FCT: DQ - Artigos em revista nacional com arbitragem científica
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- Volatile profile of two monovarietal white wines under different antioxidant environments during storage in bottlePublication . Santos, Cátia V. Almeida; Silva, Marco Diogo Richter Gomes da; Cabrita, Maria João; DQ - Departamento de Química; LAQV@REQUIMTE; Instituto Nacional de Investigação Agrária e Veterinária | EDP SciencesThe volatile organic compounds (VOCs) formed during winemaking can be modulated by several additives, namely by the use of sulphur dioxide (SO2) which has been well-accepted on winemaking as a preservative agent. However, some drawbacks associated with SO2 wine application led to the need to reduce or replace its use. In this work, VOCs profile after storage in bottle under different antioxidant conditions of two Portuguese monovarietal wines (‘Arinto’ and ‘Síria’) was studied. Wines were obtained by different winemaking environments (0, 50, 100 mg/L of SO2 and 100 mg/L ascorbic acid for ‘Síria’ and 15, 30, 45 mg/L of SO2 and 100 mg/L of ascorbic acid for ‘Arinto’ both with and without bentonite). After alcoholic fermentation, a second SO2 treatment was applied: 0 and 60 mg/L of SO2 to ‘Arinto’ wines and 30 and 60 mg/L of SO2 to ‘Síria’ wines. Wines were kept over lees for three months, bottled and analysed after three months in bottle. The VOCs present were analysed by HS-SPME-GC/MS six months after fermentation. The maturation conditions did not influence the evolution of free and total SO2. Regarding the VOCs profile evolution, the ANOVA analysis showed that esters are the most important group, presenting significant differences among samples. Through the PCA analysis, using wines after fermentation as reference, 74.13 % and 54.92 % of the variation were explained by the first two principal components for ‘Arinto’ and ‘Síria’, respectively. VOCs profile evolution of wines seems to be mainly influenced by the fermentation conditions.
- In vitro bioaccessibility of antioxidant compounds from structured fruits developed with gellan gum and agarPublication . Leal, Amanda Rodrigues; de Siqueira Oliveira, Luciana; da Costa, Juliana Nascimento; Alves, Carlos Artur Nascimento; Mata, Paulina; de Sousa, Paulo Henrique Machado; DQ - Departamento de Química; Universidade Federal do CearáThis study aims to evaluate the bioaccessibility of antioxidant compounds of structured fruits. Samples were prepared with 50% of each pulp (mango/caja, mango/cashew apple and mango/acerola), agar and gellan gum (low acyl-LA and high acyl-HA) in LA:HA ratios of: 100:0, 75:25 and 50:50, in a concentration of 0.75%. There was a reduction in the antioxidant compounds contents after in vitro digestion. The bioaccessible ascorbic acid levels ranged from 15.10% (LA100/HA0 mango/acerola) to 71.18% (LA50/HA50 mango/cashew apple); Total Extractable Polyphenols (TEP) ranged from 24.58% (mango/caja pulp) to 75.50% (LA75/HA25 mango/acerola); antioxidant activity ranged from 21.10% (LA75/HA25 mango/caja) to 51.05% (LA75/HA25 mango/acerola). Mango/acerola ascorbic acid bioaccessibility was lower and the mango/cashew apple HA gellan gum sample antioxidant activity was higher than pulp, probably due to temperature increasing at processing. It was concluded that the agar and gellan gum (HA and LA) hydrocolloids were able to contain these compounds in the production process of the structured and during digestion, which proves the similarity of structured fruits with fresh pulps.
- The fundamental importance of basic sciencePublication . Lopes, Luiz G. F.; Sadler, Peter J.; Bernardes-Génisson, Vânia; Moura, José J. G.; Chauvin, Remi; Bernhardt, Paul V.; Sousa, Eduardo H. S.; DQ - Departamento de Química; Sociedade Brasileira de Quimica / Sociedade Brasileira de Qu�micaDuring the last 150 years or more, society has witnessed many key scientific discoveries and inventions, which have dramatically improved not only our quality of life, but our lifespan. However, the motivation of scientists to provide scientific advances has generally not been the achievement of these goals, but mainly driven by research curiosity. Fundamental scientific studies, also known as basic science, have paved the way to a society of knowledge by means of continuously evolving education systems, and have led to applied science and technological breakthroughs changing the World. However, without basic science such life-changing advances would not happen, which is poorly understood by the society. Having this in mind, chemists and biochemists working in a chemistry network highlight here examples of how basic science has played a crucial role and led to major breakthroughs. In seven short stories, the authors describe cases and historical events where basic research discoveries have advanced science, and opened avenues for future achievements. Investment in basic science is crucial for a nation’s health and wealth. The support of scientists driven by curiosity ultimately can benefit the whole of society, not only in innovative products, but also in the improvement of the understanding of our own lives.
- Química de coordenação e Biologia: controlo da actividade enzimática por alteração da coordenação de centros metálicos catalíticosPublication . Maia, Luísa B.; Pauleta, Sofia R.; Moura, José J. G.; DQ - Departamento de Química; CQFB-REQUIMTE - Centro de Química Fina e Biotecnologia (Lab. Associado REQUIMTE); Sociedade Portuguesa de Química
- Química Bioinorgânica e luz - fotossíntese, oxigénio e águaPublication . Moura, José J. G.; Maia, Luísa B.; Pauleta, Sofia R.; Moura, Isabel Maria Andrade Martins Galhardas de; DQ - Departamento de Química; UCIBIO - Applied Molecular Biosciences Unit; Sociedade Portuguesa de Química
- Química Verde no desenvolvimento de materiais de afinidade para purificação de princípios ativos farmacêuticosPublication . Viveiros, Raquel; DQ - Departamento de Química; LAQV@REQUIMTEA indústria farmacêutica despende uma quantidade muito significativa de seus recursos financeiros em processos de purificação de APIs (Princípios Ativos Farmacêuticos) para cumprir os limites de impurezas impostas pelas agências reguladoras (FDA e EMEA). Para responder a esta demanda mundial, têm sido propostos vários materiais, como os polímeros molecularmente impressos (MIPs). Esses materiais de afinidade do tipo “chave-fechadura” são produzidos usando diferentes metodologias convencionais. O uso dos princípios da Química Verde tem mudado a forma como os polímeros são produzidos. As tecnologias verdes aplicadas ao desenvolvimento de MIPs apareceram não só devido às preocupações com o meio ambiente, mas também devido às características do produto final e a sua produção económica. Os MIPs têm sido desenvolvidos no laboratório usando a tecnologia de dióxido de carbono supercrítico (scCO2). Estes materiais de afinidade já foram desenvolvidos para uma vasta gama de aplicações, desde a remoção de impurezas farmacêuticas até ao enriquecimento de produtos naturais. Os materiais de afinidade do tipo “chave-fechadura” são obtidos prontos a usar, na forma de pós secos, fáceis de manusear, com distribuição de tamanhos de partícula homogénea e sem resíduos de solventes orgânicos.