http://hdl.handle.net/11624/152 2026-05-06T01:30:53Z 2026-05-06T01:30:53Z Rodrigues, Michele Junkherr http://hdl.handle.net/11624/4256 2026-04-27T14:32:36Z 2025-01-01T00:00:00Z

Title: Análise da eficiência de tecnologias limpas baseadas na espectroscopia no infravermelho e na cromatografia para reconhecimento da qualidade do óleo essencial de Melaleuca. Authors: Rodrigues, Michele Junkherr Abstract: CLEAN TECHNOLOGIES BASED ON INFRARED SPECTROSCOPY TO PREDICT THE QUALITY OF MELALEUCA ESSENTIAL OIL. Quality control of essential oils is carried out mainly by gas chromatography, aiming to identify their chemical composition and detect possible adulterations with synthetic substances or other oils. In this study, thirty-six commercial samples of Melaleuca sp. essential oil were analyzed for their chemical composition and physicochemical properties. Fifteen main components were identified, with Terpinen-4-ol, α-Terpinene, Terpinolene, and p Cymene being the most abundant. For comparative purposes, a control essential oil was extracted by hydrodistillation using the Clevenger method and characterized, along with the commercial samples, by gas chromatography coupled with mass spectrometry (GC MS). The refractive index of the samples was correlated with the results obtained by infrared spectroscopy (FTIR), allowing the identification of adulterated samples through multivariate analysis. Additionally, the optimization of chromatographic analysis of the essential oil directly from Melaleuca sp. leaves was performed using the Headspace technique, enabling the quantification of its major compounds. The results indicate that both spectroscopy, for adulteration detection, and the Headspace technique, for direct leaf analysis, are promising tools for the rapid characterization of essential oil. These approaches prove to be faster, more environmentally responsible, and potentially cleaner alternatives for the quality control of this product. Future studies may focus on the characterization of minor compounds in the oil directly from the leaves and by spectroscopy, as well as improving adulteration quality control using rapid physicochemical methods correlated with spectroscopy.

2025-01-01T00:00:00Z Schüler, Silmo http://hdl.handle.net/11624/4239 2026-05-05T13:31:32Z 2026-01-01T00:00:00Z

Title: Potencialidades na utilização de plantas alimentícias subutilizadas, em substituição aos alimentos importados, para o desenvolvimento de uma agricultura sustentável em Angola, África. Authors: Schüler, Silmo Abstract: This exploratory and quantitative thesis aimed to identify underutilized food plants in Angola and characterize the nutritional composition of those most cited in the scientific literature. It also analyzed, quantified (in terms of volume and value), and chemically characterized the main foods imported by the country. In addition, a comparative analysis of the nutritional equivalence between underutilized local foods and the principal imported foods was conducted. The objective was to generate evidence to support public policies that promote national food production while preserving biodiversity associated with local ecosystems through the development of a sustainable agri-food system. Ten underutilized plant species were surveyed: one legume species, macoba bean (Voandzeia subterranea Thouars); two cereal species, massambala (Sorghum bicolor (L.) Moench) and massango (Pennisetum glaucum (L.) R.Br.); three fruit tree species, imbondeiro (Adansonia digitata L.), maboqueiro (Strychnos spinosa Lam.), and dendezeiro (Elaeis guineensis Jacq.); two tuber species, inhame (Dioscorea spp.) and assipi (Colocasia esculenta (L.) Schott); and two leafy vegetable species, fumbua (Gnetum africanum Welw.) and uce (Hibiscus sabdariffa L.). An additional fifteen underutilized food species were also identified. In 2022, Angola imported 804,098 tons of corn, wheat and flour, potatoes, oranges and juice, edible oil, and fresh, dehydrated, frozen, or preserved vegetables, totaling USD 706,492,000. In this context, and considering the demonstrated nutritional quality of the underutilized food plants analyzed in this study, the consumption of imported foods in Angola could be partially replaced by the local production of these underutilized species. Such an approach would contribute to the development of sustainable agriculture while generating local employment and income. Therefore, the development and implementation of public policies are recommended to strengthen food production systems based on these underutilized plants, providing a sustainable solution to food scarcity, food and nutritional insecurity, malnutrition, environmental sustainability, and the conservation of associated ecosystems in Angola.

2026-01-01T00:00:00Z Meurer, Daiana Elisa http://hdl.handle.net/11624/4229 2026-03-23T13:14:19Z 2025-01-01T00:00:00Z

Title: Avaliação da manutenção dos serviços ecossistêmicos fornecidos pela avifauna em área sob interferência de atividade mineradora em leito de curso hídrico. Authors: Meurer, Daiana Elisa Abstract: This study investigates the ecological role of birds and their importance in providing ecosystem services for the conservation of biodiversity. The research was structured in two phases: a bibliometric review and an applied field study. The bibliometric analysis (2020–2025) revealed a global landscape led by China and the U.S., focusing on the impacts of agricultural intensification, yet highlighting a lack of direct quantification of the services provided by birdlife. The field study assessed the bird community along the Vacacaí River, comparing areas with (CM) and without sand mining (SM). A total of 104 species (37 families) were recorded, with a sampling efficiency of 82.54% (Jackknife 1). The results indicated greater diversity in the CM area (Shannon-Weaver: 3.317) and greater relative richness in the SM area (Margalef: 9.122). Community structure showed significant seasonal variation (p = 0.029), with NMDS clustering indicating cohesion in winter and dispersion in summer. Insectivores (32.7%) and species with low sensitivity to disturbances (72.4%) predominated. It is concluded that seasonality, and not mining alone, is the main structuring factor of the local community, reinforcing the need for continuous monitoring to maintain ecological functions in the region.

2025-01-01T00:00:00Z Dahmer, Mainara Nicaretta http://hdl.handle.net/11624/4170 2025-12-19T14:49:23Z 2023-01-01T00:00:00Z

Title: Biodegradação do fungicida piraclostrobina em água utilizando as bactérias bacillus subtilis e pseudomonas aeruginosa. Authors: Dahmer, Mainara Nicaretta Abstract: Fungicides are applied in various agricultural practices to reduce microbial load and enable high productivity. Prolonged exposure to these pesticides harms the environment and affects the health of humans and other forms of life, which is why the degradation of these compounds through microbial bioremediation has been the focus of numerous studies. With the objective of studying the bacterial biodegradation of the fungicide pyraclostrobin in liquid media, this dissertation brings together a review article with bibliometric analysis and an article with experimental data. The bibliometric analysis was carried out using the terms “biodegradation” and “fungicides”, focusing on bioremediation using bacteria and microbial consortia for the last 10 years. Twenty articles were selected from the Scopus database based on keywords and the Biblioshiny software was used to carry out a detailed analysis of the publications. There was an increase in publications related to microbial bioremediation, with studies on strobilurins showing increasing scientific interest. Among the countries that made the most contributions in the area, Greece stood out. In the dissertation's experimental research, the biodegradation of the fungicide pyraclostrobin (a strobilurin) in water was evaluated. The experiments were carried out using a complete factorial design in which two variables were used, the bacteria (Pseudomonas aeruginosa and Bacillus subtilis) in isolation and the time of exposure to the fungicide (5 and 10 days). The experiments with bacteria in a consortium were conducted for 5 days. The samples were analyzed by High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) and Liquid Chromatography coupled to Mass Spectrometry (LC-MS). The results showed that both bacteria biodegraded pyraclostrobin, with Pseudomonas aeruginosa showing a significantly higher degradation rate (57.9% in ten days). The consortium between bacteria did not show better results when compared to Pseudomonas aeruginosa used alone; therefore, it did not present synergistic effects capable of leading to an increase in the biodegradation of pyraclostrobin. It was concluded that the biodegradation of pyraclostrobin by Pseudomonas aeruginosa demonstrated promise for the removal of this fungicide when dispersed in a liquid medium. However, more research is still needed to focus on the use of consortia between different microorganisms to improve degradation rates and the efficiency of removing these compounds from the environment.

2023-01-01T00:00:00Z