A carregar...
148 resultados
Resultados da pesquisa
A mostrar 1 - 10 de 148
- Uma nova era para Quercus spp.: sustentabilidade de recursos naturais subvalorizadosPublication . Ferreira da Vinha, Ana; Barreira, João C.M.; Costa, Anabela S.G.; Oliveira, M. Beatriz P.P.The genus Quercus spp. belongs to the family Fagaceae, being widespread throughout the Northern Hemisphere. Quercus fruits (acorns) play an important role on the rural economy for animal feeding. However, their nutri!onal value and high phytochemical contents have raised the interest of many researchers looking for underu!lized foods to integrate the human diet. Previous studies highlighted acorns as a rich natural source of essen!al nutrients and individual phytochemicals with an!oxidant, an! tumoral and cardioprotec!ve proper!es. Other reports inclusively described their use in folk medicine for the treatment of atherosclerosis, diabetes and Alzheimer’s disease. At the industrial level, some Quercus spp. fruits are already used as edible oil and flour, but a wide diversity of other specialty products could be developed. Accordingly, the comprehensive characteriza!on of these fruits may lead to an increase in their added value for further applica!ons in several industries, such as food, pharmaceu!cal, or cosme!cs, genera!ng addi!onal profits and, essen!ally, improving social, economic and environmental sustainability.
- Baobab fruit: assessment of seed kernel lipid fractionPublication . Passos, Fábio; Nunes, M. Antónia; Pimentel, Filipa; Costa, Anabela S.G.; Ferreira da Vinha, Ana; Oliveira, M. Beatriz P.P.Fruit seeds are important sources of oils for nutritional, pharmaceutical and industrial purposes, despite their differences in fatty acids composition. To study the viability of baobab seed kernel valorization as a new alternative edible oil source, it is essential to characterize its lipid fraction. Oil was obtained by Soxhlet extraction with petroleum ether (2.5 h). Fatty acid methyl esters (FAME) were then analyzed by GC, in a Shimadzu GC-2010 gas chromatograph with a flame ionization detector (Shimadzu, Columbia). Vitamin E profile (α, β, γ and δ-tocopherols and α, β, γ and δ-tocotrienols) was determined by NP-HPLC/DAD/FLD, in an HPLC integrated system (Jasco, Japan).
- 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.
- Valorization of Arbutus unedo L. berries: a study on their nutritional and phytochemical compositionPublication . Albuquerque, C.; Ferreira da Vinha, Ana; Costa, A.S.G.; Alves, R.C.; Oliveira, M.B.P.P.In the Mediterranean region, fruits and leaves of Arbutus unedo L. (Ericaceae) are traditionally used due to their therapeutic benefits (antiseptic, diuretic, laxative, hypotensive). The fruits are also used in the production of jams, or fermented and distilled into liquors, common practices in rural areas of Portugal. As they are still considered an underutilized fruit-tree species, the aim of this study was to study the nutritional and phytochemical composition of fresh A. unedo L. berries harvested in the North of Portugal (Minho), to promote their consumption and valorization. Nutritional composition was evaluated according to AOAC methodologies. Total phenolics, flavonoids, anthocyanins, and carotenoids contents were evaluated by spectrophotometric methods.
- Avaliação do teor fenólico e actividade anti-oxidante em dióspiros (diospyrus kaki) cultivados em diferentes áreas geográficas de Portugal ContinentalPublication . Calhandro, M.; Ferreira da Vinha, Ana; Machado, M.A oxidação é um processo metabólico que leva à produção de energia necessária para as atividades essenciais das células. No entanto, o metabolismo do oxigénio, nas células vivas, origina a formação de radicais livres levando ao stress oxidativo, que tem sido associado ao aparecimento de muitas doenças crónicas e degenerativas, como cancro, doenças cardiovasculares, Alzheimer e o próprio processo de envelhecimento.
- Efeitos sinérgicos entre a cafeína e os fenólicos totais, na capacidade antioxidante de seis plantas usadas na medicina tradicional portuguesaPublication . Costa, A.; Soares, M.O.; Herdeiro, T.; Machado, M.; Ferreira da Vinha, AnaOs chás, de recorrente uso na medicina tradicional, verificam teores significativos de compostos fenólicos, os quais estão relacionados com o elevado potencial antioxidante.
- Nutraceuticals based on portuguese grape pomaces as a potential additive in food productsPublication . Ferreira da Vinha, Ana; Silva, Carla Sousa e; Sousa, Gonçalo de Magalhães e; Moutinho, Carla; Brenha, João; Sampaio, RicardoPortuguese wine industry by-products are often undervalued but constitute a potential source of bioactive phenoliccompounds that can be applied as a natural additive in several industries. In this context, the present study aimed to evaluate the nutritional composition, and the phenolic profile of two Portuguese Vitis vinifera L. grape pomaces (Touriga Nacional (red variety) and Alvarinho (white variety), and to correlate their chemical characterizations with their antioxidant activities. Strong correlations were observed between the presence of phenolic compounds and antioxidant activities, which enhances the application of pomace extracts in food and pharmaceutical areas. The high content of total phenolic compounds (25 - 41 g/ kg dry extract) and of flavonoids (9.2 - 18 g/ kg dry extract) found in both samples make these pomaces excellent candidates as food additives in food products, as well as antioxidant agents, such as natural dyes. Some polyphenols were identified by High Performance Liquid Chromatography (HPLC), being rutin and catequin the highest compounds found in red grape pomace (Touriga Nacional) while quercetin was only quantified in white grape pomace (Alvarinho). Cis-resveratrol was quantified in both grape pomace, which opens horizons for its use since this compound has considerable chemopreventive effects in the three main gains of carcinogenesis. As expected, the anthocyanin content was significantly higher in red grape pomace (37 g/ kg dry extract), emphasizing its interest as a natural food additive. Based on the findings, it is possible to conclude that these by-products have additional value, making them potentially useful in the food, pharmaceutical, and cosmetic industries.
- Fishing industry by-products: further applications in food, pharmaceutical and cosmetic industriesPublication . Ferreira da Vinha, Ana; Barbosa, Joana; Silva, Carla Sousa eThe agro-food industries, including the fishing industry, annually produce large quantities of by-products, whose valuation is still minimal or practical null. Currently, it is known that only a small part is reused for direct animals feeding or for composting. Considering that these by-products contain important levels of nutrients and bioactive compounds, some alternative ways of using by-products from the fishing industry are mentioned, namely for pharmaceutical and cosmetic industries. Nevertheless, the importance of sustainability must be taken in consideration, once it is an overly complex concept that involves economic and social development, without causing major damage to the environment. Biotechnology advances for marine by-products conversion into products of interest are numerous. Despite this, the fish sector is facing several issues such as wild fish stocks reduction while, at the same time, aquaculture rises, augmentation of the importations on a global market, and consumers behaviors. All those influent parameters affect and complicate the definition of an upgrading strategy for the by-products as they directly depend to the raw material processed. In view of the importance that the fishing industry has at international level, this work has attempted to characterize and enhance the by-products generated by this activity, through a detailed description of the nutritional, chemical and biological properties presented in fisheries waste, which can benefit, in the near future, the food, pharmaceutical and cosmetic industries.
- 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.
- High-value compounds in papaya by-products (Carica papaya L. var. Formosa and Aliança): potential sustainable use and exploitationPublication . Ferreira da Vinha, Ana; S.G.Costa, Anabela; Espírito Santo, Liliana; Ferreira, Diana Melo; Silva, Carla Sousa e; Pinto, E.; Almeida, Agostinho; Oliveira, M. Beatriz P.P.Background: Food waste is a global and growing problem that is gaining traction due to its environmental, ethical, social, and economic repercussions. Between 2022 and 2027, the worldwide papaya market is expected to have a huge increase, meaning a growth in organic waste, including peels and seeds. Thus, this study evaluated the potential use of peels and seeds of two mature papaya fruits as a source of bioactive compounds, converting these by-products into value-added products. Proximate analysis (AOAC methods), mineral content (ICP-MS), free sugars (HPLC-ELSD), fatty acid composition (GC-FID), vitamin E profile (HPLC-DAD-FLD), and antioxidant activity (DPPH and FRAP assays) were evaluated. Results: Both by-products showed high total protein (20–27%), and dietary fiber (32–38%) contents. Papaya peels presented a high ash content (14–16%), indicating a potential application as a mineral source. 14 fatty acids were detected, with α-linolenic acid (30%) as the most abundant in the peels and oleic acid (74%) in the seeds. Both by-products showed high antioxidant activity. Conclusion: Papaya by-products display great potential for industrial recovery and application, such as formulation of new functional food ingredients.