Browsing by Author "Oliveira, M.B.P.P."
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- Acorns as a food resourcePublication . Pacheco, R.; Ferreira da Vinha, Ana; Oliveira, M.B.P.P.The oaks (Quercus spp.) comprise the largest genus Fagaceae, an important family of evergreen or deciduous trees of temperate and tropical climatic areas. The acorn is a one-seeded nut, the hard, dry and indehiscent fruit of oaks, derived from a unilocular ovary of fused carpels. Acorns are an interesting source of carbohydrates, fats and fibers and also contain protein, amino acids and vitamins, mostly A and C. Additionally, it has been proven its antioxidant effects. Appreciation of acorn has been increasing, because of its potential as a food resource. The goal of the present review is to compile the published information about nutritional, phytochemical and bioactive composition of acorns.
- Antioxidant activity and antimicrobial properties of lemon grass essential oilPublication . Ferreira da Vinha, Ana; Soares, M.O.; Barreira, Sérgio; Castro, A.; Alves, R.C.; Oliveira, M.B.P.P.Essential oils have been explored comprehensively as potential sources of compounds with antioxidant and antimicrobial activities.
- Bioactive compounds and reducing ability of medicinal herbal infusions: a regard over their labelsPublication . Baptista, N.; Costa, A.; Ferreira da Vinha, Ana; Nunes, A.; Alves, R.; Cunha, L.M.; Oliveira, M.B.P.P.Consumer interest in a healthy diet has been growing exponentially. Consequently, food industries provide, nowadays, an increasing number of products (including teas and infusions) that label beneficial health and/or well-being effects. In this work, a preliminary survey of several herbs commonly used in commercial mixtures for infusions (horsetail, lemongrass, green tea, fennel, St. John’s wort, senna and tilia) was performed. Infusions of single plants (n=13) and mixtures (n=18) were analyzed and their labels verified in order to identify possible gaps in their claims. Total phenolics, total flavonoids and tannins contents, as well as the reducing ability (using FRAP assay) of samples, were determined.
- Carotenoids content of cherry tomato fruits: a comparative studyPublication . Aires, A.B.; Arantes, M.; Costa, A.S.G.; Alves, R.C.; Ferreira da Vinha, Ana; Oliveira, M.B.P.P.Consumption of cherry tomato fruits has been increasing due to the rising public demand for convenience and awareness of fruit's health benefits. Carotenoids, natural pigments synthesized by plants and microorganisms but not by animals, contribute to the different colours of tomato fruits and are recognized as playing an important role in several biological functions. In this work, we studied some carotenoid contents (chlorophyll a, chlorophyll b, lycopene and beta-carotene) of five cherry tomato cultivars (red cherry chucha, red cherry, striped cherry, yellow cherry, and red cherry cacho).
- Chemical characterization of coffee silverskin: in view of health and sustainabilityPublication . Costa, A.S.G.; Ferreira da Vinha, Ana; Santos, J.; Alves, R.C.; Oliveira, M.B.P.P.Laurus nobilis L. is an aromatic plant, whose leaves are frequently used as spice. Leaf extracts and essential oil have also been used in folk medicine for the treatment of several dysfunctions and in cosmetic industry.
- Commercial smoothies containing fruit and fermented milk: stability of quality attributes during storagePublication . Nunes, M.A.; Costa, A.; Ferreira da Vinha, Ana; Alves, R.; Rocha, A.; Oliveira, M.B.P.P.There is an expanding demand of consumers for natural food products that are fresh or minimally processed and convenient. Smoothies are blended beverages containing fruits, fruit purées, pulps and/or fruit juices, yoghurt or milk that preserve the desirable characteristics of fruits. The effect of processing and storage on commercial smoothies could affect quality attributes, like color and acidity, important parameters for the consumer acceptability of the product. The aim of this work was to analyze the physical and chemical properties associated with quality attributes, in different smoothie formulations available in the Portuguese market (n=16). Samples were divided into five groups, according to composition. The total titratable acidity, pH value and soluble solid content were determined using standard methods (NP EN 12147:1999, NP EN 1132:1996 and NP EN 12143:1999, respectively). The color was measured using a colorimeter, expressed in CIE units (L*, a*, b*) and converted to hue angle (h0) and chroma (C*). Analyses were performed into three moments after purchase (0, 14 and 21 days).
- Comparison of the nutritional value of fresh and freeze-dried elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) tuberPublication . Machado, L.; Costa, A.S.G.; Ferreira da Vinha, Ana; Alves, R.C.; Oliveira, M.B.P.P.Yams are members of different families, like Dioscoreae, Colocasia, Alocasia and Xanthosoma (Aracea) and are one of the oldest plants known. Elephant foot yam (Aracea) tuber has a great interest in food shortage periods for several populations.
- Cymbopogon citratus EO antimicrobial activity against multi-drug resistant Gram-positive strains and non-albicans-Candida speciesPublication . Soares, M.O.; Ferreira da Vinha, Ana; Barreira, Sérgio; Coutinho, F.; Aires-Gonçalves, S.; Oliveira, M.B.P.P.; Pires, P.C.; Castro, A.We studied the antibacterial and antifungal activity of Cymbopogon citratus. These properties were studied on hospital isolated multidrug resistant strains Staphylococcus aureus, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumonia and their respective ATCC control strains. Pathogenic Candida albicans, Candida parapsilosis, and Candida tropicalis were also tested. Results of the present investigation provide evidence that the EO of Cymbopogon citratus could have a potential application in the treatment and prevention of diseases caused by Staphylococcus aureus methicillin-resistant strains and by vancomicin-resistant Staphylococcus epidermidis. Cymbopogon citratus EO is also effective against Candida albicans as well as the emerging Candida parapsilosis and Candida tropicalis pointing to its usefulness as an antifungal agent.
- Development of an HPLC/DAD method for determination of phenolic profile in portuguese olive fruitsPublication . Ferreira da Vinha, Ana; Andrade, P.B.; Silva, B.M.; Pereira, J.A.; Valentão, P.; Seabra, R.M.; Oliveira, M.B.P.P.Phenolics are characteristic constituents of green plants occurring in virtually all parts of the plant but with quantitative distributions that vary between different organs of the plant and within different populations of the same plant species. Phenolics in olive pulp and oil constitute a complex mixture and the complete chemical nature has not, as yet, been elucidated1 Phenolic compounds may contribute to fruit quality in a number of ways; for example, by contributing to sensory attributes, such as colour and flavour, and through the contribution of some specific phenolics, in particular oleuropein, to the intense bitterness of the olive fruit. Factors contributing to the variability in phenolic distribution include cultivar and genetics, geographical origin, maturity, climate, position on tree, rootstock and agricultural practices. In the case of processed products, technological processes to which olive fruits are exposed may also impact significantly on the phenolic content. Here we studied the following aspects of the determination of polyphenols in Portuguese olive fruits: extraction, chromatographic separation, and quantification.
- Dietary supplements for cognitive function improvement: control of amino acid levelsPublication . Pimentel, F.B.; Botelho, J.; Costa, C.G.; Costa, A.S.G.; Ferreira da Vinha, Ana; Alves, R.C.; Oliveira, M.B.P.P.Neurodegenerative diseases affect cognitive functions by progressive and irreversible destruction of brain cells. The medical treatment is often complemented with dietary supplementation in order to suppress the lack of nutrients that is common in these situations. Some amino acids are especially important to prevent or delay the progress of such diseases. For example, tryptophan, tyrosine, and phenylalanine are biosynthetic precursors of important neurotransmitters (serotonin, dopamine, and norepinephrine), and glutamate and aspartate are themselves brain neurotransmitters. The aim of this study was to evaluate the amino acids composition of commercial dietary supplements (n=8) for improvement of memory and cognitive function.
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