Thiago Barbosa Cahú

Fucoidan, a sulfated polysaccharide extracted from the cell wall of macroalgae such as S. muticum , exhibits promising biological properties. This study investigated a green extraction using deep eutectic solvents (DESs), with an emphasis on process optimization and bioactive evaluation of fucoidan. The most efficient DES was lactic acid with glycerol (LacAc:Gly) at 60°C, with 4% water and a solid/liquid ratio of 0.1167, resulting in a yield of 6.6%, a sulfate content of 0.170 mg/mg, and a uronic acid content of 0.023 mg/mg. The chemical and structural composition of fucoidan were evaluated by colorimetric methods, FTIR, and NMR. Antioxidant activity was assessed by 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonate (ABTS, 25.84%), 2‐diphenyl‐1‐pricylhydrazyl (DPPH, 30.45%), and ferric reducing antioxidant power (FRAP, 690 µg/µg) assays. Cellular assays with L929 fibroblasts showed that concentrations of 50 and 75 µg/mL stimulated cell viability, with 179% colony formation and 449 invasive cells, suggesting positive effects on cell proliferation and migration. Therefore, the results indicate that fucoidan extracted with LacAc:Gly has high bioactive potential, demonstrating the viability of green eutectic solvents as a sustainable alternative for the utilization of bioactive compounds from brown algae.

This study assessed the effects of dietary shrimp head meal (SHM) on growth performance, metabolism, antioxidant status, and health of Nile tilapia ( Oreochromis niloticus ) fingerlings. Five isonitrogenous and isoenergetic diets were precisely formulated on a digestible nutrient basis, containing graded SHM levels (0, 5, 10, 15, and 20%), and fed for 45 days to fish (3.24 ± 0.07 g) reared in 50 L tanks (10 fish tank ⁻¹ ; four replicates diet ⁻¹ ) within a recirculating aquaculture system. Growth performance increased significantly with SHM inclusion, and quadratic regression analyses suggested an estimated inclusion level near 16% associated with maximal weight gain and feed conversion efficiency. Improved eviscerated weight and whole-body protein, together with reduced hepatosomatic and viscerosomatic indexes and lipid content, indicated a shift toward lean growth and efficient nutrient utilization. Enhanced villus height and elevated digestive enzyme activities (amylase, proteases, and lipases) confirmed superior nutrient assimilation. Antioxidant defenses were strengthened by higher catalase and glutathione activities in liver and muscle, while feed malondialdehyde content decreased with increasing SHM levels during storage. Hematological and biochemical improvements, including higher erythrocyte, leukocyte, and platelet counts, elevated serum protein fractions, and lower glucose, cholesterol, alanine aminotransferase, and aspartate aminotransferase levels, reflected enhanced metabolic regulation, immune competence, and hepatoprotection. Collectively, these results demonstrate that SHM functions not only as a sustainable protein source but also as a functional feed ingredient that enhances physiological resilience. The valorization of shrimp-processing residues through SHM inclusion supports circular bioeconomic development and sustainable intensification in aquaculture.

Aquaculture plays a critical role in food security, with Nile tilapia (Oreochromis niloticus) being one of the most widely farmed species due to its resilience and adaptability. However, the reliance on traditional feed ingredients poses sustainability challenges. This study aimed to investigate the immunomodulatory effects of incorporating shrimp cephalothorax lipid extract (SCLE) and shrimp cephalothorax meal (SCM) in Nile tilapia diets as sustainable feed alternatives. Two experiments were conducted using diets with varying levels of SCLE (0.4%, 0.8%, 1.2%, and 1.6%) and SCM (5%, 10%, 15%, and 20%). A total of 200 healthy, uniformly sized Nile tilapia fingerlings were selected for two trials with average weights of 4.38±0.13 g and 3.24±0.07 g, respectively. Fish were distributed across 20 tanks and fed ad libitum for 45 days. Hematological parameters were analyzed, revealing that diets with SCLE significantly increased leukocyte, thrombocyte, and hematocrit levels, particularly at 1.6% inclusion. SCM inclusion also led to higher leukocyte counts, especially at 20%. These findings suggest that SCLE and SCM positively impact the innate immune system of Nile tilapia, enhancing their ability to resist pathogens. Additionally, the use of shrimp by-products in aquafeeds presents a viable strategy for reducing environmental waste and promoting more sustainable practices in aquaculture.

Objetivou realizar a caracterização do queijo azul com aplicação de quitosana. Para isto foram produzidos seis queijos azuis, sendo três controles (sem quitosana) e três tratamentos com quitosana. Foi realizada análise sensorial com 90 dias de maturação, análises microbiológicas e físico-químicas dos queijos azuis produzidos no tempo 0 de produção e com 60, 90 e 120 dias de maturação. Na análise sensorial houve diferença entre os queijos sem e com quitosana no sabor salgado, sendo o queijo com quitosana mais bem avaliado, apresentando pontuação de 6,40, na escala hedônica de 1 a 9 pontos, contra 5,85 pontos do queijo sem quitosana. Nas análises microbiológicas, os queijos azuis com quitosana não apresentaram crescimento de microrganismo patogênico. Não houve diferença entre os tratamentos para análise de gordura no extrato seco, com valores médios de 55,24 e 55,20 % para os queijos sem e com quitosana, respectivamente. O teor médio de umidade foi de 51,75 e 49,26 % para queijos sem e com quitosana, nesta ordem, apresentando diferença entre os tratamentos. A presença da quitosana favoreceu o sabor salgado do queijo azul e colaborou com a qualidade microbiológica deste produto sem comprometer a atividade do Penicillium roqueforti.

The need to fully exploit fishing resources due to increasing production and consequent waste generation requires research to promote the sustainability of the fishing industry. Fish waste from the industry is responsible for relevant environmental contamination. However, these raw materials contain high amounts of collagen and other biomolecules, being attractive due to their industrial and biotechnological applicability. Thus, to reduce the waste from pirarucu (Arapaima gigas) processing, this study aimed to obtain collagen from pirarucu skin tissue. The extraction process used 0.05 M sodium hydroxide, 10% butyl alcohol, and 0.5 M acetic acid, with extraction temperature of 20°C. The obtained yield was 27.8%, and through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), it was determined that the collagen obtained was type I. This study showed that collagen solubility was highest at pH 3 and the lowest solubility was at concentrations of 3% sodium chloride. The denaturation temperature of collagen was 38.1°C, and its intact molecular structure was observed using the Fourier transform infrared spectrophotometry technique with an absorption radius of 1. The results showed that it was possible to obtain collagen from pirarucu skin at 20°C, which has the typical characteristics of commercial type I collagen. In conclusion, the procedures used may be considered to be an interesting alternative for collagen extraction, a new product obtained from the processing of fish waste.

In this work, the objective was to use the resinous exudate of a typical plant of the Brazilian Northeast, the cashew tree gum (Anacardium occidentale L.) as an alternative mounting medium in the histological technique, economically viable and environmentally healthy. Cashew gum was processed according to the adapted method from Rinaudo and Milas. The refractive index reading, and the viscosity measurement were performed using an Abbes refractometer and an MVD-20 digital viscometer, respectively. According to the authorization of the Animal Use Committee of the Federal University of Pernambuco, different organs of Wistar rats were histologically processed and the permanent preparations were mounted with cashew resin gum (MGRC). The refractive index of the MGRC was 1.343 and the viscosity of the medium without mineral oil was 1143.7 ± 267.4 mPas.s and with the mineral oil it was 939.9 ± 103.7 mPas.s. The preparations mounted with MGRC, regardless of the type of stain used, presented with clear images and morphology of the structures conserved. The MGRC proved to be a satisfactory alternative to commercial assembly means, being economically viable and generating benefits such as personal biosecurity as it is non-toxic, in addition to not harming the environment.

Recent advances in microalgae biotechnology have proven that these microorganisms contain a number of bioactive molecules, that can be used as food additives that help prevent disease. The green microalga Chlorella vulgaris presents several biomolecules, such as lutein and astaxanthin, with antioxidant capacity, which can play a protective role in tissues. In this study, we produced and analyzed a C. vulgaris functional alcoholic beverage (produced using a traditional Brazilian alcoholic beverage, cachaça, and C. vulgaris biomass). Assays were conducted in vitro by radical scavenging tests, and in vivo, by modeling cortical spreading depression in rat brains. Scavenging radical assays showed that consumption of the C. vulgaris alcoholic beverage had a DPPH inhibition of 77.2%. This functional alcoholic beverage at a concentration of 12.5 g L^-1 significantly improved cortical spreading depression velocity in the rat brains (2.89 mm min^-1), when compared with cachaça alone (3.68 mm min^-1) and control (distilled water; 3.25 mm min^-1). Moreover, animals that consumed the functional beverage gained less weight than those that consumed just alcohol and the control groups. These findings suggest that the C. vulgaris functional alcoholic beverage plays a protective physiologic role in protecting brain cells from the effects of drinking ethanol.