DigitUMa

University of Madeira Institutional Repository

Bem-vindo ao Repositório Digital da UNIVERSIDADE DA MADEIRA.

O Repositório da Universidade da Madeira (UMa), conhecido pelo acrónimo DigitUMa, tem como objetivo a disponibilização, em regime de livre acesso e texto integral, de toda a produção científica realizada pelos docentes, investigadores da UMa, discentes dos 2º e 3º ciclos e pelos funcionários.

O Repositório Institucional, DigitUMa, assenta na política de Acesso Aberto à informação e conhecimento científicos.

Email antonio.freitas@staff.uma.pt

Recent Submissions

Editorial: Food bioactives: cutting-edge methodologies for extraction and characterization

Publication . Pereira, Jorge A. M.; Casado, Natalia; Câmara, José S.; Augusto Machado Pereira, Jorge; Câmara, José

2022-12-09Journal article

Open access

Behind the scenes of anthocyanins—From the health benefits to potential applications in food, pharmaceutical and cosmetic fields

Publication . Câmara, José S.; Monica Locatelli; Pereira, Jorge A. M.; Oliveira, Hélder; Arlorio, Marco; Fernandes, Iva; Perestrelo, Rosa; Freitas, Victor; Bordiga, Matteo; Câmara, José; Augusto Machado Pereira, Jorge

Anthocyanins are widespread and biologically active water-soluble phenolic pigments responsible for a wide range of vivid colours, from red (acidic conditions) to purplish blue (basic conditions), present in fruits, vegetables, and coloured grains. The pigments’ stability and colours are influenced mainly by pH but also by structure, temperature, and light. The colour-stabilizing mechanisms of plants are determined by inter- and intramolecular co-pigmentation and metal complexation, driven by van der Waals, π–π stacking, hydrogen bonding, and metal-ligand interactions. This group of flavonoids is well-known to have potent anti-inflammatory and antioxidant effects, which explains the biological effects associated with them. Therefore, this review provides an overview of the role of anthocyanins as natural colorants, showing they are less harmful than conventional colorants, with several technological potential applications in different industrial fields, namely in the textile and food industries, as well as in the development of photosensitizers for dye-sensitized solar cells, as new photosensitizers in photodynamic therapy, pharmaceuticals, and in the cosmetic industry, mainly on the formulation of skin care formulations, sunscreen filters, nail colorants, skin & hair cleansing products, amongst others. In addition, we will unveil some of the latest studies about the health benefits of anthocyanins, mainly focusing on the protection against the most prevalent human diseases mediated by oxidative stress, namely cardiovascular and neurodegenerative diseases, cancer, and diabetes. The contribution of anthocyanins to visual health is also very relevant and will be briefly explored.

2022-12-02Journal article

Open access

Green extraction approach based on μSPEed® followed by HPLC-MS/MS for the determination of atropine and scopolamine in tea and herbal tea infusions

Publication . González-Gómez, Lorena; Pereira, Jorge A. M.; Morante-Zarcero, Sonia; Câmara, José S.; Sierra, Isabel; Augusto Machado Pereira, Jorge; Câmara, José

liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been proposed for the analysis of atropine and scopolamine in tea and herbal tea infusions. For this, a digiVOL® Digital Syringe was used with different sorbents and working conditions to obtain a fast and efficient µSPEed® extraction. The best performance was achieved with a PS/DVB sorbent phase, sample loading of 5 × 500 µL and elution with 2 × 100 µL aliquots of methanol. The strategy based on µSPEed® followed by HPLC-MS/MS was validated, attaining quantitation limits lower than 0.15 ng mL− 1 and recoveries between 94 and 106% for both analytes and applied to seventeen tea and herbal tea infusions. Fourteen infusions showed contamination with one or both analytes above the maximum content legislated (sum of atropine and scopolamine < 0.2 ng mL− 1).

2022-11Journal article

Open access

Improved analytical approach for determination of tropane alkaloids in leafy vegetables based on µ-QuEChERS combined with HPLC-MS/MS

Publication . González-Gómez, Lorena; Morante-Zarcero, Sonia; Pereira, Jorge A. M.; Câmara, José S.; Sierra, Isabel; Augusto Machado Pereira, Jorge

This work presents an optimized methodology based on the miniaturization of the original QuEChERS (μ-QuEChERS) followed by liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) for the determination of tropane alkaloids (TAs), atropine, and scopolamine in leafy vegetable samples. The analytical methodology was successfully validated, demonstrating quantitation limits (MQL) ≤ 2.3 ng/g, good accuracy, and precision, with recoveries between 90–100% and RSD ≤ 13% for both analytes. The method was applied to the analysis of TA-producing plants (Brugmansia versicolor, Solandra maxima, and Convolvulus arvensis). High concentrations of scopolamine were found in flowers (1771 mg/kg) and leaves (297 mg/kg) of B. versicolor. The highest concentration of atropine was found in flowers of S. maxima (10.4 mg/kg). Commercial mixed leafy vegetables contaminated with B. versicolor and S. maxima were analysed to verify the efficacy of the method, showing recoveries between 82 and 110% for both analytes. Finally, the method was applied to the analysis of eighteen samples of leafy vegetables, finding atropine in three samples of mixed leafy vegetables, with concentrations of 2.7, 3.2, and 3.4 ng/g, and in nine samples with concentrations ≤MQL. In turn, scopolamine was only found in a sample of chopped Swiss chard with a concentration ≤MQL.

2022-09-20Journal article

Open access

Vidas paralelas. Filopémen e Flaminino

Publication . Pereira, Reina Marisol Troca; Pinheiro, Joaquim; Pinheiro, Joaquim

O objetivo deste livro é fornecer, em língua portuguesa, uma tradução do par biográfico Filopémen-Flaminino, com uma breve introdução e notas de apoio à leitura e compreensão do texto.

2024Book

Open access