http://repositorio.ufc.br/handle/riufc/82 Thu, 13 Aug 2026 12:18:18 GMT 2026-08-13T12:18:18Z http://repositorio.ufc.br/handle/riufc/87378 Título: Atividades biológicas de extratos e frações da macroalga marinha vermelha Hypnea pseudomusciformis (Nauer, Cassano & Oliveira) Autor(es): Rebouças, Beatriz Emilly Alves Abstract: This study aimed to investigate the biotechnological potential of the red marine macroalga Hypnea pseudomusciformis, collected from Pacheco Beach, Caucaia, Ceará, Brazil. Extracts and fractions were analyzed to evaluate their biological activities, toxicity, and application in edible films. The algal biomass was subjected to sequential extraction using solvents of increasing polarity (hexane, ethyl acetate, and methanol), in addition to the extraction of sulfated polysaccharides. Subsequently, the extracts were fractionated by liquid-liquid partitioning and analyzed by thin-layer chromatography, leading to the preliminary characterization of the present secondary metabolites. The contents of total phenolic compounds and flavonoids were quantified, and the antioxidant activities were evaluated by the DPPH and ABTS+ free radical scavenging methods, ferrous ion chelating power (FIC), ferric ion reducing power (FRAP), and -carotene bleaching inhibition. The obtained fractions were also subjected to toxicological assays against seeds of improved Aodai cucumber (Cucumis sativus), Artemia sp. nauplii, and zebrafish (Danio rerio), evaluating possible phytotoxic and/or cytotoxic effects. Additionally, the incorporation of the fractions into carrageenan-based edible films was investigated, evaluating physicochemical properties such as water vapor permeability, thickness, solubility, and colorimetric parameters. The results demonstrated that the extracts and fractions contained different chemical profiles and biological activities, highlighting the influence of solvent polarity on the extraction of bioactive compounds. The variable antioxidant capacity of algal extracts, across different assays, showed their potential for application as a natural source of antioxidants. In toxicological tests, the response depended on the concentration, with greater toxicity at higher concentrations, especially for the hexane fraction. The edible films incorporated with the fractions showed alterations in physical and colorimetric properties, demonstrating potential for application in biodegradable packaging systems with functional potential. Thus, the results obtained show that H. pseudomusciformis constitutes a promising source of bioactive compounds with potential application in the pharmaceutical, food, and biotechnological fields. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/87378 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/86807 Título: Efeitos da aplicação de óleos essenciais à dieta de tilápia-do-nilo (Oreochromis niloticus) Autor(es): Cunha, Angélica de Oliveira Portela Abstract: Global population growth poses challenges to sustainable food production, highlighting aquaculture as a strategic alternative for supplying animal protein. In this context, Nile tilapia (Oreochromis niloticus) stands out due to its high adaptability to intensive farming systems, rapid growth, and wide commercial acceptance. However, the intensification of production favors the emergence of diseases and the excessive use of antibiotics, driving the search for natural additives capable of improving fish performance and health. Thus, essential oils emerge as promising additives due to their antimicrobial, antioxidant, and immunomodulatory properties. The present study evaluated the palatability and the zootechnical and histological effects of dietary supplementation with different essential oils for juvenile Nile tilapia under controlled laboratory conditions. The essential oils of Cassia Cinnamon (Cinnamomum cassia), Lemongrass (Cymbopogon flexuosus), Eucalyptus (Eucalyptus staigeriana), and Oregano (Origanum vulgare) were individually supplemented at concentrations of 0.1, 1, and 10 mL/kg of commercial feed. Zootechnical performance was evaluated through Mean Weight, Total Weight Gain (TWG), Apparent Feed Conversion Ratio (FCR), and Survival, while palatability was assessed through feed intake tests and latency to the first feeding attack. The results demonstrated a positive effect of supplementation at intermediate concentrations (1 mL/kg), reinforcing the existence of an optimal inclusion range. Cassia Cinnamon and Lemongrass showed the greatest growth increments, with estimated additional gains of approximately 1.3 g and 1.2 g compared to the control group, respectively. Cassia Cinnamon presented the best overall productive performance, with greater zootechnical stability and absence of relevant histological alterations, whereas Lemongrass promoted growth enhancement associated with mild gastric alterations compatible with adaptation to dietary stimulus. Oregano stood out for its functional effects on palatability and feeding behavior, while Eucalyptus showed more discrete effects, mainly related to the initial acceptance of the diets. Overall, the essential oils proved to be biologically safe, maintaining high survival rates (92.5–100%) with no adverse effects on water quality or tissue integrity. It is concluded that the evaluated essential oils present potential as functional and attractant-palatability additives in Nile tilapia farming, especially at intermediate concentrations, highlighting Cassia Cinnamon as a promoter of productive performance, Lemongrass for its growth-stimulating potential associated with adaptive responses of the digestive tract, and Oregano as a modulator of feeding behavior and physiological responses in fish. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86807 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/86254 Título: Filmes à base de polissacarídeos sulfatados da alga marinha vermelha (hypnea pseudomusciformis) incorporados com óleo de babaçu: elaboração e caracterização Autor(es): Lima, Erivan Santos Abstract: The production of biodegradable packaging has increased, along with the interest of researchers and industries, aiming to reduce the impact caused by the use and disposal of packaging made from synthetic materials derived from fossil hydrocarbons. This study aimed to develop and characterize biodegradable films based on sulfated polysaccharide (SP) extracted from the red alga Hypnea pseudomusciformis, incorporated with babassu oil at different concentrations. Polysaccharide extraction was carried out using two methods (aqueous extraction - AE and refined aqueous extraction - RAE), with yields of 31.50% and 10.35%, respectively. Six treatments were prepared, varying the concentration of carrageenan (5%, 10%, 15%) and babassu oil (1%, 3%, 6%), using glycerol as a plasticizer. The films were evaluated for physical (thickness, moisture), optical (color, transparency), barrier (water solubility), thermal (DSC, TGA), chemical (FTIR) properties, and soil biodegradability. Statistical analysis included descriptive statistics, multivariate analysis, and the use of R software. The results showed that oil incorporation improved handling and visual homogeneity, especially in treatments with 5% polysaccharide + 1% oil (T4) and 15% polysaccharide + 6% oil (T6). FTIR analysis confirmed the carrageenan structure in the films and the presence of babassu oil through the band at ~1740 cm⁻¹. Biodegradability was high (>70% after 10 days), and the addition of oil increased the thermal stability of the films, with T6 showing the highest resistance (lowest mass loss). It is concluded that the combination of SP and babassu oil is viable for the production of biodegradable films, allowing their properties (such as transparency, moisture resistance, and degradation rate) to be adjusted through formulation, demonstrating their potential for specific applications in sustainable packaging. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86254 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85495 Título: Caracterização da pesca e da comercialização de Cyanocyclas brasiliana (Deshayes, 1854) (Mollusca: Bivalvia), no Delta do Parnaiba - PI Autor(es): Xavier, Athos Campêlo Ferreira Abstract: The species Cyanocyclas brasiliana is a bivalve mollusk of great economic and social importance for artisanal fishing on the coast of Piauí. For this reason, it has been the subject of recent studies seeking to understand its production chain, as well as its morphological and physicochemical characteristics. The extraction of this resource is based on shellfish gathering, a traditional harvesting practice passed down from generation to generation, especially among local families in the Parnaíba Delta. Carried out predominantly by women during low tide, this activity has significant socioeconomic relevance, ensuring family subsistence through the capture, processing, and commercialization of the shellfish. The present study aimed to characterize the fishing and commercialization of C. brasiliana in the Delta region, specifically in the municipality of Ilha Grande. To this end, the research was conducted through the observation of fishing practices and interviews with community members, aiming to obtain a comprehensive understanding of the entire dynamics of the production chain. The fishing of the bivalve mollusk Cyanocyclas brasiliana in the Parnaíba Delta is characterized by the use of selective, low-impact artisanal techniques, strongly guided by traditional ecological knowledge. However, processing and post-capture management lack infrastructure and sanitary control, limiting food security and access to more demanding markets. The commercialization chain is short, informal, and dominated by middlemen, which reduces the negotiating power of the shellfish gatherers and the value added to the product. It is concluded that the socio-environmental and economic sustainability of the activity depends on the articulation between public policies, structural improvements in post-capture, and the strengthening of community social organization (such as cooperatives), aiming to ensure the autonomy of producers and the efficient management of resources. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85495 2026-01-01T00:00:00Z