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Browsing CEBIMED - Papers/ Artigos Científicos by Author "Alves, Rita C."
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- How functional foods endure throughout the shelf storage? Effects of packing materials and formulation on the quality parameters and bioactivity of smoothiesPublication . Nunes, M. Antónia; Costa, Anabela S.G.; Barreira, João C.M.; Ferreira da Vinha, Ana; Alves, Rita C.; Rocha, Ada; Oliveira, M. Beatriz P.P.Smoothies are blended beverages that could contain fruit pulp, fruit juice, vegetables, yoghurt, milk, or honey. These beverages are typical examples of the food industry reply to the increase awareness of consumers for healthier foods with simple ingredients and clean labels. As emerging products, different profiling studies are needed to ensure their claimed properties. Accordingly, different physicochemical parameters, bioactive compounds, as well as the antioxidant activity, were assessed in commercial smoothies along different shelf storage periods. ANOVA, HCA and LDA statistical tools were used to allow a suitable comprehension of the obtained results. Some significant differences were found at initial time, which might be associated to smoothies’ composition. On the other hand, the physicochemical and chromatic parameters were stable during the shelf storage, while the content in bioactive compounds and the antioxidant activity indicators were significantly affected (independently of the applied thermal treatment). Nevertheless, none of the assayed formulations or packing types showed to be more susceptible to undergone specifically relevant changes during shelf storage. Overall, the results advice in favor of an earlier consumption of these products (far from the expiring date) in order to obtain the desired health effects.
- Impact of boiling on phytochemicals and antioxidant activity of green vegetables consumed in the Mediterranean dietPublication . Ferreira da Vinha, Ana; Alves, Rita C.; Barreira, Sérgio; Costa, Anabela S.G.; Oliveira, M. Beatriz P.P.The effect of boiling (10 minutes) on eleven green vegetables frequently consumed in the Mediterranean diet was evaluated. For that, some physicochemical parameters and the contents of vitamin C, phenolics and carotenoids, as well as the antioxidant activity, were determined in raw and boiled samples. The raw vegetables analysed in this study were good sources of vitamin C, carotenoids and phenolic compounds, with contents ranging from 10.6 to 255.1 mg/100 g, 0.03 to 3.29 mg/100 g and 202.9 to 1010.7 mg/100 g, respectively. Boiling promoted losses in different extensions considering both the different bioactive compounds and the distinct vegetables analysed. Contrary to phenolics (more resistant), vitamin C was the most affected compound. Boiling also originated significant losses in the antioxidant activity of the vegetables. Considering all the parameters analysed, the vegetables most affected by boiling were broccoli and lettuce. The least affected ones were collard and tronchuda cabbage.
- Improving bioactive compounds extractability of Amorphophallus paeoniifolius (Dennst.) NicolsonPublication . Costa, Anabela S.G.; Barreira, João C.M.; Ruas, Adilson; Ferreira da Vinha, Ana; Pimentel, Filipa B.; Alves, Rita C.; Ferreira, Isabel C.F.R.; Oliveira, M. Beatriz P.P.Elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) is an underground, unbranched deciduous plant that produces a large tubercle (rhizome) with recognized health effects. In this study, the influence of solvent nature (water, water/etanol (1:1) and absolute ethanol) and processing type (fresh, lyophilized and boiled) on the antioxidant activity and bioactive compounds extractability of elephant foot yam was evaluated. Extracts were compared for their contents in total phenolics, flavonoids and tannins. Moreover, their antioxidant capacity was assessed by the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity assays. Phenolics (154 mg GAE/L) and tannins (109 mg GAE/L) were maximized in lyophilized samples extracted with the hydroalcoholic solvent, which attained also the highest FRAP value (711 mg FSE/L). In turn, flavonoids reached the highest yields in lyophilized samples (95 mg ECE/L) extracted with pure ethanol, as well as the highest DPPH• scavenging activity. These findings might have practical applications to define the best processing methodology regarding the enhancement of elephant foot yam, either for prompt consumption, as well as to develop food supplements or pharmaceutical related products.
- Monomeric and oligomeric flavan-3-ols and antioxidant activity of leaves from different Laurus sp.Publication . Ferreira da Vinha, Ana; Guido, Luís F.; Costa, Anabela S.G.; Alves, Rita C.; Oliveira, M. Beatriz P. P.The phenolic profile and antioxidant activity of three endemic Laurus sp. from Portugal were analysed. Dried leaves of L. nobilis L., L. azorica (Seub.) Franco, and L. novocanariensis Rivas Mart., Lousã, Fern. Prieto, E. Días, J. C. Costa & C. Aguiar, collected in the mainland and in the Azores and Madeira archipelagos, respectively, were used to prepare different extracts (aqueous, ethanolic and hydroalcoholic). They were studied regarding their DPPH˙ scavenging activity, total phenolic and flavonoid contents, and the main phenolic compounds were identified by HPLC-DAD-ESI-MS/MS. Total flavonoid contents were 30.1, 46.3, and 36.7 mg of epicatechin equivalents per g of sample (dry weight) for L. nobilis, L. azorica and L. novocanariensis, respectively. Epicatechin was the major compound, representing ∼12.1% of total flavan-3-ols in L. nobilis, ∼25.6% in L. azorica, and ∼19.9% in L. novocanariensis. Although all samples presented a similar phenolic profile, significant differences were observed in their total contents and antioxidant activity.
- Multi-frequency multimode modulated technology as a clean, fast, and sustainable process to recover antioxidants from a coffee by-productPublication . Puga, H.; Alves, Rita C.; Costa, Anabela S.; Ferreira da Vinha, Ana; Oliveira, M. Beatriz P.P.Coffee chaff is a major coffee roasting by-product that could be valued as a source of antioxidants. In the present work, we compared classic, but optimized, solid-liquid extraction conditions with a new concept, namely, the Multi-frequency Multimode Modulated (MMM) vibration technique. The extracts obtained by both methods were analysed and compared in relation to several parameters, namely, phenolics profile (by HPLC/DAD), 5-caffeoylquinic acid content, total phenolics content, and Ferric Reducing Antioxidant Power. Compared to an optimized solid-liquid extraction (using a hydroethanolic solvent (1:1) at 40 °C for 60 min), the acoustic probe allowed a higher recovery of antioxidants in only 10 min and using only water as extraction solvent. Moreover, the effects that arise from the acoustic cavitation in the medium allowed the suppression of the sample preparation step (grinding). These results show that this type of technology can be of high interest to recover antioxidants from natural matrices, in a green, fast and very efficient way.
- Nutritional, chemical and antioxidant/pro-oxidant profiles of silverskin, a coffee roasting by-productPublication . Costa, Anabela S.G.; Alves, Rita C.; Ferreira da Vinha, Ana; Costa, Elísio; Nunes, M. Antónia; Almeida, Agostinho A.; Santos-Silva, Alice; Oliveira, M. Beatriz .P.P.Coffee silverskin (a coffee roasting by-product) contains high amounts of dietary fibre (49% insoluble and 7% soluble) and protein (19%). Potassium (∼5 g/100 g), magnesium (2 g/100 g) and calcium (0.6 g/100 g) are the major macrominerals. The vitamin E profile of silverskin comprises α-tocopherol, β-tocopherol, ɣ-tocopherol, δ-tocopherol, β-tocotrienol, ɣ-tocotrienol, and δ-tocotrienol. The fatty acid profile is mainly saturated (C16:0 and C22:0), but the total amount of fat is low (2.4%). Caffeine (1.25 g/100 g), chlorogenic acid (246 mg/100 g), and 5-hydroxymethylfurfural (5.68 mg/100 g) are also present in silverskin. Total phenolics and flavonoids are partially responsible for the in vitro antioxidant activity. Silverskin extracts protected erythrocytes from oxidative AAPH- and H2O2-induced hemolysis, but at high concentrations a pro-oxidant effect on erythrocyte morphology was observed.
- Organic versus conventional tomatoes: influence on physycochemical parameters, bioactive compounds and sensorial attributesPublication . Ferreira da Vinha, Ana; Barreira, Sérgio; Costa, Anabela S.G.; Alves, Rita C.; Oliveira, M. Beatriz P.P.he effect of organic and conventional agricultural systems on the physicochemical parameters, bioactive compounds content, and sensorial attributes of tomatoes ("Redondo" cultivar) was studied. The influence on phytochemicals distribution among peel, pulp and seeds was also accessed. Organic tomatoes were richer in lycopene (+20%), vitamin C (+30%), total phenolics (+24%) and flavonoids (+21%) and had higher (+6%) in vitro antioxidant activity. In the conventional fruits, lycopene was mainly concentrated in the pulp, whereas in the organic ones, the peel and seeds contained high levels of bioactive compounds. Only the phenolic compounds had a similar distribution among the different fractions of both types of tomatoes. Furthermore, a sensorial analysis indicated that organic farming improved the gustative properties of this tomato cultivar.
- Pre-meal tomato (Lycopersicon esculentum) intake can have anti-obesity effects in young women?Publication . Ferreira da Vinha, Ana; Barreira, Sérgio; Costa, Anabela S.G.; Alves, Rita C.; Oliveira, M. Beatriz P.P.The effect of pre-meal tomato intake in the anthropometric indices and blood levels of triglycerides, cholesterol, glucose, and uric acid of a young women population (n = 35, 19.6 ± 1.3 years) was evaluated. During 4 weeks, daily, participants ingested a raw ripe tomato (∼90 g) before lunch. Their anthropometric and biochemical parameters were measured repeatedly during the follow-up time. At the end of the 4 weeks, significant reductions were observed on body weight (−1.09 ± 0.12 kg on average), % fat (−1.54 ± 0.52%), fasting blood glucose (−5.29 ± 0.80 mg/dl), triglycerides (−8.31 ± 1.34 mg/dl), cholesterol (−10.17 ± 1.21 mg/dl), and uric acid (−0.16 ± 0.04 mg/dl) of the participants. The tomato pre-meal ingestion seemed to interfere positively in body weight, fat percentage, and blood levels of glucose, triglycerides, cholesterol, and uric acid of the young adult women that participated in this study.
- Smothies comerciais: estabilidade dos compostos antioxidantesPublication . Nunes, M. Antónia; Costa, Anabela; Barreira, João; Ferreira da Vinha, Ana; Alves, Rita C.; Rocha, Ada; Oliveira, BeatrizOs smoothies são bebidas resultantes da mistura de frutas, sumos e polpas de frutas, hortícolas, iogurte ou leite. A mais-valia associada a estes produtos é o conceito “natural” e “fresco”, sem adição de açúcares e/ou corantes, aproximando o seu conteúdo às características da fruta no seu estado natural. Neste estudo, determinou-se o teor de compostos bioativos (compostos fenólicos, flavonoides e taninos) e a capacidade antioxidante (inibição do DPPH• e poder redutor, FRAP) de smoothies disponíveis no mercado português. Para estudar as alterações ao longo do armazenamento, as amostras foram analisadas em três períodos distintos: momento da aquisição, 14 e 21 dias depois. Os resultados demonstraram, de forma inequívoca, a diminuição do teor de compostos bioativos e da capacidade antioxidante ao longo do tempo. Além do mais, este decréscimo de bioatividade ocorreu independentemente do tipo de formulação utilizada, sem que qualquer das matrizes tivesse evidenciado um efeito protetor.