CBQF - Livros e Partes de Livros / Books and Books Parts
Permanent URI for this collection
Browse
Recent Submissions
- Simulation of food solar dryingPublication . Ramos, Inês N.; Brandão, Teresa R. S.; Silva, Cristina L. M.This chapter discusses the simulation process of food solar drying, presenting the basic issues of mass and heat transfer under time-varying conditions. Food drying embraces several phenomena, and scientists do not completely understand its underlying mechanisms. However, mathematical simulation and modelling provide comprehensions to improve the knowledge on the drying mechanisms, allow the prediction of the drying behaviour as well as being essential tools in the design of solar drying equipment. The major difficulty in simulating food solar drying arises from variable meteorological conditions that change air temperature, moisture and velocity inside the solar equipment, during the drying process. Therefore, an integrated mass and heat transfer model under dynamic conditions is presented, and appropriate assumptions are discussed. A meteorological model and desorption isotherms are taken into consideration as well. The integrated model includes food’s shrinkage, changing boundary conditions and variable thermal properties and water diffusivity with time and space (non-isotropic characteristics).
- Genetic engineering and the law: past, present and beyond: 20+1 criteria to help focus the path to our common futurePublication . Silva, MargaridaGenetic engineering (GE) is a powerful molecular tool deployed daily in life sciences labs everywhere. When taken out into the world complex issues arise, many unanswered to this day. Three moments in time are considered in this analysis: the past, with the first generation of genetically modified (transgenic) crops, the present, focusing on the current generation of new breeding techniques, and the future, looking into what synthetic biology and cell manufacturing have promised. Twenty criteria that have shown promise in winnowing sustainability from failure, drawn from history, ecology and the law, are applied as tests to help understand whether society is moving towards the right outcome. An additional 21st criterion is suggested and an urgent call for change is issued.
- Fighting listeria monocytogenes with Bacteriophages: biotechnology for food safetyPublication . Estorninho, Maria João; Teixeira, PaulaThere are many nature-based antimicrobial solutions that could be used to decrease food spoilage and increase food safety. The use of bacteriophages (phages), viruses that infect bacteria but not human, animal or plant cells, is an example of a biotechnological approach for food preservation. Bacteriophage P100, marketed as LISTEX, was the first bacteriophage product to be Generally Recognized As Safe (GRAS) by the US FDA. This phage is active against the foodborne pathogen Listeria monocytogenes, responsible for a severe infection in the elderly, neonates and the immunocompromised. In this article, ECJ Case T-568/19, Micreos Food Safety BV vs European Commission, is analysed as a starting point for a discussion on whether a novel legal approach to the use of phages in the European Union is needed.
- Data for Life Cycle Analysis Proof of Concept: Deliverable 3.1 (D18)Publication . Vasconcelos, Marta; Gomes, Ana Maria; Santos, Carla Sancho dos; Pinto, Elisabete; Petrusan, Janos; Löhrich, Nora; Lehrack, Uwe; Tran, Fanny; Iannetta, Pete; Williams, MikeDeliverable description: Nutritional profile data for grain legumes will be gathered and provided for the Life Cycle Analysis proof of concept (WP5). Profiling will include that of including macro- and micro-nutrients and prebiotic properties (of selected legumes). This data will also help identify the relative suitability, and trade-offs, of different legume species for food- and feed-applications.
- The impact of green roofs (GR) runoff in storm water quality and quantityPublication . Santos, Cristina; Monteiro, Cristina; Matos, Cristina; Briga-Sá, Ana; Silva-Afonso, Armando; Pimentel-Rodrigues, CarlaNature-based solutions are being worldwide implemented in highly impermeabilized city centres, due to the environmental benefits they generate and their contribution to urban sustainability and resilience, especially regarding stormwater management issues. The impact of Nature-based Solutions in the surrounding environment where they are set up, considering all the environmental aspects they have an effect on, with a special focus on stormwater management, is a fundamental aspect that must be addressed before promoting their large-scale implementation. In this scope, this study intended to address the influence of Green Roofs (GR) on rainwater quality and quantity, based on scientific experimental studies published worldwide. The compiled results show that GR dimensions, GR composition of the different layers and plant species used, amongst other characteristics, have a major influence on the quality and quantity of the rainwater downstream. In some reported cases, the quality of the drained rainwater resulted worst and for some conditions, the effect on rainwater retention was minimal, contrary to what was expected. The factors that resulted in these inconveniences are well defined and must be minimized in future GR construction and maintenance. GR are key elements to make resilient cities and thus, a clear understanding of their operation is fundamental to avoid water degradation and minimize potential impacts of malfunctioning of these structures. Furthermore, it is essential to choose the best combination of GR materials regarding water retention, to set GR systems adapted to local climate conditions and the present climate change scenario, with high performance in water management, to help urban areas dealing with extreme precipitation events, avoiding thus the consequent floods and economic damages that arise.
- Determination of soluble and insoluble dietary fiber content of marine macroalgae and microalgaePublication . Nova, Paulo; Martins, Ana Pimenta; Silva, Joana Gabriela; Pereira, Rui; Abreu, Helena; Silva, Ana Machado; Freitas, Ana; Gomes, Ana
- Extraction of carotenoids supported by ohmic heating and characterization of biological properties and stability throughout gastrointestinal tractPublication . Coelho, Marta; Pereira, Ricardo; Rodrigues, António; Teixeira, José; Pintado, Manuela
- Functional mango peel powders: what is the impact of different drying methods on their phytochemical composition and antioxidant activity?Publication . Marçal, Sara; Araújo-Rodrigues, Helena; Vilas-Boas, Ana A.; Campos, Débora A.; Pintado, ManuelaIn 2018, mangoes were among the six most-produced fruits worldwide (1). Annually, 15–25 million tons of mango byproducts are generated (2). According to the previous studies, one of the best strategies to valorise mango peels in the food industry is to convert them into powders (2). Hence, this study aims to evaluate the impact of different drying methods on mango peels’ nutritional composition, bioactive compounds, and antioxidant activity. Firstly, mango peels were washed with peracetic acid (PAA) (mango peels to disinfectant solution ratio: 1:1 (kg:L); PAA concentration: 27 mg/mL; disinfection time: 19 min) (fresh sample (FS))(1) . Then, they were submitted to three different processes: freeze-drying (freeze-dried samples (FD)); hot-air drying at 65 ºC for 48 h, with constant air circulation (hot-air dried samples (HAD)); and freezing at -20 ºC for 30 days and then hot-air drying at 65 ºC for 48 h, with constant air cir- culation (Frozen and hot-air dried samples (FZ+HAD)). The dry matter, soluble and insoluble fiber, protein, fat, and ash of these four samples were determined according to AOAC methods. Carotenoids were extracted with hexane: acetone (50%:50%; v:v). Moreover, free and bound phenolic compounds were obtained by performing a methanolic extraction and an alkaline and acid hydrolysis, respectively. The main mango peels’ carotenoids and phenolic compounds were identified using HPLC analysis. Finally, total free and bound phenolic compounds were quantified through Folin-Ciocalteu method, and their antioxidant activity was evaluated through DPPH and ABTS assays. Overall, the different drying methods did not impact mango peels’ soluble and insoluble fiber, protein, fat, and ash con- tent. Considering the four analysed samples, these parameters ranged between 19.47±0.48 - 20.73±0.44, 19.60±0.62 – 21.04±1.89, 4.93±0.13 – 6.02±0.44, 1.56±0.01 – 1.92±0.03, and 2.05±0.19 – 2.89±0.11, respectively. All of them were ex- pressed in g/100DW. However, drying markedly impacted mango peels’ phenolic compounds, carotenoids, and antioxidant activity. All drying methods caused a statistically significant decrease in total free phenolic compounds (FS: 12.76±0.80 mg of gallic acid equivalents (GAEs) / gDW; FD: 10.04±0.17 mg of GAEs/ gDW; HAD: 7.69±0.12 mg of GAEs/ gDW; FZ+HAD: 6.63±0.05 mg of GAEs/ gDW). The main free phenolic compounds identified in all samples were mangiferin (FS: 873.61±71.43; FD: 863.71±6.15; HAD: 647.61±1.86 FZ+HAD: 447.88 ± 5.37), gallic acid (FS: 590±30.93; FD: 650.48±11.85; HAD: 850.29±10.99 FZ+HAD: 523.60 ±10.83), quercetin-3-O-galactoside (FS: 467.20±34.15; FD: 464.31±1.97; HAD: 391.07±4.29 FZ+HAD: 502.41±22.73) and penta-O-galloyl-β-D-glucose (FS: 397.60±22.56; FD: 384.30±5.63; HAD: 362.88±5.03 FZ+HAD: 167.94 ±3.36). Compared with other dried peels, FZ+HAD samples showed a significantly lower amount of these compounds (excluding quercetin-3-O-galactoside). Gallic acid (basic hydrolyse: FS: 476.99±52.51; FD: 42.65±0.94; HAD: 152.66±15.35 FZ+HAD: 207.74±4.23; acid hydrolyse: FS: 83.00±12.98; FD: 12.27±0.16; HAD: 23.25±0.02 FZ+HAD: 28.26±0.76) and 4–hydroxybenzoic acid (basic hydrolyse: FS: 59.26±5.00; FD: 16.69.65±0.69; HAD: 50.39±4.17 FZ+HAD: 46.15±6.23; acid hydrolyse: FS: 23.13±0.75; FD: 2.58±0.14; HAD: 6.12±0.25 FZ+HAD: 5.63±0.50) were the main phenolic compounds obtained in both basic and acid hydrolysis. All phenolic compound amounts were expressed in μg/ gDW. Regarding carotenoids, drying also had a negative impact. FS samples contained violaxanthin (2.94±0.05 μg/gDW), lutein (4.83±0.52 μg/gDW), and β-carotene (104.46 ±0.25 μg/gDW), while in dried samples, only lutein (lower than quanti- fication limit) and β-carotene (FD: 36.19 ± 0.53 μg/gDW HAD: 36.06 ± 2.45 μg/gDW; FZ+Oven: 40.65 ± 3.66 μg/gDW) were detected. All drying methods impaired the antioxidant activity of free and bound phenolic compounds. As expected, freeze drying enabled a better preservation of free phenolic compounds’ antioxidant activity. No statistically significant differences were found between the antioxidant activity of free phenolic compounds from HAD and FZ+HAD samples. Concerning bound phenolic compounds’ antioxidant activity, overall, no significant differences were detected between dried samples. This study showed that mango peel powders had a high amount of fiber, phenolic compounds, and carotenoids, suggest- ing that they have a high potential to be used as functional ingredients. However, drying processes, namely hot air drying, should be optimized to enable better preservation of mango peels’ bioactive compounds and antioxidant activity.
- Development of an innovative laminated dough with half-fat contentPublication . Sousa, Sergio; Coelho, Marta; Adlakha, Kritika; Martins, Ana; Correia, Marta; Pimenta, Ana; Monteiro, Maria João; Teixeira, Paula; Gomes, Ana; Pintado, Manuela
- Infraestruturas verdes urbanas: soluções tecnológicas para aumentar a resiliência e sustentabilidade urbanaPublication . Monteiro, Cristina; Santos, Cristina; Briga-Sá, Ana; Matos, CristinaA alteração da paisagem nas grandes áreas urbanas tem sido uma realidade desde a segunda metade do século XX, como consequência do êxodo populacional das zonas rurais para as grandes cidades, na procura de melhores condições e qualidade de vida. Esta alteração manifesta-se principalmente pelo aumento das superfícies construtivas (edificado, arruamentos), em substituição das infraestruturas verdes aí existentes, cujas características de elevada impermeabilização, modificam significativamente a gestão do ambiente urbano. Por outro lado, as alterações climáticas que se têm manifestado nas últimas décadas, bem como os eventos extremos que daí decorrem, juntamente com a elevada impermeabilização das grandes áreas urbanas, provocam elevados prejuízos económicos, sociais e, principalmente, ambientais. Os eventos extremos, nomeadamente os eventos de intensa precipitação num curto espaço de tempo, que alternam com as ondas de calor, afiguram-se como um desafio cada vez mais frequente e que os responsáveis pelo ordenamento do território urbano estão já a enfrentar. Desta forma, é urgente implementar infraestruturas sustentáveis de base tecnológica que fomentem o uso de vegetação nas grandes cidades altamente impermeabilizadas como forma de aumentar a resiliência e sustentabilidade urbanae, simultaneamente, contribuir para um ambiente urbano mais favorável e saudável para a população que aí se estabelece. Paralelamente, é urgente que o crescimento e o desenvolvimento urbano se pautem por contrforma ativa para as metas estabelecidas no Acordo Verde Europeu (European Green Deal), relativamente a atingir a neutralidade carbónica em 2050, além de contribuir para os Objetivos do Desenvolvimento Sustentável definidos na Agenda 2030 pelas Nações Unidas [1], nomeadamente os ODS 6 (Água Pvc otável e Saneamento), ODS 11 (Cidades e Comunidades Sustentáveis) e o ODS 13 (Acção Climática) [2]. As infraestruturas verdes urbanas, também denominadas por soluções baseadas na natureza, mostram-se como uma solução tecnológica efetiva que contribui para a sustentabilidade do meio urbano, mimetizando o que ocorre na natureza no ambiente construtivo. Este tipo de infraestruturas pode ser definido como uma rede de zonas cujo objetivo é o bem-estar e a qualidade de vida da população. Existem diversos tipos de infraestruturas verdes que podem ser implementadas no ambiente urbano: parques urbanos, valas e trincheiras de infiltração, pavimentos permeáveis, corredores verdes, leitos de plantas, jardins de chuva, coberturas ajardinadas e jardins verticais [3]. Todas estas tipologias de infraestrutras verdes, oferecem elevados benefícios ambientais nas grandes cidades, pois além de contribuírem para a diminuição da poluição atmosférica, contribuem para a gestão das águas pluviais e também para a regulação da temperatura, conhecida normalmente como efeito ilha de calor, duas consequências que têm vindo a ser agravadas com as alterações climáticas. Além disso, contribuem para a restauração da vegetação e da biodiversidade em ambiente urbano, promovendo a sustentabilidade e resiliência das cidades e, simultaneamente, a melhoria da qualidade de vida. Assim, as infraestruturas verdes são consideradas como uma solução atrativa para minimizar problemas sociais e económicos, devendo por isso ser plenamente integradas em diversos domínios políticos. No entanto, para que as infraestruturas verdes sejam implementadas com sucesso e cumpram em pleno os objetivos para o qual foram planeadas, é imprescindível que sejam desenhadas e adaptadas ao local onde irão ser implementadas. As coberturas ajardinadas e os jardins verticais são dois exemplos de infraestruturas verdes que nos últimos anos têm vindo a ser divulgadas e implementadas nas cidades densamente povoadas, pela grande vantagem que oferecem e que se prende com a possibilidade de serem implementadas ao nível dos edifícios (cobertura e paredes) não necessitando, por isso, de usar área ao nível do solo, apresentando-se assim como uma mais valia dada a limitação de espaço existente. Desta forma, é imperativo aumentar os diversos tipos de infraestruturas verdes nos grandes centros urbanos, por forma a ampliar e disseminar o conhecimento sobre o seu funcionamento, bem como ultrapassar as barreiras sociais, económicas e políticas que ainda existem. Na implementação em larga escala deste tipo de infraestrutura, é importante envolver todas as partes interessadas e consciencializar os decisores políticos para os seus benefícios, por forma a aumentarmos a resiliência e sustentabilidade das nossas cidades, não só para a geração presente mas para as gerações futuras.