, with low MICs (0.5–2 mg/mL) and MBCs (1–3 mg/mL) being registered. Additionally, NPs inhibited biofilm formation of all tested microorganisms (inhibitions between 30 and 87%) and biofilm quorum sensing. Lastly, the dye NPs were effective in managing MRSA infection of HaCat cells as they significantly reduced intracellular and extracellular bacterial counts.

  • Chitosan Nanoparticles as Bioactive Vehicles for Textile Dyeing: A Proof of Concept
    Eduardo M. Costa, Sara Silva, Manuela Machado, Sérgio C. Sousa, Freni K. Tavaria, and Manuela Pintado

    MDPI AG
    In recent years bioactive textiles have risen to the forefront of consumers perception due to their potential protection against virus, fungi and bacteria. However, traditional textile staining is an eco-damaging process that and current methods of textile functionalization are expensive, complicated and with great environmental impact. With that in mind, this work sought to show a possible solution for this problematic through the usage of a novel one step textile dyeing and functionalization method based upon nanoencapsulated textile dyes (NTDs). To do so navy blue everzol NTDs were produced with chitosan, cotton dyed, characterized through FTIR and SEM and biological potential evaluated through biocompatibility screening and antimicrobial activity against skin pathogens. The data obtained showed that NTDs effectively dyed the target textile through a coating of the cotton fibre and that NTDs formed hydrogen bonds with the cellulose fibre via electrostatic interactions of the chitosan amino groups with cotton sulphate groups. From a biocompatibility perspective NTDs dyed cotton had no deleterious effects upon a skin cell line, as it promoted cellular metabolism of HaCat cells, while traditionally died cotton reduced it by 10%. Last but not least, NTDs dyed cotton showed significant antimicrobial activity as it reduced viable counts of MRSA, MSSA and A. baumannii between 1 and 2 log of CFU while traditional dyed cotton had no antimicrobial activity. Considering these results the novel method proposed shows is a viable and ecological alternative for the development of antimicrobial textiles with potential biomedical applications.

  • Antiadhesive and Antibiofilm Effect of Malvidin-3-Glucoside and Malvidin-3-Glucoside/Neochlorogenic Acid Mixtures upon Staphylococcus
    Sara Silva, Eduardo M. Costa, Manuela Machado, Rui Morais, Conceição Calhau, and Manuela Pintado

    MDPI AG
    Several reports on the biological activity of anthocyanin-rich extracts have been made. However, despite the association of said activity with their anthocyanin content, to the best of our knowledge, there are no previous works regarding the antimicrobial, antibiofilm and/or antiadhesive properties of anthocyanins alone. Therefore, the present work aimed to determine the effects of malvidin-3-glucoside, a major component of a previously reported extract, and the impact of its association with neochlorogenic acid (the only non-anthocyanin phenolic present in said extract), upon several Staphylococcus strains with varying resistance profiles. Results show that, while malvidin-3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures were unable to considerably inhibit bacterial growth after 24 h, they still possessed an interesting antibiofilm activity (with reductions of biofilm entrapped cells up to 2.5 log cycles, metabolic inhibition rates up to 81% and up to 51% of biomass inhibition). When considering the bacteria’s capacity to adhere to plain polystyrene surfaces, the inhibition ranges were considerably lower (21% maximum value). However, when considering polystyrene surfaces coated with plasmatic proteins this value was considerably higher (45% for adhesion in the presence of extract and 39% for adhesion after the surface was exposed to extract). Overall, the studied anthocyanins showed potential as future alternatives to traditional antimicrobials in adhesion and biofilm formation prevention.

  • Impact of a Purified Blueberry Extract on In Vitro Probiotic Mucin-Adhesion and Its Effect on Probiotic/Intestinal Pathogen Systems
    Sara Silva, Eduardo M. Costa, Hélder Oliveira, Vitor De Freitas, Rui M. Morais, Conceição Calhau, and Manuela Pintado

    MDPI AG
    Several arguments have been made to substantiate the need for natural antimicrobials for the food industry. With blueberry extracts, the most compelling are both their healthy connotation and the possibility of obtaining a multipurpose solution that can be an antioxidant, colorant, and antimicrobial. From an antimicrobial perspective, as blueberry/anthocyanin-rich extracts have been associated with a capacity to inhibit harmful bacteria while causing little to no inhibition on potential probiotic microorganisms, the study of potential benefits that come from synergies between the extract and probiotics may be of particular interest. Therefore, the present work aimed to evaluate the effect of an anthocyanin-rich extract on the adhesion of five different probiotics as well as their effect on the probiotics’ capacity to compete with or block pathogen adhesion to a mucin/BSA-treated surface. The results showed that, despite some loss of probiotic adhesion, the combined presence of extract and probiotic is more effective in reducing the overall amount of adhered viable pathogen cells than the PROBIOTIC alone, regardless of the probiotic/pathogen system considered. Furthermore, in some instances, the combination of the extract with Bifidobacterium animalis Bo allowed for almost complete inhibition of pathogen adhesion.

  • Integrated ultrafiltration, nanofiltration, and reverse osmosis pilot process to produce bioactive protein/peptide fractions from sardine cooking effluent
    Soudabeh Ghalamara, Ezequiel R. Coscueta, Sara Silva, Carla Brazinha, Carlos D. Pereira, and Manuela E. Pintado

    Elsevier BV

  • Pomegranate Oil’s Potential as an Anti-Obesity Ingredient
    Manuela Machado, Eduardo M. Costa, Sara Silva, Luís M. Rodriguez-Alcalá, Ana M. Gomes, and Manuela Pintado

    MDPI AG
    In recent years, pomegranate oil has obtained more attention due to its content of conjugated linolenic acids and possible application in the prevention of many diseases. The purpose of this work was to evaluate the potential ability of pomegranate oil to modulate obesity-related metabolism and immune response using in vitro models. In this regard, pomegranate oil was characterized in terms of fatty acids profile, tocopherols and phytosterols, and antioxidant capacity. After evaluation of the safety profile, pomegranate oil’s capacity to modulate obesity-related metabolism was evaluated through adipolysis and adipokines secretion quantification in 3T3-L1 differentiated adipocytes and hepatic lipid accumulation assay in Hep G2 hepatocytes. The immunomodulatory activity was evaluated in Caco-2 cells by quantification of pro-inflammatory cytokines IL-6, IL-8, and TNF-α. This oil showed high antioxidant capacity and was mainly composed of conjugated fatty acid, namely punicic acid. Its chemical composition was responsible for its capacity to reduce the lipid accumulation in Hep G2 cells and 3T3-L1 differentiated adipocytes. In short, pomegranate oil shows great potential for the development of functional foods and nutraceuticals targeting obesity.

  • Evaluation of Microbial‐Fructo‐Oligosaccharides Metabolism by Human Gut Microbiota Fermentation as Compared to Commercial Inulin‐Derived Oligosaccharides
    Dalila Roupar, Marta C. Coelho, Daniela A. Gonçalves, Soraia P. Silva, Elisabete Coelho, Sara Silva, Manuel A. Coimbra, Manuela Pintado, José A. Teixeira, and Clarisse Nobre

    MDPI AG
    The prebiotic potential of fructo-oligosaccharides (microbial-FOS) produced by a newly isolated Aspergillus ibericus, and purified by Saccharomyces cerevisiae YIL162 W, was evaluated. Their chemical structure and functionality were compared to a non-microbial commercial FOS sample. Prebiotics were fermented in vitro by fecal microbiota of five healthy volunteers. Microbial-FOS significantly stimulated the growth of Bifidobacterium probiotic strains, triggering a beneficial effect on gut microbiota composition. A higher amount of total short-chain fatty acids (SCFA) was produced by microbial-FOS fermentation as compared to commercial-FOS, particularly propionate and butyrate. Inulin neoseries oligosaccharides, with a degree of polymerization (DP) up to 5 (e.g., neokestose and neonystose), were identified only in the microbial-FOS mixture. More than 10% of the microbial-oligosaccharides showed a DP higher than 5. Differences identified in the structures of the FOS samples may explain their different functionalities. Results indicate that microbial-FOS exhibit promising potential as nutraceutical ingredients for positive gut microbiota modulation.

  • Exploring the bioactive potential of brewers spent grain ohmic extracts
    Teresa Bonifácio-Lopes, Ana Vilas-Boas, Manuela Machado, Eduardo M. Costa, Sara Silva, Ricardo N. Pereira, Débora Campos, José A. Teixeira, and Manuela Pintado

    Elsevier BV

  • Blueberry counteracts prediabetes in a hypercaloric diet-induced rat model and rescues hepatic mitochondrial bioenergetics
    Sara Nunes, Sofia D. Viana, Inês Preguiça, André Alves, Rosa Fernandes, João S. Teodoro, Patrícia Matos, Artur Figueirinha, Lígia Salgueiro, Alexandra André,et al.

    MDPI AG
    The paramount importance of a healthy diet in the prevention of type 2 diabetes is now well recognized. Blueberries (BBs) have been described as attractive functional fruits for this purpose. This study aimed to elucidate the cellular and molecular mechanisms pertaining to the protective impact of blueberry juice (BJ) on prediabetes. Using a hypercaloric diet-induced prediabetic rat model, we evaluated the effects of BJ on glucose, insulin, and lipid profiles; gut microbiota composition; intestinal barrier integrity; and metabolic endotoxemia, as well as on hepatic metabolic surrogates, including several related to mitochondria bioenergetics. BJ supplementation for 14 weeks counteracted diet-evoked metabolic deregulation, improving glucose tolerance, insulin sensitivity, and hypertriglyceridemia, along with systemic and hepatic antioxidant properties, without a significant impact on the gut microbiota composition and related mechanisms. In addition, BJ treatment effectively alleviated hepatic steatosis and mitochondrial dysfunction observed in the prediabetic animals, as suggested by the amelioration of bioenergetics parameters and key targets of inflammation, insulin signaling, ketogenesis, and fatty acids oxidation. In conclusion, the beneficial metabolic impact of BJ in prediabetes may be mainly explained by the rescue of hepatic mitochondrial bioenergetics. These findings pave the way to support the use of BJ in prediabetes to prevent diabetes and its complications.

  • Anthocyanin recovery from grape by-products by combining ohmic heating with food-grade solvents: Phenolic composition, antioxidant, and antimicrobial properties
    Marta Coelho, Sara Silva, Eduardo Costa, Ricardo N. Pereira, António Sebastião Rodrigues, José António Teixeira, and Manuela Pintado

    MDPI AG
    Usually, wine-making by-products are discarded, presenting a significant environmental impact. However, they can be used as a source of bioactive compounds. Moreover, consumers’ increasing demand for naturally nutritious and healthy products requires new formulations and food product improvement, together with sustainable, environmentally friendly extraction methods. Thus, this work aimed to compare ohmic heating (OH) with conventional methodology (CONV), using food-grade solvents, mainly water, compared to standard methanol extraction of anthocyanins. No significant differences were found between the CONV and OH for total phenolic compounds, which were 2.84 ± 0.037 and 3.28 ± 0.46 mg/g DW gallic acid equivalent, respectively. The same tendency was found for antioxidant capacity, where CONV and OH presented values of 2.02 ± 0.007 g/100 g and 2.34 ± 0.066 g/100 g ascorbic acid equivalent, respectively. The major anthocyanins identified were malvidin-3-O-acetylglucoside, delphinidin-3-O-glucoside, petunidine-3-O-glucoside, cyanidin-3-O-glucoside, and peonidine-3-O-glucoside. These extracts displayed antimicrobial potential against microorganisms such as Yersinia enterocolitica, Pseudomonas aeruginosa, Salmonella enteritidis, methicillin-sensitive Staphylococcus aureus, a methicillin-resistant Staph. aureus (MRSA), and Bacillus cereus. In conclusion, OH provides similar recovery yields with reduced treatment times, less energy consumption, and no need for organic solvents (green extraction routes). Thus, OH combined with water and citric acid allows a safe anthocyanin extraction from grape by-products, thus avoiding the use of toxic solvents such as methanol, and with high biological potential, including antimicrobial and antioxidant activity.

  • Are olive pomace powders a safe source of bioactives and nutrients?
    Tânia Bragança Ribeiro, Ana Oliveira, Marta Coelho, Mariana Veiga, Eduardo M Costa, Sara Silva, João Nunes, António A Vicente, and Manuela Pintado

    Wiley
    AbstractBACKGROUNDThe olive oil industry generates significant amounts of semi‐solid wastes, namely olive pomace. Olive pomace is a by‐product rich in high‐value compounds (e.g. dietary fibre, unsaturated fatty acids, polyphenols) widely explored to obtain new food ingredients. However, conventional extraction methods frequently use organic solvents, while novel eco‐friendly techniques have high operational costs. The development of powdered products without any extraction step has been proposed as a more feasible and sustainable approach.RESULTSThe present study fractionated and valorized the liquid and pulp fraction of olive pomace obtaining two stable and safe powdered ingredients, namely a liquid‐enriched powder (LOPP) and a pulp‐enriched powder (POPP). These powders were characterized chemically, and their bioactivity was assessed. LOPP exhibited a significant amount of mannitol (141 g kg−1), potassium (54 g kg−1) and hydroxytyrosol derivatives (5 mg g−1). POPP exhibited a high amount of dietary fibre (620 g kg−1) associated with a significant amount of bound phenolics (7.41 mg GAE g−1 fibre DW) with substantial antioxidant activity. POPP also contained an unsaturated fatty acid composition similar to that of olive oil (76% of total fatty acids) and showed potential as a reasonable source of protein (12%). Their functional properties (solubility, water‐holding and oil‐holding capacity), antioxidant capacity and antimicrobial activity were also assessed, and their biological safety was verified.CONCLUSIONSThe development of olive pomace powders for application in the food industry could be a suitable strategy to add value to olive pomace and obtain safe multifunctional ingredients with higher health‐promoting effects than dietary fibre and polyphenols. © 2020 Society of Chemical Industry

Publications

Among the various other publications I produced throughout my career, I must acknowledge the 8 book chapters I authored and the 24 oral (8 by invitation) and 49 poster communications I presented in various international conferences.

GRANT DETAILS

From Fundação para a Ciência and Tecnologia, I have been awarded a Travel Grant and a Ph.D. scholarship.
From the company Frulact S.A. I have been awarded a M.Sc. thesis grant.
From Centro de Biotecnologia and Química Fina, I have been awarded in 2020, 2021 and 2022 the CBQF annual incentive for extraordinary outputs.

RESEARCH OUTPUTS (PATENTS, SOFTWARE, PUBLICATIONS, PRODUCTS)

Manuela Pintado, Eduardo Costa, Sara Silva, Mariana Veiga, Freni Tavaria, Jorge Faria. Nanodyes, methods of obtention and uses thereof – PPP 115083
Manuela Pintado, Sara Silva,Eduardo M Costa, Mariana Veiga, Bruno Horta, Rui Morais. New extract, methods and use of thereof - PPP 109901.

CONSULTANCY

February 2017 until June 2017: Case study development on the cultivation of blueberries in Portugal: Identification of opportunities and possible additional exploitation venues.
Since 2018 Cosmeceutical and Biomedical consultant in the development of novel natural compound-based cosmetic formulations for the Bio4Life4You (Portugal) company.

Industry, Institute, or Organisation Collaboration

I have participated in 7 industry-academia R&D projects centred upon the development of agro-food by-products based sustainable solutions, culminating in over 17 novel solutions in food, cosmetics and nutraceutical industries.

INDUSTRY EXPERIENCE

From March 2019 to October 2022, I was employed my Amyris USA in their joint venture with CBQF (Alchemy Project). This was the largest ever publicly funded R&D project in Portugal.

STARTUP

In 2012 I was part of a natural product based functional beverage start-up (Pranamix).

SOCIAL, ECONOMIC, or ACADEMIC BENEFITS

I was a founding member of a Sustainability Team aimed at minimizing chemical extraction processes’ environmental impact.
I participated in scientific outreach activities as an organizing committee member of the 1st & 2nd Iberian Acorn Conference (speaker in the 1st) and as a speaker in the 1st National Marathon of Circular Economy Projects and in the European Researcher'Night as a speaker.