Loading...
5 results
Search Results
Now showing 1 - 5 of 5
- Comparison between the phytochemical and antioxidant properties of plants used in plant infusions for medicinal purposesPublication . Ferreira da Vinha, Ana; Barreira, Sérgio; Castro, Ana; Machado, MarisaIt has already been acknowledged among the medical community that plant based treatments represent an interesting contribution to modern therapeutics due to the presence in their composition of molecules with pharmacological and antioxidant action. The aim of this study was to evaluate the contents of total phenolics, flavonoids, and caffeine in six plants used traditionally by healers in Portugal and usually consumed as tea or infusion namely: Camellia sinensis, Melissa officinalis, Lippia citriodora, Cymbopogon citratus, Matricaria chamomilla, and Tilia cordata. Total phenolics ranged from 32.05 mg GAE/100g for aqueous extracts obtained from leaves of L. citriodora to 145.28 mg GAE/100g for aqueous extracts of C. sinensis. Significant variations in the flavonoid content were also found among analyzed plants and depending on the nature of the extract, with C. sinensis standing out again with the highest values (78.31 mg CE/100g) and the ethanolic extract obtained from the flowers of T. cordata exhibiting the lowest content (25.15 mg CE/100g). The concentration of caffeine was also very diverse and followed the sequence M. officinalis < T. cordata < C. citratus < M. chamomilla < L. citriodora < C. sinensis. The antioxidant activity of each plant was evaluated in vitro using a standard model system, the DPPH assay, and was found to vary according to C. citratus (90.9%) > C. sinensis (87.8%) > M. officinalis (50.7%) > M. chamomilla (45.3%) > T. cordata (32.2%) > L. citriodora (28.0%). The aqueous extracts presented lower antioxidant activity than the corresponding ethanolic ones.
- 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.
- Avocado and its by-products: natural sources of nutrients, phytochemical compounds and functional propertiesPublication . Ferreira da Vinha, Ana; Silva, Carla Sousa e; Soares, Marta De Oliveira; Barreira, SérgioAvocado (Persea americana Mill.) is a tropical and subtropical fruit that is native to Mexico and Central America. This fruit is gaining increasing worldwide acceptance and has received extensive marketing and a wide distribution due to its relevant nutritional benefits for human health. This work presents relevant information on the production, composition and application of avocado, with an emphasis on its by-products, focusing on the proper use of waste and the possibility of monetizing waste for nutritional and environmental purposes. The entire avocado is rich in bioactive compounds (pulp, peel and seed) and presents several health benefits, such as antimicrobial, antioxidant and anticancer activities, as well as dermatological uses and others. Therefore, several food grade ingredients can be obtained from avocado wastes, particularly premium-grade fats or extracts with a high functional power. Studies should continue to identify the profiles and phytochemicals available to the business sector, which can also be implemented to valorize the nutritional and functional potential of avocado seeds and peels.
- 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.
- Capsicum annuum L. with different colors provide bioavailable phytochemicals with health benefitsPublication . Madeira, Ana; Silva, Carla Sousa e; Barreira, Sérgio; Ferreira da Vinha, Ana