http://repositorio.ufc.br/handle/riufc/82 2026-06-27T22:39:21Z 2026-06-27T22:39:21Z Cunha, Angélica de Oliveira Portela http://repositorio.ufc.br/handle/riufc/86807 2026-06-17T17:45:16Z 2026-01-01T00:00:00Z

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

2026-01-01T00:00:00Z Lima, Erivan Santos http://repositorio.ufc.br/handle/riufc/86254 2026-05-15T19:29:41Z 2026-01-01T00:00:00Z

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

2026-01-01T00:00:00Z Xavier, Athos Campêlo Ferreira http://repositorio.ufc.br/handle/riufc/85495 2026-03-27T16:06:40Z 2026-01-01T00:00:00Z

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

2026-01-01T00:00:00Z Oton, Levi Ferreira http://repositorio.ufc.br/handle/riufc/85490 2026-03-27T14:03:44Z 2026-01-01T00:00:00Z

Título: Primeiro relato de uma lectina relacionada ao fibrinogênio em esponjas marinhas: caracterização bioquímica, estrutural e avaliação do potencial antibiofilme da lectina de Aplysina cauliformis (Carter, 1822) Autor(es): Oton, Levi Ferreira Abstract: Marine sponges are sessile invertebrates recognized for producing a vast chemical arsenal with biotechnological properties, with lectins standing out for their antimicrobial, anticancer, and immunomodulatory activities. Recently, studies with the lectin AcL (Aplysina cauliformis) revealed synergistic effects with antibiotics, highlighting the need for an in-depth biochemical and structural characterization, as well as an evaluation of its potential against bacterial biofilms. The present study aimed to isolate, purify, and biochemically and functionally characterize AcL, determining its primary and tertiary structures, as well as its interaction thermodynamic parameters and antibiofilm potential.The results revealed that AcL presents a molecular mass of approximately 35 kDa under reducing conditions and 66 kDa under nonreducing conditions, suggesting a dimeric organization stabilized by disulfide bonds. DLS analyses confirmed that the protein is predominantly in a stable dimeric state in solution, with a hydrodynamic diameter between 7 and 8 nm. Amino acid sequencing identified 13 peptides (40% coverage of the genomic sequence), revealing that AcL has 320 residues and is characterized as the first report of a marine sponge lectin containing a fibrinogen-related domain (FReD). Three-dimensional modeling demonstrated an unprecedented architecture for poriferans, composed of an N-terminal fibrillar domain (long alpha-helix) and a C-terminal beta-sandwich domain. In ITC assays, AcL demonstrated high affinity for the PSM glycoprotein (KD = 134 nM), with the interaction being driven mostly by entropic effects. Regarding antibiofilm activity, AcL strongly inhibited biomass formation in all tested strains, with reductions exceeding 80% for S. aureus at concentrations starting from 125 μg/mL, in addition to significant inhibition (over 50%) for S. epidermidis and a dose-dependent effect against E. coli. Although there was no drastic reduction in the count of viable cells at most concentrations, the effectiveness in destabilizing the biofilm biomass was compelling. It is concluded that AcL inaugurates a new class of lectins in the phylum Porifera, positioning itself as a promising molecule for the development of anti-virulence strategies and marine biotechnology. Tipo: Dissertação

2026-01-01T00:00:00Z