Percorrer por autor "Heleno, Sandrina A."
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- Adansonia digitata L. (mukua): um possível alimento funcionalPublication . Fernandes, Filipa Alexandra; Carocho, Márcio; Calhelha, Ricardo C.; Pires, Tânia C.S.; Freitas, José Carlos; Prieto Lage, Miguel A.; Heleno, Sandrina A.; Barros, LillianAdansonia digitata L. é espécie africana com vários usos tradicionais, nomeadamente medicinal e alimentar [1,2]. A polpa do seu fruto, comumente conhecido como mukua, está aprovada como um ingrediente alimentar pela Comissão Europeia e pela “Food and Drug Administration of the United States of America” [1]. Assim o objetivo deste trabalho foi comprovar a potencialidade da polpa da mukua como um alimento funcional através da sua caracterização nutricional, mineral e bioativa. O perfil nutricional foi obtido aplicando metodologias oficiais de análise AOAC [3]. O conteúdo mineral foi determinado por espectrofotometria de absorção atómica e o potencial bioativo foi determinado através da atividade antioxidante pelo ensaio antioxidante celular (CAA) e um ensaio de inibição de substâncias reativas do ácido tiobarbitúrico (TBARS). Além disso, a atividade antimicrobiana foi também determinada, através do método de microdiluição, e a atividade antitumoral foi avaliada em três linhas celulares tumorais humanas: adenocarcinoma gástrico (AGS), carcinoma de mama (MCF-7), células de carcinoma de pulmão (NCI-H460), e a citotoxicidade em culturas de células não tumorais de rim de macaco africano (VERO), através do ensaio da Sulforrodamina B. Relativamente aos resultados obtidos, a polpa de mukua apresentou um teor de humidade muito baixo (11,9 + 0,3 g/100 g ms). Os macronutrientes presentes em maior quantidade foram os hidratos de carbono (89,6 ± 0,2 g/100 g ms), seguidos das proteínas (2,7 ± 0,3 g/100 g ms) e da gordura bruta (1,8 + 0,1 g/100 g ms), representando um valor energético de 386 ± 1 kcal/100 g ms. Quanto ao perfil mineral, a amostra revelou um alto teor em potássio (20,4 ± 0,8 g/100 g ms), estando também presentes minerais como o magnésio (3,28 ± 0,08 g/100 g ms), o cálcio (2,79 ± 0,07 g/100 g ms), o manganês (2,02 ± 0,09 g/100 g ms) e o ferro (1,53 ± 0,09 g/100 g ms). Em relação à atividade antioxidante, a polpa inibiu cerca de 32% da oxidação celular no método CAA e exibiu um valor de EC50 de 23,0 ± 0,1 μg/mL no ensaio de TBARS. Para a atividade antimicrobiana, a polpa apresentou atividade bacteriostática contra a maioria das bactérias testadas. No ensaio de citotoxicidade, a polpa demonstra capacidade de inibir a proliferação celular contra as linhas tumorais testadas, principalmente contra AGS com valores de GI50 de 92 ± 1 μg/mL, sem toxicidade para as células não-tumorais. Este estudo mostra que a polpa de mukua, além de ser nutricionalmente interessante, possui alto teor em minerais, nomeadamente em potássio que é um composto essencial para a bom funcionamento do corpo, estando associado à prevenção de doenças como diabetes, osteoporose e ainda doenças cardiovasculares. Além disso, a polpa da mukua possui alto potencial bioativo, o que indica que o seu consumo pode oferecer benefícios para a saúde, tornando-o num potencial alimento funcional.
- Análise metabolómica dirigida em cogumelos silvestres do género Boletus.Publication . Heleno, Sandrina A.; Vieira, Vanessa; Gamalho, Azucena M.; Barros, Lillian; Martins, Anabela; Ferreira, Isabel C.F.R.Os cogumelos são muito apreciados pelas suas propriedades organolépticas e nutricionais, mas também pelas suas propriedades medicinais devido à acumulação de metabolitos bioactivos [1,2]. Neste trabalho, apresentaremos uma análise metabolómica dirigida em espécies silvestres do género Boletus provenientes do Nordeste de Portugal: B. aereus, B. edulis, B. reticulatus (comestíveis), B. purpureus, B. satanas e B. rhodoxanthus (não-comestíveis). Foram analisados metabolitos primários incluindo açúcares (cromatografia líquida de alta eficiência acoplada a detecção por índice de refracção, HPLC-RI), ácidos gordos (cromatografia gasosa acoplada a detecção por ionização de chama, GC-FID), tocoferóis (HPLC-fluorescência) e ácido ascórbico (espectrofotometria). Analisaram-se também metabolitos secundários, nomeadamente ácidos fenólicos, por HPLC-DAD). Os metabolitos antioxidantes foram relacionados com a actividade captadora de radicais DPPH (2,2-difenil-1-picril-hidrazilo), poder redutor e inibição da peroxidação lipídica.
- Analysis of phenolic, polysaccharidic and lipidic fractions of mushrooms from northeast PortugalPublication . Heleno, Sandrina A.; Barros, Lillian; Martins, Anabela; Queiroz, Maria João R.P.; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Mushrooms consumption continues to increase due to their functional benefits and presence of bioactive compounds. Herein, phenolic, polysaccharidic and lipidic fractions of wild mushrooms from Northeast Portugal (Coprinopsis atramentaria, Lactarius bertillonii, Lactarius vellereus, Rhodotus palmatus and Xerocomus chrysenteron) were analysed. Protocatechuic, phydroxybenzoic, p-coumaric and cinnamic acids were found in the phenolic fraction; ramnose, xylose, fucose, arabinose, fructose, glucose, manose, mannitol, sucrose, maltose and trehalose were quantified in polysaccharidic fraction; linoleic and stearic (only in Lactarius sp.) acids, and β- and γ-tocopherols were the main compounds in the lipidic fraction.
- Anthocyanin profile of elderberry juice: A natural-based bioactive colouring ingredient with potential food applicationPublication . Silva, Ricardo Fernando Ribeiro; Barreira, João C.M.; Heleno, Sandrina A.; Barros, Lillian; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.Elderberry (Sambucus nigra L.) is a widely disseminated plant that produces bright black berries containing high quantities of anthocyanins, acknowledged for their bioactivity and dye capacity. Besides other applications, anthocyanins might be employed as natural colouring agents to reduce/eliminate the use of artificial dyes, while providing positive e ects on consumers’ health. Herein, the anthocyanins profile of elderberry juice was characterised by HPLC-DAD-ESI/MSn. In addition, its antioxidant capacity and cytotoxicity were also evaluated. As a proof-of-concept of its colouring capacity, elderberry juice was added (di erent percentages) to a highly appreciated and consumed pastry product (croissant) and compared with a commercial dye (black carrot). In general, the nutritional properties of control and coloured croissants were similar, despite some individual di erences in sugars and fatty acids. In turn, the appearance obtained with elderberry juice incorporation might be considered innovative, besides partially maintaining the anthocyanins content of fresh juice and showing considerable antioxidant activity.
- Anthocyanins from rubus fruticosus l. And morus nigra l. applied as food colorants: a natural alternativePublication . Vega, Erika N.; Molina, Adriana K.; Pereira, Carla; Dias, Maria Inês; Heleno, Sandrina A.; Rodrigues, Paula; Fernandes, Isabel P.; Barreiro, M.F.; Stojković, Dejan; Soković, Marina; Carocho, Márcio; Barreira, João C.M.; Ferreira, Isabel C.F.R.; Barros, LillianGiven the importance of colour in the general acceptance or rejection of a product, the use of colorants is a widespread practice, particularly in the food industry. At the same time, with the increasing consumers’ awareness of the health effects that some artificial colorants can exert, there is a growing tendency to prioritize foodstuffs containing natural additives. In this work, Morus nigra L. and Rubus fruticosus L. fruit juices were characterized in terms of anthocyanins, organic acids, free sugars, and tocopherols, as also regarding their bioactive properties. Given their richness in anthocyanins, this study also aimed to prepare different solid colouring formulations by the spray-drying technique, using as stabilizers maltodextrin and arabic gum. Six free sugars and two organic acids were detected in the fruit juices, as well as the four tocopherol isoforms. Two cyanidin derivatives were found in M. nigra (cyanidin-3-O-glucoside and cyanidin-O-rhamnoside) and other four in R. fruticosus (cyanidin-O-hexoside, cyanidin-3-O-glucoside, cyanidin-O-pentoside, and cyanidin-3-O-dioxaloilglucoside). The developed colouring formulations revealed a good stability over time, in terms of anthocyanin concentration and colour parameters, and revealed to be safe for consumption, either concerning their low microbial load and lack of cytotoxicity. Thus, they represent a promising natural alternative to the massively used artificial colorants.
- Anti-inflammatory activity of mushrooms extracts, identified phenolic acids and their possible metabolitesPublication . Taofiq, Oludemi; Calhelha, Ricardo C.; Heleno, Sandrina A.; Barros, Lillian; Martins, Anabela; Abreu, Rui M.V.; Queiroz, Maria João R.P.; Ferreira, Isabel C.F.R.Mushrooms are rich sources of many bioactive compounds, such as phenolic acids, that play an important role in the organism, acting as antioxidants, antitumors, antimicrobials, immunomodulators, among others. However, their anti-inflammatory activity has not been deeply studied. In the present study, the ethanolic extracts of fourteen edible mushroom species were firstly characterized in terms of phenolic acids and related compounds by HPLC-PDA, followed by the study of the anti-inflammatory activity of those extracts and corresponding identified compounds, by using LPS (lipopolysaccharide) activated RAW 264.7 macrophages and measuring the inhibition in NO production. Furthermore, methylated and glucuronated derivatives of the identified compounds (p-hydroxybenzoic, p-coumaric and cinnamic acids) were synthesised and evaluated for the same bioactivity to understand the contribution of these compounds for the overall activity of the extracts, and to establish structure-activity relationships. Pleurotus ostreatus, Macrolepiota procera, Boletus impolitus and Agaricus bisporus revealed the strongest anti-inflammatory potential, presenting also the highest concentration in cinnamic acid, which was also the individual compound displaying the highest activity. The derivative compounds of p-coumaric acid revealed the strongest properties, especially the compound CoA-M1 (presenting an ester instead of the carboxylic group), that exhibited a very similar activity to the one showed by dexamethasone, used as anti-inflammatory standard. On the contrary, p-hydroxybenzoic acid derivatives revealed the lowest activity. Overall, the conjugation reactions change the chemical structure of phenolic acids and may increase or decrease their activity; nevertheless, the glucuronated and methylated derivatives of the studied compounds are still displaying anti-inflammatory activity.
- Antifungal activity of Chamomilla recutita L. and Foeniculum vulgare Mill. aqueous extracts in cottage cheesePublication . Alves, Maria José; Heleno, Sandrina A.; Caleja, Cristina; Oliveira, Joana; Pimentel, Vanessa; Kostić, Marina; Soković, Marina; Ferreira, Isabel C.F.R.Introduction: The use of natural substances with fungicide, insecticide and herbicide properties is the focus of intensive research in order to develop sustainable foodstuff. Objectives: To assess the inhibition effect of Chamomilla recutita and Foeniculum vulgare aqueous extracts, against yeasts and fungi directly in cottage cheese along storage at 4ºC (t0, after 7 days (t7) and after 14 (t14) days). Methodology: Cottage cheese was incorporated with aqueous extracts of C. recutita and F. vulgare. Yeasts and molds were grown in Dichloran Rose Bengal Chloramphenicol medium (Agar-DRBC). The antifungal activity was evaluated by the microdilution method in plate. Results: After observation of the cottage cheese cultures in specific medium at t0, it can be stated that it was not verified any growth neither in control nor in the samples incorporated with the plant extracts. However, at t7 and t14 it was observed growth of yeasts and fungi in control, while the samples with C. recutita and F. vulgare revealed no growth of yeasts in Agar-DRBC. Thus, we note that both C. recutita and F. vulgare inhibited the growth of yeasts and fungi directly in the cottage cheese. Fungal colonies present in curd control were identified and verified as being the yeast Candida krusei and filamentous fungus Cladospoirium herbarum. C. recutita and F. vulgare showed antifungal activity against C. krusei (MIC = 50 mg/ml and 25 mg/ml, respectively) and C. herbarum (MIC = 100 mg/ml in both cases). Conclusion: The two tested plant extracts were able to inhibit the growth of the mentioned yeast and fungi, being able to increase the shelf life of the cottage cheese.
- Antimicrobial activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl estersPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Esteves, Ana P.; Ćirić, Ana; Glamočlija, Jasmina; Martins, Anabela; Soković, Marina; Queiroz, Maria João R.P.Ganoderma lucidumis one of the most famous traditional medicinal mushrooms, being used as functional food and in preventive medicines [1 ]. p-Hydroxybenzoic and cinnamic acids were previously identified, by our research group, in wild G. lucidum from Northeast of Portugal [2].Many studies suggest that phenolic compounds are rapidly metabolized in the human organism being glucuronidation the most prevalent metabolic pathway for phenolic compounds in humans. Despite the large data concerning the antimicrobial effects of phenolic acids [3], studies dealing with the antimicrobial properties of their metabolites or derivatives are scarce due to the fact that most of these compounds are not commercially available. Herein we describe the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids. Their antimicrobial activity was evaluated and compared to the parent acids and G. lucidum extract.p-Hydroxybenzoic and cinnamic acids, as also their protected glucuronide derivatives revealed high antimicrobial (antibacterial and antifungal) activity, even better than the one showed by commercial standards. Despite the variation in the order of parent acids and the protected glucuronide derivatives, their antimicrobial activity was always higher than the one revealed by the extract. The synthesized acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds.
- Antimicrobial activity of rosemary, eucalyptus and propolis individual and mixed extractsPublication . Abir, Tebai; Oliveira, Izamara; Falcão, Soraia; Ben Rejeb, Ines; Barros, Lillian; Heleno, Sandrina A.Preservative-free meals and the use of natural products as natural alternatives are becoming more popular as consumers become more aware of the potential health problems associated with artificial food preservatives. The current study focused on exploring the potential of plant extracts (rosemary and eucalyptus) and propolis, or their mixtures, to develop a highly bioactive formulation. Extracts were prepared individually and mixtures of eucalyptus/propolis, eucalyptus/rosemary, and rosemary/propolis using hydroethanolic extracts (80% ethanol) in different ratios of 50:50, 60:40, and 40:60, respectively., were also prepared. The selected matrices were prepared by two different maceration processes: i) 1 g of the sample was macerated in 30 mL of 80% hydroethanolic solution using magnetic stirring; ii) 1 g of sample in 10 mL of hydroethanolic solution was macerated in a water bath at 70°C, this being, the recommended protocol for extraction of phenolic compounds from propolis [1]. The extracts were further analyzed for their antimicrobial ability by microdilution method using pathogenic microorganisms. The individual extracts of rosemary and eucalyptus showed remarkably strong antibacterial activity against most bacterial strains, often equivalent to that obtained with the common antibiotic’s streptomycin, methicillin, and ampicillin. Both mixtures, eucalyptus/rosemary (60:40) collected from maceration by magnetic stirring and eucalyptus/propolis (60:40) derived from maceration with water bath, showed the most promising results, with inhibition ability against all bacteria. As for the antifungal ability, no inhibition was obtained at the maximum tested concentration of 10 mg/mL. In addition to these encouraging results for antimicrobial activity, further bioactivity assays will be performed to evaluate the properties of the different extracts.
- Antimicrobial and demelanizing activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl estersPublication . Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Esteves, Ana P.; Ćirić, Ana; Glamočlija, Jasmina; Martins, Anabela; Soković, Marina; Queiroz, Maria João R.P.Mushroom extracts or isolated compounds may be useful in the search of new potent antimicrobial agents. Herein, it is described the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, two compounds identified in the medicinal mushroom Ganoderma lucidum. Their antimicrobial and demelanizing activities were evaluated and compared to the parent acids and G. lucidum extract. p-Hydroxybenzoic and cinnamic acids, as also their protected glucuronide derivatives revealed high antimicrobial (antibacterial and antifungal) activity, even better than the one showed by commercial standards. Despite the variation in the order of parent acids and the protected glucuronide derivatives, their antimicrobial activity was always higher than the one revealed by the extract. Nevertheless, the extract was the only one with demelanizing activity against A. niger. The acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds.