Browsing by Author "Costa, C."
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- Antibacterial and antioxidant potential of aqueous extracts of bio-residues from agrocybe cylindracea and pleurotus ostreatus myceliumPublication . Sousa, A. S.; Marçal, S.; Costa, C.; Ferreira, I.; Barros, J.; Nunes, J.; Freitas, A. C.; Morais, A. M. M. B.; Pintado, M.The production of fresh mushrooms results in a large quantity of bio-residues, which may account for more than 20% of a crop volume and contributes to production costs and environmental impact, if not used. These products consist mainly of stalks, mushrooms of irregular dimensions and shape and basal material. Thus, the main objective of MicoBioExtract project is the valorisation of these bio-residues and the development of add-value by-products with bioactive compounds such as polysaccharides and phenolic compounds produced by mushrooms. In the present work, the aqueous extracts from Agrocybe cylindracea byproducts (ACB) and Pleurotus ostreatus mycelium (POM) were evaluated for potential antioxidant and antimicrobial activities. Water soluble substances were extracted from mushrooms according to two different methods. In method 1 it was performed a hot extraction (extract 1A; 90 °C; 1 h; 500 rpms). In method 2, the biomass was submitted to an extraction at room temperature (extract 2B) and the resulting residue was extracted with hot water (extract 2C; 90 °C; 1 h; 500 rpms). The aqueous extracts from POM were obtained only by method 1. Extracts were lyophilized and their bioactivity evaluated measuring the antioxidant (ABTS, DPPH and ORAC) and antimicrobial (determination of the minimum inhibitory concentration – MIC) activities. The mutagenicity was also tested (Ames assay with and without S9). Moreover, it was determined the total phenolics content of the extracts and α and β – glucans (Folin Ciocalteu and Beta-Glucan Assay methods, respectively). The results obtained from antioxidant methods showed that all extracts from both mushrooms are a potential source of natural antioxidant and phenolic compounds. According to ABTS, extract 2B from ACB showed the best value with 8.48±0.33 mg ascorbic acid equivalent (AAE)/g dry extract and 4.14±0.52 mg AAE/g dry extract for POM. Regarding the antimicrobial activity, MIC results showed that ACB and POM extracts inhibited the growth of Gram- (Salmonella enteritidis) and Gram+ (Bacillus cereus and Listeria monocytogenes). Concerning the mutagenicity, the results showed no toxic effect except for extract 1A from ACB. Regarding the β-glucan content, the extracts from ACB presented higher content of β-glucan than the C extracts from POM. Thus, aqueous extracts from mushroom bio-residues showed potential antioxidant and antimicrobial properties and to develop a circular bioeconomy approach.
- A aplicação da análise do ciclo de vida no planeamento da gestão integrada de resíduos sólidos urbanosPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Application of LCA to solid waste management strategiesPublication . Xara, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Application of LCA to solid waste management strategiesPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Evaluation of MSW management practices in Portugal using Life Cycle AssessmentPublication . Xará, S.; Almeida, M. Fonseca; Silva, M.; Costa, C.This paper describes a case study where the evolution of MSW management practices for three municipalities in Portugal were analyzed using the Life Cycle Assessment technique. This evolution was mainly due to legislative pressures that led to changes in MSW collection and treatment or disposal systems implemented between 1990 and 2000. The municipalities participating in the study were Porto, Maia and Gondomar, all part of LIPOR, the intermunicipal entity responsible for the MSW management of 8 municipalities in the Porto region. Environmental burdens from these two management scenarios were calculated based on an inventory model developed by White et al. (1995), using some on-site specific parameters related with the system's operation conditions. Results show the advantage of the 2000 practices, both in terms of energy consumptio and emissions of gases with greenhouse effect.
- Life cycle analysis and solid waste management: household batteriesPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Life cycle assessment and solid waste management: the systemsPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Life Cycle Assessment and solid waste management: the systemsPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.
- Porto 1990/2000: Evaluation of environmental burdens from MSW management using Life Cycle AssessmentPublication . Xará, Susana; Almeida, M. F.; Silva, M.; Costa, C.The environmental burdens to air and water resulting from the MSW management practices in the municipality of Porto were evaluated for 1990 and 2000 using the model developed by White et al (White et al, 1995). The operations considered in the study are collection, sorting, biological treatment, thermal treatment and landfilling. Savings from energy and recycling of recovered materials are also quantified. For each pollutant, the main source, among the operations considered, was identified. Results have shown that landfilling was the main source for air and water emissions in 1990, followed by collection. In 2000, thermal treatment was the main source for air pollutants and landfilling the main source of water pollutants, in both cases followed by collection. In 1990, collection was the main source for air emissions of particulates, CO, NOx, SOx to air, and of Organic compounds, Phenol and Fluoride to water. In 2000 it was the main source of NOx to air and TOC, phenol, total metals and fluoride to water. Biological treatment was the main source of N2O and nitrate to air in 1990 and of BOD, COD and ammonia to water in 2000.
- Preliminary inventory of alkaline batteries incinerationPublication . Xará, Susana; Almeida, M. F.; Silva, M.; Costa, C.