Percorrer por autor "Saraiva, Jorge A."
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- An overview on the market of edible flowersPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A; Saraiva, Jorge A.; Ramalhosa, ElsaEdible flowers have become the latest food fashion, such as in United Kingdom, Portugal and Australia, making this niche market very challenging. Producers and points of sale of edible flowers (supermarkets, local markets, online) are increasing around the world, whereas consumers and professional chefs are demanding higher quality products. Despite being a growing market, information available on production, export and import is still scarce, without statistical data, with information restricted to that given by some producers and points of sale. So, this review aims to provide valuable information on the current situation of the edible flowers’ world market, with particular emphasis in Portugal, as well as, to give knowledge about legislation, promotional projects and campaigns, consumers and chefs perceptions, and to indicate the future trends regarding edible flowers.
- Analysis of the UDP-glucuronosyltransferase gene in Portuguese patients with a clinical diagnosis of Gilbert and Crigler–Najjar syndromesPublication . Costa, Elísio; Vieira, Emília; Martins, Marcia; Saraiva, Jorge A.; Cancela, Eugénia; Costa, Miguel Rocha; Bauerle, Roswitha; Freitas, Teresa R.; Carvalho, João; Santos-Silva, Ermelinda; Barbot, José; Santos, RosárioWe describe the molecular study in a cohort of 120 Portuguese patients with the clinical diagnosis of Gilbert syndrome and in one with the diagnosis of Crigler–Najjar syndrome type II, as well as a prenatal diagnosis of Crigler–Najjar syndrome type I. Among the 120 unrelated patients with Gilbert syndrome, 110 were homozygous for the [TA]7 allele ([TA]7/[TA]7), and one patient was a compound heterozygote for two different insertions ([TA]7/[TA]8). The remaining 9 patients were heterozygous for the TA insertion ([TA]6/[TA]7). Additional studies in these 9 patients revealed heterozygosity for the c.674T>G, c.488_491dupACCT and c.923G>A mutations, in 1, 1 and 4 patients, respectively. The patient with Crigler–Najjar syndrome type II was a compound heterozygote for [TA]7 and the c.923G>A mutation. The undocumented polymorphisms c.-1126C>T and c.997-82T>C were also detected in the course of this study. Prenatal diagnosis in a family with a boy previously diagnosed as Crigler–Najjar syndrome type I and homozygosity for the c.923G>A mutation revealed that the fetus was unaffected. Homozygosity for the [TA] insertion was found to be the most frequent cause of GS in our population. Identification of further mutations in the UGT1A1 gene was also seen to contribute significantly towards diagnosis.
- Assessing the activity coefficients of water in cholinium-based ionic liquids: experimental measurements and COSMO-RS modelingPublication . Khan, Imran; Kurnia, Kiki A.; Sintra, Tânia E.; Saraiva, Jorge A.; Pinho, Simão; Coutinho, João A.P.The vapor liquid-equilibrium of water + ionic liquids is relevant for a wide range of applications of these compounds. It is usually measured by ebulliometric techniques, but these are time consuming and expensive. In this work it is shown that the activity coefficients of water in a series of cholinium-based ionic liquids can be reliably and quickly estimated at 298.15K using a humidity meter instrument. The cholinium based ionic liquids were chosen to test this experimental methodology since data for water activities of quaternary ammonium salts are available in the literature allowing the validation of the proposed technique. The COSMO-RS method provides a reliable description of the data and was also used to understand the molecular interactions occurring on these binary systems. The estimated excess enthalpies indicate that hydrogen bonding between water and ionic liquid anion is the dominant interaction that governs the behavior of water and cholinium-based ionic liquids systems, while the electrostatic-misfit and van der Walls forces have a minor contribution to the total excess enthalpies.
- Borage, calendula, cosmos, Johnny Jump up, and pansy flowers: volatiles, bioactive compounds, and sensory perceptionPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A.; Malheiro, Ricardo; Rodrigues, Nuno; Saraiva, Jorge A.; Ramalhosa, ElsaThe aim of the present work was to study the main volatile and bioactive compounds (monomeric anthocyanins, hydrolysable tannins, total flavonoids, and total reducing capacity) of five edible flowers: borage (Borage officinalis), calendula (Calendula arvensis), cosmos (Cosmos bipinnatus), Johnny Jump up (Viola tricolor), and pansies (Violaxwittrockiana), together with their sensory attributes. The sensory analysis (10 panelists) indicated different floral, fruity, and herbal odors and taste. From a total of 117 volatile compounds (SPME-GC-MS), esters were most abundant in borage, sesquiterpenes in calendula, and terpenes in cosmos, Johnny Jump up, and pansies. Some bioactive and volatile compounds influence the sensory perception. For example, the highest content of total monomeric anthocyanins (cosmos and pansies) was associated with the highest scores of colors intensity, while the floral and green fragrances detected in borage may be due to the presence of ethyl octanoate and 1-hexanol. Therefore, the presence of some volatiles and bioactive compounds affects the sensory perception of the flowers.
- Borage, camellia, centaurea and pansies: Nutritional, fatty acids, free sugars, vitamin E, carotenoids and organic acids characterizationPublication . Fernandes, Luana; Ramalhosa, Elsa; Pereira, J.A.; Saraiva, Jorge A.; Casal, SusanaThe present study aimed to evaluate the nutritional and bioactive potential of four edible flowers (borage, centaurea, camellia, and pansies). Significant differences were observed among the four. Water was the main constituent (> 76%, fresh weight - fw). Linoleic and palmitic acids were the major fatty acids found in borage and red and yellow pansies, while in camellia it was the arachidic acid. In white pansies, behenic and arachidic acids were predominant. Concerning vitamin E, α-tocopherol was the major vitamer. Carotenoids values varied between 5.8 and 181.4 mg β-carotene/100 g dry weight (dw) in centaurea and borage, respectively, being particularly rich in lutein. Malic acid was the major organic acid, except in centaurea, where succinic acid was predominant. Fructose, glucose and sucrose were detected in all flowers. These results can contribute to the knowledge of these edible flowers and consequently increase their popularity among consumers and in the food industry.
- Caracterização do perfil fenólico de agrião por HPLCDAD-ESI/MS e otimização da extração por alta pressão hidrostática utilizando a metodologia de superfície de respostaPublication . Pinela, José; Prieto Lage, Miguel A.; Barros, Lillian; Carvalho, Ana Maria; Oliveira, Beatriz; Saraiva, Jorge A.; Ferreira, Isabel C.F.R.A tecnologia de alta pressão (AP) é cada vez mais utilizada na indústria alimentar como método de pasteurização a frio. A sua utilização para extração de compostos de elevado valor acrescentado a partir de matrizes vegetais é relativamente recente e tem sido indicada como uma boa alternativa aos métodos convencionais, pois evita a degradação de moléculas termossensíveis e pode melhorar a eficiência da extração em termos de rendimento, qualidade e seletividade [1-4]. Neste sentido, este trabalho teve como objetivos caracterizar o perfil fenólico de agrião (Nasturtium officinale R. Br.), uma planta semiaquática de crescimento rápido com propriedades medicinais [5], e otimizar a extração destes compostos por AP utilizando a metodologia de superfície de resposta. As amostras de agrião liofilizadas foram processadas por AP de acordo com um desenho fatorial completo de cinco níveis, combinando as variáveis tempo de processamento (t, 1.5-33.5 min), pressão (P, 0.1-600 MPa) e solvente (S, 0-100 % de etanol, v/v). Os compostos fenólicos foram analisados por HPLC-DAD-ESI/MS e os resultados da quantificação foram usados como variáveis de resposta. Os flavonoides predominaram sobre os ácidos fenólicos e, em geral, foram quantificados mais derivados glicosídeos de quercetina e de isoramnetina do que ácidos fenólicos. Quatro derivados glicosídeos de kaempferol foram identificados pela primeira vez nesta espécie. Os modelos teóricos obtidos foram ajustados com sucesso aos dados experimentais, validados estatisticamente e utilizados nas etapas de otimização e predição. As condições ótimas de AP para extração foram as seguintes: t= 3,1 min, P= 600 MPa e S= 100% e originaram 64,68±2,97 mg/g de extrato [4]. Este estudo destacou a AP como uma tecnologia promissora para extrair compostos fenólicos (ácidos fenólicos e flavonoides) de agrião de forma seletiva usando um solvente verde e tempos de extração reduzidos.
- Caracterização físico-química da flor de Borago officinalis em dois estados de floraçãoPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A.; Saraiva, Jorge A.; Ramalhosa, ElsaA borragem (Borago officinalis) é uma planta anual, cultivada para usos medicinais e culinários. As flores de borragem têm despertado algum interesse aos chefs de cozinha gourmet e consumidores, uma vez que podem ser usadas na decoração de saladas e bebidas, conferindo um ligeiro sabor a pepino. No entanto, grande parte dos estudos referentes a esta planta incidem em sementes, principal constituinte comercial usado para extração de óleo, sendo as flores de borragem pouco estudadas. Nesse sentido, o presente trabalho teve como objetivo caracterizar o botão e a flor completa, do ponto de vista físico-químico, nomeadamente em termos de: dimensões, cor, aw, humidade, cinzas, proteína, gordura total, fibra dietética, hidratos de carbono, energia e carotenoides totais, de forma a avaliarem-se eventuais diferenças entre dois estados de floração. Em simultâneo, avaliaram-se as pétalas. Relativamente à caracterização do botão e flor completa, correspondentes a dois estados de floração distintos, e às pétalas verificou-se que o botão e a flor completa apresentaram um menor teor hídrico, e consequentemente teores mais elevados de todos os macronutrientes face às pétalas, mas sem significado estatístico. O botão demonstrou ser aquele com maiores teores de fibra dietética e lípidos, enquanto a flor completa apresentou os maiores teores de cinzas e proteína. Para além disso, a flor completa foi aquela que apresentou o maior teor de carotenoides, em comparação com os botões e pétalas, provavelmente devido à sua concentração nas sépalas. Os resultados mostraram que as pétalas são essencialmente constituídas por água (90,5+/-0,4%). Quanto aos restantes macronutrientes da amostra fresca, a fibra dietética total é o constituinte maioritário (3,84+/-0,03 g/100 g), seguido dos hidratos de carbono (3,49+/-0,44 g/100 g). Nesse sentido, as pétalas frescas de borragem apresentaram um baixo teor calórico (28+/-2 kcal/100 g). Em relação aos valores de aw, estes foram semelhantes entre as três amostras (0,982-0,983). Em suma, o presente trabalho permitiu aumentar o conhecimento geral sobre as características físico-químicas da flor borragem, fornecendo mais informação aos consumidores. Por outro lado, o conhecimento dos constituintes maioritários nos diferentes estados de floração pode favorecer a sua utilização seletiva. Assim sendo, a flor completa deve ser escolhida quando se pretende maximizar a quantidade de carotenoides, enquanto o botão deverá ser selecionado no caso de se pretender ingerir uma maior quantidade de fibras.
- Cold extraction of phenolic compounds from watercress by high hydrostatic pressure: Process modelling and optimizationPublication . Pinela, José; Prieto Lage, Miguel A.; Barros, Lillian; Carvalho, Ana Maria; Oliveira, Beatriz; Saraiva, Jorge A.; Ferreira, Isabel C.F.R.High hydrostatic pressure (HHP) was applied to the extraction of phenolic compounds from watercress (Nasturtium officinale). The process was optimized by response surface methodology using a five-level central composite design combining the independent variables of processing time (t, 1.5–33.5 min), pressure (P, 0.1–600 MPa) and solvent (S, 0–100% of ethanol, v/v). The individual and grouped phenolic compounds, analyzed by HPLC-DAD-ESI/MS, and the extraction yield were used as response variables. The theoretical models were fitted to the experimental data, statistically validated, and used in the prediction and optimization steps. The optimal HHP conditions for the extraction of phenolic compounds were: t = 3.1 min, P = 600 MPa and S = 100%, and originated 64.68 ± 2.97 mg/g of extract. This study highlighted the HHP as a promising technology to cold extract phenolic compounds (phenolic acids and flavonoids) from watercress in a selective way using a green solvent and reduced extraction times.
- Conventional and emergent technologies for honey processing: A perspective on microbiological safety, bioactivity, and qualityPublication . Scepankova, Hana; Pinto, Carlos A.; Paula, Vanessa B.; Estevinho, Leticia M.; Saraiva, Jorge A.Honey is a natural food of worldwide economic importance. Over the last decades, its potential for food, medical, cosmetical, and biotechnological applications has been widely explored. One of the major safety issues regarding such applications is its susceptibility to being contaminated with bacterial and fungi spores, including pathogenic ones, which may impose a hurdle to its consumption in a raw state. Another factor that makes this product particularly challenging relies on its high sugar content, which will lead to the formation of hydroxymethylfurfural (HMF) when heated (due to Maillard reactions). Moreover, honey’s bioactivity is known to be affected when it goes through thermal processing due to its unstable and thermolabile components. Therefore, proper food processing methodologies are of utmost importance not only to ensure honey safety but also to provide a high-quality product with low content of HMF and preserved biological properties. As so, emerging food processing technologies have been employed to improve the safety and quality of raw honey, allowing, for example, to reduce/avoid the exposure time to high processing temperatures, with consequent impact on the formation of HMF. This review aims to gather the literature available regarding the use of conventional and emergent food processing technologies (both thermal and nonthermal food processing technologies) for honey decontamination, preservation/enhancement of honey biological activity, as well as the sensorial attributes.
- Crisopídeos no olival de Trás-os-Montes: abundância de espécies, distribuição estacional e parasitismo das posturas.Publication . Pereira, J.A.; Saraiva, Jorge A.; Cabanas, J.E.; Bento, Albino