CBQF - Documentos de Conferências / Conference Objects
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- Circular economy synergies: leveraging agrifood waste for sustainable shoe materialsPublication . Silva, Sara; Ribeiro, Tânia; Silva, Isa; Marçal, Sara; Pintado, ManuelaThe shoe industry needs more sustainable practices to reduce its environmental impact not only in terms of processes and generated waste but also in its dependence on virgin raw materials. To address the last, there is an unconventional synergy that can prove to be disruptive. A synergy with the agrifood sector. While cascading use and food first principles mean that priority should be given to food and feed applications, there are several wastes generated by this sector that are not suitable for either application, and these are the ones that could be of particular interest for use to reduce raw material dependence by the shoe industry. Cork is a sustainable material commonly used in the footwear sector due to its lightweight, cushioning, and thermal insulating properties. However, there is increasing interest in enhancing it by incorporating additional materials derived from industrial byproducts. Beyond sustainability benefits, these modifications can potentially improve moisture absorption, alter microbial survival, and aesthetic design features, making them ideal for shoe insoles and similar applications where comfort and hygiene are critical. Thus, this study explores the potential of incorporating diverse industrial byproducts into cork-based shoe materials to improve both functional and design aspects, contributing to sustainability strategies within the footwear industry.
- Thermally processed eggshells as a renewable source of calcium carbonate for industrial usePublication . Silva, Sara; Marçal, Sara; Ribeiro, Tânia; Pintado, ManuelaCalcium carbonate (CaCO?) is a vital industrial material used extensively in pharmaceuticals, food production, construction, and environmental remediation. Current CaCO? sourcing methods, primarily reliant on mining limestone and chalk, present significant environmental challenges, including habitat destruction, high energy consumption, and carbon emissions. To address these concerns, this study explores the potential of agrifood waste, specifically eggshells, as a circular and sustainable source of CaCO?. Eggshells, are a rich and readily available biogenic source of CaCO? thus, exploiting them as an alternative source of CaCO? can reduce waste production while providing an eco-friendly alternative for the shoemaking industry. However, when considering its incorporation into thermoresistant plastic, like the one used to produce shoe soles, its protein content can represent a limitation to its application, as previous works have shown it to be correlated with non-compliant soles. Thus, the current work exploited the transformation of eggshells into an enriched mineral substrate for incorporation into thermoplastic materials used in the production of shoe soles.
- Targeting skin-associated candida: antifungal efficacy of selected essential oilsPublication . Lopes, Ana I.; Oliveira, Cláudia S.; Pintado, Manuela E.; Tavaria, Freni K.Introduction: Candida spp. are commensal yeasts that inhabit the skin and mucous membranes and are the leading cause of invasive fungal infections (Lopes et al. 2024). Mucocutaneous candidiasis is a common condition, often treated with azoles and polyenes, which can cause side effects and promote resistance (Tortorano et al., 2021). Essential oils (EOs), natural compounds with antimicrobial activity, present a promising alternative due to their multi- targeted action, thereby reducing the likelihood of resistance (Zuzarte et al., 2011). Objective: To study the antimicrobial activity of three EOs – eucalyptus, lavender, and thyme – against two species of Candida (C. albicans and C. tropicalis). Conclusions: Eucalyptus, lavender, and thyme EOs presented antifungal activity against C. albicans and C. tropicalis. Thyme possessed the lowest MIC; the inhibition curves corroborated this result. All EOs showed anti-biofilm activity. The flow cytometry assay showed that all oils were able to damage yeast cells; thyme oil presented the highest percentages of dead and injured cells. Fluorescence microscopy supported flow cytometry findings, revealing live (green), injured (yellow), and dead (red) cells following EO exposure. Thyme EO was the one with the best antifungal activity. These promising results suggest EOs, especially thyme, can be applied to formulations to treat Candida-related skin infections.
- Targeting skin-associated candida: antifungal efficacy of selected essential oilsPublication . Lopes, Ana I.; Oliveira, Cláudia S.; Pintado, Manuela E.; Tavaria, Freni K.Background: Candida spp. are commensal yeasts that inhabit the skin and mucous membranes and are the leading cause of invasive fungal infections. Mucocutaneous candidiasis is a common condition, often treated with azoles and polyenes, which may cause side effects and foster resistance. Essential oils (EOs), natural compounds with antimicrobial activity, present a promising alternative due to their multi-target action, reducing the likelihood of resistance. Objective: To study the antimicrobial activity of three EOs – eucalyptus, lavender, and thyme – against two species of Candida (C. albicans and C. tropicalis). Methods: The antimicrobial potential of the EOs against the selected yeasts was assessed using the following tests: (i) agar diffusion assay; (ii) determination of minimum inhibitory (MIC) and fungicidal concentrations (MFC); (iii) growth inhibition curves at MIC, 2×MIC, and ½MIC; (iv) anti-biofilm activity at MIC, ½MIC, and ¼MIC; (v) membrane integrity analysis by flow cytometry using propidium iodide (PI) and thiazole orange (TO); and (vi) fluorescence microscopy of yeasts exposed to eucalyptus EO at ¼MIC. Results: C. albicans inhibition zones were 5.13 mm (eucalyptus), 5.0 mm (lavender), and complete inhibition with thyme EO. All EOs fully inhibited C. tropicalis. MIC and MFC values ranged from 0.08% to 2.5% (v/v), with thyme EO having the lowest values for both yeasts. Inhibition curves confirmed MIC results. Thyme EO also showed the greatest inhibition of biofilm formation. Flow cytometry revealed membrane damage in both species, with C. tropicalis showing a higher proportion of dead and damaged cells. Thyme EO consistently induced the highest levels of cell damage across all concentrations tested. Fluorescence microscopy supported flow cytometry findings, revealing live (green), injured (yellow), and dead (red) cells following EO exposure. Conclusion: All tested EOs displayed antifungal activity, with thyme EO being the most effective. C. albicans was more resistant than C. tropicalis, highlighting species-specific EO sensitivity.
- Combination of SPE and pH adjustment for the simultaneous spectrophotometric determination of copper, zinc and manganese in waterPublication . Ferreira, Francisca; Ribas, Tânia; Mesquita, Raquel; Rangel, AntónioCopper, zinc, and manganese are commonly found in both natural and treated water sources. Although these metals are essential micronutrients, their accumulation, even at low concentrations, can lead to serious health issues. Therefore, continuous and accurate monitoring of these elements in environmental and drinking water is crucial to ensure public safety. Solid Phase Extraction (SPE) is a widely used sample preparation technique that relies on sorbent materials to separate and concentrate specific analytes from complex matrices. In heavy metal analysis, SPE offers several advantages, such as enhanced sensitivity, selectivity, and compatibility with automated systems. Ion-exchange resins selectively bind to ions based on their charge and therefore are one of the most effective sorbents for metal ion separation. While cation-exchange resins retain positively charged metal ions like Cu²⁺, Zn²⁺, and Mn²⁺, anion-exchange resins bind to negatively charged species. This selectivity allows for cleaner separation and more accurate quantification in multi-parametric analysis. The objective of this work was to develop an automatic sequential injection analysis (SIA) system integrated with an in-line cation-exchange resin column (Toyopearl) for the simultaneous determination of copper (II), zinc, and manganese in water samples. This system employs a cationic resin coupled with a colorimetric reagent (Zincon) whose selectivity varies with pH, enabling the separation of target metal ions and consequent individual quantification. This method presents a reliable and reagent-efficient alternative to conventional techniques, with strong potential for real-time or on-site monitoring applications.
- Innovative water sampling strategy for the simultaneous sampling and sample preparation for cadmium quantificationPublication . Ribas, Tânia; Rodrigues, Francisco; Mesquita, Raquel; Rangel, AntónioThe content of certain metal ions in aquatic ecosystems has emerged as an environmental concern, posing significant risks to both aquatic life and human health. Some metal ions, including cadmium, are usually present at a trace level in environmental waters. Nevertheless, even at low exposure levels, cadmium can lead to serious health problems. Its increasing presence in natural waters is largely attributed to its widespread use in products such as batteries and electronic components. Consequently, regular monitoring of water quality is crucial for effective pollution control. Traditional methods for metal ions assessment in environmental waters usually involve bottle sampling, the addition of some preservatives, and sample treatment, and analyte quantification. However, the sampling and sample preparation procedures can compromise sample integrity due to factors such as temperature variation, UV radiation, oxygen exposure, changes in pH, use of organic solvents, microbial activity, among others. Consequently, sample degradation can introduce uncertainty in the analyte. Besides the potential sample degradation, these processes may increase the time required for analysis and the complexity of the process. Solid phase extraction (SPE) is one of the widely used techniques for sample preparation, aimed at sample matrix clean-up and/or analyte enrichment. This work presents a novel SPE-based method that integrates both sampling and sample preparation into a single step for cadmium quantification in freshwater. This was achieved by devising a portable column packed with Chelex-100 resin, a weak cation exchange resin that offers high selectivity towards metal ions. For sample collection, the water passes through the column, using a syringe, and, during this step, the metal ions are retained and the water matrix discarded (matrix clean-up). Subsequently, a lower volume of eluent is used to recover the metal ions, promoting in this way the enrichment of the analyte for further analysis (ICP or AAS). This approach takes advantage of the resin’s properties to enrich cadmium, which is typically present in concentrations between 3 and 5 μg L -1 , often below the limit of detection of several traditional methods.
- Packed ionic resins to perform solid phase extraction (SPE) and solid phase spectrophotometry (SPS) for metal ions determination and speciation in a smart sampling approachPublication . Mesquita, Raquel; Pereira, Mafalda; Melo, Maria; Ribas, Tânia; Rangel, AntónioThe adverse effects in the environment of metal ions are well documented, notably for those displaying toxic effects for living organisms according to their concentration. Novel sampling and real-time monitoring methods will have a significant impact on understanding the spatial-temporal distribution of the metal ions and will contribute to act on-time to detect and mitigate sources of contamination of aquatic systems. So, a project, Aqua_Smart, has been implemented to devise an integrated smart sampling and automatic monitoring of toxic metal ions in aquatic systems. The aim is to attain metal ions assessment by employing on-site smart sampling approaches to tackle the bioavailability of some metallic ions in different water bodies. The idea relies upon the use of solid phase extraction (SPE) for analyte retention as a replacement for transporting high volumes of samples to the laboratory. The SPE process is achieved by using ionic exchange resins to selectively collect the analytes, and, for analysis, we propose to use flow- based methods, like sequential injection (SI) analysis (Mesquita & Rangel, 2009) with miniaturized optical detection. The use of an automated SI method with optical detection in the flow cell also enables to carry out the determination in the solid phase itself in a solid phase spectrophotometry approach. This approach efficiency is demonstrated with the speciation of iron(II) and iron(III) in different types of natural waters. Additionally, for employing ionic exchange for the metal ion retention, the charge of the ion is highly relevant, and although most metal ions are cations in aquatic systems, it is also known that some metal ions form chloro-complexes with chloride, resulting in negatively charged complexes. So, considering the chloride content of high salinity waters like seawater, some metal ions, namely cobalt, are indeed complexed. Consequently, another approach for smart sampling is the use of polymer inclusion membranes, PIMs. These can be described as a thin, flexible and stable polymeric film that presents the property of selectively separating solute/s of interest depending on the composing extractant. These membranes can be prepared by using an ion-exchanger immobilized in a polymeric matrix. A PIM prepared for anionic species retention may act as exchangers to selectively collect a specific metal ion negatively charged complex from an aquatic system, after being incorporated in miniaturized devices. After a proof-of-concept of this process, previously demonstrated for the cobalt determination in sea water, several studies of the PIM preparation were carried out. These studies aimed to obtain the best performance in flow methods of the PIM as a sorbent. For this purpose, an electrospinning process was used to produce solid fibres.
- Transforming non-edible parts of pineapple into fat substitutes for cake formulationsPublication . Moggi, Fernanda; Campos, Gabriel; Kern, Nina; Madaleno, Luna; Sousa, Sérgio; Brassesco, María E.; Silva, Cristina L. M.; Miller, Fátima A.; Brandão, Teresa R.S.The non-edible parts of many fruits, such as peels and seeds, contain fibres, which gives them the potential to be used as functional ingredients since fibres may serve as fat replacers in various food formulations. If these fruit parts are properly transformed into edible forms, there is potential for the reuse and recovery of food waste. In the case of pineapples, approximately 70% of the total weight of the fruit is not consumed, with rinds, core, and crown usually discarded. To turn pineapple rinds into pasteurized purées and assess their potential as a butter substitute in cupcakes. To assess protein and dietary fibre contents in the cupcakes. To characterize the cupcakes in terms of texture profile (hardness, adhesiveness, cohesion, gumminess and chewiness). To use a focus group to discuss insights, opinions, and perceptions on the cupcake formulations.
- Thermosonication impact on blueberry juice quality preservationPublication . Panaro, Eleonora; Silva, Cristina L. M.; Brandão, Teresa R. S.; Miller, Fátima A.The FIVE A DAY rule promotes fruit juice consumption for its flavor and nutritional benefits, aiming to fulfill daily nutrient requirements. However, thermal processing challenges food products' nutritional quality, prompting a rise in non-thermal methods within the beverage market to promote healthier choices. This study explores the application of ultrasound, an emerging, cost effective, energy-efficient, and eco-friendly technology. Blueberries, recognized as superfruits for their high content of health-promoting compounds, were chosen for their phenolic and anthocyanin amounts. To develop a high-quality blueberry juice through the application of thermosonication treatments. • Safety indicator - Listeria innocua, a non-pathogenic surrogate of Listeria monocytogenes. • Quality indicators – Total phenolics, anthocyanins and rheological properties (shear rate and shear stress).
- Effect of a soil biofertilizer in the functional profile of the soil microbial community through the biolog assayPublication . Lima-Filho, Sonny; Pacheco, João; Ganilho, Catarina; Crespo, Rute; Andreani, Tatiana; Godinho, Mariana; Pereira, Sofia; Pereira, RuthIntroduction: The dependency on crops of products with synthetic chemical compounds, whether fertilizers or pesticides, for saving the development and yield has been a challenge to the environment, and new alternatives are being sought to change this reality. The excessive use of chemicals affects human health and soil quality. Therefore, there is a significant need to produce green compounds that are environmentally sustainable, aimed at improving or restoring microbial activity in the soil. Biofertilizers are compounds that contain biological substances capable of stimulating plant development, by providing nutrients and other plant-growth promoting compounds, of increasing soil microbial activity, and of reducing the environmental impacts of mineral fertilizers. Aims: To assess the effects of applying a biofertilizer inoculum, containing rhizospheric microorganisms, that positively interact with plant roots, on the functional profile of the bulk soil microbial community; To evaluate soil microbial activity after 30 and 60 days of organic biofertilizer application through the BIOLOG assay. Conclusion: The soil without inoculum was the one with the lowest microbial activity (measured by the AWCD) after both incubation periods, although the differences do not seem to be significant (data under analysis); The presence of the plant was able to compensate for the possible effect of the biofertilizer on the highest consumption of some substrates in detriment of others, as suggested by the Eveness index (C, D); Both the plant and the biofertilizer inoculum promoted a higher soil functional biodiversity of the soil, as measured by the Shannon Index (E, F) and the Richness (G, H), calculated based on the number and type of carbon substrates mineralized by the soil microbial community.