Browsing by Author "Rede, Diana"
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- Assessment of the antioxidant capacity of commercial coffee using conventional optical and chromatographic methods and an innovative electrochemical DNA-based biosensorPublication . Morais, Stephanie L.; Rede, Diana; Ramalhosa, Maria João; Correia, Manuela; Santos, Marlene; Delerue-Matos, Cristina; Moreira, Manuela M.; Soares, Cristina; Barroso, Maria FátimaAs one of the most popular beverages in the world, coffee is a rich source of non-enzymatic bioactive compounds with antioxidant capacity. In this study, twelve commercial coffee beverages found in local Portuguese markets were assessed to determine their total phenolic and flavonoid contents, as well as their antioxidant capacity, by conventional optical procedures, namely, ferric reducing antioxidant power and DPPH-radical scavenging assay, and non-conventional procedures such as a homemade DNA-based biosensor against two reactive radicals: HO• and H2O2. The innovative DNA-based biosensor comprised an adenine-rich oligonucleotide adsorbed onto a carbon paste electrode. This method detects the different peak intensities generated by square-wave voltammetry based on the partial damage to the adenine layer adsorbed on the electrode surface by the free radicals in the presence/absence of antioxidants. The DNA-based biosensor against H2O2 presented a higher DNA layer protection compared with HO• in the presence of the reference gallic acid. Additionally, the phenolic profiles of the twelve coffee samples were assessed by HPLC-DAD, and the main contributors to the exhibited antioxidant capacity properties were caffeine, and chlorogenic, protocatechuic, neochlorogenic and gallic acids. The DNA-based sensor used provides reliable and fast measurements of antioxidant capacity, and is also cheap and easy to construct.
- Ecotoxicological impact of two soil remediation treatments in Lactuca sativa seedsPublication . Rede, Diana; Santos, Lúcia H.M.L.M.; Ramos, Sandra; Oliva-Teles, Filipe; Antão, Cristina; Sousa, Susana R.; Delerue-Matos, CristinaPharmaceuticals have been identified as environmental emerging pollutants and are present in different compartments, including soils. Chemical remediation showed to be a good and suitable approach for soil remediation, though the knowledge in their impact for terrestrial organisms is still limited. Therefore, in this work, two different chemical remediation treatments (Fenton oxidation and nanoremediation) were applied to a soil contaminated with an environmental representative concentration of ibuprofen (3 ng g-1). The phytotoxic impact of a traditional soil remediation treatment (Fenton oxidation) and of a new and more sustainable approach for soil remediation (nanoremediation using green nano-scale zerovalent iron nanoparticles (nZVIs)) was evaluated in Lactuca sativa seeds. Percentage of seed germination, root elongation, shoot length and leaf length were considered as endpoints to assess the possible acute phytotoxicity of the soil remediation treatments as well as of the ibuprofen contaminated soil. Both chemical remediation treatments showed to have a negative impact in the germination and development of lettuce seeds, exhibiting a reduction up to 45% in the percentage of seed germination and a decrease around 80% in root elongation comparatively to the contaminated soil. These results indicate that chemical soil remediation treatments could be more prejudicial for terrestrial organisms than contaminated soils.
- Exploring geographical influences on physicochemical characteristics of honey: the Montesinho Natural Park scenarioPublication . Soares, Sónia; Magalhães, Leandro; Moreira, Manuela M.; Rede, Diana; Fernandes, Virgínia Cruz; Viegas, Olga; Pinto, Edgar; Almeida, Agostinho; Azevedo, Rui; Delerue-Matos, CristinaIn recent years, there has been a substantial increase in the global consumption of honey, driven by the high demand for natural products that offer health benefits. Consequently, consumers show a preference for honey, recognised for its superior quality, namely honey with a Protected Designation of Origin (PDO) or honey produced in protected areas, as it is associated with superior attributes and characteristics. Portugal is one of the leading countries in the production of PDO honey, with Montesinho Natural Park (MNP) being an excellent example of high-quality Portuguese honey, known for its distinctive attributes. However, environmental threats pose a double challenge, leading to a decline in honey production and compromising its overall quality. This study aimed to assess the specific physicochemical parameters and nutritional characteristics of MNP honey and investigate their correlation with the different locations of apiaries. MNP honey samples (n=13) were obtained from local producers or purchased at supermarkets. Standard physicochemical parameters, such as 5-hydroxymethylfurfural, diastase activity, moisture and ash content, free acidity, electrical conductivity and pH, were determined according to honey legislation. Additionally, colour parameters, protein, low-molecular-weight carbohydrates (mono- and disaccharides), and mineral content were determined. The results obtained were consistent with the requirements outlined in the legislation and those described in the literature. The results suggest that geographical factors within the park and boundaries do not contribute to variations in the analysed parameters. A significant level of homogeneity was evident in all parameters evaluated among the MNP honey samples. This is the first comprehensive study of the physicochemical properties of honey from various apiaries within the MNP.
- Exploring the impacts of microplastics and associated chemicals in the terrestrial environment – Exposure of soil invertebrates to tire particlesPublication . Selonen, Salla; Dolar, Andraž; Jemec Kokalj, Anita; Sackey, Lyndon N.A.; Skalar, Tina; Fernandes, Virgínia; Rede, Diana; Delerue-Matos, Cristina; Hurley, Rachel; Nizzetto, Luca; van Gestel, Cornelis A.M.Abrasion of tire wear is one of the largest sources of microplastics to the environment. Although most tire particles settle into soils, studies on their ecotoxicological impacts on the terrestrial environment are scarce. Here, the effects of tire particles (<180 μm) on three ecologically relevant soil invertebrate species, the enchytraeid worm Enchytraeus crypticus, the springtail Folsomia candida and the woodlouse Porcellio scaber, were studied. These species were exposed to tire particles spiked in soil or in food at concentrations of 0.02%, 0.06%, 0.17%, 0.5% and 1.5% (w/w). Tire particles contained a variety of potentially harmful substances. Zinc (21 900 mg kg-1) was the dominant trace element, whilst the highest concentrations of the measured organic compounds were detected for benzothiazole (89.2 mg kg-1), pyrene (4.85 mg kg-1), chlorpyrifos (0.351 mg kg-1), HCB (0.134 mg kg-1), methoxychlor (0.116 mg kg-1) and BDE 28 (0.100 mg kg-1). At the highest test concentration in soil (1.5%), the tire particles decreased F. candida reproduction by 38% and survival by 24%, and acetylcholinesterase (AChE) activity of P. scaber by 65%, whilst the slight decrease in the reproduction of E. crypticus was not dose-dependent. In food, the highest test concentration of tire particles reduced F. candida survival by 38%. These results suggest that micro-sized tire particles can affect soil invertebrates at concentrations found at roadsides, whilst short-term impacts at concentrations found further from the roadsides are unlikely.
- Individual and mixture toxicity evaluation of three pharmaceuticals to the germination and growth of Lactuca sativa seedsPublication . Rede, Diana; Santos, Lúcia H.M.L.M.; Ramos, Sandra; Oliva-Teles, Filipe; Antão, Cristina; Sousa, Susana R.; Delerue-Matos, CristinaThis work aims to assess, individually and in mixtures, possible phytotoxic effects of three pharmaceuticals (paracetamol, ibuprofen and amoxicillin) on germination and early growth of Lactuca sativa seeds. Pharmaceuticals are an important group of emerging contaminants, whose presence has been described in several environmental compartments, including soils. However, knowledge on their possible impact in terrestrial organisms is still sparse and even more when mixtures are considered. Germination tests are important to evaluate the quality of soil and the toxic effects that contaminants can pose to plants. The acute effects of individual pharmaceuticals as well as binary and ternary mixtures were assessed using different endpoints, namely: percentage of seed germination, root elongation, shoot and leaf length, after an exposure time of five days. Overall, in the exposure of L. sativa seeds to individual pharmaceuticals there are indications of acute toxicity in the early plant growth. However, this inhibitory effect tends to be cancelled in the acute exposure to mixtures. This study shows the importance of evaluating the toxicity of mixtures of pharmaceuticals, since they might have distinct toxic effects when compared to the single compounds, and also because, probably, it is the closest scenario to the reality that can be found in the environment.
- Unveiling the geographical influence on honey's physicochemical profile: a case study from Montesinho Natural ParkPublication . Soares, Sónia; Magalhães, Leandro; Moreira, Manuela M.; Rede, Diana; Fernandes, Virgínia Cruz; Viegas, Olga; Pinto, Edgar; Almeida, Agostinho; Azevedo, Rui; Delerue-Matos, CristinaIn recent years, global honey consumption has significantly increased due to the rising demand for natural products with health benefits. Consumers are particularly drawn to honey recognized for its superior quality, such as Protected Designation of Origin (PDO) honey or honey produced in protected areas, which is associated with distinctive characteristics. Portugal stands among the top producers of PDO honey, with Montesinho Natural Park (MNP) being a notable example of high-quality Portuguese honey. Despite its reputation, environmental challenges threaten both honey production and quality in this region. This study aims to evaluate the physicochemical parameters and nutritional characteristics of honey from MNP and investigate the correlation between these properties and the geographical location of the apiaries. Honey samples (n=13) were collected from local producers and supermarkets. Standard physicochemical parameters, including 5-hydroxymethylfurfural (HMF), diastase activity, moisture and ash content, free acidity, electrical conductivity, and pH, were analysed following honey legislation guidelines. Additional parameters, such as colour, protein content, low-molecular-weight carbohydrates, and mineral composition, were also assessed. The findings indicate that all honey samples complied with legal standards and align with previously published data, showing a high degree of homogeneity across the physicochemical properties analysed. Principal Component Analysis (PCA) revealed that parameters such as colour, HMF, and specific minerals (Mg, Ca, K, Mn, Sr, Cu, Ba) contributed to the clustering of honey samples, suggesting that geographical variations among apiary locations might influence these properties. However, these differences do not affect the overall quality of the PDO honey produced in MNP. This study represents the first comprehensive characterization of honey from different apiaries within MNP. While the results demonstrate the consistency and quality of MNP honey, further research is necessary to explore the relationship between geographic origin and quality under varying environmental conditions. These insights could be valuable for maintaining sustainable beekeeping practices in the region and preserving the unique attributes of MNP honey.