Joana P.A. Ferreira

Dr. Joana P.A. Ferreira

Santarém Polytechnic University, School of Agriculture, Santarém, Portugal
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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 May 2019 in Biomass Conversion and Biorefinery
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CQCarla Queirós
Carla Queirós
SCSofia Cardoso
Sofia Cardoso
Ana LourençoAna Lourenço
Ana Lourenço
Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
IMIsabel Miranda
Isabel Miranda
HPHelena Pereira
Helena Pereira

14 June 2017 in PLOS ONE
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IMIsabel Miranda
Isabel Miranda
Vicelina SousaVicelina Sousa
Vicelina Sousa
Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
HPHelena Pereira
Helena Pereira
Heartwood and sapwood of Quercus faginea were evaluated in relation to summative chemical composition and non-polar and polar extracts composition, including an assessment of antioxidant properties (DPPH and FRAP). Twenty trees from two sites in Portugal were analysed. Heartwood had approximately two times more solvent extractible compounds than sapwood (on average 19.0% and 9.5%). The lipophilic extractible compounds were below 1%, and most of them were polar e.g. ethanol-soluble compounds corresponded to 65% of total extractives in heartwood and 43% in sapwood. Lignin content was similar in sapwood and heartwood (28.1% and 28.6% of extractive-free wood respectively) as well as the sugar composition. Site did not influence the chemical composition. The lipophilic extractible compounds from both sapwood and heartwood included mainly saturated fatty acids (23.0% and 36.9% respectively) and aromatic compounds were also abundant in sapwood (22.9%). The ethanol-water extractibles had a high content of phenolic substances (558.0 and 319.4 mg GAE/g extract, respectively of heartwood and sapwood). The polyphenolic composition was similar in heartwood and sapwood with higher content of ellagitannins (168.9 and 153.5 mg tannic acid/g of extract in sapwood and heartwood respectively) and very low content of condensed tannins. The antioxidant activity was very high with IC50 of 2.6 μg/ml and 3.3 μg/ml for sapwood and heartwood respectively, as compared to standard antioxidants (IC50 of 3.8 μg/ml for Trolox). The ferric reducing ability was 2.8 and 2.0 mMol Trolox equivalents/g extract of heartwood and sapwood respectively. The variability between trees was low and no differences between the two sites were found. Q. faginea showed a very good potential for cooperage and other applications for which a source of compounds with antioxidant properties is desirable.

1 November 2015 in Industrial Crops and Products
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Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
IMIsabel Miranda
Isabel Miranda
Jorge GominhoJorge Gominho
Jorge Gominho
HPHelena Pereira
Helena Pereira

5 July 2018 in PLOS ONE
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HLHanna Berhanu Lemma
Hanna Berhanu Lemma
ZKZebene Kiflie
Zebene Kiflie
IMIsabel Miranda
Isabel Miranda
Ana LourençoAna Lourenço
Ana Lourenço
Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
HPHelena Pereira
Helena Pereira
False banana /Ensete ventricosum [Welw.] Cheesman/ is exploited as a food crop in Ethiopia where it represents an important staple food. The plant is harvested and large amounts of biomass residues are originated, mainly from the pseudo stem (i.e., fiber bundles obtained from the leaf sheaths after being scrapped to produce starchy food) and the inflorescence stalk. These materials were studied in relation to their summative chemical composition, composition of lignin, lipophilic and polar extracts. Moreover, their structural characteristics, in view of their valorization, were scrutinized. The analytical studies were performed with the aid of FTIR, GC/MS, Py-GC/MS and SEM. The fiber bundles are aggregates of mainly long and slender fibers with low ash, extractives and lignin contents (3.8%. 4.4% and 10.5% respectively) and high holocellulose and α-cellulose contents (87.5% and 59.6% respectively). The hemicelluloses in the fibers are mostly highly acetylated xylans and the lignin is of the H-type (H:G:S, 1:0.7:0.8). This lignin composition is in line with the FTIR peaks at 1670 cm-1 and 1250 cm-1.The inflorescence stalk has high ash content (12.3% in the main stalk and 24.6% in fines) with a major proportion of potassium, high extractives (25.9%), and low lignin and α-cellulose contents (5.8% and 17.9% respectively). The stalk includes numerous starch granules in the cellular structure with the predominant presence of parenchyma. The potential valorization routes for these materials are clearly different. The fiber bundles could be used as a fiber source for paper pulp production with the possibility of a prior hemicelluloses removal while the inflorescence stalk has nutritional value for food and fodder. Furthermore, it can also be used for sugar fermentation products.

1 March 2009 in Journal of Ethnopharmacology
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Amélia Pilar RauterAmélia Pilar Rauter
Amélia Pilar Rauter
AMAlice Martins
Alice Martins
RLRui Lopes
Rui Lopes
Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
MSMaria Luísa M. Serralheiro
Maria Luísa M. Serralheiro
HMHelder Mota-Filipe
Helder Mota-Filipe

1 January 2020 in Evidence-Based Complementary and Alternative Medicine
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Joana P.A. FerreiraJoana P.A. Ferreira
Joana P.A. Ferreira
SSSara Santos
Sara Santos
HPHelena Pereira
Helena Pereira
Purpose. Acetylcholinesterase (AChE) inhibitors are used to treat Alzheimer’s patients because they enhance cholinergic neurotransmission. It is urgent to find new and efficient inhibitors from natural sources, highly bioavailable with low or no toxicity. The plant kingdom is extremely rich in a variety of compounds that are potent AChE inhibitors: flavonoids and other phenolic compounds have been recognized as promising Alzheimer’s treatment agents. In this study, in vitro acetylcholinesterase inhibition, antioxidant activities, and total flavonoid and phenolic contents of ethanol‐water extracts from Quercus suber cork and corkback were evaluated. Methods. The acetylcholinesterase activity was determined by a colorimetric assay based on Ellman’s methodology. The Folin–Ciocalteu colorimetric method was used for total phenolic content determination and the aluminium chloride method for the determination of total flavonoid content. Antioxidant activity assays were performed using the DPPH and FRAP assays. Results. The acetylcholinesterase inhibitory activity from Q. suber cork and corkback ethanol‐water extracts was as follows: 62% inhibition with corkback extracts over 0.5 mg/mL and around 49% inhibition in cork extracts over 1.0 mg/mL extracts’ concentration. Regarding the DPPH radical scavenging activity, the concentrations of cork and corkback ethanol‐water extracts required for 50% DPPH inhibition (IC50) were 3.2 μg/mL and 4.0–5.2 μg/mL. Corkback extracts are less effective than Trolox standard (3.2 μg/mL) but cork extracts showed the same free radical scavenging activity compared to Trolox. Cork and corkback extracts have antioxidant power of 750.9–775.4 mg TEAC/g extract and 1051.2–2052.4 mg TEAC/g extract, respectively, which are significantly higher than the ones obtained with Trolox: 19.6–21.0 mg TEAC/g extract (cork assays) and 57.4–66.3 mg TEAC/g extract (corkback assays). The amounts of total phenolic (TPC) and flavonoid (TFC) compounds were 8.7–32.3 mg GAE/g and 4.8–10.7 mg CE/g dry mass for cork and 5.4–5.7 mg GAE/g and 42.5 mg CE/g dry mass for corkback extracts, respectively, using catechin (CE) and GAE (gallic acid) as standards. Conclusion. These findings demonstrate the remarkable potential of these extracts as valuable source of antioxidants with interesting acetylcholinesterase inhibitory activity.