Percorrer por autor "Carvalho, Ana P."
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- Bioactive Lipids of Seaweeds from the Portuguese North Coast: Health Benefits versus Potential ContaminationPublication . Soares, Cristina; Sousa, Sara; Machado, Susana; Vieira, Elsa; Carvalho, Ana P.; Ramalhosa, Maria João; Morais, Simone; Correia, Manuela; Oliva-Teles, MT; Domingues, Valentina; Delerue-Matos, CristinaThe total lipid content and lipidic profile of seaweeds harvested in the North Coast and purchased in Portugal were determined in this paper. The amount of total lipids in the different species of seaweeds varied between 0.7 ± 0.1% (Chondrus crispus) and 3.8 ± 0.6% (Ulva spp.). Regarding the fatty acid content, polyunsaturated fatty acids (PUFA) ranged between 0–35%, with Ulva spp. presenting the highest amount; monounsaturated fatty acids (MUFA) varied between 19 and 67%; and saturated fatty acids (SFA) were predominant in C. crispus (45–78%) and Gracilaria spp. (36–79%). Concerning the nutritional indices, the atherogenicity index (AI) was between 0.4–3.2, the thrombogenicity index (TI) ranged from 0.04 to 1.95, except for Gracilaria spp., which had a TI of 7.6, and the hypocholesterolemic/hypercholesterolemic ratio (HH) values ranged between 0.88–4.21, except for Gracilaria spp., which exhibited values between 0.22–9.26. The n6/n3 ratio was below 1 for most of the species evaluated, except for Ascophyllum nodosum, which presented a higher value, although below 2. Considering the PUFA/SFA ratio, seaweeds presented values between 0.11–1.02. The polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHCs) contamination of seaweeds under study was also quantified, the values found being much lower than the maximum levels recommended for foodstuff.
- Brazilian fruit pulps as functional foods and additives: Evaluation of bioactive compoundsPublication . Paz, Mário; Gúllon, Patricia; Barroso, M. Fátima; Carvalho, Ana P.; Domingues, Valentina F.; Gomes, Ana M.; Becker, Helena; Longhinotti, Elisane; Delerue-Matos, CristinaEight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126–3987 mg TE/100 g DW) and ferric reduction activity power (368–20819 mg AAE/100 g DW), and complemented with total phenolic content (329–12466 mg GAE/100 g DW) and total flavonoid content measurements (46–672 mg EE /100 g DW), whereas antimicrobial activity was tested against the most frequently found food pathogens. Acerola and açaí presented the highest values for the antioxidant-related measurements. Direct correlations between these measurements could be observed for some of the fruits. Tamarind exhibited the broadest antimicrobial potential, having revealed growth inhibition of Pseudomonas aeruginosa. Escherichia coli, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Açaí and tamarind extracts presented an inverse relationship between antibacterial and antioxidant activities, and therefore, the antibacterial activity cannot be attributed (only) to phenolic compounds.
- DNA-based sensor against nitrite oxide radical: Evaluation of total antioxidant capacity in beveragesPublication . Cruz, Diana; Barroso, M. Fátima; Ramalhosa, Maria João; Coelho, Andreia; Silva, Hélder da; Duarte, Abel J.; González-García, Maria Begoña; Carvalho, Ana P.; Delerue-Matos, CristinaReactive nitrogen and oxygen species are produced in cells and play an important role in the oxidative metabolism; when in abnormal concentrations, they are able to induce oxidative damage on biomolecules, namely in DNA. In this paper it is described, an electrochemical DNA-based sensor against NOradical dot radical developed for total antioxidant capacity (TAC) evaluation. The sensor consisted on dA20 (adenine-rich oligonucleotide) physically adsorbed into carbon paste electrode (CPE). When this dA20-CPE was damaged, by immersion in a freshly generated NOradical dot radical, a protective effect onto dA20 was observed in the presence of antioxidants (ascorbic, gallic, caffeic, p-coumaric acids). Electrochemical studies were performed through square wave voltammetry. The construction of the sensor is simple, fast and the results indicated that the DNA-based sensor is suitable, accurate, and can be used to the assessment of TAC in commercial samples of juices.
- Identification of Eschweilenol C in derivative of Terminalia fagifolia Mart. and green synthesis of bioactive and biocompatible silver nanoparticlesPublication . Araujo, Alyne Rodrigues de; Ramos-Jesus, Joilson; Oliveira, Taiane Maria de; Carvalho, Andressa Maria A. de; Nunes, Paulo Humberto M.; Daboit, Tatiane Caroline; Carvalho, Ana P.; Barroso, M. Fátima; Almeida, Miguel Peixoto de; Plácido, Alexandra; Rodrigues, Artur; Portugal, Camila C.; Socodato, Renato; Relvas, João B.; Delerue-Matos, Cristina; Silva, Durcilene Alves da; Eaton, Peter; Leite, José Roberto de Souza de A.A green synthetic route was developed to prepare silver nanoparticles (AgNPs) in aqueous solution for biological applications. Eschweilenol C, a compound derivative ellagic acid was identified as the main constituent of the aqueous fraction of the ethanolic extract of Terminalia fagifolia Mart. by NMR analysis. In the green synthesis, the ethanolic extract of T. fagifolia and its aqueous fraction were used to promote silver reduction and nanoparticle stabilization. The synthesized AgNPs presented a spherical or polygonal morphology shape by TEM analysis and AgNPs showed high levels of antioxidant and considerable antibacterial and antifungal activities. Synthesized nanoparticles presented significant antioxidant activity by sequestration of DPPH and ABTS radicals, in addition to iron reduction (FRAP assay) and measurement of antioxidant capacity in ORAC units, in addition, AgNP synthesized with the aqueous fraction also demonstrated antioxidant potential in microglial cells. Gram-positive and Gram-negative bacteria were susceptible to growth inhibition by the nanoparticles, among which the AgNPs formed by the ethanolic extract was the most effective. The data obtained by AFM images suggested that AgNPs could lead to the lysis of bacteria and subsequent death. The antifungal assays showed high efficiency against yeasts and dermatophytes. This work represents the first description of antifungal activity by AgNPs against Fonsecaea pedrosoi, the etiologic agent of chromoblastomycosis. In relation to biocompatibility, the AgNPs induced lower haemolysis than AgNO3.
- Liquid by-products from fish canning industry as sustainable sources of ω3 lipidsPublication . Monteiro, Ana; Paquincha, Diogo; Martins, Florinda; Queirós, Rui P.; Saraiva, Jorge A.; Švarc-Gajić, Jaroslava; Nastić, Nataša; Delerue-Matos, Cristina; Carvalho, Ana P.Fish canning industry generates large amounts of liquid wastes, which are discarded, after proper treatment to remove the organic load. However, alternative treatment processes may also be designed in order to target the recovery of valuable compounds; with this procedure, these wastewaters are converted into liquid by-products, becoming an additional source of revenue for the company. This study evaluated green and economically sustainable methodologies for the extraction of ω3 lipids from fish canning liquid by-products. Lipids were extracted by processes combining physical and chemical parameters (conventional and pressurized extraction processes), as well as chemical and biological parameters. Furthermore, LCA was applied to evaluate the environmental performance and costs indicators for each process. Results indicated that extraction with high hydrostatic pressure provides the highest amounts of ω3 polyunsaturated fatty acids (3331,5 mg L-1 effluent), apart from presenting the lowest environmental impact and costs. The studied procedures allow to obtain alternative, sustainable and traceable sources of ω3 lipids for further applications in food, pharmaceutical and cosmetic industries. Additionally, such approach contributes towards the organic depuration of canning liquid effluents, therefore reducing the overall waste treatment costs.
- Microwave-assisted extraction in goji berries: effect on composition and bioactivity, evaluated through conventional and nonconventional methodologiesPublication . Carvalho, Ana P.; Mendes, Marta; Moreira, Manuela M.; Cruz, Diana; Magalhães, Júlia M. C. S.; Barroso, M. Fátima; Ramalhosa, Maria João; Duarte, Abel; Guido, Luís; Gomes, Ana M.; Delerue-Matos, CristinaThis study aimed to evaluate the effect of microwave-assisted extraction (MAE) parameters on the composition and bioactivity of goji (Lycium barbarum) extracts. Extracts were obtained under a central composite design combination of experimental conditions, and characterised through HPLC-DAD; their bioactive capacity was ascertained for antimicrobial and antioxidant capacity, the later by spectrophotometric [2,2-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt-radical scavenging activity assay – 413–748 mg ascorbic acid equivalents/100 g DW and oxygen radical absorbance capacity – 1901–2292 mg trolox equivalents/100 g DW] and electrochemical (DNA-based sensor – 3571–6602 mg ascorbic acid/100 g DW) methods. The quantitative profile of phenolic compounds was strongly dependent on MAE conditions. Significant correlations were found between the presence of several flavonoids and solvent composition, as well as between phenolic acids with methoxy group and the response to DNA-based sensor. Results may improve targeted extractions for specific compounds, leading to the achievement of extracts richer in antioxidant capacity, as well as in the tailoring of the biosensor response sensitivity to the composition of the extracts under analysis.
- Response surface evaluation of microwave-assisted extraction conditions for Lycium barbarum bioactive compoundsPublication . Mendes, Marta; Carvalho, Ana P.; Magalhães, Júlia M. C. S.; Moreira, Manuela; Guido, Luís; Gomes, Ana M.; Delerue-Matos, CristinaThe effects of microwave-assisted extraction (MAE) on the qualitative and quantitative composition of extracted bioactive phytochemicals are strongly dependent on specific operational conditions. The impact of temperature, extraction time, and solvent dielectric properties on the MAE of antioxidant compounds from goji berry is hereby reported and discussed. Results were evaluated in terms of antioxidant capacity (ascertained by ABTS and ORAC assays), complemented with quantification of total phenolics content (TPC), and characterization of extracts through HPLC. Furthermore, the effect of storage temperature was also studied. Results revealed that temperature and solvent properties exert a significant effect on TPC and ORAC assays, whereas irradiation time plays a key role in the preparation of extracts to be evaluated through ABTS. The effect of solvent properties is tentatively explained considering the dielectric properties of methanol and water, whereas the observed effect of temperature could be explained by its influence on the solubility of phenolic compounds.
- Sardine Canning Byproducts as Sources of Functional IngredientsPublication . Carvalho, Ana P.; Amorim, Manuela; Rodríguez-Alcalá, Luís; Fontecha, Javier; Castro, Paula M. L.; Pintado, Manuela E.Sardine by-products generated during canning process entail a potential opportunity to drive them into a chain of high added-value compounds, while simultaneously decreasing the environmental impact of their discharge. This paper describes and discusses the biochemical variation of solid and liquid by-products generated during the canning process of sardine along one complete year. Additionally, by-products were also evaluated in terms of their degradation along time, monitored through microbiological and chemical analysis. Finally, their valorisation was ascertained through the recovery of lipid fractions rich in ω3 polyunsaturated fatty acids (PUFA), as well as protein fractions with anti-hypertensive activity (ACE). The variability within biochemical composition of by-products along the year is significant, especially in terms of lipid content, and their degradation is strongly dependent on the conditions in which they were collected and stored. Both liquid and solid by-products present ω6/ω3 ratios between 0.05-0.18 and thrombogenic index between 0.27-0.57, whereas low-molecular-weight fractions of protein extracts (<3 kDa) exhibited the strongest ACE activity (IC50 = 51 µg/ml). The potential viability of using liquid by-products as sources of functional ingredients is an interesting alternative to the management of these effluents in fish canning industry.