Resumo Objetivou-se elaborar três formulações de néctar misto de umbu e mangaba, além de avaliá-las quanto às suas características microbiológicas, sensoriais, físico-químicas e químicas. Antes da elaboração do néctar, três marcas de polpas de umbu e duas marcas de polpas de mangaba foram avaliadas físico-quimicamente (pH, acidez total titulável, sólidos solúveis totais, ratio, vitamina C) e quantificados os fenólicos totais. Escolhida a marca da polpa de cada fruta, iniciou-se a elaboração dos néctares simples (umbu ou mangaba), seguida da avaliação microbiológica e análise sensorial prévia, para encontrar a doçura ideal. Posteriormente, três formulações de néctar misto foram preparadas, sendo a formulação 1 composta por 25% umbu e 25% mangaba; a formulação 2 composta por 20% umbu e 30% mangaba, e a formulação 3 composta por 30% umbu e 20% mangaba, as quais foram avaliadas microbiológica, sensorial, físico-química e quimicamente. As amostras de néctares estavam seguras microbiologicamente. As três formulações de néctar misto apresentaram a mesma aceitabilidade, com índice de aceitação acima de 70%. Além disso, apresentaram os mesmos sólidos solúveis totais, fenólicos totais e atividade de sequestrar o radical difenil-picril-hidrazina. Contudo, a formulação 2 foi a mais indicada do ponto de vista nutricional e a formulação 3, a mais indicada para aplicação comercial.

Abstract The objective was to elaborate three umbu and mangaba mixed nectar formulations, as well as to evaluate their microbiological, sensory, physicochemical and chemical characteristics. Before preparing the nectars, three brands of umbu pulp and two brands of mangaba pulps were physico-chemically evaluated (pH, total titratable acidity, total soluble solids, ratio, vitamin C) and the total phenolics quantified. After choosing which pulp brands to use, the simple nectars (umbu or mangaba) were prepared, followed by a microbiological evaluation and prior sensory analysis to find the ideal sweetness. Subsequently, three formulations of the mixed nectar were prepared, where Formulation 1 was composed of 25% umbu and 25% mangaba, formulation 2 was composed of 20% umbu and 30% mangaba and formulation 3 was composed of 30% umbu and 20% mangaba, and the three formulations submitted to microbiological, sensory, physico-chemical and chemical evaluations. The nectar samples were microbiologically safe. The three formulations of mixed nectar showed the same acceptability with an acceptance rate above 70%. In addition, they presented the same total soluble solids and total phenolics contents and the same diphenyl-picryl-hydrazine radical sequestering activity. However, formulation 2 was the most indicated from a nutritional point of view, and formulation 3 the most suitable for commercial applications.

Objective: To evaluate and compare the antioxidant activity displayed by seaweed H. opuntia and B. triquetrum using different experimental in vitro antioxidant assessment models. Material and Methods: The following techniques are utilized: DPPH, Reducing power, inhibition of lipid peroxidation and inhibition of haemolysis. Results: B. triquetrum: DPPH; IC50=1.15 ± 0.06, Reducing power (concentration 128 mg/mL), OD=2.798, inhibition of lipid peroxidation; IC50=5.09± 0.25 and inhibition of haemolysis; with 12 mg/mL; 35 %. H. opuntia: DPPH; IC50=12.34 ± 0.30 mg/mL, reducing power; OD=0.800, inhibition of lipid peroxidation; IC50=1.25± 0.31 mg/mL, inhibition of lipid peroxidation; IC50=1.25± 0.31 mg/mL and inhibition of haemolysis; 82%. Conclusion: It was demonstrated that B.triquetrum extract was more effective than H. opuntia in reducing power and DPPH assays while H.opuntia was more effective in inhibition of lipid peroxidation in rat brain homogenates and the inhibition of red blood cell (RBC) haemolysis induced by AAPH. We discuss some aspects about their possible mechanisms of action.

Objetivos: Evaluar y comparar las propiedades antioxidantes mediante ensayos in vitro de extractos acuosos de las algas roja Bryothamnion triquetrum y verde Halimeda opuntia y su relación con el contenido de polifenoles. Material y Métodos: Se utilizaron las técnicas in vitro: DPPH, Capacidad reductora, Inhibición de la peroxidación lipídica e inhibición de la hemólisis inducida por AAPH. Resultados: B. triquetrum: DPPH; CI50=1,15 ± 0,06, capacidad reductora a concentración; 128 mg/mL, DO=2,798, inhibición de la peroxidación lipídica; CI50=5,09± 0,25 e inhibición de la hemólisis con 12 mg/mL; 35 %. H. opuntia: DPPH; CI50=12,34 ± 0,30 mg/mL, capacidad reductora; DO=0,800, inhibición de la peroxidación lipídica; CI50=1,25± 0,31 mg/mL e inhibición de la hemólisis; 82%. Conclusiones: Los resultados evidencian que B triquetrum resulto mucho más eficiente en los ensayos de DPPH y Capacidad reductora mientras H opuntia resulta más eficiente en Inhibición de la peroxidación lipídica e inhibición de la hemólisis. Se discuten algunos aspectos acerca de sus posibles mecanismos de acción.