Browsing by Author "Sousa, Sofia"
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- Aqueous extracts from agrocybe cylindracea and pleurotus ostreatus as source of antioxidant coatingsPublication . Marçal, Sara; Sousa, Sofia; Antunes, Filipa; Costa, Cristina; Ferreira, Inês; Barros, Joana; Nunes, João; Pintado, ManuelaAgrocybe cylindracea and Pleurotus ostreatus mushrooms are rich in polysaccharides and phenolic compounds with antioxidant and antimicrobial properties. Therefore, these mushrooms can be a good source of natural food preservatives and edible coatings. The main goal of this study was to develop an edible coating with antioxidant activity. Edible coatings are composed of biopolymers and may be carriers of additives with bioactive properties. This study developed an aqueous extraction process that allows the extraction of biopolymers and bioactive compounds (eg. phenolic compounds) from A. cylindracea and P. ostreatus mushrooms, with antioxidant activity, which can be used as preservative edible coating. To accomplish this, after a pre-treatment by maceration of frozen mushrooms two consecutive aqueous extractions were applied, where the first was at room temperature (A) and the second (B) was hot extraction (90ºC; 1h; 5 000rpm). Extracts were lyophilized and the extraction yields were determined. Total phenolics content was determined through Folin Ciocalteu and antioxidant activity through ABTS method. The yields of extracts A and B from P. ostreatus were 33.60% ± 0.39 and 15.18% ± 0.70. The yields of extracts A and B from A. cylindracea were 30.91% ± 0.89 and 14.77% ± 1.49, respectively. These results are in agreement with yields of A. cylindracea hot-water extracts reported by Tsai, Huang and Mau,2006. Phenol content of extracts from A. cylindracea (extract A: 13.35 ± 0.55; extract B: 12.79 ± 0.67 mg gallic acid equivalent (GAE) per g of dry extract) were higher than phenol content of extracts from P. ostreatus (extract A: 10.28 ± 0.70; extract B: 11.52 ± 0.62 mg GAE per g of dry extract). The ABTS radical cation-scavenging activity was also higher in extracts from A. cylindracea (extract A: 12.04 ±1.26; extract B: 6.78 ± 0.44mg ascorbic acid equivalent (AAE) per g of dry extract) than extracts from P.ostreatus (extract A: 6.39 ± 1.45; extract B: 5.75 ± 0.49mg AAE per g of dry extract). Results of this study indicate that A. cylindracea has more antioxidant activity than P. ostreatus, but both mushrooms are potential sources of natural antioxidant preservatives and polysaccharides to produce bioactive edible coatings.
- Biopsychosocial factors that influence the purpose in life among working adults and retireesPublication . Coelho, Anabela; Lopes, Manuel; Barata, Marta; Sousa, Sofia; Goes, Margarida; Bia, Florbela; Dias, Ana; João, Ana; Lusquinhos, Leonel; Oliveira, Henrique; Gaspar, TâniaThis study aimed to identify and characterize biopsychosocial factors that impact the purpose in life (PIL) among adults that are working or already retired. This cross-sectional study includes a sample of 1330 participants, of whom 62.2% were female, with ages ranging from 55 and 84 years, with a mean of 61.93 years and a standard deviation of 7.65. Results suggest that the education level, stress, spirituality (religion) and optimism, social support from friends, and quality of life related to physical health seem to contribute positively to the PIL for both groups. However, some variables such as age, marital status and environmental quality of life help explain the PIL of retired people and the quality of life related to social support helps explain the PIL of working adults. Overall, the reported findings suggest that the purpose in life is strongly related to physical, psychological, social and environmental health factors. It is highlighted that working adults and retired people have their purpose in life related to similar factors and others specific to each life stage, suggesting the need for crucial interventions to promote a healthier and more positive aging process.
- Foster care process: challenges and coping of youth and familiesPublication . Negrão, Mariana; Sousa, Sofia; Tavares, Mariana; Veiga, Elisa; Veríssimo, LurdesFamily foster care is a topic that currently gives rise to some interest, however, it still presents little research in the Portuguese context. International research shows that the main challenges of foster families are related to the separation from the child and to reduced external support in financial, emotional, psychological, and social domains. To address these challenges, families have to put together coping strategies related to family resilience in the fostering process, such as: personality traits; family cohesion; family flexibility; self-esteem; skills in problem solving and communication and organization. Regarding the youth, there are few studies on the challenges faced by children and youth in foster care but also on adaptation strategies and protective factors that may help to circumvent them. Main challenges identified relate to withdrawal of the birth family and integration into the foster family. Perception of their relationship, both with the foster family and with the biological family, can be equally a challenge or a protective factor. Regarding to adaptation strategies, psychological resilience stands out. Thus, this study intends to integrate the results of two complementary investigations, conducted as a part of two Master’s Degree Dissertations. On the one hand, a study that aims to understand the challenges and the coping strategies throughout the foster care process in the perspective of the foster care youth, and, on the other hand, a study that intends to understand the challenges and coping strategies throughout the foster care process in the perspective of foster care families. Both studies are still ongoing, in the data collection phase. Using a qualitative methodology, young people in a situation of family foster care and foster families are currently being interviewed, based on a semi-structured script. Both scripts include dimensions such as sociodemographic data, relationship between foster family and youth, challenges and coping strategies throughout the foster care process. The script for the foster families, also includes a dimension “motivations to foster”. Because it is still an ongoing study, we can not yet present any results. However, the data collection will be finished in the coming months and it is expected that the results can add to the investigation in the area of family foster care in Portugal. More specifically, because this study allows, on one hand, to understand perspectives of families and youthand, on the other hand, to address their complementarity, since the same issues, in both perspectives, are adressed.
- Isolation of metal-tolerant bacteria from metallophytes for bioaugmentation purposes in mine tailingsPublication . Moreira, Helena; Sousa, Sofia; Cunha, Joaquim; Castro, Paula M. L.; Pereira, Sofia I. A.Mining is one of the most pollutant anthropogenic activities, generating a large amount of rejected waste materials from ore processing, known as tailings. Unvegetated tailings are a source of contamination, namely metals and metalloids, for the surrounding environment, including to the nearby communities. Tailings' low nutrient and organic matter content, as well as the low pH, limit the establishment of a plant cover, although some metallophytes can be sparsely found inhabiting these areas. Metallophytes can harbor metal-tolerant bacterial strains that may be used to produce bioinoculants to help tailings revegetation along with metal stabilization.\ The Borralha mine (northern Portugal) is a former tungsten producer with several tailings exposed to atmospheric conditions, where some metallophytic plants can be found. In this work, we aimed to characterize the culturable rhizosphere bacterial community of metallophytes in the tailings area for bioaugmentation purposes under remediation approaches. To attain this goal, composite soil samples from the rhizosphere of metallophytic plants such as Agrostis capillaris, Cytisus striatus, Erica arborea, Pinus pinaster, Rubus ulmifolius, and Salix caprea were collected. The culturable bacterial community of the samples was isolated, and 65 different morphotypes were characterized genotypically (BOX-PCR, 16S rDNA sequencing) and for Cu, Cd, and Zn tolerance. The most tolerant strains were screened for growth-promoting traits, namely the productions of siderophores, organic acids, NH3 and indoleacetic acid production, ACC-deaminase activity, and phosphate solubilization capacity. The best-performing strains, especially those with higher ACC deaminase activity and IAA production, were selected and used to prepare two different bacterial consortia. The effects of these consortia in parameters such as plants' growth and soil metal stabilization were tested in a greenhouse experiment using Agrostis capillaris as a model plant, grown in tailings material. Microbial parameters were also assessed, showing an overall increase in microbial activity. Results indicate that revegetation and metal stabilization of some tailings can be improved by using bioaugmentation approaches.