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Effects of gamma irradiation on chemical composition and antioxidant potential ...
Ferrreira, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Oliveira, M.B.P.P.; Martins, Anabela; Ferreira, Isabel C.F.R.It was previously demonstrated that gamma irradiation was the processing technology with the highest capacity to maintain the chemical profile of fresh Macrolepiota procera wild mushroom, when compared to freeze-dried or oven-dried samples. Herein, it was aimed to evaluate gamma irradiation effects on processed samples. Chemical composition and antioxidant potential of irradiated (0.5 and 1 kGy) fresh, frozen a...
Development of a novel methodology for the analysis of ergosterol in mushrooms
Barreira, João C.M.; Oliveira, M.B.P.P.; Ferreira, Isabel C.F.R.Sterols are important molecules in the unsaponifiable fraction of several matrices. Ergosterol, which is an important vitamin D2 precursor, is clearly the main sterol in mushrooms. Herein, an analytical method for ergosterol determination in cultivated and wild mushrooms was developed using high-performance liquid chromatography coupled to ultraviolet detection. The chromatographic separation was achieved in an...
Propensity for biofilm formation by clinical isolates from urinary tract infect...
Alves, Maria José; Barreira, João C.M.; Carvalho, Inês; Trinta, Luís; Pereira, Liliana; Ferreira, Isabel C.F.R.; Pintado, ManuelaA group of biofilm-producing bacteria isolated from patients with urinary tract infections was evaluated, identifying the main factors contributing to biofilm formation. Among the 156 isolates, 58 (37.2%) were biofilm producers. The bacterial species (P<0.001), together with patient's gender (P = 0.022), were the factors with the highest influence for biofilm production. There was also a strong correlation of c...
Feasibility of electron-beam irradiation to preserve wild dried mushrooms: effe...
Fernandes, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Oliveira, M.B.P.P.; Martins, Anabela; Ferreira, Isabel C.F.R.Mushrooms are highly perishable matrices and to extend time of consumption they need to be preserved. Since all the available conservation technologies present disadvantages, the combination of two different processes might minimize some of the limitations. Therefore, in the present work, electron-beam irradiation (up to 10 kGy) was applied to dried samples of Boletus edulis and Russula delica, extending previo...
Triacylglycerols profiling as a chemical tool to identify mushrooms submitted t...
Fernandes, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Martins, Anabela; Ferrreira, Isabel C.F.R.; Oliveira, M.B.P.P.In order to define irradiation treatment as a routine conservation methodology, it is imperative to develop chemometric indicators with the ability to distinguish irradiated from unirradiated foodstuffs. Electron spin resonance, photostimulated luminescence and thermoluminescence methods were employed to monitor radiation-induced markers, as well as different chemical compounds produced from the lipidic fractio...
Two-dimensional PCA highlights the differentiated antitumor and antimicrobial a...
Dias, Maria Inês; Barreira, João C.M.; Calhelha, Ricardo C.; Queiroz, Maria João R.P.; Oliveira, M.B.P.P.; Soković, Marina; Ferreira, Isabel C.F.R.Natural matrices are important sources of new antitumor and antimicrobial compounds. Species such as Laurus nobilis L. (laurel) might be used for this purpose, considering its medicinal properties. Herein, in vitro activity against human tumor cell lines, bacteria, and fungi was evaluated in enriched phenolic extracts. Specifically, methanol and aqueous extracts of wild and cultivated samples of L. nobilis were...
Phytochemical characterization and antioxidant activity of Opuntia microdasys (...
Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferrreira, Isabel C.F.R.; Achour, LotfiChemical composition and antioxidant activity of Opuntia microdasys flowers in different maturity stages was evaluated. Fructose, glucose, sucrose and trehalose were found; oxalic, quinic, malic, and citric acids were also detected; five hydroxycinnamoyl, two kaempferol and six isorhamnetin derivatives; 23 fatty acids were quantified in all stages, except C20:2, which was only found in post flowering stage (F3)...
Phenolic profile, antibacterial, antimutagenic and antitumour evaluation of Ver...
Živković, Jelena; Barreira, João C.M.; Stojković, Dejan; Cebovic, Tatjana; Santos-Buelga, Celestino; Maksimović, Zoran; Ferreira, Isabel C.F.R.This study was designed to characterize the phenolic profile and evaluate the antibacterial, antimutagenic and antitumor activities of Veronica urticifolia Jacq. methanolic extract. HPLC-DAD/ESI-MS analysis revealed the presence of phenolic acids, flavonoids and phenylethanoids, with acteoside as the main component (14.9 mg/g of extract). Antibacterial effect was determined using the microbroth dilution assay a...
Chemical characterization of the medicinal mushroom Phellinus linteus (Berkeley...
Reis, Filipa S.; Barreira, João C.M.; Calhelha, Ricardo C.; Van Griensven, Leo J.I.D.; Ćirić, Ana; Glamočlija, Jasmina; Soković, MarinaMushrooms are widely appreciated for their organoleptic qualities, being also recognized as good sources of bioactive compounds that provide antioxidant, antimicrobial and cytotoxic activities. Polysaccharides (including glucans) are often pointed out as the most bioactive compounds isolated from mushrooms, but other molecules such as triterpenoids, might also be highlighted for their bioactivity. In scientific...
Phenolic profiling of Veronica spp. grown in mountain, urban and sand soil envi...
Barreira, João C.M.; Dias, Maria Inês; Živković, Jelena; Stojković, Dejan; Soković, Marina; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Veronica (Plantaginaceae) genus is widely distributed in different habitats. Phytochemistry studies are increasing because most metabolites with pharmacological interest are obtained from plants. The phenolic compounds of V. montana, V. polita and V. spuria were tentatively identified by HPLC-DAD-ESI/MS. The phenolic profiles showed that flavones were the major compounds (V. montana: 7 phenolic acids, 5 flavone...
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