Loading...
11 results
Search Results
Now showing 1 - 10 of 11
- Flores comestíveis como fonte de compostos bioativos com atividade antioxidantePublication . Guiné, Raquel P. F.; Ferrão, Ana Cristina; Correia, Paula; Goncalves, J. C.; Gonçalves, Fernando JorgeExistem muitas espécies vegetais utilizadas na gastronomia, entre as quais as flores comestíveis (FC). Para que uma flor seja considerada comestível ela deve ser não tóxica, inócua e ter propriedades nutricionais. Historicamente, as FC têm sido usadas para fins culinários há séculos em várias partes do mundo, como Ásia, Grécia antiga, Roma e também na França medieval. Adicionalmente, constituem uma boa fonte de compostos bioativos, nomeadamente fitoquímicos, associados a várias propriedades farmacológicas, destacando a proteção contra doenças cardiovasculares e os efeitos ansiolíticos, anticancerígenos, antidiabéticos, anti-inflamatórios, antioxidantes, diuréticos, imunomoduladores e antimicrobianos. Recentemente, as FC têm despertado crescente interesse, devido às suas propriedades estéticas e organoléticas, bem como potenciais benefícios para a saúde, relacionados com a ocorrência de alguns compostos bioativos. Nesta medida, o objetivo do presente trabalho foi avaliar os teores de compostos fenólicos totais, antocianinas e flavonoides, bem como a atividade antioxidante num conjunto de FC. Para a análise foram obtidos extratos de onze espécies de FC que foram utilizados para a quantificação da composição fenólica e atividade antioxidante usando métodos espectrofotométricos. Dos resultados obtidos foi possível verificar que as rosas e cravos de coloração vermelha ou rosa se destacaram como contendo maiores teores de compostos fenólicos totais (18 a 27 mg EGA/g), e ainda maiores aportes de antocianinas (3 a 5 mg EC/g). Verificou-se ainda que eram também essas as FC com maior atividade antioxidante (12 a 16 mg ET/g). De destacar por fim o cravo vermelho como contendo maior quantidade de flavonoides (cerca de 18 mg EC/g). Em conclusão, verifica-se que as FC, para além das suas potencialidades gastronómicas, podem constituir um veículo para a ingestão de compostos com efeitos benéficos para a saúde, nomeadamente no que respeita ao combate aos radicais lives responsáveis pelo envelhecimento celular.
- Flour from drone broods: A viable alternative?Publication . Correia, Paula; Vouga, C; Coelho, Catarina; Costa, Cristina Amaro Da; Guiné, Raquel P. F.; Gonçalves, Fernando Jorge; C. Goncalves, J.
- Liquefaction optimization of Crataegus monogyna JacqPublication . Dulyanska, Y; Cruz-Lopes, Luísa; Esteves, Bruno; Domingos, Idalina; Ferreira, José; Guiné, Raquel; Gonçalves, Fernando Jorge; Carvalho, L B; Barroca, M JThe objective of this work was to evaluate the potentiality of Crataegus monogyna Jacq. residues to be liquefied by polyhydric alcohols and the chemical transformations observed in this process with subsequent use to produce polyurethane foams. The variations on liquefaction yield were determined at different temperature, time, material/solvent ratio and granulometry. Results show that liquefaction performed at 180 °C with a 1:10 material/solvent ratio increases along time, reaching a maximum at 60 min. Similarly, liquefactions made during 60 min with a 1:10 material/solvent ratio show that there is an increase in liquefaction yield with the increase in temperature until 180 °C. A higher temperature could increase the liquefaction yield but would lead to a higher energy consumption in the process. There seems to be no significative advantage in increasing material/solvent ratio above 1:7, although the liquefaction yield increases for higher ratios. Granulometry testing shows that the smaller the particle the best is the liquefaction percentage. It was concluded that the best liquefaction yield, of approximately 81%, was obtained with a temperature of 180 °C, for 60 min and particle size <80 mesh for Crataegus monogyna Jacq. This material has good properties to be converted in a liquid mixture that can be used later, on the production of polyurethane foams.
- Chemical composition of Crataegus monogyna – Preliminary StudiesPublication . Dulyanska, Y.; Cruz-Lopes, Luísa; Esteves, Bruno; Barroca, M. J.; Carvalho, L. B.; Gonçalves, Fernando Jorge; Domingos, Idalina; Ferreira, José; Guiné, Raquel P. F.
- Towards the Valorization of Elderberry By-Product: Recovery and Use of Natural Ingredients for Sorbet FormulationsPublication . Neves, Cláudia M. B.; Fogeiro, Élia; Cardoso, Susana M.; Gonçalves, Fernando Jorge; Pinto, António; Ferreira Wessel, DulcineiaOne of the food industry’s greatest challenges is to find natural ingredients capable of conferring antioxidant and color properties. In addition, the agri-food industry generates by-products that are often treated as waste, despite their abundance of phytochemicals that can be recovered and used as food ingredients. This study explores the potential of elderberry pomace, an industrial by-product of juice processing rich in anthocyanins and polyphenols, as a natural food additive in blueberry sorbet. Elderberry pomace was incorporated into the sorbet formulation in powder form or as aqueous extracts at two different concentrations. The analysis of the pomace extract by UHPLC-DAD-MS showed the presence of four anthocyanins: cyanidin-3,5-O-diglucoside, cyanidin-3-O sambubioside-5-O-glucoside, cyanidin-3-O-sambubioside, and cyanidin-3-O-glucoside. The physicochemical properties of the sorbets such as pH, ◦Brix, overrun, melting rate, and color were evaluated, as well as their levels of total phenolic compounds, total monomeric anthocyanins, and in vitro antioxidant activity. The potential of sorbets to stimulate the growth of probiotic bacteria was evaluated and a sensory analysis was conducted to assess consumer acceptance. Results indicated that the sorbet containing the more concentrated extract presented higher overrun, faster melting rate, higher contents of phenolic compounds and anthocyanins, and higher antioxidant activity compared to the control. Additionally, this formulation showed a darker hue (lower L* value) and a tendency to stimulate probiotic bacteria. Moreover, the sorbets with pomace in their composition had good consumer acceptability. These findings highlight the potential of elderberry pomace to be used as a natural, sustainable ingredient in the ice cream industry, aligning with growing consumer trends towards healthier and eco-friendly products.
- Chemical composition of Ruscus aculeatus L. – Preliminary StudiesPublication . Dulyanska, Y; Cruz-Lopes, Luísa; Esteves, Bruno; Barroca, M J; Carvalho, L; Gonçalves, Fernando Jorge; Domingos, Idalina; Ferreira, José; Guiné, Raquel P. F.
- Evaluation of Phenolic Compounds, Antioxidant Activity and Bioaccessibility in Physalis Peruviana LPublication . Guiné, Raquel P. F.; Gonçalves, Fernando Jorge; Oliveira, Solange; Correia, PaulaThis work evaluated phenolic compounds in Physalis peruviana as well as their antioxidant activity and bioaccessibility, using an in vitro model of the gastrointestinal system. Three combinations of solvents were evaluated for the extraction of phenolic com- pounds. All other chemical components, their antioxidant activity and bioaccessibility were evaluated using established methods. P. peruviana is rich in fiber (4.61 g/100 g), vitamin C (26.70 mg/ 100 g), carotenoids (5.95 µg/100 g), total phenolic compounds (59.9 mgGAE/100 g), flavonoids (0.340 mgQE/10 g) and ortho- diphenols (94.6 mgGAE/100 g). The antioxidant activity varied from 7.7 to 13.7 µmolTE/g. The simulation of the digestive tract showed that only about 40-50% of the phenolic compounds remained available for intestinal absorption, and only 23 – 34% of the antioxidant activity was preserved after passing through the gastrointestinal system. Hence, these ratios have to be taken into consideration regarding the ingestion of phenolic com- pounds in order to expect desired health benefits for the human body, namely in terms of antioxidant activity.
- Effect of Aqueous Extract of Phenolic Compounds Obtained from Red Wine in Experimental Model of Colitis in MicePublication . Mateus, Vanessa; Estarreja, João; Silva, Inês; Gonçalves, Fernando Jorge; Teixeira-Lemos, Edite; Pinto, RuiBackground: Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder represented by Crohn’s disease and ulcerative colitis. Currently, there is no cure and pharmacological treatment aims to induce and maintain remission on patients. Because the therapy reveals a relatively high toxicity, during a long-term utilization, it is essential to investigate new pharmacological approaches. Polyphenols, commonly present on red wine, have shown health-beneficial effects related to their antioxidant and anti-inflammatory effects through the inhibition of NF-kB activation, COX-2 and iNOS induction. In this sense, it would be interesting to study their effects in an IBD context. Therefore, this study aims to evaluate the effects of an aqueous extract of phenolic compounds in a 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced model of colitis. Method: Experimental colitis was induced in mice through an intrarectal administration of TNBS and then the mice were treated with an aqueous extract of phenolic compounds intraperitoneally for four days. Results and Discussion: The extract demonstrated an anti-inflammatory effect, reducing TNF-α levels in the colon, and had a beneficial effect on the extraintestinal manifestations related to IBD, without any significant side effects. The extract of phenolic compounds demonstrated to be a valuable object of study for the management of IBD in the future.
- Production and characterization of powder from drone brood of honeybees (Apis mellifera)Publication . Goncalves, J. C.; Vouga, Beatriz; Costa, Cristina Amaro Da; Gonçalves, Fernando Jorge; Coelho, Catarina; Guiné, Raquel; Correia, PaulaDrone bee brood are a natural source of food with potential for human nutrition. This work aims to investigate the production and extraction of the drone bee brood (larvae and pupae), as well as the production of powder from this insect for food applications. To produce the drone brood (DB), in some hives of the colony appropriate empty frames were placed. Some measurements were done in the hive to monitor the global wellbeing of the colony, namely, temperature, relative humidity, and weight. After approximately one month, the frames were removed from the hives and frozen. The yield of DB by frame was 38%. For the extraction of the drone brood, different methods were tested, being the best ones the cold room extraction (∼ 6.5 °C), on a cold surface extraction (∼ 11 °C), and in boiling water extraction (100 °C). The results show that the extraction efficiencies were 74.3% (336.3 s), 62.5% (246.8 s) and 84.9% (332.0 s), for extraction in a cold room, on a cold surface, and in boiling water, respectively. After extraction, two drying processes were tested: evaporation and freeze-drying, being the last one the recommended, preserving in a better way the appearance and composition of the DB. DB powders presented different colour characteristics according to the extraction method used. The powder obtained by boiling extraction was darker than the one produced with cold extraction. Powders are rich in protein, fat and carbohydrates, being the fat content quite high for DB powders produced by boiling extraction method.
- Evaluation of phenolic compounds and antioxidant activity in some edible flowersPublication . Gonçalves, Fernando Jorge; C. Goncalves, J.; Ferrão, Ana Cristina; Correia, Paula; Guiné, RaquelRecently, edible fl owers ( EF ) have aroused increased interest because of their aesthetic properties as well as potential health bene fi ts related to the occurrence of some bioactive compounds. Therefore, the aim of this work was to evaluate the total phenolics, anthocyanins, fl avonoids, and antioxidant activity ( AOA ) ( following DPPH and ABTS methods ) in eleven EF. The samples were subjected to three successive extraction steps using methanol, and these extracts were then analysed for the aforementioned properties using spectrophotometric methods. The obtained extracts were used for the quantification of phenolic composition and AOA. The results indicated that, among the fl owers analysed in this study, red rose, pink rose, and red carnation possessed the highest total phenolic contents ( 27.53, 23.30, and 18.17 mg g − 1 gallic acid equivalents, respectively ) , total anthocyanins ( 3.07, 1.97, and 4.47 mg g − 1 catechin equivalents [ CE ] , respectively ) , and AOA ( 12.07, 15.77, and 12.93 mg g − 1 TE, respectively, as given by the DPPH method or 8.23, 9.27 and 8.00 mg g − 1 TE, respectively, as given by the ABTS method ) . The flowers with highest fl avonoids contents were red carnation, Mexican marigold, and pink rose ( 17.50, 16.90, and 16.57 mg g − 1 CE, respectively ) . Cluster analysis grouped the analysed flowers into two groups, those richest in phenolics with AOA and those not so rich. Finally, some important correlations were observed between the total phenolics and the AOA. In conclusion, these fl owers could represent a potential source of natural compounds with antioxidant capacity.