Percorrer por autor "Ferreira, Paula"
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- Potential of Coccolithophore microalgae as fillers in starch-based films for active and sustainable food packagingPublication . Moreira, Ana S. P.; Gonçalves, Joana; Sousa, Francisco; Maia, Inês Beatriz; Pereira, Hugo; Silva, Joana; Coimbra, Manuel A.; Ferreira, Paula; Nunes, CláudiaCoccolithophore microalgae, such as Emiliania huxleyi (EHUX) and Chrysotila pseudoroscoffensis (CP), are composed of calcium carbonate (CaCO3) and contain bioactive compounds that can be explored to produce sustainable food packaging. In this study, for the first time, these microalgae were incorporated as fillers in starch-based films, envisioning the development of biodegradable and bioactive materials for food packaging applications. The films were obtained by solvent casting using different proportions of the filler (2.5, 5, 10, and 20%, w/w). For comparison, commercial CaCO3, used as filler in the plastic industry, was also tested. The incorporation of CaCO3 and microalgae (EHUX or CP) made the films significantly less rigid, decreasing Young’s modulus up to 4.7-fold. Moreover, the incorporation of microalgae hydrophobic compounds as lipids turned the surface hydrophobic (water contact angles > 90°). Contrary to what was observed with commercial CaCO3, the films prepared with microalgae exhibited antioxidant activity, increasing from 0.9% (control) up to 60.4% (EHUX 20%) of ABTS radical inhibition. Overall, the introduction of microalgae biomass improved hydrophobicity and antioxidant capacity of starch-based films. These findings should be considered for further research using coccolithophores to produce active and sustainable food packaging material.
- A review on urinary tract infections diagnostic methods: Laboratory-based and point-of-care approachesPublication . Santos, Marta; Mariz, Marcos; Tiago, Igor; Martins, Jimmy; Alarico, Susana; Ferreira, PaulaUrinary tract infections (UTIs) are among the most common infectious diseases worldwide. This type of infections can be healthcare-associated or community-acquired and affects millions of people every year. Different diagnostic procedures are available to detect pathogens in urine and they can be divided into two main categories: laboratory-based and point-of-care (POC) detection techniques. Traditional methodologies are often timeconsuming, thus, achieving a rapid and accurate identification of pathogens is a challenging feature that has been pursued by many research groups and companies operating in this area. The purpose of this review is to compare and highlight advantages and disadvantages of the traditional and currently most used detection methods, as well as the emerging POC approaches and the relevant advances in on-site detection of pathogens ' mechanisms, suitable to be adapted to UTI diagnosis. Lately, the commercially available UTI self-testing kits and devices are helping in the diagnosis of urinary infections as patients or care givers are able to perform the test, easily and comfortably at home and, upon the result, decide when to attend an appointment/Urgent Health Care Unit.
- Salt pan brine water sulphated polysaccharides retrieved at pilot scale: ability to stimulate in vitro human macrophages and salmon head kidney cellsPublication . Ferreira, Sónia S.; Pereira, Renato B.; Bordalo, Diana; Barbosa, Helena; Ferreira, Nicole; Correia, Alexandra; Ferreira, Paula; Rodrigues, Alexandre M. C.; Navalho, João; Pereira, Eduarda; Vilanova, Manuel; Nunes, Cláudia; Coimbra, Manuel A.; Pinto, BrunoMarine environments are the warehouse of a variety of novel bioactive compounds prone to be explored by food and feed industry. The growing interest in sulphated polysaccharides has led to the search for new sustainable sources, such as seawater. These compounds are naturally concentrated in salt pan brine water due to their evaporation by wind and sunlight. To take advantage of these sources, sulphated polysaccharides were concentrated from salt pan brine water using a scalable membrane ultrafiltration system with 30 and 100 kDa cut-off. This process allowed to concentrate ten times the polymeric material of brine water into 1.9 g/L, rendering a fluffy polysaccharide rich material after drying. It was mainly composed of 23 % (w/w) of uronic acids, 19 % of sulphate esters, and 34 % (w/w) of neutral sugars. This polymeric material has shown to stimulate in vitro both human macrophages and Atlantic salmon head kidney SHK-1 cells in a range of 6.25–50 μg/mL without toxicity, showing potential to be used in both human food and aquaculture feeding.